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Community Estuarine Monitoring Manual

E N V I R O N M E N T
P R O T E C T I O N
A U T H O R I T Y
Community Estuarine
Monitoring Manual
Community Estuarine
Monitoring Manual
Community Estuarine Monitoring Manual
ThisȱpublicationȱwasȱfundedȱbyȱtheȱSouthȱAustralianȱEnvironmentȱProtectionȱAuthorityȱ(EPA)ȱasȱaȱ
technicalȱresourceȱforȱWaterwatchȱandȱotherȱcommunityȱwaterȱmonitoringȱgroupsȱ
Writtenȱandȱillustratedȱbyȱ
PeriȱColemanȱandȱFaithȱCookȱ
TheȱNationalȱLibraryȱofȱAustraliaȱ
CataloguingȬinȬPublicationȱentry:ȱ
Coleman,ȱPeriȱ
Communityȱestuarineȱmonitoringȱguidanceȱmanualȱ
Bibliographyȱ
ISBNȱ1ȱ921125ȱ29ȱ2ȱ
Estuarineȱhealth—SouthȱAustralia—Measurement—Handbooks,ȱmanuals,ȱetc.ȱȱ2.ȱWaterȱquality—ȱ
SouthȱAustralia—Measurement—Handbooks,ȱmanuals,ȱetc.ȱI.ȱCook,ȱFaith,ȱ1981–.ȱII.ȱWaterwatchȱ
SouthȱAustraliaȱ(Program).ȱIII.ȱTitle.ȱ
©ȱEnvironmentȱProtectionȱAuthorityȱ2007ȱ
Thisȱbookȱisȱcopyright.ȱCopyrightȱtoȱallȱtextȱisȱvestedȱtoȱtheȱCrown,ȱbyȱtheȱauthorsȱandȱpublishers.ȱAȱ
rightȱofȱunlimitedȱuseȱofȱallȱillustrationsȱisȱprovidedȱtoȱtheȱCrownȱbyȱtheȱartists,ȱwhileȱretainingȱ
copyright.ȱApartȱfromȱanyȱfairȱdealingȱforȱtheȱpurposesȱofȱprivateȱstudy,ȱresearch,ȱcriticismȱorȱreview,ȱ
asȱpermittedȱunderȱtheȱCopyrightȱAct,ȱnoȱpartȱmayȱbeȱreproducedȱbyȱanyȱprocessȱwithoutȱwrittenȱ
permission.ȱEnquiriesȱshouldȱbeȱmadeȱtoȱtheȱEnvironmentȱProtectionȱAuthorityȱofȱSouthȱAustralia.ȱ
PublishedȱinȱAustraliaȱbyȱtheȱEnvironmentȱProtectionȱAuthorityȱwithȱassistanceȱfromȱDeltaȱ
EnvironmentalȱConsulting.ȱ
ȱ
ȱ
Printedȱonȱrecycledȱpaperȱ
Acknowledgements
TheȱSouthȱAustralianȱEnvironmentȱProtectionȱAuthorityȱ(EPA)ȱ
hasȱfundedȱtheȱdevelopmentȱofȱthisȱresource.ȱȱ
PeriȱColemanȱandȱFaithȱCookȱ(DeltaȱEnvironmentalȱ
Consulting)ȱcompiledȱtheȱguidanceȱmanualȱinȱconsultationȱ
withȱstaffȱofȱWaterwatchȱSA,ȱinȱparticularȱLindaȬMarieȱHall.ȱ
Theȱfollowingȱcommunityȱgroupsȱwereȱinvolvedȱinȱtheȱ
communityȱtrialsȱofȱsomeȱofȱtheȱcoreȱactivities:ȱPortȱNoarlungaȱ
PrimaryȱSchoolȱWaterwatchȱgroup,ȱSouthernȱDistrictsȱ
Waterwatchȱgroup,ȱNoarlungaȱPrimaryȱSchool,ȱMiddleȱBeachȱ
SamphireȱDiscoveryȱTrail,ȱStȱKildaȱMangroveȱInterpretiveȱ
Centre,ȱtheȱMinoriesȱWaterwatchȱgroup,ȱLeFevreȱPrimaryȱ
SchoolȱandȱVitasȱKarnaitis.ȱThanksȱforȱyourȱenthusiasm,ȱinȱ
coldȱwetȱweather,ȱeveryone!ȱ
TheȱdocumentȱwasȱreviewedȱbyȱDrȱJohnȱCugleyȱofȱtheȱEPA,ȱ
andȱWaterwatchȱstaffȱSheraleeȱCox,ȱNickȱFewsterȱandȱChrisȱ
Burgess.ȱȱ
DrȱSueȱMurrayȬJonesȱofȱtheȱCoastȱandȱMarineȱBranchȱofȱtheȱ
DepartmentȱforȱEnvironmentȱandȱHeritageȱeditedȱtheȱdraftȱ
guidelines.ȱHerȱattentionȱtoȱdetailȱisȱappreciated,ȱandȱanyȱ
remainingȱmistakesȱareȱtheȱentireȱresponsibilityȱofȱtheȱauthors.ȱ
Thisȱmanualȱwouldȱbeȱlightȱinȱcontentȱindeed,ȱwithoutȱtheȱ
workȱofȱconcurrentȱprojectsȱsuchȱasȱtheȱlocalȱestuaryȱ
identificationȱresourcesȱbeingȱdevelopedȱbyȱChrisȱBallȱfromȱ
ReefȱWatchȱSA.ȱSimilarly,ȱtheȱfreelyȱavailableȱresourcesȱ
providedȱbyȱgovernmentȱagenciesȱinȱbothȱtheȱstateȱ(Coastalȱ
AtlasȱofȱSA)ȱandȱfederalȱ(NationalȱPollutantȱInventory)ȱlevelsȱ
fleshȱoutȱtheȱbonesȱprovidedȱinȱtheseȱguidelines.ȱ
ȱ
ȱ
Table of Contents
Introduction .........................................1
Lookingȱatȱtheȱvegetationȱandȱhabitat ......... 73
Meetȱtheȱmonitoringȱframework.................... 2
Keepingȱaȱvisualȱrecordȱofȱplanktonȱblooms.....74
Understandingȱestuaries ............................. 5
Gettingȱtoȱknowȱphytoplanktonȱwithȱaȱnetȱtow .75
Estuaries—valuesȱandȱimpacts...................... 7
Countingȱplanktonȱinȱaȱwaterȱsample ............78
Workingȱinȱtheȱfield—safetyȱ&ȱenvironment ..... 9
Monitoringȱaȱseaweedȱbed .........................82
Workingȱinȱtheȱfield—permitsȱ&ȱpoliteness......11
MonitoringȱanȱintertidalȱSAMȱbed ................86
Designingȱyourȱmonitoringȱprogram .............12
MonitoringȱsubmergedȱSAMȱbeds ................88
Selectingȱyourȱmonitoringȱsites ....................16
Howȱcontinuousȱisȱtheȱfringingȱvegetation? .....90
Samplingȱsiteȱobservations...................... 17
Monitoringȱmangroveȱleaf/twigȱlitterȱȱȱȱȱȱȱ
production ............................................92
Recordingȱweatherȱdetails ..........................18
Recordingȱtimeȱandȱtideȱheight ....................19
Recordingȱodoursȱandȱoddȱthings .................20
Recordingȱwaterȱdepth..............................21
Recordingȱsurfaceȱwaterȱconditions ...............22
Monitoringȱmangroveȱexpansion..................94
Studyingȱsaltmarshȱplants ..........................95
MonitoringȱMelaleucaȱleaf/twigȱlitterȱȱȱȱȱȱȱȱȱȱ
production ............................................98
Recordingȱwaterȱcolour .............................23
Usingȱaerialȱphotographsȱtoȱmapȱhabitatȱȱȱȱȱȱȱȱ
change ............................................... 100
Measuringȱflowȱrate .................................24
Measuringȱbeachȱlitter ............................ 103
Understandingȱestuarineȱprocesses............ 25
Observingȱanimalȱlife .......................... 105
Measuringȱtheȱwaterȱtemperature .................26
Tidalȱflats—lookingȱforȱbenthicȱinvertebrates . 106
MeasuringȱpH ........................................28
Tidalȱflats—countingȱcrabȱburrows ............. 109
Measuringȱwaterȱclarity.............................30
Tidalȱflats—countingȱsurfaceȱsnails ............. 111
Measuringȱsalinity ...................................32
Tidalȱflats—recordingȱwadingȱbirds ............ 113
Mappingȱyourȱestuary ..............................36
Rockyȱshore—countingȱsnails.................... 115
Isȱyourȱestuaryȱpositiveȱorȱnegative?..............38
Saltmarsh—lookingȱforȱinvertebrates ........... 118
Classifyingȱyourȱestuary ............................40
Saltmarsh—countingȱcrabsȱandȱfish............. 121
Mappingȱtheȱsalinityȱgradientȱofȱyourȱestuary ..41
Acrossȱtheȱestuary—recordingȱraptors ......... 123
Mappingȱtheȱsalinityȱprofileȱofȱyourȱestuary.....42
Mappingȱturbidityȱplumes .........................44
Acrossȱtheȱestuary—recordingȱinvasiveȱȱȱȱȱȱȱȱȱȱ
species ............................................... 125
Whereȱisȱtheȱ‘turbidityȱmaximum’? ...............46
Acrossȱtheȱestuary—monitoringȱbacteria....... 127
Effectȱofȱtidalȱrestrictionsȱonȱwetlands ............48
References ....................................... 130
Chemicalȱassessments ........................... 55
Appendixȱ1—MonitoringȱFramework .......... 132
Measuringȱdissolvedȱoxygen .......................56
Appendixȱ2—BeaufortȱScale ..................... 139
Measuringȱsulphide .................................58
Appendixȱ3—Waterȱcolourȱchart ................ 140
Measuringȱorthophosphate.........................59
Appendixȱ4—Planktonȱidentificationȱflowȱȱȱȱȱȱȱȱȱȱȱȱȱ
chart ................................................ 141
Measuringȱammonium ..............................61
MeasuringȱchlorophyllȬa............................63
Measuringȱalkalinity ................................65
Measuringȱtotalȱsuspendedȱsolids .................67
Massȱbalancesȱtoȱestimateȱpollutants..............69
MeasuringȱsoilȱsalinityȱandȱsoilȱpH ...............71
ȱ
Appendixȱ5—Forms ............................... 142
Appendixȱ6—Equipment ......................... 158
Glossary.......................................... 169
Eȱ S T U A R I N E
MONITORING
GUIDANCE
MANUAL
Introduction
ȱ
ȱ
ȱ
1
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Meet the monitoring framework
WaterwatchȱAustraliaȱisȱaȱnationalȱcommunityȱwaterȬmonitoringȱprogramȱthatȱencouragesȱallȱ
Australiansȱtoȱbecomeȱinvolvedȱwith,ȱandȱactiveȱin,ȱtheȱprotectionȱandȱmanagementȱofȱtheirȱwaterwaysȱ
andȱcatchments.ȱȱ
Previously,ȱWaterwatchȱconcentratedȱonȱfreshwaterȱmonitoring,ȱbutȱrecentlyȱaȱnumberȱofȱcommunityȱ
groupsȱinȱestuarineȱareasȱhaveȱbecomeȱinterestedȱinȱmonitoringȱtheirȱestuaries.ȱTheȱinterestȱstemsȱfromȱ
theȱmaximȱthatȱ‘estuariesȱareȱtheȱreportȱcardȱofȱtheȱcatchment’ȱ(NationalȱLandȱandȱWaterȱAudit,ȱ2002).ȱȱ
Inȱresponseȱtoȱthisȱinterest,ȱtheȱEPAȱhasȱdevelopedȱanȱestuarineȱmonitoringȱframeworkȱthatȱisȱsuitableȱ
forȱuseȱbyȱaȱwideȱrangeȱofȱcommunityȱgroups.ȱTheȱmonitoringȱframeworkȱ(Appendixȱ1)ȱpresentsȱaȱ
rangeȱofȱactivitiesȱthatȱcommunityȱgroupsȱmayȱwishȱtoȱexplore.ȱTheȱactivitiesȱareȱdesignedȱwithȱtheȱ
goalsȱof:ȱȱ
–
helpingȱtheȱcommunityȱunderstandȱtheirȱestuaryȱ
–
providingȱsimpleȱyetȱreliableȱdataȱaboutȱtheȱconditionȱofȱtheȱestuary.ȱ
Theȱactivitiesȱareȱbrokenȱintoȱcoreȱandȱextensionȱactivities.ȱCoreȱactivitiesȱmayȱbe:ȱ
–
conductedȱbyȱtheȱwidestȱrangeȱofȱpeopleȱȱ
–
inȱtheȱwidestȱrangeȱofȱestuariesȱ
–
withȱbasicȱequipment.ȱȱ
Theȱcoreȱactivitiesȱshouldȱresultȱinȱaȱgoodȱlevelȱofȱunderstandingȱofȱestuarineȱprocessesȱwhileȱyieldingȱ
reliableȱdataȱonȱcommonȱestuarineȱparameters.ȱȱ
Extensionȱactivitiesȱareȱdesignedȱtoȱbeȱundertaken:ȱ
–
byȱolderȱgroupsȱȱ
–
byȱgroupsȱwithȱaȱspecialȱinterestȱinȱcertainȱareasȱ(forȱexampleȱtheȱrestorationȱofȱMuttonȱCove)ȱȱ
–
whereȱthereȱareȱcertainȱtypesȱofȱhabitatȱȱ
–
whenȱparametersȱrequiringȱprocessingȱbackȱinȱaȱlaboratoryȱareȱbeingȱexamined.ȱȱ
Theȱextensionȱactivitiesȱshouldȱprovideȱaȱdeeperȱunderstandingȱofȱestuarineȱprocessesȱandȱyieldȱaȱwiderȱ
rangeȱofȱinformationȱaboutȱtheȱfunctioningȱofȱtheȱspecificȱestuaryȱbeingȱstudied.ȱ
Theȱfollowingȱtwoȱlistsȱsummariseȱtheȱcoreȱandȱextensionȱactivitiesȱsuggestedȱinȱthisȱestuarineȱ
monitoringȱframework.ȱ
Core activities
Samp lingȱs it eȱ obs erv at io n s ȱ
–
recordingȱweatherȱdetailsȱ
–
readingȱtimeȱandȱtideȱheightȱ
–
recordingȱodoursȱandȱoddȱthingsȱ
–
recordingȱwaterȱdepthȱ
–
recordingȱsurfaceȱwaterȱconditionsȱ
–
recordingȱwaterȱcolour.ȱ
Underst anding ȱestuarine ȱp r oc e ss es ȱ
–
measuringȱwaterȱtemperatureȱ
–
measuringȱpHȱ
–
measuringȱwaterȱclarityȱ
–
measuringȱsalinity.ȱ
2
ESTUARINE
MONITORING
GUIDANCE
MANUAL
C h e m ic a lȱ ass e ssm ent s ȱ
–
measuringȱdissolvedȱoxygenȱ
–
measuringȱorthophosphateȱ
–
measuringȱammoniumȱ
–
measuringȱalkalinity.ȱ
Looking ȱ atȱth eȱveg et at ion ȱandȱh ab i t a t ȱ
–
keepingȱaȱvisualȱrecordȱofȱplanktonȱbloomsȱ
–
measuringȱbeachȱlitter.ȱ
O b se rv ingȱ an imal ȱ life ȱ
–
tidalȱflats—countingȱcrabȱburrowsȱ
–
tidalȱflats—countingȱsurfaceȱsnailsȱ
–
tidalȱflats—recordingȱwadingȱbirdsȱ
–
acrossȱtheȱestuary—recordingȱraptorsȱ
–
acrossȱtheȱestuary—recordingȱinvasiveȱspecies.ȱ
E x ten sio n a c t ivi t ies
Samp lingȱs it eȱ obs erv at io n s ȱ
–
measuringȱflowȱrate.ȱ
Underst anding ȱestuarine ȱp r oc e ss es ȱ
–
mappingȱyourȱestuaryȱ
–
isȱyourȱestuaryȱpositiveȱorȱnegative?ȱ
–
classifyingȱyourȱestuaryȱ
–
mappingȱtheȱsalinityȱgradientȱofȱyourȱestuaryȱ
–
mappingȱtheȱsalinityȱprofileȱofȱyourȱestuaryȱ
–
mappingȱturbidityȱplumesȱ
–
whereȱisȱtheȱ‘turbidityȱmaximum’ȱforȱyourȱestuary?ȱ
–
effectȱofȱtidalȱrestrictionsȱonȱwetlands.ȱ
C h e m ic a lȱ ass e ssm ent s ȱ
–
measuringȱsulphideȱ
–
measuringȱchlorophyllȬaȱ
–
measuringȱtotalȱsuspendedȱsolidsȱ
–
estimatingȱpollutantȱloadsȱwithȱmassȱbalancesȱ
–
measuringȱsoilȱsalinityȱandȱsoilȱpH.ȱ
Looking ȱ atȱth eȱveg et at ion ȱandȱh ab i t a t ȱ
–
gettingȱtoȱknowȱphytoplanktonȱwithȱaȱnetȱtowȱ
–
countingȱphytoplanktonȱinȱaȱwaterȱsampleȱ
–
monitoringȱaȱseaweedȱbedȱ
–
monitoringȱanȱintertidalȱSAMȱbedȱ
–
monitoringȱsubmergedȱSAMȱbedsȱ
–
howȱcontinuousȱisȱtheȱfringingȱvegetation?ȱ
–
monitoringȱmangroveȱleaf/twigȱlitterȱproductionȱ
–
monitoringȱmangroveȱexpansionȱ
3
ESTUARINE
MONITORING
GUIDANCE
MANUAL
–
studyingȱsaltmarshȱplantsȱ
–
monitoringȱMelaleucaȱleaf/twigȱlitterȱproductionȱ
–
usingȱaerialȱphotographsȱtoȱmapȱhabitatȱchange.ȱ
O b se rv ingȱ an imal ȱ life ȱ
–
tidalȱflats—lookingȱforȱbenthicȱinvertebratesȱ
–
rockyȱshore—countingȱgrazingȱsnailsȱ
–
saltmarsh—lookingȱforȱinvertebratesȱinȱsaltmarshȱhabitatsȱ
–
saltmarsh—countingȱcrabsȱandȱfishȱinȱsaltmarshȱcreeksȱ
–
acrossȱtheȱestuary—monitoringȱbacteria.ȱ
Theȱframeworkȱrecognisesȱthatȱdifferentȱgroupsȱwillȱwantȱtoȱdoȱdifferentȱthingsȱinȱtheirȱestuary.ȱSomeȱ
existingȱWaterwatchȱgroupsȱwillȱbeȱcomfortableȱwithȱtheȱrangeȱofȱactivitiesȱthatȱtheyȱcurrentlyȱ
undertake,ȱandȱmayȱonlyȱwishȱtoȱuseȱequipmentȱandȱmethodsȱthatȱworkȱoverȱaȱwiderȱrangeȱofȱsalinitiesȱ
thanȱcurrentlyȱcateredȱforȱinȱWaterwatchȱkits.ȱ
Otherȱgroupsȱmayȱbeȱattemptingȱtoȱunderstandȱorȱtrackȱdownȱaȱpollutionȱissueȱinȱtheirȱestuary,ȱwhileȱ
stillȱothersȱmayȱbeȱengagedȱinȱrestorationȱworkȱinȱestuarineȱwetlandsȱandȱmayȱneedȱguidanceȱonȱhowȱtoȱ
monitorȱtheȱprogressȱofȱtheȱrestorationȱwork.ȱ
Theȱnextȱsectionȱofȱtheseȱguidelinesȱdiscussesȱhowȱyourȱgroupȱcouldȱselectȱactivitiesȱfromȱtheȱcoreȱandȱ
extensionȱareasȱtoȱbuildȱupȱaȱspecificȱmonitoringȱprogramȱthatȱmeetsȱyourȱgroups’ȱneeds.ȱ
Definitions
Theȱactivityȱframeworkȱhasȱaȱnumberȱofȱcodes,ȱabbreviationsȱandȱsymbols:ȱ
Ageȱgroups:ȱȱ
Theȱageȱgroupsȱshownȱinȱtheȱframeworkȱareȱtheȱminimumȱrecommendedȱagesȱforȱeachȱactivity.ȱTheȱ
recommendationȱmayȱbeȱbasedȱonȱskillȱissuesȱorȱsafety.ȱȱ
Timeȱrequirements:ȱ
1ȱ=ȱlessȱthanȱ10ȱminutesȱ
2ȱ=ȱ10ȱminutesȱtoȱ1ȱhourȱ
3ȱ=ȱ1–2ȱhoursȱ
4ȱ=ȱmoreȱthanȱ2ȱhoursȱ
Activityȱsymbols:ȱȱ ȱ
ȱ=ȱthisȱactivityȱisȱaȱdesk–basedȱactivityȱȱ
3ȱ=ȱthisȱactivityȱcontainsȱsomeȱfieldȱactivitiesȱ
Inȱaddition,ȱthereȱisȱaȱglossaryȱatȱtheȱendȱofȱtheseȱguidelines,ȱtoȱprovideȱdefinitionsȱforȱtechnicalȱtermsȱ
usedȱinȱtheȱframeworkȱandȱguidelines.ȱ
ȱ
ȱ
ȱ
4
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Understanding estuaries
Estuariesȱareȱwhereȱfreshwaterȱcreeks,ȱstreamsȱandȱriversȱmeetȱtheȱocean.ȱTheyȱmayȱbeȱhugeȱ(likeȱtheȱ
Coorong)ȱorȱtinyȱsuchȱasȱtheȱsmallȱtidalȱcreeksȱenteringȱtheȱtwoȱgulfs,ȱGulfȱStȱVincentȱandȱSpencerȱGulf.ȱ
Whatȱhappensȱinȱanȱestuaryȱdependsȱonȱtheȱinteractionsȱbetweenȱtheȱamountsȱofȱfreshwaterȱflowingȱinȱ
(viaȱrainfall,ȱrunoff,ȱseepageȱandȱeffluentȱoutfalls),ȱtheȱamountȱofȱtidalȱexchangeȱthatȱoccursȱeachȱday,ȱ
theȱrateȱofȱevaporationȱandȱtheȱsizeȱandȱfrequencyȱofȱwaves.ȱ
Theȱfollowingȱdefinitionȱofȱanȱestuaryȱisȱusedȱinȱthisȱmanual:ȱȱ
Anȱestuaryȱisȱaȱnarrow,ȱsemiȬenclosedȱcoastalȱbodyȱofȱwater,ȱwhichȱhasȱaȱfreeȱconnectionȱwithȱtheȱ
openȱseaȱatȱleastȱintermittentlyȱandȱwithinȱwhichȱtheȱsalinityȱofȱtheȱwaterȱisȱmeasurablyȱdifferentȱ
fromȱtheȱsalinityȱinȱtheȱopenȱocean.ȱ
ThisȱisȱaȱwiderȱdefinitionȱthanȱthatȱofȱCameronȱandȱPritchardȱ(1963),ȱwhichȱassumedȱthatȱallȱestuariesȱ
containedȱaȱmeasurableȱdilutionȱofȱseawater.ȱSouthȱAustralianȱestuariesȱhaveȱveryȱlowȱflowsȱofȱ
freshwater,ȱandȱareȱthereforeȱfrequentlyȱhypersalineȱ(moreȱsaltyȱthanȱtheȱopenȱocean).ȱInȱthisȱaspectȱ
theyȱareȱsimilarȱtoȱmanyȱestuariesȱinȱareasȱsuchȱasȱTexasȱandȱpartsȱofȱtheȱMediterraneanȱSea.ȱ
Forȱtheȱpurposesȱofȱtheseȱguidelines,ȱweȱwillȱconsiderȱthatȱtheȱheadȱofȱanȱestuaryȱisȱtheȱlandwardȱlimit,ȱ
orȱwhereȱyouȱcanȱnoȱlongerȱseeȱanyȱtidalȱvariation,ȱandȱtheȱmouthȱisȱthatȱpartȱwhereȱeitherȱtheȱsalinityȱisȱ
indistinguishableȱfromȱthatȱofȱtheȱsea,ȱorȱthereȱisȱsomeȱformȱofȱestuarineȱbarrierȱorȱsandbar.ȱ
Weȱcanȱdevelopȱanȱunderstandingȱofȱtheȱprocessesȱthatȱaffectȱanȱestuaryȱbyȱlookingȱatȱtwoȱtypesȱofȱ
classification.ȱWeȱcanȱexamineȱtheȱestuaryȱandȱassessȱitsȱsalinityȱregimeȱ(positiveȱorȱnegative).ȱWeȱcanȱ
alsoȱclassifyȱitȱaccordingȱtoȱtheȱmajorȱforcesȱ(tides,ȱriverȱflows,ȱevaporationȱandȱwaves)ȱthatȱhaveȱshapedȱ
it.ȱUnderstandingȱtheȱtypeȱofȱestuaryȱweȱareȱlookingȱatȱallowsȱusȱtoȱunderstandȱwhatȱhappensȱtoȱwaterȱ
thatȱentersȱitȱandȱwhereȱtheȱdifferentȱhabitatsȱwillȱoccur.ȱ
Po si ti ve and n eg ative es tu aries
Theȱclassicalȱestuaryȱhasȱfreshwaterȱenteringȱtheȱheadȱofȱtheȱestuary,ȱwhichȱgraduallyȱbecomesȱsaltierȱ
closerȱtoȱtheȱocean.ȱThisȱisȱconsideredȱtoȱbeȱaȱ‘positive’ȱestuary.ȱTheseȱestuariesȱrequireȱenoughȱ
freshwaterȱenteringȱtoȱnotȱonlyȱdiluteȱtheȱseawater,ȱbutȱalsoȱtoȱalsoȱmakeȱupȱforȱtheȱeffectȱofȱevaporationȱ
fromȱtheȱestuaryȱsurfaceȱitself.ȱPositiveȱestuariesȱareȱcommonȱinȱareasȱwhereȱthereȱisȱhighȱrainfallȱandȱ
lowȱevaporation,ȱbutȱcanȱexistȱinȱlowȬrainfallȱareasȱwhereȱaȱsmallȱriverȱisȱfedȱfromȱanȱextremelyȱlargeȱ
catchment.ȱInȱSouthȱAustraliaȱpositiveȱestuariesȱoccurȱinȱtheȱSouthȱEast,ȱonȱKangarooȱIsland,ȱandȱwouldȱ
haveȱoccurredȱinȱtheȱpastȱinȱpartsȱofȱtheȱRiverȱMurrayȱestuary,ȱinȱLakesȱAlexandrinaȱandȱAlbertȱ(Geddesȱ
andȱHall,ȱ1990).ȱ
SouthȱAustralianȱestuariesȱareȱmoreȱcommonlyȱ‘negative’ȱestuaries,ȱwhereȱtheȱamountȱofȱfreshwaterȱ
enteringȱtheȱestuaryȱasȱrainȱorȱrunoffȱisȱlessȱthanȱtheȱamountȱofȱfreshwaterȱlostȱasȱevaporationȱfromȱtheȱ
estuaryȱsurface.ȱTheȱsalinityȱgradientȱinȱnegativeȱestuariesȱvariesȱfromȱhypersalineȱtoȱeusalineȱ(marineȱ
salinity).ȱTheȱCoorongȱisȱaȱwellȬknownȱnegativeȱestuary.ȱ
The OzEs tu aries class ifi cation
Thereȱareȱseveralȱdifferentȱclassificationȱsystemsȱforȱestuaries.ȱMostȱseekȱtoȱclassifyȱtheȱestuaryȱonȱtheȱ
basisȱofȱtidalȱinfluenceȱ(isȱthereȱaȱlargeȱorȱsmallȱexchangeȱofȱseawaterȱdaily?)ȱandȱrainfallȱ(isȱthereȱaȱlargeȱ
riverȱorȱrainfallȱinputȱandȱwhatȱisȱtheȱevaporationȱlike?).ȱȱ
GeoscienceȱAustraliaȱhasȱproducedȱaȱCDȱROMȱaboutȱAustralianȱestuaries,ȱdesignedȱforȱeducationalȱuse,ȱ
thatȱincludesȱaȱclassificationȱsystemȱforȱestuariesȱ(commonlyȱcalledȱtheȱOzEstuariesȱclassification,ȱ
developedȱbyȱHeapȱetȱal,ȱ2001).ȱTheȱsystemȱclassifiesȱestuariesȱintoȱthreeȱmajorȱtypes,ȱdependingȱonȱ
whetherȱtheyȱareȱdominatedȱbyȱtheȱtidesȱ(mainlyȱfoundȱinȱnorthernȱAustraliaȱwhereȱtidesȱareȱlarge),ȱbyȱ
riversȱ(theseȱareȱdeltaȱestuaries)ȱorȱbyȱwavesȱ(whereȱaȱsandyȱbarrierȱofȱsomeȱkindȱisȱformedȱbyȱwaves).ȱ
Eachȱofȱtheseȱgroupsȱcanȱbeȱsubdivided,ȱprovidingȱsixȱsubclasses:ȱtideȱdominatedȱdeltas,ȱwaveȱ
dominatedȱdeltas,ȱwaveȱdominatedȱestuaries,ȱstrandȱplains,ȱandȱtideȱdominatedȱestuariesȱandȱtidalȱflats.ȱȱ
5
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Aȱquickȱsummaryȱofȱtheseȱclassesȱfollows.ȱIfȱyouȱwishȱtoȱunderstandȱtheȱclassificationȱmethod,ȱyouȱ
shouldȱobtainȱaȱcopyȱofȱtheȱCDȱROMȱAustralianȱEstuariesȱandȱCoastalȱWaterwaysȱfromȱGeoscienceȱ
Australia.ȱ
Tideȱd om i nat edȱd e lta ȱ
Deltasȱareȱriverȱdominated,ȱsoȱtheyȱcanȱhaveȱstrongȱfreshwaterȱinfluence.ȱThisȱmayȱbeȱonlyȱepisodic,ȱinȱ
theȱcaseȱofȱSouthȱAustralianȱdeltas.ȱTheȱlargeȱquantityȱofȱsiltȱtheyȱcarryȱtoȱtheȱseaȱisȱdepositedȱaroundȱ
theȱmouthȱofȱtheȱdelta,ȱcausingȱtheȱcharacteristicȱwedgeȬȱshapedȱdeltaȱtoȱformȱ(forȱexampleȱatȱtheȱLightȱ
River,ȱinȱGulfȱStȱVincent).ȱTheȱdailyȱtidalȱinfluenceȱinȱaȱtideȬdominatedȱdeltaȱrapidlyȱmixesȱtheȱsaltyȱandȱ
freshȱwater.ȱȱ
W aveȱd om i na ted ȱd e lt a ȱ
Whereȱwavesȱareȱstrongȱenoughȱtoȱdepositȱsedimentȱinȱtheȱmainȱbasinȱofȱoldȱestuaries,ȱwaveȱdominatedȱ
deltasȱmayȱform.ȱThisȱtypeȱofȱestuaryȱmayȱbeȱseenȱinȱSouthȱAustraliaȱatȱtheȱOnkaparingaȱestuary.ȱTheȱ
influenceȱofȱtheȱtideȱisȱnotȱlargeȱandȱsoȱtheseȱdeltasȱmayȱbecomeȱstratified,ȱwithȱaȱwedgeȱofȱsaltȱwaterȱ
underlyingȱtheȱfresherȱsurfaceȱwater.ȱȱ
W aveȱd om i na ted ȱe st u aryȱ
Wavesȱareȱstrongȱmoversȱofȱcoarseȱsandyȱsediments,ȱandȱwhereȱwaveȱenergiesȱareȱstrongȱenoughȱtheyȱ
canȱproduceȱaȱbarrierȱnearȱtheȱmouthȱofȱanȱestuary.ȱAȱwellȬknownȱSouthȱAustralianȱexampleȱisȱtheȱ
MurrayȱMouthȱandȱCoorong.ȱTheȱsandyȱobstructionsȱtendȱtoȱattenuateȱtheȱtideȱinsideȱtheȱestuary,ȱ
resultingȱinȱstratificationȱorȱpartialȱmixingȱofȱtheȱfreshȱandȱtidalȱwaterȱinȱtheȱlagoon–likeȱareaȱbehindȱtheȱ
sandȱbarrier.ȱ
St rand ȱp l a in ȱ
Strandȱplainȱestuariesȱareȱtinyȱlagoonsȱwithȱminimalȱfreshwaterȱinfluence.ȱTheȱsandȱbarrierȱisȱkeptȱinȱ
placeȱbyȱtheȱwavesȱandȱthereȱisȱsoȱsmallȱaȱfreshwaterȱflowȱthatȱtheȱsandȱmayȱcloseȱtheȱopeningȱ
completely.ȱTheseȱestuariesȱmayȱonlyȱbeȱopenȱtoȱtheȱseaȱforȱpartȱofȱtheȱyear,ȱduringȱtheȱperiodȱofȱhighestȱ
freshwaterȱflow.ȱTheȱsalinityȱgradientȱinȱtheseȱsmallȱestuariesȱisȱspreadȱoverȱtime,ȱasȱwellȱasȱspace,ȱasȱ
theȱwaterȱbecomesȱmoreȱsalineȱoverȱsummer,ȱandȱlessȱsoȱoverȱwinter.ȱTheȱlackȱofȱwave,ȱtidalȱorȱriverȱ
flowsȱinȱtheȱlagoonȱcanȱallowȱtheȱwaterȱtoȱdevelopȱsalinity,ȱtemperatureȱandȱdissolvedȱoxygenȱ
stratifications.ȱ
Tideȱd om i nat edȱ est uary ȱ
Whereȱfreshwaterȱflowsȱareȱlow,ȱtideȱdominatedȱestuariesȱmayȱdevelop.ȱTheȱnorthernȱpartsȱofȱSpencerȱ
GulfȱandȱGulfȱStȱVincentȱmayȱbeȱconsideredȱtoȱbeȱessentiallyȱestuariesȱthatȱdrainȱtheȱaridȱlandsȱtoȱtheȱ
north.ȱTheȱtracksȱofȱoldȱriversȱ(paleorivers)ȱrunȱintoȱtheȱnorthernȱgulfs,ȱandȱshowȱonȱtheȱsurfaceȱasȱ
chainsȱofȱsaltȱlakes.ȱFreshwaterȱdrainageȱintoȱtheȱgulfsȱalongȱtheseȱdepressionsȱisȱfairlyȱrare.ȱTideȱ
dominatedȱestuariesȱhaveȱobviousȱtides,ȱwellȬmixedȱsalinitiesȱandȱextensiveȱmangroveȱsystems.ȱȱ
T i d a lȱ f l a t sȱ
SmallȱtidalȱflatȱestuariesȱareȱveryȱcommonȱinȱSouthȱAustralia,ȱparticularlyȱinȱtheȱtwoȱgulfsȱ(First,ȱSecondȱ
andȱThirdȱCreeksȱatȱPortȱPirie,ȱtheȱPortȱRiver/BarkerȱInletȱestuary,ȱGawlerȱRiverȱandȱPortȱBroughtonȱ
estuariesȱareȱaȱfew).ȱTheyȱareȱfoundȱinȱareasȱwithȱhighȱtidalȱinfluenceȱandȱtendȱtoȱdrainȱrightȱoutȱatȱlowȱ
tide.ȱTheirȱsmallȱsizeȱandȱtheȱstrongȱtidalȱinfluenceȱtendȱtoȱresultȱinȱtheȱsalinityȱbeingȱwellȱmixed.ȱWithȱ
theȱlowȱrainfallȱandȱaridȱconditions,ȱmanyȱofȱtheseȱestuariesȱareȱextremelyȱnegative,ȱwithȱsalinitiesȱinȱtheȱ
landwardȱpartsȱofȱtheȱestuaryȱfrequentlyȱexceedingȱthatȱofȱseawater.ȱTheseȱsmallȱestuariesȱusuallyȱhaveȱ
aȱriparianȱzoneȱofȱmangrovesȱbackedȱwithȱsaltmarsh.ȱȱ
6
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Estuaries—values and impacts
Estuarineȱareasȱareȱnurseriesȱforȱfishȱandȱlardersȱforȱmigratoryȱbirds.ȱTheȱvariedȱestuarineȱhabitatsȱformȱ
naturalȱfiltersȱandȱbuffersȱbetweenȱtheȱlandȱandȱtheȱsea.ȱȱ
Aȱtypicalȱpatternȱofȱhabitats,ȱidentifiedȱfirstȱbyȱChapmanȱ(1960),ȱisȱfoundȱinȱlowȱenergyȱcoastalȱareasȱinȱ
Australia.ȱTheȱdiagramȱbelowȱ(Figureȱ1)ȱisȱaȱsimpleȱwayȱtoȱvisualiseȱtheȱhabitatsȱthatȱmayȱbeȱfoundȱinȱ
theȱmarineȱandȱbrackishȱpartsȱofȱanȱestuary,ȱinȱwetȱorȱdryȱpartsȱofȱAustralia.ȱ
ȱ
Figure 1—Habitat zones along estuaries
Whileȱeachȱhabitatȱmayȱappearȱtoȱbeȱquiteȱseparateȱfromȱtheȱothers,ȱtheyȱareȱactuallyȱmutuallyȱ
dependant.ȱForȱexample,ȱseagrassesȱrequireȱclearȱwater,ȱandȱmangrovesȱandȱsaltmarshesȱactȱasȱfiltersȱtoȱ
clarifyȱrunoffȱfromȱtheȱland.ȱAtȱtheȱsameȱtime,ȱmangrovesȱandȱsaltmarshesȱwillȱerodeȱwhereȱwaterȱ
movementȱisȱhigh,ȱandȱseagrassȱbedsȱactȱasȱdampersȱtoȱreduceȱwaterȱmovementȱinȱtheȱnearȱshoreȱarea.ȱ
7
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Thereforeȱitȱisȱimportantȱtoȱmanageȱestuarineȱhabitatsȱasȱaȱwhole,ȱratherȱthanȱconcentratingȱonȱaȱsingleȱ
habitat.ȱ
MajorȱpressureȱhasȱbeenȱappliedȱtoȱtheȱterrestrialȱestuarineȱhabitatsȱinȱtheȱmoreȱurbanȱpartsȱofȱSouthȱ
Australia.ȱForȱexample,ȱinȱAdelaideȱtheȱsupratidalȱareasȱhaveȱbeenȱalmostȱentirelyȱdeveloped,ȱtheȱreedȱ
swampsȱfromȱHindmarshȱtoȱPortȱAdelaideȱareȱnoȱlongerȱinȱevidence,ȱandȱmuchȱofȱtheȱupperȱsaltmarshȱ
hasȱbeenȱconvertedȱtoȱindustrialȱlandȱinȱtheȱWingfieldȱdistrict.ȱEvenȱsomeȱofȱtheȱmangroveȱareasȱinȱtheȱ
NorthȱArmȱareaȱhaveȱbeenȱimpoundedȱandȱdeveloped.ȱ
Apartȱfromȱdevelopmentȱpressures,ȱestuarineȱhabitatsȱcomeȱunderȱpressureȱfromȱpollutingȱeffluentȱ
outfalls,ȱsedimentationȱasȱaȱresultȱofȱoverȱclearingȱinȱupperȱcatchments,ȱtheȱoverfishingȱofȱfishȱandȱ
invertebrateȱstocks,ȱandȱtheȱchangesȱtoȱhydrologyȱthatȱcomeȱwithȱsealingȱsurfaces,ȱdammingȱrivers,ȱ
divertingȱflows,ȱandȱbuildingȱdikesȱandȱseawalls.ȱ
ȱ
ȱ
ȱ
8
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Working in the field—safety & environment
Safetyȱisȱtheȱmostȱimportantȱconsiderationȱinȱconductingȱfieldwork.ȱMostȱsafetyȱissuesȱcanȱbeȱaddressedȱ
withȱaȱmodicumȱofȱforethought.ȱGroupȱleadersȱneedȱtoȱvisitȱsitesȱbeforeȱtakingȱgroupsȱintoȱtheȱfield,ȱtoȱ
assessȱanyȱpossibleȱrisks.ȱGroupȱleadersȱshouldȱdiscussȱtheȱarea,ȱtheȱactivitiesȱandȱanyȱsafetyȱ
requirementsȱwithȱtheȱrestȱofȱtheȱgroupȱbeforeȱtakingȱthemȱoutȱtoȱtheȱsite.ȱSpecialȱtrainingȱ(suchȱasȱhowȱ
toȱhandleȱbrokenȱglassȱorȱtreatȱaȱspillȱofȱreagents)ȱshouldȱbeȱrehearsedȱbeforeȱfieldȱactivitiesȱareȱ
attempted.ȱȱ
Theȱdetailsȱofȱwhatȱtrainingȱisȱrequiredȱwillȱdependȱonȱtheȱactivitiesȱbeingȱundertaken,ȱandȱtheȱskillȱandȱ
ageȱofȱtheȱparticipants.ȱEachȱgroupȱleaderȱneedsȱtoȱassessȱtheirȱgroup’sȱparticularȱneeds.ȱSomeȱbasicȱ
fieldworkȱsafetyȱandȱenvironmentalȱcareȱrulesȱareȱpresentedȱbelow.ȱTheyȱrevolveȱaroundȱtheseȱ
principles:ȱ
–
ensuringȱyouȱdoȱnotȱfindȱyourselfȱinȱstrifeȱwithȱnoȱhelpȱavailableȱ
–
dressingȱappropriatelyȱ
–
beingȱawareȱofȱdangerousȱsituationsȱ
–
treatingȱyourselfȱandȱothersȱwithȱconsiderationȱ
–
leavingȱasȱlittleȱevidenceȱasȱpossibleȱbehindȱyou.ȱ
E nsu re he lp is avai lable
–
workȱwithȱatȱleastȱoneȱotherȱpersonȱȱ
–
letȱsomebodyȱknowȱwhereȱyouȱareȱgoingȱandȱwhatȱtimeȱyouȱexpectȱtoȱreturnȱ
–
carryȱaȱmobileȱphone,ȱorȱradioȱ(ifȱoutȱofȱmobileȱreceptionȱzones)ȱȱ
–
carryȱaȱfirstȱaidȱkit.ȱȱ
D r e s s a p p ro p ri a t e l y
–
wearȱappropriateȱclothingȱandȱfootwearȱtoȱsuitȱtheȱareaȱyouȱareȱmonitoring;ȱforȱexample,ȱyourȱ
footwearȱmayȱneedȱtoȱwithstandȱimmersion,ȱhaveȱgoodȱgrip,ȱandȱprotectȱagainstȱsharpȱobjectsȱȱ
–
longȱsleeves,ȱsunscreenȱandȱaȱhatȱwillȱpreventȱsunburnȱ
–
insectȱrepellentȱmayȱbeȱnecessaryȱatȱcertainȱtimesȱofȱtheȱyearȱ
–
useȱglovesȱforȱhandlingȱlitter.ȱ
Be aware of dangerous situ ations
–
checkȱtheȱtideȱtimetableȱbeforeȱgoingȱintoȱwetȱareas,ȱorȱyouȱmayȱbeȱtrappedȱbyȱtheȱtideȱ
–
bridgeȬbasedȱactivitiesȱmayȱbeȱdangerous—theȱwaterȱmayȱbeȱdeepȱandȱpassingȱtrafficȱmayȱalsoȱ
beȱaȱhazard.ȱSafetyȱjacketsȱensureȱyouȱcanȱbeȱseenȱ
–
aȱseaworthyȱboatȱisȱoneȱwhereȱtheȱrunningȱgearȱisȱinȱgoodȱorder,ȱthereȱisȱappropriateȱsafetyȱ
equipmentȱandȱthereȱareȱlifeȱjacketsȱforȱeachȱpassenger.ȱNeverȱleaveȱshoreȱwithȱanythingȱlessȱ
–
followȱboatingȱsafetyȱcodesȱ
–
mangalsȱandȱsaltmarshesȱhaveȱunevenȱterrain,ȱdenseȱgrowthȱandȱillȬdefinedȱwaterways.ȱAlwaysȱ
useȱestablishedȱpathsȱwhereȱpossible.ȱDressȱbrightly,ȱsoȱthatȱyouȱcanȱbeȱfoundȱmoreȱeasilyȱifȱyouȱ
fallȱorȱbecomeȱlost.ȱAvoidȱmuddyȱpatchesȱinȱmangalsȱandȱ‘rottenȱspots’ȱinȱsaltmarshes.ȱWearȱ
tightȬfittingȱwetsuitȱbooteesȱratherȱthanȱwellingtonsȱinȱmuddyȱareas,ȱasȱyouȱareȱlessȱlikelyȱtoȱloseȱ
them.ȱ
T r e a t y o u rs e lf , a n d ot h e rs , w i th con s i d e ra t i o n
–
neverȱpushȱsomeoneȱwhoȱisȱtiredȱorȱcoldȱtoȱcontinueȱworkingȱ
–
carryȱwater,ȱandȱdrinkȱfrequently.ȱ
9
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Leave as little eviden ce as possible behind you
–
transectȱandȱotherȱmarkersȱshouldȱonlyȱbeȱplacedȱwhereȱtheyȱcannotȱcauseȱdamageȱtoȱboatȱ
propellers,ȱandȱshouldȱbeȱmadeȱofȱwood,ȱnotȱsteelȱȱ
–
removeȱanyȱrubbishȱthatȱyouȱhaveȱcreatedȱ
–
usedȱsampleȱreagentsȱshouldȱbeȱpouredȱintoȱaȱliddedȱbucketȱthatȱhasȱkittyȱlitterȱinȱit.ȱSealȱitȱandȱ
takeȱitȱhomeȱwithȱyouȱtoȱputȱoutȱwithȱtheȱsolidȱwaste.ȱ
10
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Working in the field—permits & politeness
Thereȱareȱotherȱaspectsȱtoȱconsiderȱwhenȱworkingȱinȱtheȱfield.ȱYouȱmayȱneedȱaȱpermitȱtoȱconductȱ
monitoringȱactivitiesȱinȱaȱnumberȱofȱsituations.ȱ
NativeȱvegetationȱisȱprotectedȱoutsideȱtheȱimmediateȱAdelaideȱarea,ȱandȱonȱallȱCrownȱLands.ȱAnyȱ
activitiesȱwhereȱlivingȱorȱdeadȱplantȱmatterȱisȱremovedȱ(forȱidentificationȱorȱforȱmeasurement)ȱmayȱ
requireȱaȱpermitȱunderȱtheȱNativeȱVegetationȱActȱ1991,ȱwhichȱisȱadministeredȱbyȱtheȱNationalȱParksȱandȱ
WildlifeȱServiceȱ(NPWS).ȱAdditionally;ȱthisȱauthorityȱisȱresponsibleȱforȱadministeringȱallȱconservationȱ
reservesȱinȱtheȱstate,ȱmostȱofȱwhichȱhaveȱrestrictionsȱonȱtheȱtypesȱofȱactivitiesȱthatȱmayȱtakeȱplaceȱwithinȱ
them.ȱ
AdviceȱonȱwhetherȱaȱpermitȱisȱrequiredȱforȱaȱspecificȱactivityȱunderȱtheȱNativeȱVegetationȱAct,ȱorȱtheȱ
NationalȱParksȱandȱWildlifeȱActȱ1973,ȱmayȱbeȱobtainedȱfromȱtheȱNPWSȱonȱ(08)ȱ8204ȱ8776.ȱȱ
MangroveȱplantsȱareȱadditionallyȱprotectedȱunderȱtheȱFisheriesȱActȱ1982.ȱThisȱActȱalsoȱprovidesȱ
protectionȱforȱmanyȱmarineȱandȱestuarineȱareasȱsuchȱasȱAquaticȱReserves.ȱIntertidalȱareasȱthatȱareȱpartȱ
ofȱAquaticȱReservesȱmayȱhaveȱotherȱrestrictionsȱonȱtakingȱinvertebratesȱorȱotherȱanimals.ȱTheȱactivitiesȱ
thatȱcanȱbeȱconductedȱinȱtheseȱareasȱareȱdefinedȱinȱtheȱFisheriesȱActȱRegulations,ȱandȱonȱboardsȱerectedȱ
atȱboatȱrampsȱinȱaquaticȱreserves.ȱAdviceȱonȱpermitsȱthatȱmayȱbeȱrequiredȱunderȱtheȱFisheriesȱActȱmayȱ
beȱobtainedȱfromȱPrimaryȱIndustriesȱandȱResourcesȱSAȱ(PIRSA)ȱonȱ(08)ȱ8226ȱ0222.ȱ
Groundwaterȱpiezometersȱlessȱthanȱ2.5ȱmetresȱdeepȱdoȱnotȱrequireȱaȱpermitȱunderȱtheȱWaterȱResourcesȱ
Actȱ1997;ȱhowever,ȱdeeperȱmonitoringȱboresȱdo.ȱShallowȱpiezometersȱputȱinȱplaceȱforȱmonitoringȱ
groundwaterȱchangesȱinȱsaltmarshesȱareȱquiteȱlikelyȱtoȱbeȱlocatedȱonȱCrownȱland,ȱsoȱalthoughȱnoȱpermitȱ
mayȱbeȱrequiredȱunderȱtheȱWaterȱResourcesȱAct,ȱpermissionȱmayȱstillȱbeȱrequiredȱfromȱtheȱNPWS.ȱ
Politenessȱisȱaȱbasicȱrequirementȱforȱestablishingȱaȱmonitoringȱprogramȱthatȱisȱwellȱsupportedȱbyȱtheȱ
community.ȱManyȱpeopleȱuseȱestuaries.ȱSomeȱpeopleȱdependȱonȱlocalȱestuariesȱtoȱmakeȱaȱliving,ȱ
(adjacentȱlandowners,ȱcommercialȱfishermen)ȱandȱotherȱpeopleȱenjoyȱrecreationalȱactivitiesȱinȱestuaries.ȱ
Theȱfollowingȱadviceȱwillȱensureȱthatȱgroupsȱconductingȱmonitoringȱdoȱnotȱcauseȱoffenceȱtoȱotherȱ
estuaryȱusers.ȱ
–
alwaysȱobtainȱpermissionȱfromȱlandownersȱbeforeȱenteringȱtheirȱlandȱ
–
leaveȱgatesȱexactlyȱtheȱwayȱyouȱfoundȱthemȱ
–
doȱnotȱlitterȱtheȱmonitoringȱsiteȱ
–
beȱawareȱthatȱuntendedȱmarkersȱareȱjustȱanotherȱformȱofȱlitter—removeȱtemporaryȱmarkersȱasȱ
soonȱasȱtheȱactivityȱisȱfinished.ȱPermanentȱmarkersȱforȱinterȬannualȱcomparisonȱstudiesȱshouldȱ
beȱwellȱmaintained,ȱmarkedȱwithȱaȱcontactȱlabel,ȱandȱplacedȱsoȱtheyȱareȱnotȱhazardousȱtoȱotherȱ
usersȱ
–
manyȱareasȱaroundȱestuariesȱareȱownedȱbyȱtheȱCrown,ȱbutȱmanagedȱbyȱdifferentȱauthoritiesȱ
(localȱgovernment,ȱCoastȱProtectionȱBoard,ȱNWPSȱorȱPIRSA).ȱToȱsetȱupȱaȱmonitoringȱprogramȱonȱ
theseȱareas,ȱdiscussȱwhatȱyouȱwouldȱlikeȱtoȱdoȱwithȱtheȱmanagingȱauthorityȱ
–
beȱawareȱthatȱtheȱnaturalȱvariationȱthatȱoccursȱinȱmanyȱhabitatsȱfromȱoneȱyearȱtoȱanotherȱcanȱbeȱ
large,ȱandȱitȱmayȱtakeȱseveralȱyearsȱofȱmonitoringȱbeforeȱitȱisȱpossibleȱtoȱidentifyȱwhetherȱaȱ
particularȱeventȱhasȱaȱnaturalȱorȱmanȬinducedȱcause.ȱYouȱmayȱwishȱtoȱseekȱexpertȱadviceȱwhenȱ
interpretingȱyourȱresultsȱ
–
ifȱprivateȱbodiesȱsuchȱasȱindustriesȱorȱresearchersȱprovideȱyouȱwithȱinformationȱtoȱhelpȱyouȱ
understandȱyourȱestuary,ȱneverȱprovideȱthatȱinformationȱtoȱothersȱwithoutȱaskingȱpermissionȱ
fromȱtheȱpeopleȱwhoȱgaveȱitȱtoȱyou.ȱ
11
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Designing your monitoring program
Theȱrangeȱofȱactivitiesȱprovidedȱbyȱtheȱframeworkȱisȱlargeȱsoȱasȱtoȱallowȱasȱmanyȱcommunityȱgroupsȱasȱ
possibleȱtoȱbecomeȱinvolvedȱinȱmonitoringȱtheirȱestuarineȱareas.ȱNotȱallȱtheȱactivitiesȱwillȱbeȱsuitableȱforȱ
yourȱgroup,ȱorȱforȱtheȱhabitatsȱthatȱoccurȱinȱyourȱspecificȱestuary.ȱȱ
Beforeȱdoingȱanything,ȱitȱisȱimportantȱtoȱdevelopȱaȱmonitoringȱprogramȱthatȱyourȱgroupȱwillȱbeȱableȱtoȱ
undertake.ȱItȱneedsȱtoȱcontainȱsufficientȱactivitiesȱtoȱprovideȱtheȱgroupȱwithȱanswersȱtoȱtheirȱquestionsȱ
aboutȱtheirȱestuaryȱwhileȱmaintainingȱinterest,ȱbutȱalsoȱmustȱtakeȱupȱonlyȱtheȱtimeȱthatȱyouȱhaveȱ
available.ȱTheȱdecisionsȱyouȱwillȱneedȱtoȱmakeȱinclude:ȱȱ
–
decidingȱwhatȱyouȱwishȱtoȱknowȱaboutȱyourȱestuaryȱ
–
choosingȱwhichȱactivitiesȱareȱsuitableȱforȱyourȱgroupȱandȱyourȱestuaryȱ
–
decidingȱhowȱmuchȱtimeȱyouȱhaveȱavailableȱtoȱmonitorȱyourȱestuaryȱ
–
decidingȱonȱhowȱfrequentlyȱyouȱwillȱmonitorȱeachȱparameterȱyouȱhaveȱchosenȱ(monthly?ȱ
quarterly?ȱannually?)ȱȱ
–
determiningȱinȱwhatȱorderȱtoȱundertakeȱtheȱactivitiesȱyouȱhaveȱchosenȱ
–
understandingȱwhatȱlevelȱofȱdataȱqualityȱyouȱwishȱtoȱstriveȱfor.ȱ
Choosing activities
Inȱgeneral,ȱitȱisȱadvisableȱtoȱselectȱactivitiesȱfromȱeachȱofȱtheȱgroupsȱprovidedȱinȱtheȱmonitoringȱ
framework.ȱTheȱcoreȱactivitiesȱfromȱtheȱsectionsȱSamplingȱsiteȱobservationsȱandȱUnderstandingȱestuarineȱ
processesȱareȱtheȱbasicȱactivitiesȱthatȱallȱmonitoringȱprogramsȱcouldȱideallyȱbeȱbuiltȱon.ȱThen,ȱifȱwaterȱ
qualityȱisȱanȱinterest,ȱconsiderȱtheȱcoreȱactivitiesȱfromȱtheȱChemicalȱassessmentsȱsectionȱofȱtheȱframework.ȱ
Atȱthisȱpoint,ȱconsiderȱwhetherȱyourȱgroupȱwouldȱlikeȱtoȱunderstandȱestuarineȱprocessesȱandȱwaterȱ
qualityȱinȱmoreȱdetail.ȱIfȱso,ȱthereȱareȱextensionȱactivitiesȱavailableȱinȱthoseȱsectionsȱthatȱwillȱdeepenȱ
yourȱunderstandingȱofȱtheseȱaspectsȱofȱyourȱestuary.ȱ
Theȱbiologicalȱsectionsȱofȱtheȱframeworkȱhaveȱfewerȱcoreȱactivities,ȱandȱmoreȱextensionȱactivities.ȱThisȱisȱ
becauseȱmanyȱofȱtheseȱactivitiesȱreflectȱhabitatsȱthatȱmay,ȱorȱmayȱnot,ȱbeȱpresentȱinȱyourȱestuary.ȱTheȱ
activitiesȱyourȱgroupȱchoosesȱshouldȱbeȱbasedȱonȱtheȱhabitatsȱinȱyourȱestuary,ȱorȱinȱtheȱpartȱofȱyourȱ
estuaryȱthatȱyouȱareȱsampling.ȱManyȱofȱtheseȱactivitiesȱrequireȱmoreȱtimeȱtoȱconduct,ȱmoreȱcomplexȱ
equipment,ȱorȱaȱhigherȱskillȱlevel.ȱȱ
TheȱcoreȱactivitiesȱdescribedȱinȱLookingȱatȱvegetationȱandȱhabitatȱandȱinȱObservingȱanimalȱlifeȱmayȱbeȱ
conductedȱbyȱpeopleȱfromȱaȱwideȱrangeȱofȱageȱandȱskillȱlevels.ȱTheseȱcoreȱactivitiesȱareȱalsoȱsuitableȱforȱ
mostȱestuaries.ȱȱ
W h i ch a c t i v i ty f i rs t ?
Whenȱconductingȱfieldwork,ȱtimingȱandȱtheȱorderȱofȱactivitiesȱmatter.ȱTryȱtoȱmonitorȱatȱtheȱsameȱtimeȱofȱ
day,ȱandȱalsoȱattemptȱtoȱmonitorȱatȱtheȱsameȱpartȱofȱtheȱtidalȱcycle.ȱTheȱlatterȱisȱnotȱalwaysȱpossible,ȱbutȱ
atȱleastȱkeepȱaȱrecordȱofȱtheȱstateȱofȱtheȱtide.ȱ
Toȱobserveȱsomeȱaspectsȱofȱwaterȱquality,ȱsuchȱasȱdissolvedȱoxygen,ȱwhichȱchangeȱoverȱtheȱperiodȱofȱaȱ
day,ȱyouȱmayȱconsiderȱaȱoneȬoffȱsamplingȱeventȱthatȱmonitorsȱthatȱparameterȱonȱanȱhourlyȱ(orȱevenȱ
moreȱfrequent)ȱbasis,ȱsoȱthatȱyouȱmayȱseeȱtheȱdiurnalȱvariationȱthatȱoccursȱinȱyourȱestuary.ȱ
Whenȱmonitoring,ȱitȱisȱimportantȱthatȱtheȱresultȱofȱundertakingȱoneȱactivityȱdoesȱnotȱinfluenceȱtheȱnextȱ
activity.ȱForȱexample,ȱwaterȱdepthȱtestingȱusingȱaȱSecchiȱdiskȱorȱmeasuringȱstaffȱstirsȱupȱsediment,ȱ
makingȱtheȱlocationȱunsuitableȱforȱtestingȱwaterȱclarityȱ(Secchiȱdepth)ȱorȱforȱcollectingȱsamplesȱforȱ
measuringȱsuspendedȱsolids.ȱAsȱaȱgeneralȱrule,ȱonȱarrivingȱatȱaȱsite,ȱundertakeȱtheȱobservationalȱ
activitiesȱfirstȱ(weather,ȱsurfaceȱwaterȱconditions,ȱetc).ȱThenȱcollectȱanyȱclearȱwaterȱsamplesȱthatȱyouȱwillȱ
needȱforȱmeasuringȱwaterȱchemistry.ȱFinally,ȱundertakeȱthoseȱactivitiesȱthatȱmayȱdisturbȱtheȱbenthicȱ
sediments.ȱȱ
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D a ta q u a li t y
Credibilityȱdoesnȇtȱmeanȱhavingȱtheȱmostȱexactingȱtechniques.ȱItȱmeansȱdeliveringȱonȱyourȱ
promises,ȱnoȱmatterȱhowȱsmallȱorȱlargeȱtheyȱare.ȱ
ȱMegȱKerr,ȱRIȱRiverȱRescueȱ
Goodȱresultsȱrequireȱcleanlyȱcollectedȱsamples,ȱwellȬmaintainedȱequipmentȱandȱcarefulȱmethods.ȱ
ComparativeȱstudiesȱofȱWaterwatchȱcommunityȬcollectedȱdataȱandȱprofessionallyȬcollectedȱdataȱinȱ
Victoriaȱ(Nicholsonȱetȱal.,ȱ2002)ȱandȱTasmaniaȱ(Otley,ȱ2000)ȱhaveȱshownȱthatȱdespiteȱdifferencesȱinȱtheȱ
levelȱofȱscientificȱtraining,ȱdataȱsetsȱcollectedȱbyȱtheȱtwoȱgroupsȱwereȱcomparableȱforȱtheȱparametersȱofȱ
electricalȱconductivityȱ(salinity)ȱandȱpH.ȱTheȱTasmanianȱstudyȱfoundȱthatȱtheȱtwoȱgroupsȱcouldȱproduceȱ
similarȱresultsȱinȱaȱwholeȬofȬcatchmentȱsurveyȱforȱaȱwideȱrangeȱofȱparameters.ȱInȱVictoria,ȱturbidityȱandȱ
phosphorusȱdataȱcollectedȱbyȱcommunityȱgroupsȱwasȱlessȱconsistentȱandȱhadȱaȱcoarserȱresolutionȱthanȱ
dataȱcollectedȱbyȱprofessionalȱgroups.ȱ
Groupsȱcollectȱdataȱforȱdifferentȱreasons.ȱSomeȱgroupsȱmayȱbeȱmonitoringȱanȱareaȱtoȱdetectȱlongȬtermȱ
trends,ȱothersȱmayȱbeȱtryingȱtoȱtrackȱdownȱaȱpointȬsourceȱpollutant,ȱandȱstillȱothersȱmayȱbeȱusingȱtheirȱ
monitoringȱasȱpartȱofȱanȱoverallȱeducationȱprogram.ȱTheȱlevelȱofȱconfidenceȱthatȱeachȱgroupȱwillȱrequireȱ
inȱanyȱsingleȱmeasurementȱwillȱthereforeȱbeȱdifferent.ȱItȱisȱimportantȱtoȱdecideȱwhatȱlevelȱofȱdataȱ
confidenceȱyourȱgroupȱrequiresȱandȱisȱcapableȱofȱproducing,ȱandȱthenȱdesignȱtheȱqualityȱplanȱsectionȱofȱ
yourȱgroup’sȱmonitoringȱprogramȱtoȱmeetȱthatȱlevel.ȱ
WaterwatchȱSAȱhasȱdevelopedȱaȱrangeȱofȱdataȱqualityȱcategoriesȱforȱcommunityȱwaterȱmonitoringȱthatȱ
groupsȱmayȱchooseȱtoȱaimȱfor.ȱTheseȱlevelsȱare:ȱ
1
AdvancedȱKnownȱQualityȱData—whereȱtestȱmethodsȱareȱchosenȱthatȱareȱcomparableȱinȱ
resolutionȱtoȱmethodsȱusedȱbyȱotherȱwaterȱdataȱusers,ȱwhereȱsamplingȱfrequencyȱisȱatȱleastȱ
sixȱtimesȱannually,ȱwhereȱequipmentȱisȱcalibratedȱforȱeachȱevent,ȱresultsȱareȱreportedȱdirectlyȱ
fromȱtheȱequipmentȱandȱreportingȱunitsȱareȱrecorded,ȱdataȱonȱsamplingȱconditionsȱareȱ
reported,ȱduplicatesȱareȱtested,ȱgroupȱtrainingȱoccursȱannuallyȱandȱ‘mysteryȱsolutions’ȱareȱ
attemptedȱtwiceȱannually.ȱTheseȱdataȱmayȱbeȱmadeȱavailableȱtoȱexternalȱusers,ȱwithȱtheȱ
provisionȱofȱtheȱtoleranceȱlimitsȱ(theȱmethodȱresolution)ȱforȱeachȱparameter.ȱ
2ȱȱȱStandardȱKnownȱQualityȱData—whereȱtestȱmethodsȱareȱchosenȱthatȱareȱcomparableȱinȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱȱ
resolutionȱtoȱmethodsȱusedȱbyȱotherȱwaterȱdataȱusers,ȱwhereȱsamplingȱfrequencyȱisȱatȱleastȱ
fourȱtimesȱannually,ȱwhereȱequipmentȱisȱcalibratedȱforȱeachȱevent,ȱresultsȱareȱreportedȱ
directlyȱfromȱtheȱequipmentȱandȱreportingȱunitsȱareȱrecorded,ȱdataȱonȱsamplingȱconditionsȱ
areȱreported,ȱandȱgroupȱtrainingȱandȱ‘mysteryȱsolutions’ȱareȱattemptedȱonceȱannually.ȱTheȱ
dataȱmayȱbeȱmadeȱavailableȱtoȱexternalȱusersȱforȱtrendȱmonitoringȱpurposes,ȱwithȱtheȱ
provisionȱofȱwiderȱtoleranceȱlimitsȱ(rȱtwiceȱtheȱmethodȱresolution)ȱforȱeachȱparameter.ȱ
3
UnknownȱQualityȱData—whereȱtestȱmethodsȱareȱchosenȱthatȱareȱofȱcoarserȱresolutionȱthanȱ
otherȱwaterȱusersȱmayȱrequire,ȱinitialȱgroupȱtrainingȱhasȱbeenȱattended,ȱdataȱsheetsȱareȱfilledȱ
inȱtoȱtheȱbestȱofȱtheȱgroup’sȱabilityȱbutȱmayȱnotȱbeȱcomplete,ȱandȱwhereȱsamplingȱfrequencyȱ
isȱatȱleastȱonceȱannually.ȱTheseȱdataȱareȱofȱexcellentȱvalueȱinȱtheȱclassroomȱsituationȱwhereȱ
theȱmeasurementsȱmayȱbeȱincorporatedȱintoȱpartsȱofȱtheȱmathematics,ȱscience,ȱandȱsocietyȱ
andȱenvironmentȱcurricula.ȱ
S am p l eȱc o l le ct ing ȱ
Howȱsamplesȱareȱcollectedȱandȱhandledȱmayȱinfluenceȱyourȱresults.ȱTheȱfollowingȱpointsȱwillȱhelpȱyouȱ
toȱcollectȱsamplesȱthatȱareȱrepresentativeȱofȱtheȱwaterȱbodyȱyouȱareȱexamining:ȱ
–
sampleȱbeforeȱundertakingȱactivitiesȱthatȱwillȱdisturbȱanyȱsedimentȱinȱtheȱwaterȱbody.ȱ
–
toȱcollectȱsamplesȱforȱimmediateȱtestingȱuseȱcleanȱpolyethyleneȱorȱPETȱbottles.ȱEnsureȱthereȱareȱ
noȱdetergentȱresiduesȱifȱusingȱcleanedȱbottles.ȱForȱsamplesȱtoȱbeȱanalysedȱbyȱaȱlaboratory,ȱ
discussȱwhatȱbottles,ȱcleaningȱprotocolsȱandȱsamplingȱmethodsȱareȱrequiredȱwithȱtheȱlaboratory.ȱ
Labelȱanyȱbottlesȱyouȱareȱsendingȱtoȱaȱlaboratoryȱpriorȱtoȱsamplingȱwithȱaȱsampleȱnumber,ȱtheȱ
location,ȱdateȱandȱanalysesȱrequired.ȱ
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–
sampleȱdirectlyȱintoȱtheȱsamplingȱbottleȱorȱjarȱunlessȱaȱmixedȱsampleȱisȱnecessary,ȱinȱwhichȱcaseȱ
ensureȱthatȱtheȱlargerȱmixingȱcontainerȱhasȱbeenȱpreparedȱinȱtheȱsameȱmannerȱasȱtheȱsamplingȱ
container.ȱȱ
–
youȱshouldȱrinseȱtheȱsamplingȱcontainerȱinȱtheȱsampleȱstreamȱseveralȱtimes,ȱunlessȱtheȱbottleȱhasȱ
beenȱpreparedȱforȱsendingȱtoȱaȱlaboratory.ȱInȱwhichȱcase,ȱtheȱbottleȱmayȱcontainȱpreservativeȱthatȱ
mustȱbeȱretained,ȱsoȱshouldȱnotȱbeȱrinsedȱinȱtheȱsampleȱstream.ȱ
–
whenȱsampling,ȱsubmergeȱtheȱbottleȱcarefully.ȱTheȱmouthȱofȱtheȱbottleȱshouldȱbeȱheldȱbelowȱtheȱ
bodyȱofȱtheȱbottleȱandȱplungedȱintoȱtheȱwaterȱbeforeȱbeingȱtippedȱupȱtoȱallowȱwaterȱtoȱenter.ȱTheȱ
mouthȱshouldȱremainȱatȱleastȱ200ȱmmȱbelowȱtheȱsurface.ȱAȱsamplingȱdipperȱsimplifiesȱobtainingȱ
aȱcleanȱsubȬsurfaceȱsample.ȱ
–
inȱflowingȱwater,ȱalwaysȱensureȱthatȱyourȱhandȱisȱdownstreamȱofȱtheȱcollectingȱbottleȇsȱmouthȱ
andȱthatȱtheȱmouthȱofȱtheȱbottleȱisȱfacingȱintoȱtheȱcurrent.ȱ
–
itȱisȱnecessaryȱthatȱtheȱpersonȱtakingȱtheȱsamplesȱuseȱtheirȱdiscretionȱwhileȱcollecting,ȱsoȱasȱnotȱtoȱ
takeȱaȱnonȬrepresentativeȱsample.ȱWhenȱsampling,ȱavoidȱdislodgingȱbenthicȱalgalȱmats,ȱscrapingȱ
againstȱtheȱestuaryȱfloorȱorȱjettyȱorȱbridgeȱpylons,ȱorȱotherwiseȱdisturbingȱtheȱsediment.ȱCareȱ
shouldȱbeȱtakenȱsoȱthatȱnoȱlargerȱanimalsȱorȱalgaeȱmatsȱareȱincludedȱinȱtheȱsample,ȱunlessȱthatȱisȱ
whatȱyouȱwishȱtoȱsample.ȱ
–
whenȱsamplingȱwaters,ȱflowingȱorȱwellȬmixedȱwaterȱisȱpreferable,ȱbutȱthisȱmayȱnotȱalwaysȱbeȱ
available,ȱparticularlyȱwhenȱveryȱstillȱconditionsȱcauseȱstratificationȱinȱestuaries.ȱInȱthisȱcase,ȱ
attemptȱtoȱcollectȱthreeȱequallyȱsizedȱsamples,ȱfromȱtheȱsurface,ȱmidzoneȱandȱdeeperȱwaters,ȱmixȱ
themȱtogetherȱandȱsubȬsampleȱtheȱmixture,ȱorȱcollectȱseveralȱseparateȱsamplesȱifȱyouȱwishȱtoȱ
determineȱaȱprofile.ȱȱ
–
whereȱpossible,ȱsampleȱinȱtheȱmiddleȱofȱtheȱestuary,ȱorȱatȱleastȱinȱdeeperȱwater.ȱȱ
–
onceȱcollected,ȱmeasureȱtheȱparametersȱyouȱareȱinterestedȱinȱimmediately.ȱLeavingȱtheȱwaterȱ
standingȱinȱaȱsmallȱcontainerȱwillȱallowȱsomeȱparametersȱtoȱchangeȱ(temperatureȱ&ȱdissolvedȱ
oxygen,ȱforȱexample).ȱ
–
ifȱcollectingȱfromȱaȱboat,ȱshutȱoffȱtheȱmotorȱbeforeȱarrivingȱatȱtheȱsiteȱandȱdriftȱtheȱlastȱfewȱmetresȱ
toȱreduceȱdisturbanceȱatȱtheȱsampleȱsite.ȱAlwaysȱsampleȱupstreamȱfromȱtheȱmotor,ȱinȱcaseȱanyȱ
hydrocarbonsȱhaveȱescapedȱ(thisȱisȱparticularlyȱtheȱcaseȱwithȱolderȱwaterȬcooledȱtwoȬstrokeȱ
engines).ȱ
Equipmentȱcalibration ȱ
Theȱoldȱsayingȱthatȱaȱworkmanȱisȱonlyȱasȱgoodȱasȱhisȱtoolsȱappliesȱequallyȱtoȱmeasuringȱwaterȱqualityȱasȱ
itȱdoesȱtoȱanyȱotherȱactivity.ȱToȱensureȱtheȱinformationȱyouȱcollectȱisȱasȱaccurateȱasȱpossible,ȱlookȱafterȱ
yourȱequipmentȱandȱcalibrateȱitȱregularly.ȱAdviceȱonȱdifferentȱtypesȱofȱequipmentȱisȱgivenȱbelow:ȱ
–
calibrateȱandȱmaintainȱyourȱequipmentȱbeforeȱgoingȱoutȱtoȱaȱsamplingȱsiteȱandȱuseȱanȱequipmentȱ
checklist.ȱTheȱmiddleȱofȱtheȱestuaryȱisȱnoȱplaceȱtoȱdiscoverȱsomethingȱwon’tȱworkȱproperlyȱorȱ
thatȱyouȱhaveȱleftȱsomethingȱatȱhome.ȱȱ
–
ifȱyouȱareȱusingȱaȱmeter,ȱreferȱtoȱtheȱinstructionȱmanualȱthatȱcameȱwithȱtheȱmeterȱtoȱdiscoverȱhowȱ
toȱcalibrateȱit.ȱYouȱwillȱmostȱlikelyȱneedȱtoȱuseȱbufferȱsolutionsȱofȱknownȱconductivityȱandȱpH.ȱȱ
–
checkȱwhatȱtypeȱofȱbatteryȱtheȱmeterȱuses,ȱandȱcarryȱaȱspareȱoneȱinȱtheȱmeter’sȱcarryȱcase.ȱȱ
–
coil,ȱdon’tȱkink,ȱmeterȱcables.ȱ
–
treatȱyourȱmeterȱwithȱrespect.ȱItȱisȱaȱdelicateȱinstrument.ȱAlwaysȱcarryȱaȱmeterȱinȱaȱcarryȱcaseȱorȱ
box.ȱDoȱnotȱletȱitȱrattleȱaroundȱlooseȱinȱtheȱbottomȱofȱyourȱsamplingȱtubȱorȱboat.ȱ
–
rinseȱtheȱprobesȱofȱyourȱmeterȱinȱfreshȱwaterȱafterȱsamplingȱinȱtheȱestuary,ȱandȱstoreȱthemȱasȱ
recommendedȱinȱtheȱmeter’sȱmanual.ȱ
–
checkȱtheȱexpiryȱdatesȱonȱallȱtestȱkitȱreagentsȱbeforeȱtakingȱthemȱoutȱinȱtheȱfield.ȱOldȱreagentsȱ
mayȱgiveȱinaccurateȱresults.ȱ
–
ifȱyouȱareȱusingȱpHȱpapers,ȱbeȱawareȱthatȱtheyȱmayȱbecomeȱinaccurateȱifȱtheyȱareȱold,ȱorȱmayȱ
takeȱlongerȱtoȱreact.ȱBeforeȱgoingȱoutȱtoȱtheȱsamplingȱsite,ȱtryȱaȱfewȱpapersȱinȱpHȱbufferȱsolutionsȱ
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ofȱ4ȱorȱ10,ȱtoȱcheckȱtheirȱaccuracyȱandȱhowȱlongȱtheyȱtakeȱtoȱreact.ȱIfȱtheyȱareȱunacceptable,ȱthrowȱ
theȱpackȱawayȱandȱopenȱaȱnewȱpack.ȱ
–
thermometersȱandȱhydrometersȱrequireȱcheckingȱonceȱaȱyearȱagainstȱaȱcertifiedȱinstrumentȱ
(returnȱthemȱtoȱyourȱWaterwatchȱcoordinator).ȱBeingȱglass,ȱtheseȱinstrumentsȱusuallyȱbreakȱveryȱ
obviously,ȱbutȱoccasionallyȱoneȱmayȱdevelopȱaȱvisuallyȱundetectableȱcrackȱthatȱinterferesȱwithȱitsȱ
accuracy.ȱ
–
treatȱyourȱglassȱitemsȱofȱequipmentȱwithȱrespect.ȱCarryȱthemȱinȱaȱpaddedȱboxȱandȱhandleȱthemȱ
gently.ȱBrokenȱinstrumentsȱshouldȱbeȱplacedȱinȱaȱsharpsȱcontainerȱforȱdisposal.ȱ
–
refractometersȱmayȱbeȱcalibratedȱusingȱdistilledȱwaterȱandȱaȱstandardȱsaltȱsolution.ȱ
–
refractometersȱhaveȱaȱglassȱprismȱandȱtheseȱmayȱbeȱdamagedȱeasily.ȱTheȱprismȱmayȱbreak,ȱorȱ
mayȱbeȱjoltedȱoutȱofȱalignment.ȱShouldȱthisȱhappen,ȱtheȱinstrumentȱmayȱneedȱreplacing,ȱorȱ
repairingȱatȱanȱopticalȱspecialist.ȱ
–
theȱdistance–markedȱcordsȱonȱSecchiȱdisksȱmayȱstretchȱorȱshrinkȱwithȱuseȱandȱrepeatedȱwettingȱ
andȱdrying.ȱBeforeȱgoingȱoutȱintoȱtheȱfield,ȱcheckȱtheȱaccuracyȱofȱtheȱmarkingsȱonȱtheȱcordȱusingȱ
aȱmetalȱtape.ȱ
Method s, ȱ r ec o rd sȱ and ȱ qu a lityȱp lan sȱ
Rawȱdataȱmayȱbeȱveryȱmisleading.ȱToȱuseȱinformationȱcorrectly,ȱyouȱneedȱtoȱknowȱhowȱitȱwasȱcollected,ȱ
whatȱexactlyȱwasȱbeingȱmeasuredȱandȱtheȱprecisionȱwithȱwhichȱitȱwasȱmeasured,ȱamongstȱotherȱthings.ȱ
Aȱdataȱqualityȱplanȱisȱtheȱdocumentȱthatȱprovidesȱendȱusersȱofȱyourȱdataȱwithȱinformationȱonȱthoseȱ
items.ȱ
Theȱusualȱdataȱqualityȱplanȱcontainsȱaȱmapȱshowingȱyourȱsamplingȱsite,ȱaȱsamplingȱtimetable,ȱaȱlistȱofȱ
equipmentȱandȱtestȱmethodsȱthatȱyouȱuse,ȱdetailsȱofȱtheȱmethodȱrangesȱandȱresolutions,ȱdetailsȱofȱtheȱ
reportingȱunitsȱforȱeachȱmethod,ȱdetailsȱonȱhowȱyouȱcheckȱforȱdataȱqualityȱ(calibrationȱofȱequipment,ȱ
duplicateȱsamples,ȱetc)ȱandȱdetailsȱonȱtheȱtrainingȱyourȱgroupȱhasȱreceived.ȱTheȱdocumentȱdoesȱnotȱ
needȱtoȱbeȱlong,ȱandȱyourȱWaterwatchȱcoordinatorȱcanȱassistȱyouȱinȱdevelopingȱit.ȱ
Theȱotherȱrecordsȱyouȱneedȱtoȱmaintainȱareȱtheȱsamplingȱrecords.ȱAlwaysȱattemptȱtoȱfillȱinȱtheȱsiteȱ
recordsȱwithȱasȱmuchȱdetailȱasȱyouȱcanȱatȱtheȱtimeȱofȱsampling.ȱKeepȱthemȱinȱaȱfileȱorȱfolder,ȱsoȱthatȱyouȱ
doȱnotȱmislayȱthemȱasȱyouȱbuildȱupȱaȱcollectionȱofȱsheets.ȱRememberȱtoȱsendȱinȱcopiesȱofȱyourȱsiteȱ
recordsȱtoȱyourȱWaterwatchȱcoordinatorȱifȱyouȱwishȱtheȱdataȱtoȱbeȱavailableȱforȱothersȱtoȱuse.ȱȱ
Finally,ȱconsiderȱwhatȱyouȱareȱtryingȱtoȱdetermine,ȱandȱuseȱmethodsȱthatȱareȱappropriate.ȱItȱisȱnotȱ
usuallyȱnecessaryȱtoȱmeasureȱlocationsȱonȱaȱ50–mȱtransectȱtoȱtheȱmillimetre.ȱItȱisȱpointlessȱtryingȱtoȱ
measureȱnutrientsȱthatȱoccurȱinȱtheȱrangeȱofȱ0–0.5ȱmg/Lȱusingȱtestsȱwithȱmeasuringȱstepsȱofȱ1ȱmg/L.ȱ
ȱ
ȱ
ȱ
15
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Selecting your monitoring sites
Theȱsitesȱthatȱyouȱsampleȱwillȱdependȱonȱwhetherȱyouȱareȱattemptingȱtoȱmonitorȱanȱentireȱestuaryȱ(aȱ
hugeȱprojectȱinȱaȱlargeȱestuary,ȱbutȱfeasibleȱforȱaȱsingleȱgroupȱthatȱisȱmonitoringȱaȱsmallȱestuarineȱcreek,ȱ
orȱwhenȱdoingȱspecificȱactivitiesȱsuchȱasȱmappingȱtheȱsalinityȱgradient),ȱorȱwhetherȱyourȱgroupȱisȱ
responsibleȱforȱmonitoringȱjustȱoneȱsiteȱasȱpartȱofȱmanyȱgroupsȱmonitoringȱanȱestuary.ȱȱ
Bearingȱinȱmindȱthatȱwaterȱsamplesȱtakenȱatȱtheȱshallowȱedgesȱofȱanȱestuaryȱareȱlikelyȱtoȱbeȱ
unrepresentative,ȱselectȱsitesȱwhereȱthereȱisȱsafeȱaccessȱtoȱdeeperȱwater.ȱInȱlongȱestuariesȱinȱurbanȱareas,ȱ
aȱseriesȱofȱbridgesȱmayȱprovideȱusefulȱplatforms,ȱandȱallowȱyouȱtoȱgainȱsamplesȱfromȱbothȱsidesȱandȱtheȱ
middleȱofȱeachȱspan.ȱJettiesȱandȱwharfsȱareȱotherȱoptionsȱthatȱshouldȱbeȱconsidered.ȱȱ
Shouldȱyouȱbeȱmonitoringȱanȱentireȱestuaryȱ(suchȱasȱsmallȱestuarineȱtidalȱcreeks),ȱattemptȱtoȱhaveȱ
samplingȱsitesȱthatȱcoverȱtheȱspectrumȱofȱsalinitiesȱfoundȱinȱtheȱestuary.ȱ
Ifȱyourȱgroupȱhasȱaȱspecificȱinterest,ȱyourȱsamplingȱlocationsȱmayȱreflectȱthat.ȱForȱexample,ȱsomeȱgroupsȱ
mayȱbeȱinterestedȱinȱremediationȱofȱtidalȱwetlands,ȱandȱtheseȱgroupsȱmayȱsampleȱtheȱwetlandȱtheyȱareȱ
workingȱon.ȱOtherȱgroupsȱmayȱwishȱtoȱmonitorȱtheȱeffectsȱofȱstormwaterȱorȱeffluentȱoutfallsȱ(byȱ
mappingȱturbidityȱplumes,ȱforȱexample).ȱ
ȱ
ȱ
ȱ
16
Eȱ S T U A R I N E
MONITORING
GUIDANCE
MANUAL
Sampling site observations
ȱ
ȱ
ȱ
ȱ
ȱ
ȱ
ȱ
17
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Recording weather details
Weatherȱaffectsȱtheȱestuarineȱenvironmentȱitselfȱandȱyourȱabilityȱtoȱ
recordȱaccurateȱinformationȱaboutȱtheȱestuary.ȱȱ
Hotȱweatherȱmayȱreduceȱtheȱabilityȱofȱestuarineȱwatersȱtoȱholdȱ
dissolvedȱoxygen,ȱwindyȱconditionsȱmayȱstirȱupȱsediment,ȱandȱ
heavyȱrainȱmayȱintroduceȱplumesȱofȱturbidȱrunoff.ȱAdditionally,ȱitȱ
mayȱbeȱdifficultȱtoȱobtainȱaccurateȱSecchiȱdiskȱmeasurementsȱinȱ
strongȱglareȱorȱwhenȱtheȱsurfaceȱofȱtheȱwaterȱisȱchoppy.ȱ
Inȱgeneral,ȱcalmȱconditionsȱareȱbestȱforȱmonitoring.ȱAvoidȱ
monitoringȱinȱstrongȱstorms,ȱasȱthereȱareȱmonitoringȱ
representativenessȱasȱwellȱasȱsafetyȱissuesȱtoȱconsider.ȱ
Activity:
3 Core
Age: All
Time: 1
Why? The weather affects
many other parameters
being measured in a
monitoring program, so
should be included to aid
interpretation of the
collected data.
What you may need:
–
siteȱrecordȱformȱ
–
Beaufortȱscaleȱ
–
thermometerȱ
–
weatherȱrecordsȱforȱpreviousȱfewȱdaysȱfromȱtheȱBureauȱofȱMeteorologyȱ(BOM)ȱwebsiteȱ
<www.bom.gov.au>.ȱ
What to do:
Onȱyourȱsiteȱrecordȱform,ȱrecordȱtheȱweatherȱatȱtheȱtimeȱyouȱareȱvisitingȱyourȱsamplingȱsite.ȱ
Youȱmayȱrecordȱwhetherȱitȱisȱsunnyȱorȱcloudy,ȱandȱestimateȱhowȱmuchȱofȱtheȱskyȱisȱcoveredȱbyȱcloud.ȱIfȱ
itȱisȱraining,ȱrecordȱthis,ȱandȱalsoȱrecordȱwhetherȱitȱhasȱrainedȱearlierȱthatȱday.ȱ
Youȱmayȱuseȱtheȱsameȱthermometerȱthatȱyouȱuseȱforȱmeasuringȱwaterȱtemperatureȱtoȱmeasureȱairȱ
temperature.ȱPlaceȱtheȱthermometerȱinȱaȱshadedȱdryȱplaceȱandȱallowȱitȱtoȱequilibrateȱforȱfiveȱminutes,ȱ
thenȱreadȱtheȱtemperature.ȱWetȱthermometersȱorȱthoseȱinȱtheȱsunȱwillȱgiveȱerroneousȱreadings.ȱȱ
AȱversionȱofȱAdmiralȱBeaufort’sȱwindȱspeedȱscaleȱhasȱbeenȱprovidedȱinȱAppendixȱ2,ȱtoȱallowȱyouȱtoȱ
estimateȱwindȱspeed.ȱTheȱversionȱusedȱinȱthisȱmanualȱisȱtheȱoneȱthatȱincludesȱindicatorsȱthatȱoneȱmayȱ
seeȱonȱland,ȱandȱisȱmoreȱsuitableȱforȱuseȱinȱestuariesȱthanȱtheȱversionsȱthatȱareȱusedȱonȱtheȱopenȱsea.ȱ
IfȱyouȱcanȱobtainȱtheȱweatherȱrecordsȱforȱtheȱpreviousȱfewȱdaysȱfromȱtheȱBOMȱwebsite,ȱattachȱtheseȱ
behindȱyourȱsiteȱrecordȱsheet.ȱTheȱweatherȱleadingȱupȱtoȱyourȱsamplingȱeventȱmayȱhaveȱaȱbearingȱonȱ
whatȱyouȱdiscoverȱonȱsite.ȱForȱexample,ȱaȱseriesȱofȱhot,ȱhumidȱnightsȱcanȱresultȱinȱveryȱlowȱoxygenȱ
levelsȱjustȱbeforeȱsunriseȱandȱcanȱsometimesȱcauseȱfishȱdeaths.ȱ
ȱ
ȱ
ȱ
18
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Recording time and tide height
What you may need:
–
siteȱrecordȱformȱ
Activity:
–
timepieceȱ
Age: All
–
tideȱtimetable.ȱ
Time: 1
What to do:
Onȱyourȱsiteȱrecordȱform,ȱrecordȱtheȱtimeȱyouȱvisitȱyourȱsamplingȱ
site.ȱLookȱupȱtheȱtideȱtimetableȱforȱtheȱnearestȱtideȱstationȱtoȱyourȱ
monitoringȱsiteȱandȱdecideȱwhatȱstageȱtheȱtideȱisȱat.ȱIsȱitȱhighȱtide,ȱ
lowȱtide,ȱebbȱ(falling)ȱtide,ȱorȱfloodȱ(rising)ȱtide?ȱ
Alsoȱrecordȱtheȱtimeȱandȱheightȱofȱtheȱtideȱthatȱoccurredȱ
immediatelyȱbeforeȱyourȱvisit,ȱandȱtheȱtimeȱandȱheightȱofȱtheȱnextȱ
tideȱthatȱwillȱoccur.ȱ
19
3 Core
Why? The state of the tide
affects many other
parameters being measured
in a monitoring program, so
should be included to aid
interpretation of the
collected data.
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Recording odours and odd things
What you may need:
–
Activity:
siteȱrecordȱform.ȱ
3 Core
Age: All
What to do:
Ifȱyourȱsiteȱsmells,ȱrecordȱthisȱonȱyourȱsiteȱrecord,ȱalongȱwithȱaȱ
descriptionȱofȱtheȱsmell.ȱDoesȱitȱsmellȱlikeȱfish,ȱsewage,ȱnewȬcutȱ
grass,ȱrottenȱeggs,ȱoverȬripeȱfruitȱorȱfuel?ȱ
Asȱwellȱasȱsmell,ȱtakeȱaȱnoteȱofȱanythingȱelseȱunusual—areȱnewȱ
pipesȱdischargingȱnearȱtheȱsite?ȱIsȱthereȱanȱoilȱslickȱonȱtheȱwater?ȱOilȱ
slicksȱfromȱpollutionȱareȱusuallyȱbrightlyȱcoloured,ȱbutȱsometimesȱinȱ
summer,ȱtheȱfaintestȱslickȱofȱrainbowȱcoloursȱonȱtheȱwaterȱsurfaceȱmayȱȱ
beȱfromȱtheȱoilȱinȱmangroveȱleaves.ȱ
Time: 1
Why? Algal blooms, some
effluents and anoxic
conditions all produce
various odours.
Theȱpresenceȱofȱdeadȱfishȱandȱcrabsȱisȱanȱindicatorȱthatȱshouldȱbeȱrecorded,ȱasȱwellȱasȱtheȱpresenceȱofȱ
scumȱorȱfoamȱonȱtheȱwater,ȱrustȬcolouredȱoozeȱfromȱtheȱsoilȱnextȱtoȱtheȱwater,ȱtheȱpresenceȱofȱlotsȱofȱ
floatingȱrubbish,ȱorȱunusuallyȱturbidȱ(muddy)ȱwater.ȱ
ȱ
20
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Recording water depth
What you may need:
–
Secchiȱdiskȱorȱdepthȱstaffȱ(directionsȱforȱmakingȱaȱSecchiȱdiskȱ
areȱincludedȱinȱAppendixȱ6)ȱ
Activity:
–
siteȱrecordȱform.ȱ
Age: All
3 Core
To ensure good results:
Time: 1
Asȱmeasuringȱtheȱwaterȱdepthȱmayȱdisturbȱtheȱsediment,ȱthisȱ
measurementȱshouldȱbeȱmadeȱafterȱallȱotherȱmeasurementsȱhaveȱ
beenȱtaken.ȱ
Why? The depth of water
may affect other
parameters being
measured, such as
temperature and dissolved
oxygen.
TheȱmarkedȱcordȱonȱaȱSecchiȱdiskȱmayȱstretchȱorȱshrinkȱoverȱtime,ȱsoȱ
itȱshouldȱbeȱcheckedȱagainstȱaȱmetalȱruleȱbeforeȱusingȱitȱinȱtheȱfield.ȱ
What to do:
GentlyȱlowerȱtheȱSecchiȱdiskȱintoȱtheȱwaterȱuntilȱitȱjustȱtouchesȱtheȱ
bottomȱofȱtheȱwaterway.ȱReadȱtheȱwaterȱdepthȱfromȱtheȱcord.ȱ
Inȱshallowȱwater,ȱaȱmeasuringȱstaffȱmayȱbeȱusedȱinsteadȱofȱaȱSecchiȱdisk.ȱȱ
Toȱpreventȱtheȱstaffȱdiggingȱintoȱanyȱsoftȱsediment,ȱtheȱstaffȱȱ
shouldȱhaveȱaȱfootplateȱfitted.ȱ
21
Safety: Deep water may be
dangerous.
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Recording surface water conditions
Windsȱacrossȱtheȱsurfaceȱofȱtheȱestuaryȱhelpsȱmixȱtheȱfresherȱsurfaceȱ
waterȱwithȱtheȱsaltierȱwaterȱbelow.ȱStratificationȱ(layering)ȱofȱ
salinity,ȱtemperatureȱandȱdissolvedȱoxygenȱmayȱoccurȱinȱveryȱcalmȱ
conditions.ȱLargeȱwindȬdrivenȱwavesȱindicateȱthatȱmuchȱmixingȱwillȱ
beȱoccurring,ȱalongȱwithȱadditionalȱoxygenȱincorporation.ȱ
3 Core
Age: All
Time: 1
Why? The water surface
conditions indicate how
much mixing is occurring in
the estuary.
What you may need:
–
Activity:
siteȱrecordȱform.ȱ
What to do:
Safety: Deep water may be
dangerous. Avoid
monitoring in rough
conditions.
Observeȱtheȱwaterȱsurface.ȱDoesȱitȱlook:ȱ
–
calmȱlikeȱaȱmirror?ȱ
–
ruffledȱorȱcoveredȱwithȱsmallȱscaleȬlikeȱripples?ȱ
–
coveredȱwithȱshortȱwaveletsȱthatȱdoȱnotȱhaveȱcrests?ȱ
–
moderatelyȱroughȱwithȱlongerȱwavesȱwithȱoccasionalȱwhiteȱ
glassyȱfoamȱcrests?ȱ
–
quiteȱroughȱwithȱwavesȱwithȱ‘whiteȱhorses’ȱofȱfoamȱwhereȱ
theirȱcrestsȱareȱbreaking?ȱ
Recordȱtheȱwaterȱsurfaceȱconditionȱonȱtheȱsiteȱrecordȱform.ȱ
ȱ
ȱ
22
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Recording water colour
Waterȱoftenȱhasȱaȱslightȱdegreeȱofȱcolour,ȱandȱthisȱcanȱindicateȱtheȱ
chemicalsȱdissolvedȱinȱit,ȱorganicȱmaterialsȱsuchȱasȱpeat,ȱbloomsȱofȱ
phytoplankton,ȱandȱsoilȱerosion.ȱFieldȱmeasurementsȱofȱcolourȱ
tendȱtoȱbeȱsubjective,ȱandȱaȱwideȱrangeȱofȱcolourȱscalesȱhaveȱbeenȱ
developedȱforȱmeasuringȱcolourȱinȱwater,ȱrangingȱfromȱtheȱ
platinumȱscale,ȱtoȱtheȱForel–UleȱscaleȱandȱtheȱBorgerȱandȱMunsellȱ
colourȱsystems.ȱ
Laboratoriesȱuseȱspectrophotometersȱtoȱdetermineȱtheȱhue,ȱ
saturationȱandȱluminanceȱofȱcolouredȱwater,ȱtherebyȱobtainingȱaȱ
quantitativeȱresult.ȱInȱtheȱfield,ȱoneȱobservesȱtheȱapparentȱcolourȱ
ofȱwaterȱreflectedȱfromȱtheȱwhiteȱquadrantsȱofȱaȱSecchiȱdisk,ȱandȱ
comparesȱtheȱcolourȱtoȱanȱarbitraryȱcolourȱchart,ȱsetȱofȱcolouredȱ
glassȱstandards,ȱorȱsetȱofȱcolouredȱwaterȱvials.ȱ
Activity:
3 Core
Age: All
Time: 1
Why? Water colour can
indicate dissolved matter,
the colour of the substrate,
the presence of muddy
sediments, floating oils or
the presence of an algal
bloom.
Safety: Deep water can be
dangerous.
Aȱusefulȱsetȱofȱcolourȱdefinitionsȱhasȱrecentlyȱevolvedȱwithȱtheȱ
adventȱofȱtheȱinternet.ȱToȱdefineȱcoloursȱusedȱonȱHTML–codedȱ
webȱpagesȱthatȱwillȱbeȱdisplayedȱonȱTVȱandȱPCȱmonitors,ȱanȱRGBȱ
(red,ȱgreen,ȱblue)ȱcolourȱcodeȱisȱused.ȱThisȱallowsȱpeopleȱworkingȱ
allȱoverȱtheȱworldȱtoȱdefineȱcoloursȱtheȱsameȱway.ȱȱ
TheȱcolourȱchartȱprovidedȱinȱAppendixȱ3ȱusesȱtheȱHTMLȬRGBȱ
codes,ȱandȱhasȱaȱsimilarȱrangeȱofȱcoloursȱtoȱtheȱForel–Uleȱcolourȱ
scaleȱthatȱisȱcommonlyȱusedȱinȱestuarineȱstudies.ȱ
What you may need:
–
Secchiȱdiskȱ(directionsȱforȱmakingȱaȱSecchiȱdiskȱareȱincludedȱinȱAppendixȱ6)ȱ
–
siteȱrecordȱformȱ
–
waterȱcolourȱchart.ȱ
To ensure good results:
TheȱmarkedȱcordȱonȱaȱSecchiȱdiskȱmayȱstretchȱorȱshrinkȱoverȱtime,ȱsoȱtheȱmarkingsȱonȱtheȱcordȱshouldȱ
beȱcheckedȱagainstȱaȱmetalȱruleȱbeforeȱusingȱtheȱSecchiȱdiskȱinȱtheȱfield.ȱ
Ifȱyouȱreprintȱtheȱcolourȱchart,ȱcheckȱtheȱcolourȱvaluesȱagainstȱtheȱprintedȱchartȱinȱAppendixȱ3ȱofȱthisȱ
manualȱtoȱensureȱtheyȱhaveȱreproducedȱcorrectly.ȱ
SubmergeȱtheȱSecchiȱdiskȱinȱaȱshadyȱareaȱ(shadyȱsideȱofȱboat,ȱjettyȱorȱbridge)ȱifȱpossible,ȱtoȱreduceȱtheȱ
effectȱofȱglare.ȱ
What to do:
GentlyȱlowerȱtheȱSecchiȱdiskȱintoȱtheȱwaterȱuntilȱtheȱdiskȱisȱoneȱmetreȱbelowȱtheȱsurface.ȱLookȱatȱtheȱ
colourȱreflectingȱbackȱfromȱtheȱwhiteȱquadrantȱofȱtheȱdisk.ȱȱ
Compareȱthisȱcolourȱwithȱyourȱcolourȱchartȱandȱrecordȱtheȱcolourȱcodeȱthatȱisȱclosestȱtoȱtheȱwaterȱcolourȱ
reflectingȱbackȱfromȱtheȱSecchiȱdisk.ȱ
23
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring flow rate
Flowsȱinȱestuariesȱareȱveryȱcomplex.ȱRecordingȱflowȱrateȱcanȱhelpȱ
youȱdetermineȱwhetherȱerosionȱorȱaccretionȱofȱtheȱshorelineȱisȱ
likelyȱtoȱoccur,ȱwhetherȱanȱareaȱisȱlikelyȱtoȱhostȱcertainȱtypesȱofȱ
aquaticȱvegetation,ȱandȱ(ifȱtheȱflowȱrateȱisȱtakenȱinȱaȱstormwaterȱ
drain,ȱeffluentȱoutfallȱorȱcreekȱthatȱisȱjoiningȱtheȱestuary)ȱtheȱloadȱ
ofȱpollutantsȱthatȱisȱenteringȱtheȱestuary.ȱ
Flowȱrateȱmayȱaffectȱturbidityȱorȱwaterȱclarity,ȱdissolvedȱoxygenȱ
concentrationȱandȱstratification.ȱWhenȱexaminingȱfringingȱ
wetlandsȱitȱisȱimportantȱtoȱrecordȱflowȱrateȱtoȱhelpȱdetermineȱ
whetherȱtidalȱrestrictionsȱareȱoccurringȱinȱtheseȱvulnerableȱareas.ȱ
Theȱrateȱofȱflowȱmayȱbeȱmultipliedȱbyȱtheȱcross–sectionalȱareaȱofȱ
theȱwaterwayȱbeingȱmeasuredȱtoȱdetermineȱtheȱvolumeȱofȱwaterȱ
passingȱaȱgivenȱpointȱoverȱaȱperiodȱofȱtime.ȱDetailsȱforȱcalculatingȱ
thisȱareȱcontainedȱinȱtheȱbookȱWaterwatchȱAustraliaȱNationalȱ
TechnicalȱManual,ȱVolumeȱ4–PhysicalȱandȱChemicalȱParametersȱ
(WaterwatchȱAustraliaȱSteeringȱCommittee,ȱ2002).ȱ
Activity:
3 Extension
Age: All
Time: 2
Why? The speed that water
moves provides an indicator
of the volume of
stormwater, riverine or
tidal flows in an estuary.
Different habitats occur in
areas of different flow
rates.
Safety: Fast flowing, or
deep, water may be
dangerous.
What you may need:
–
activityȱrecordȱformȱ
–
severalȱorangesȱ
–
aȱnetȱonȱaȱpoleȱ
–
aȱ50Ȭmȱmeasuringȱtapeȱ
–
aȱstopwatch.ȱ
To ensure good results:
Theȱlongerȱtheȱdistanceȱyouȱtimeȱyourȱorangeȱover,ȱtheȱmoreȱlikelyȱyouȱareȱtoȱobtainȱanȱaccurateȱresult,ȱ
soȱuseȱaȱminimumȱdistanceȱofȱ10ȱmetres,ȱbutȱpreferablyȱuseȱaȱ50Ȭmȱdistance.ȱChooseȱanȱareaȱwhereȱthereȱ
areȱnoȱstructuresȱorȱrockyȱoutcropsȱjuttingȱintoȱtheȱflow,ȱasȱtheseȱwillȱmodifyȱtheȱflowȱaroundȱthem.ȱ
What to do:
Useȱyourȱtapeȱtoȱmarkȱtheȱdistanceȱyouȱwillȱmeasureȱtheȱflowȱrateȱover.ȱPlaceȱaȱpersonȱatȱtheȱbeginningȱ
andȱendȱofȱtheȱdistance.ȱTheȱpersonȱatȱtheȱstartȱofȱtheȱdistanceȱshouldȱhaveȱaȱstopwatch.ȱTheȱpersonȱatȱ
theȱendȱofȱtheȱdistanceȱshouldȱhaveȱaȱnetȱonȱaȱpoleȱforȱcatchingȱtheȱoranges.ȱȱ
Placeȱanȱorangeȱinȱtheȱwaterȱupstreamȱofȱtheȱfirstȱperson.ȱAsȱtheȱorangeȱpassesȱtheȱfirstȱperson,ȱtheyȱ
shouldȱstartȱtiming.ȱAsȱtheȱorangeȱpassesȱtheȱsecondȱpersonȱtheyȱshouldȱcallȱoutȱloudly,ȱthenȱattemptȱtoȱ
netȱtheȱorange.ȱTheȱfirstȱpersonȱshouldȱstopȱtheȱwatchȱasȱsoonȱasȱtheyȱhearȱtheȱsecondȱpersonȱcallȱout.ȱ
Repeatȱthisȱatȱleastȱthreeȱtimes.ȱTryȱtoȱuseȱtheȱsameȱorange,ȱbutȱasȱtheȱorangeȱisȱbiodegradable,ȱlosingȱ
theȱoddȱoneȱ(ifȱtheȱflowȱisȱfast,ȱforȱexample)ȱisȱnotȱsignificant.ȱ
Takeȱanȱaverageȱofȱtheȱreadings,ȱandȱuseȱthisȱasȱtheȱtimeȱinȱtheȱfollowingȱcalculation:ȱ
Flow rate (m/sec) = distance travelled
time taken u 0.9
where 0.9 is the correction factor because velocity
varies between the middle and edge of a channel
24
Eȱ S T U A R I N E
MONITORING
GUIDANCE
MANUAL
Understanding estuarine processes
ȱ
25
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring the water temperature
Waterȱtemperatureȱisȱimportantȱforȱtheȱfunctioningȱofȱestuariesȱandȱ
theȱecosystemsȱwithinȱthem.ȱItȱalsoȱinfluencesȱaȱnumberȱofȱchemicalȱ
andȱphysicalȱparameters,ȱsoȱshouldȱbeȱmeasuredȱwheneverȱaȱwaterȱ
qualityȱprogramȱisȱrunȱinȱanȱestuarineȱenvironment.ȱȱ
Higherȱwaterȱtemperaturesȱdecreaseȱtheȱabilityȱofȱwaterȱtoȱholdȱ
oxygen,ȱreduceȱtheȱdensityȱofȱtheȱwaterȱ(howȱheavyȱitȱis)ȱandȱmayȱ
alsoȱincreaseȱtheȱchanceȱofȱanȱalgalȱbloom.ȱRapidȱtemperatureȱshiftsȱ
affectȱtheȱhealthȱofȱmanyȱspeciesȱofȱaquaticȱanimals,ȱandȱmayȱstressȱ
themȱconsiderably.ȱȱ
Long–termȱtemperatureȱchangesȱmayȱhaveȱaȱconsiderableȱimpactȱ
onȱestuarineȱecosystems.ȱWarmerȱwaterȱtemperaturesȱencourageȱ
rapidȱgrowthȱofȱheatȬtolerantȱorganisms,ȱwhichȱoftenȱincludeȱ
introducedȱspeciesȱbroughtȱinȱbyȱshipsȱfromȱtropicalȱports.ȱAsȱanȱ
example,ȱPacificȱOysters,ȱintroducedȱforȱaquaculture,ȱwillȱoftenȱ
reproduceȱinȱtheȱwarmȱshelteredȱwatersȱofȱestuaries,ȱwhereȱtheyȱ
settleȱonȱrockyȱshoresȱandȱreduceȱtheȱspaceȱavailableȱforȱnativeȱ
species.ȱ
Activity:
3 Core
Age: All
Time: 1
Why? Temperature plays an
important role in
determining the amount of
oxygen that can remain in
the water, as well as
affecting the reproductive
status of many organisms.
Warmer or cooler water
than usual for an area may
allow invasive species to
gain a foothold.
Lowȱtemperaturesȱslowȱdownȱgrowthȱandȱdecreaseȱfoodȱ
availabilityȱtoȱfishȱandȱotherȱgrazingȱanimals.ȱȱ
Temperature also controls
the rate of many of the
chemical processes that
occur in an estuary.
Factorsȱthatȱinfluenceȱwaterȱtemperatureȱincludeȱtimeȱofȱday,ȱ
season,ȱdepthȱofȱwater,ȱflowȱrate,ȱtidalȱinfluence,ȱnearbyȱcoolingȱ
waterȱoutfallsȱandȱtheȱlocationȱandȱdepthȱofȱtheȱsamplingȱpoint.ȱ
Recordingȱtheseȱotherȱfactorsȱwhenȱtakingȱyourȱtemperatureȱ
readingȱwillȱhelpȱensureȱthatȱyourȱdataȱisȱmoreȱusefulȱforȱtheȱ
managementȱofȱyourȱestuary.ȱ
Safety: Use alcohol
thermometers, not mercury
ones. Glass thermometers
may break. Handle gently.
Broken pieces should be
placed in a sharps
container.
Thereȱareȱseveralȱmethodsȱusedȱtoȱmeasureȱwaterȱtemperature.ȱTheȱ
mostȱcommonȱmethodsȱuseȱaȱglassȱorȱelectronicȱthermometer.ȱAȱ
glassȱthermometerȱisȱtheȱcheaper.ȱAnȱaccurateȱelectronicȱ
thermometerȱisȱquiteȱexpensiveȱinȱcomparison.ȱAccurateȱelectronicȱ
temperatureȱsensorsȱareȱcommonlyȱfoundȱinȱmultiȬsensorȱCTPȱ
meters,ȱwhereȱconductivity,ȱtemperatureȱandȱpHȱareȱmeasuredȱ
together.ȱȱ
Temperatureȱreadingsȱareȱusedȱtoȱinterpretȱotherȱparameters.ȱHigherȱwaterȱtemperatureȱinfluencesȱtheȱ
abilityȱofȱwaterȱtoȱholdȱoxygen,ȱandȱmayȱinfluenceȱsalinityȱreadings.ȱReferȱtoȱtheȱactivitiesȱMeasuringȱ
salinityȱandȱMeasuringȱdissolvedȱoxygenȱforȱmoreȱdetails.ȱ
What you may need:
–
siteȱrecordȱformȱ
–
redȱspiritȱthermometerȱ
–
collectionȱbottleȱattachedȱtoȱaȱpoleȱforȱsampling.ȱ
To ensure good results:
Theȱthermometerȱshouldȱbeȱcalibratedȱyearlyȱagainstȱaȱcertifiedȱthermometer.ȱȱ
Thermometersȱshouldȱbeȱcheckedȱpriorȱtoȱeveryȱuseȱforȱbubblesȱinȱtheȱredȱspiritȱorȱcracksȱinȱtheȱglass.ȱIfȱ
bubblesȱorȱgapsȱareȱfoundȱinȱtheȱredȱspirit,ȱtheȱthermometerȱshouldȱbeȱ‘shakenȱdown’ȱuntilȱtheȱbubblesȱ
orȱgapsȱdisappear.ȱIfȱcracksȱareȱfoundȱtheȱthermometerȱshouldȱbeȱreplaced.ȱ
26
ESTUARINE
MONITORING
GUIDANCE
MANUAL
What to do:
Collectȱaȱwaterȱsampleȱfromȱatȱleastȱaȱmetreȱoutȱfromȱtheȱshoreȱ(preferablyȱfurtherȱout)ȱandȱfromȱ
approximatelyȱ200–mmȱbelowȱtheȱsurface.ȱȱ
Placeȱtheȱthermometerȱintoȱtheȱwaterȱsampleȱasȱsoonȱasȱitȱisȱcollectedȱandȱleaveȱtheȱthermometerȱinȱtheȱ
waterȱuntilȱtheȱreadingȱstabilisesȱ(thisȱmayȱtakeȱupȱtoȱtwoȱminutes).ȱȱ
RecordȱtheȱreadingȱonȱtheȱsiteȱrecordȱformȱasȱdegreesȱCelsiusȱ(qC)ȱȱ
ȱ
ȱ
ȱ
27
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring pH
pHȱisȱtechnicallyȱtheȱhydrogenȱpotentialȱofȱaȱliquid.ȱInȱcommonȱ
languageȱitȱisȱaȱmeasureȱofȱtheȱacidityȱorȱalkalinity.ȱ
pHȱrangesȱfromȱ1ȱtoȱ14.ȱWhenȱaȱliquidȱhasȱaȱpHȱofȱ7ȱitȱisȱconsideredȱ
neutral.ȱAȱpHȱofȱlessȱthanȱ7ȱisȱacidicȱandȱmoreȱthanȱ7ȱisȱalkalineȱorȱ
basic.ȱȱ
TheȱpHȱvalueȱofȱwaterȱisȱcriticalȱtoȱtheȱsurvivalȱofȱmanyȱaquaticȱ
plantsȱandȱanimals,ȱthusȱmonitoringȱofȱpHȱisȱanȱimportantȱpartȱofȱ
allȱwaterȱqualityȱmonitoringȱprograms.ȱpHȱvaluesȱofȱwaterȱinȱtheȱ
environmentȱmayȱvaryȱconsiderably.ȱPureȱwaterȱisȱneutral.ȱ
FreshwaterȱstreamsȱoftenȱhaveȱaȱpHȱofȱbetweenȱ6.5ȱandȱ8.0.ȱ
EstuarineȱwatersȱusuallyȱhaveȱaȱpHȱofȱbetweenȱ6.5ȱandȱ9.2ȱ(EPA,ȱ
2003).ȱ
pHȱreadingsȱmayȱriseȱwithȱrisingȱsalinity,ȱasȱmanyȱofȱtheȱsaltsȱ
foundȱinȱAustralianȱstreamsȱareȱalkaline.ȱHighȱpHȱreadingsȱmayȱ
alsoȱindicateȱtheȱpresenceȱofȱanȱalgalȱbloom.ȱȱ
Areasȱwithȱlargeȱamountsȱofȱpeatȱorȱorganicȱlitterȱinȱtheȱwaterȱcanȱ
haveȱveryȱlowȱ(<ȱ5)ȱpHȱreadingsȱasȱaȱresultȱofȱhumicȱacidsȱreleasedȱ
fromȱtheȱrottingȱorganicȱmatter.ȱȱ
PollutionȱmayȱraiseȱorȱlowerȱpHȱvaluesȱoutsideȱtheirȱnormalȱlimits.ȱ
Adelaideȱhasȱlargeȱareasȱofȱpotential,ȱandȱactual,ȱacidȱsulphateȱsoilsȱ
thatȱareȱtheȱresultȱofȱdikingȱareasȱofȱsaltmarshȱawayȱfromȱtheȱsea.ȱ
Theseȱareasȱareȱleachingȱandȱgeneratingȱveryȱacidȱgroundwaterȱ
(oftenȱlessȱthanȱ4),ȱwhichȱthenȱenterȱourȱestuaries.ȱSomeȱindustrialȱ
wastes,ȱparticularlyȱfromȱcausticȱplants,ȱcanȱbeȱhighlyȱalkaline,ȱandȱ
theseȱareȱregularlyȱdischargedȱintoȱestuarineȱenvironments.ȱȱ
Activity:
3 Core
Age: All
Time: 2
Why? The pH of water
controls the solubility of
many metals such as iron
and copper. Low pH may
indicate acid rain events or
acid soil drainage. Values
outside the range 5-10
indicate industrial pollution
or cataclysmic events.
Estuaries are normally
between 6.5 and 8.5 (lower
in their freshwater end,
higher at the marine end).
Safety: Dispose of all
reagent/sample mixes
appropriately. If water is
suspected to be strongly
acidic or alkaline avoid skin
contact when handling
samples.
pHȱmayȱbeȱmeasuredȱusingȱpHȱstripsȱ(withȱaȱresolutionȱofȱ0.5ȱpHȱunits),ȱpHȱliquidȱtestȱkitsȱ(withȱaȱ
resolutionȱofȱ0.2ȱunits)ȱorȱwithȱaȱprobeȱandȱmultiȬpurposeȱmeterȱ(withȱaȱresolutionȱofȱlessȱthanȱ0.1ȱpHȱ
units).ȱTheȱpHȱstripsȱareȱtheȱcheapestȱandȱmostȱruggedȱoptionȱbutȱareȱlessȱpreciseȱthanȱtheȱotherȱtwoȱ
methods.ȱSomeȱtypesȱofȱstripȱareȱaffectedȱbyȱsalinity.ȱȱ
ToȱdetectȱsmallerȱsignificantȱvariationsȱinȱpH,ȱsomeȱknowledgeȱofȱtheȱestuaryȱbeingȱmonitoredȱandȱitsȱ
normalȱpHȱvaluesȱisȱrequired.ȱExtremeȱreadingsȱwillȱbeȱimmediatelyȱobvious,ȱhoweverȱsomeȱestuariesȱ
mayȱnaturallyȱbeȱlowȱinȱpH,ȱwhileȱotherȱestuaries,ȱpossiblyȱwithȱmoreȱseaȱinfluence,ȱwillȱbeȱ
considerablyȱhigher.ȱTheȱnaturalȱpHȱrangeȱofȱmostȱestuarineȱorȱmarineȱareasȱinȱtheȱstateȱshouldȱbeȱ
betweenȱ6.5ȱandȱ9.2ȱpHȱunits.ȱValuesȱoutsideȱthisȱrangeȱwouldȱindicateȱsomeȱformȱofȱpastȱorȱpresentȱ
humanȱinterferenceȱ
What you may need:
–
siteȱrecordȱformȱ
–
aȱboxȱofȱpHȱstripsȱthatȱareȱsuitableȱforȱseawater,ȱorȱalternativelyȱaȱmeterȱ
–
aȱpHȱbufferȱsolutionȱwithȱaȱvalueȱofȱ4ȱorȱ10ȱ
–
sampleȱdipperȱmountedȱtoȱaȱpoleȱforȱwaterȱsampling.ȱ
To ensure good results
pHȱstripsȱmayȱbecomeȱinaccurateȱorȱnotȱreactȱatȱallȱasȱtheyȱage,ȱorȱifȱtheyȱareȱexposedȱtoȱwater.ȱIfȱyourȱ
packetȱofȱstripsȱbecomesȱwetȱpleaseȱdisposeȱofȱthem.ȱȱ
28
ESTUARINE
MONITORING
GUIDANCE
MANUAL
TestȱyourȱpHȱstripsȱbeforeȱeachȱmonitoringȱeventȱtoȱmakeȱsureȱthatȱtheyȱprovideȱanȱaccurateȱreadingȱinȱ
aȱreasonableȱlengthȱofȱtime.ȱThisȱisȱdoneȱbyȱimmersingȱoneȱofȱtheȱstripsȱintoȱaȱfreshȱsolutionȱofȱknownȱ
pH,ȱcheckingȱthatȱtheȱstripȱprovidesȱtheȱcorrectȱreading,ȱandȱthenȱdisposingȱofȱtheȱusedȱstrip.ȱShouldȱ
yourȱtestȱstripȱnotȱperformȱadequately,ȱpleaseȱdisposeȱofȱtheȱentireȱpackȱandȱopenȱaȱnewȱone.ȱ
EstuariesȱgenerallyȱhaveȱaȱbasicȱpH,ȱsoȱtheȱmostȱappropriateȱpHȱbufferȱforȱestuarineȱmonitoringȱwouldȱ
beȱtheȱpH10ȱbuffer.ȱUsingȱaȱpH7ȱbufferȱisȱnotȱrecommendedȱasȱtheȱunreactedȱcolourȱofȱmostȱpHȱstripsȱisȱ
inȱtheȱneutralȱrange.ȱȱ
IfȱyouȱareȱusingȱaȱpHȱmeterȱorȱcombinedȱCTPȱmeter,ȱensureȱitȱisȱcalibratedȱpriorȱtoȱgoingȱoutȱintoȱtheȱ
field.ȱ
What to do:
Collectȱaȱwaterȱsampleȱfromȱatȱleastȱaȱmetreȱoutȱfromȱtheȱshoreȱ(preferablyȱfurtherȱout)ȱandȱfromȱ
approximatelyȱ200ȱmmȱbelowȱtheȱsurface.ȱȱ
PlaceȱaȱpHȱstripȱinȱtheȱwaterȱsampleȱandȱleaveȱitȱinȱtheȱwaterȱuntilȱnoȱfurtherȱcolourȱchangeȱoccursȱ(upȱ
toȱfiveȱminutes).ȱ
RemoveȱpHȱstripȱfromȱsampleȱandȱimmediatelyȱcompareȱtheȱcoloursȱonȱtheȱstripȱwithȱthoseȱonȱtheȱ
packet.ȱȱ
Recordȱtheȱreadingȱonȱtheȱsiteȱrecordȱform.ȱȱ
Shouldȱyouȱbeȱusingȱaȱmeter,ȱgentlyȱplaceȱtheȱprobesȱintoȱtheȱsampleȱandȱallowȱthemȱtoȱequilibrateȱwithȱ
theȱsampleȱtemperature.ȱOnceȱtheȱreadingȱhasȱstabilised,ȱrecordȱitȱonȱtheȱsiteȱrecordȱform.ȱ
ȱ
ȱ
ȱ
29
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring water clarity
Waterȱclarityȱisȱanȱindirectȱmeasureȱofȱtheȱamountȱofȱsuspendedȱ
solidsȱinȱtheȱwater.ȱAsȱtheȱamountȱofȱsuspendedȱsolidsȱincreases,ȱ
theȱdepthȱthatȱlightȱcanȱpenetrateȱisȱreduced.ȱThereȱisȱnoȱdirectȱ
correlationȱbetweenȱtheȱweightȱofȱsolidsȱpresentȱinȱtheȱwaterȱandȱ
waterȱclarity.ȱThisȱisȱdueȱtoȱtheȱeffectsȱofȱparticleȱsize–manyȱsmallerȱ
particlesȱreflectȱmoreȱlightȱthanȱaȱfewȱbigȱparticles.ȱȱ
Waterȱclarityȱ(measuredȱwithȱaȱSecchiȱdisk)ȱisȱfrequentlyȱusedȱasȱanȱ
alternativeȱtoȱturbidityȱmeasurement.ȱHowever,ȱtheȱrelationshipȱ
betweenȱturbidityȱ(measuredȱinȱnephelometricȱturbidityȱunitsȱorȱ
NTUs)ȱandȱclarityȱ(measuredȱinȱdepth)ȱisȱnotȱperfect.ȱAnȱ
approximateȱcorrelationȱisȱgivenȱinȱtheȱdataȱinterpretationȱsection,ȱ
asȱthisȱisȱcommonȱpracticeȱinȱclearȱwaters.ȱ
Waterȱclarityȱmayȱbeȱnaturallyȱlowȱ(turbid)ȱduringȱorȱjustȱafterȱ
flooding.ȱLowerȱwaterȱclarityȱcanȱalsoȱbeȱanȱindicationȱofȱunsoundȱ
landȱuseȱmanagementȱinȱtheȱestuary’sȱcatchment.ȱHigherȱlevelsȱofȱ
erosionȱinȱtheȱcatchmentȱwillȱresultȱinȱlowerȱwaterȱclarityȱinȱtheȱ
estuaryȱforȱaȱlongerȱperiodȱofȱtime.ȱȱ
Reducedȱwaterȱclarityȱcanȱaffectȱmarineȱplantȱgrowthȱandȱreducesȱ
theȱdepthȱrangeȱandȱextentȱofȱseagrassȱandȱmacrophyteȱbeds.ȱTheȱ
fineȱparticlesȱmayȱdeterȱsomeȱfishȱspeciesȱorȱclogȱtheȱfeedingȱ
apparatusȱofȱfilterȱfeedingȱanimals.ȱAȱwideȱrangeȱofȱtoxicȱorȱharmfulȱ
pollutantsȱcanȱattachȱthemselvesȱtoȱfineȱsediment,ȱsoȱlowȱwaterȱ
clarityȱmayȱalsoȱindicateȱhighȱlevelsȱofȱotherȱpollutants.ȱȱ
Activity:
3 Core
Age: All
Time: 2
Why? Water clarity controls
the depths at which
submerged plants can grow.
The turbidity (cloudiness)
of water may indicate
erosion or algal blooms and
is a useful measure for
mapping stormwater
plumes. EPA guidelines for
estuaries suggest that
1 NTU or less is good, while
more than 10 NTU is poor.
Safety: Secchi disks are
deployed in deep water
(eg from bridges, jetties,
wharfs and boats).
CommonȱmethodsȱforȱmeasuringȱwaterȱclarityȱincludeȱtheȱSecchiȱdisk,ȱtheȱturbidityȱmeterȱandȱtheȱ
turbidityȱtube.ȱEstuariesȱoftenȱhaveȱveryȱhighȱwaterȱclarityȱreadingsȱcomparedȱtoȱfreshwaterȱriversȱandȱ
streams,ȱsoȱSecchiȱdisksȱareȱrecommendedȱforȱestuarineȱareas.ȱTurbidityȱmetersȱareȱavailableȱforȱtheȱ
turbidityȱrangesȱfoundȱinȱestuaries,ȱandȱtheyȱgiveȱaȱusefulȱandȱoftenȱmoreȱaccurateȱmeasureȱofȱlightȱ
availabilityȱtoȱbenthicȱplants.ȱHowever,ȱtheyȱareȱconsiderablyȱmoreȱcostly,ȱlessȱrobustȱandȱrequireȱ
calibrationȱusingȱformazineȱstandards,ȱwhichȱareȱtoxic.ȱTurbidityȱtubesȱareȱnotȱsufficientlyȱsensitiveȱforȱ
clearȱmarineȱwaters.ȱ
What you may need:
–
siteȱrecordȱformȱ
–
Secchiȱdiskȱ(directionsȱforȱmakingȱaȱSecchiȱdiskȱareȱincludedȱinȱAppendixȱ1)ȱ
–
tapeȱmeasureȱ(ifȱSecchiȱdiskȱcordȱisȱnotȱmarkedȱwithȱmillimetres).ȱȱ
To ensure good results:
Secchiȱdepthȱreadingsȱshouldȱideallyȱnotȱbeȱtakenȱwithinȱtwoȱhoursȱofȱsunsetȱorȱsunrise,ȱtheyȱshouldȱbeȱ
doneȱwithȱaȱclearȱsky,ȱcalmȱwaterȱandȱwithoutȱwearingȱsunglasses.ȱ
Youȱmayȱfindȱyouȱobtainȱmoreȱconsistencyȱinȱtheȱreadingsȱifȱyouȱtakeȱthemȱfromȱtheȱshadyȱsideȱofȱtheȱ
boatȱorȱjetty.ȱȱ
Useȱaȱminimalȱstretchȱnylonȱrope,ȱorȱotherȱshrinkȱresistantȱline,ȱforȱtheȱSecchiȱdisk.ȱCheckȱtheȱlengthȱofȱ
theȱropeȱeveryȱsixȱmonthsȱtoȱensureȱthatȱitȱhasȱnotȱstretchedȱorȱshrunk.ȱRinseȱtheȱdiskȱoffȱafterȱuseȱsoȱ
thatȱsaltȱdoesȱnotȱbuildȱupȱonȱtheȱcordȱorȱdisk.ȱ
30
ESTUARINE
MONITORING
GUIDANCE
MANUAL
What to do:
ȱ
Figure 2—Taking a Secchi depth reading
AȱSecchiȱdiskȱisȱaȱspecialȱdiskȱmarkedȱwithȱblackȱandȱwhiteȱquarters.ȱSlowlyȱlowerȱtheȱSecchiȱdiskȱintoȱ
theȱwaterȱuntilȱtheȱblackȱandȱwhiteȱdiskȱjustȱdisappearsȱfromȱsight.ȱNoteȱthisȱdepth.ȱȱ
Whenȱtheȱdiskȱdisappears,ȱraiseȱtheȱdiskȱslowlyȱuntilȱitȱjustȱbecomesȱvisibleȱagain.ȱYouȱneedȱtoȱbeȱableȱtoȱ
distinguishȱbetweenȱtheȱblackȱandȱwhiteȱsectionsȱofȱtheȱdisk.ȱNoteȱthisȱdepth.ȱ
TheȱSecchiȱdepthȱisȱtheȱaverageȱbetweenȱtheȱtwoȱreadings.ȱMostȱSecchiȱdisksȱhaveȱaȱmarkedȱcord,ȱwhichȱ
makesȱrecordingȱtheseȱdepthsȱeasy,ȱprovidingȱyouȱareȱnotȱtooȱhighȱaboveȱtheȱwater.ȱIfȱtheȱdiskȱreachesȱ
theȱbottomȱofȱtheȱestuaryȱandȱcanȱstillȱbeȱseenȱthenȱrecordȱtheȱdepthȱasȱ‘greaterȱthan’ȱandȱtheȱdepthȱofȱ
theȱwaterȱatȱthatȱpoint.ȱ
RecordȱtheȱSecchiȱdepth,ȱmeasurementȱsite,ȱviewingȱdistanceȱfromȱobserverȱtoȱwaterȱlineȱandȱanythingȱ
elseȱyouȱthinkȱmayȱhaveȱanȱeffectȱonȱtheȱresult,ȱonȱyourȱsiteȱrecordȱform.ȱȱ
Theȱconversionȱbetweenȱturbidityȱandȱwaterȱclarityȱvaries,ȱhoweverȱaȱroughȱ‘ruleȱofȱthumb’ȱforȱSouthȱ
Australianȱestuariesȱ(developedȱbyȱtheȱEPA)ȱisȱincludedȱbelowȱ(Tableȱ1).ȱȱ
Table 1—Secchi depth and turbidity relationship
2ȱNTUȱ
10ȱmȱ
5ȱNTUȱ
4ȱmȱ
10ȱNTUȱ
2ȱmȱ
25ȱNTUȱ
0.9ȱmȱ
100ȱNTUȱ
0.2ȱmȱ
31
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring salinity
Salinityȱisȱaȱmeasureȱofȱtheȱamountȱofȱdissolvedȱsaltsȱinȱaȱgivenȱunitȱ
ofȱwater.ȱTheȱsalinityȱofȱseawaterȱisȱnormallyȱaroundȱ3–4%.ȱEstuariesȱ
haveȱaȱsalinityȱgradient,ȱwhichȱmeansȱthatȱtheȱsalinityȱatȱoneȱendȱofȱ
theȱestuaryȱwillȱdifferȱfromȱthatȱatȱtheȱother.ȱȱ
Eachȱestuaryȱhasȱitsȱownȱsalinityȱregime.ȱHumanȱactivities,ȱsuchȱasȱ
usingȱwaterȱforȱirrigationȱorȱstormwaterȱdischarge,ȱhaveȱalteredȱ
theseȱsalinityȱregimesȱsignificantlyȱinȱmanyȱestuaries.ȱTakingȱregularȱ
salinityȱreadingsȱgivesȱyouȱanȱindicationȱofȱwhatȱkindȱofȱsalinityȱ
regimeȱoccursȱinȱyourȱestuaryȱandȱthereforeȱwhatȱyouȱmayȱexpectȱ
fromȱotherȱparameters.ȱȱ
TheȱsalinityȱrangeȱisȱwideȱinȱSouthȱAustralianȱestuariesȱandȱthisȱ
makesȱfindingȱinstrumentsȱtoȱmeasureȱsalinityȱdifficult.ȱOneȱmethodȱ
isȱtoȱmeasureȱtheȱchangeȱinȱconductivityȱthatȱoccursȱwhenȱsaltsȱareȱ
dissolvedȱinȱwater.ȱCommonȱpocketȱconductivityȱmetersȱhaveȱaȱ
rangeȱfromȱfreshwaterȱtoȱaboutȱhalfȱthatȱofȱseawater.ȱSomeȱestuariesȱ
inȱSouthȱAustraliaȱhaveȱsalinitiesȱofȱupȱtoȱthreeȱorȱfourȱtimesȱthatȱofȱ
seawater.ȱConductivityȱmetersȱthatȱmeasureȱtheseȱsortsȱofȱsalinitiesȱ
costȱaȱconsiderableȱamountȱandȱrequireȱregularȱcalibrationȱ
specificallyȱforȱtheȱsalinityȱrangesȱthatȱareȱmostȱcommonlyȱ
encounteredȱinȱtheȱareaȱwhereȱtheyȱareȱused.ȱFinally,ȱtheȱconversionȱ
ofȱconductivityȱtoȱsalinityȱasȱtotalȱdissolvedȱsolidsȱ(TDS)ȱinȱg/L,ȱ
althoughȱaȱwellȬknownȱrelationship,ȱisȱnotȱaȱsimpleȱlineȱinȱtheȱrangeȱ
ofȱsalinitiesȱfoundȱinȱestuaries.ȱȱ
Activity:
3 Core
Age: All
Time: 2
Why? Salinity is the
dissolved salt content of
water. Salinity and
temperature are the
primary controllers of
stratification in estuaries.
Salinity affects the amount
of oxygen that can remain
dissolved in water, and has
an impact on the
flocculation rate of
suspended particles. Plants
and animals are distributed
in estuaries according to
their salinity preferences.
Safety: If using glass
instruments, handle
carefully. Keep a sharps
container on hand for
broken glass.
Theȱchangeȱinȱtheȱwayȱlightȱrefractsȱthroughȱsaltyȱwaterȱisȱtheȱbasisȱ
forȱanotherȱmethodȱthatȱusesȱaȱrefractometerȱtoȱmeasureȱsalinity.ȱ
Refractometersȱareȱbothȱrelativelyȱfragileȱandȱhaveȱaȱveryȱsmallȱscale,ȱ
makingȱreadingȱtheseȱinstrumentsȱaȱlittleȱdifficultȱforȱnoviceȱusers.ȱ
Theȱuseȱofȱhydrometersȱtoȱmeasureȱspecificȱgravityȱ(whichȱcorrelatesȱwellȱtoȱTDSȱasȱg/L)ȱisȱ
recommendedȱinȱthisȱprogram,ȱasȱtheyȱareȱavailableȱinȱaȱwideȱselectionȱofȱsalinityȱranges,ȱareȱ
economicalȱandȱcanȱbeȱpurchasedȱwithȱaȱqualityȱcertification.ȱȱ
Hydrometersȱconsistȱofȱaȱblownȱglassȱtube,ȱsealedȱatȱbothȱends,ȱwithȱaȱbubbleȱofȱairȱinȱtheȱmiddleȱandȱaȱ
weightȱatȱtheȱbottom.ȱHydrometersȱworkȱonȱtheȱprincipleȱthatȱtheȱmoreȱsaltȱtheȱwaterȱcontainsȱtheȱ
heavierȱorȱdenserȱitȱbecomesȱandȱtheȱbetterȱitȱisȱatȱfloatingȱthings.ȱThisȱisȱwhyȱitȱisȱeasierȱtoȱswimȱinȱsaltȱ
waterȱthanȱinȱfreshwater.ȱ
Aȱlitreȱofȱpureȱwaterȱweighsȱapproximatelyȱoneȱkgȱandȱhasȱaȱhydrometerȱreading,ȱorȱspecificȱgravity,ȱofȱ
1.000ȱatȱ15.6°C.ȱIfȱyouȱdissolvedȱ20ȱgramsȱofȱsaltȱintoȱthatȱwater,ȱitsȱvolumeȱwouldȱbeȱsimilarȱ(well,ȱaȱ
smidginȱmore),ȱbutȱitȱwouldȱweighȱ20ȱgramsȱmore,ȱandȱtheȱhydrometerȱreadingȱwouldȱgoȱupȱ
accordingly.ȱȱ
Aȱtableȱhasȱbeenȱincludedȱinȱthisȱsectionȱthatȱallowsȱyouȱtoȱconvertȱtheȱhydrometerȱreadingȱofȱyourȱ
estuaryȱwaterȱintoȱTDSȱg/L.ȱAsȱwaterȱchangesȱvolumeȱdependingȱonȱtemperature,ȱallȱhydrometerȱ
readingsȱneedȱtoȱbeȱcorrectedȱtoȱreflectȱtheȱtemperatureȱofȱtheȱwaterȱasȱwell,ȱandȱtheȱtableȱincludesȱthisȱ
correction.ȱȱ
32
ESTUARINE
MONITORING
GUIDANCE
MANUAL
What you may need:
–
siteȱrecordȱformȱ
–
hydrometerȱinȱtheȱSGȱrangeȱ1.000–1.050ȱ
–
samplingȱcontainerȱattachedȱtoȱaȱpoleȱ
–
thermometer.ȱ
To ensure good results:
Useȱaȱhydrometerȱthatȱhasȱbeenȱcheckedȱagainstȱaȱknownȱstandardȱ(usuallyȱrecordedȱonȱtheȱboxȱorȱonȱaȱ
certificateȱaccompanyingȱtheȱhydrometer.ȱIfȱtheȱhydrometerȱisȱcrackedȱorȱbrokenȱitȱneedsȱtoȱbeȱreplacedȱ
withȱaȱnewȱone.ȱTheseȱareȱavailableȱfromȱmostȱscientificȱsupplyȱhouses.ȱȱ
Spinningȱtheȱhydrometerȱinȱtheȱwaterȱaȱlittleȱasȱitȱisȱplacedȱintoȱtheȱsampleȱwillȱbreakȱtheȱsurfaceȱtensionȱ
ofȱtheȱwaterȱandȱensureȱaȱmoreȱaccurateȱresult.ȱȱ
Careȱmustȱbeȱtakenȱthatȱtheȱhydrometerȱisȱsuspendedȱinȱtheȱwaterȱwithoutȱtouchingȱtheȱsidesȱofȱtheȱ
samplingȱcontainerȱtoȱensureȱaȱtrueȱresultȱisȱobtained.ȱ
Waterȱinȱaȱnarrowȱcontainerȱorȱsurroundingȱaȱverticalȱtubeȱformsȱaȱslightlyȱcurvedȱsurface,ȱcalledȱaȱ
‘meniscus’.ȱTheȱwaterȱlevelȱisȱreadȱatȱtheȱbottomȱofȱtheȱmeniscus.ȱȱ
What to do:
Collectȱaȱwaterȱsampleȱfromȱatȱleastȱaȱmetreȱoutȱfromȱtheȱ
shoreȱ(orȱfurther)ȱandȱapproximatelyȱ200ȱmmȱbelowȱtheȱ
surface.ȱȱ
Measureȱtheȱtemperatureȱaccordingȱtoȱtheȱwaterȱ
temperatureȱguideline.ȱRecordȱthisȱonȱtheȱsiteȱrecordȱ
form.ȱȱ
Placeȱtheȱhydrometerȱinȱtheȱwaterȱsample.ȱLeaveȱitȱuntilȱ
itȱsettles.ȱReadȱoffȱtheȱnumberȱthatȱisȱnearestȱtoȱtheȱbaseȱ
ofȱtheȱmeniscusȱ(seeȱFigureȱ3).ȱȱ
Recordȱtheȱuncorrectedȱreadingȱonȱdatasheet.ȱMeasureȱ
theȱtemperatureȱofȱtheȱwaterȱandȱrecordȱit.ȱTheȱg/LȱTDSȱ
mayȱthenȱbeȱcalculatedȱinȱtheȱfield,ȱorȱlater,ȱandȱrecorded.ȱȱ
Theȱsalinityȱofȱwaterȱmayȱbeȱstatedȱinȱaȱvarietyȱofȱways.ȱIfȱ
tryingȱtoȱcompareȱsalinityȱreadingsȱwithȱtheȱresultsȱofȱ
anotherȱgroupȱorȱsurvey,ȱitȱisȱimportantȱthatȱtheȱsalinityȱ
unitȱisȱknown.ȱAȱconversionȱchartȱbetweenȱsomeȱofȱtheȱ
moreȱcommonȱtypesȱofȱsalinityȱreadingsȱisȱprovidedȱinȱ
Tableȱ3.ȱ
Figure 3—Reading a hydrometer
Shouldȱyouȱbeȱusingȱaȱconductivityȱmeterȱtoȱmeasureȱ
salinity,ȱbeȱsureȱtoȱfollowȱtheȱmanufacturer’sȱinstructions.ȱ
Manyȱconductivityȱmetersȱandȱprobesȱhaveȱtemperatureȱ
compensation,ȱwhichȱautomaticallyȱcompensatesȱtheȱ
readingȱtoȱanȱECȱvalueȱatȱ25°C.ȱYouȱwillȱneedȱtoȱreferȱtoȱ
theȱowner’sȱmanualȱtoȱfindȱoutȱifȱtheȱmeterȱyouȱareȱusingȱ
hasȱthisȱfeature,ȱandȱmakeȱaȱnoteȱonȱtheȱdatasheet.ȱȱ
Ifȱthereȱisȱnoȱautomaticȱtemperatureȱcompensationȱonȱyourȱmeter,ȱthenȱyourȱECȱreadingsȱwillȱneedȱtoȱbeȱ
modifiedȱusingȱtheȱformulaȱbelow:ȱȱ
K25 (conductivity at 25 °C) =
conductivity
1 + 0.019 (water temperature — 25)
33
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Table 2—Obtaining TDS g/L from SG and temperature
5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 19.0 20.0 21.0 22.0 23.0 24.0 25.0 26.0 27.0 28.0 29.0 30.0 31.0 32.0 33.0
1.000
0.0 0.2 0.3 0.3 0.3 0.3 0.4 0.4 0.4 0.5 0.6 0.8 1.1 1.4 1.6 1.9 2.1 2.5 2.9 3.2 3.6 4.0 4.4 4.8 5.1
1.001 0.2 0.2 0.2 0.2 0.5 0.5 0.6 0.6 0.7 0.8 1.0 1.2 1.5 1.6 1.9 2.1 2.4 2.5 2.8 3.1 3.4 3.8 4.2 4.5 4.9 5.1 5.5 5.9 6.4
1.002 1.5 1.5 1.6 1.6 1.6 1.8 1.9 2.0 2.1 2.3 2.4 2.5 2.8 2.9 3.2 3.4 3.7 4.0 4.2 4.6 4.9 5.1 5.5 5.9 6.3 6.6 7.0 7.5 7.9
1.003 2.8 2.8 2.8 2.9 2.9 3.1 3.2 3.3 3.4 3.6 3.7 3.8 4.1 4.2 4.5 4.8 5.0 5.3 5.5 5.9 6.2 6.6 6.8 7.2 7.6 8.0 8.4 8.8 9.2
1.004 4.1 4.1 4.1 4.2 4.2 4.4 4.5 4.6 4.8 4.9 5.0 5.1 5.4 5.5 5.8 6.1 6.3 6.6 7.0 7.2 7.5 7.9 8.3 8.5 8.9 9.3 9.7 10.1 10.5
1.005 5.3 5.4 5.4 5.4 5.5 5.5 5.7 5.8 5.9 6.2 6.3 6.6 6.7 7.0 7.1 7.4 7.6 7.9 8.3 8.5 8.9 9.2 9.6 10.0 10.2 10.6 11.1 11.5 11.9
1.006 6.6 6.6 6.7 6.7 6.8 6.8 7.0 7.1 7.2 7.5 7.6 7.9 8.0 8.3 8.5 8.8 9.1 9.3 9.6 9.8 10.2 10.5 10.9 11.3 11.6 12.0 12.4 12.8 13.2
1.007 7.9 7.9 7.9 8.0 8.1 8.1 8.3 8.4 8.5 8.8 8.9 9.2 9.3 9.6 9.8 10.1 10.4 10.6 10.9 11.3 11.5 11.9 12.2 12.6 13.0 13.4 13.8 14.2 14.6
1.008 9.2 9.2 9.2 9.3 9.3 9.4 9.6 9.7 9.8 10.0 10.2 10.5 10.6 10.9 11.1 11.4 11.7 11.9 12.2 12.6 12.8 13.2 13.6 13.9 14.3 14.7 15.1 15.5 15.9
1.009 10.4 10.5 10.5 10.6 10.6 10.7 10.9 11.0 11.1 11.3 11.5 11.8 11.9 12.2 12.4 12.7 13.0 13.2 13.6 13.9 14.1 14.5 14.9 15.3 15.7 16.1 16.5 16.9 17.3
1.010 11.7 11.7 11.8 11.8 11.9 12.0 12.2 12.3 12.4 12.6 12.8 13.1 13.2 13.5 13.7 14.0 14.3 14.5 14.9 15.2 15.6 15.8 16.2 16.6 17.0 17.4 17.8 18.2 18.7
1.011 13.0 13.0 13.1 13.1 13.2 13.4 13.5 13.6 13.7 13.9 14.1 14.4 14.5 14.8 15.0 15.3 15.6 16.0 16.2 16.5 16.9 17.3 17.5 17.9 18.3 18.8 19.2 19.6 20.0
1.012 14.1 14.3 14.3 14.4 14.5 14.7 14.8 14.9 15.0 15.2 15.4 15.7 15.8 16.1 16.3 16.6 17.0 17.3 17.5 17.9 18.2 18.6 19.0 19.3 19.6 20.1 20.5 20.9 21.4
1.013 15.4 15.4 15.6 15.7 15.8 15.8 16.0 16.2 16.3 16.5 16.7 17.0 17.1 17.4 17.7 17.9 18.3 18.6 18.8 19.2 19.5 19.9 20.3 20.6 21.0 21.4 21.9 22.3 22.7
1.014 16.7 16.7 16.9 17.0 17.0 17.1 17.3 17.5 17.7 17.8 18.0 18.3 18.6 18.7 19.0 19.3 19.6 19.9 20.1 20.5 20.9 21.2 21.6 22.0 22.3 22.7 23.2 23.6 24.0
1.015 17.9 18.0 18.0 18.2 18.3 18.4 18.6 18.8 19.0 19.1 19.3 19.6 19.9 20.0 20.4 20.6 20.9 21.2 21.6 21.8 22.2 22.5 22.9 23.3 23.6 24.0 24.6 25.0 25.3
1.016 19.2 19.3 19.3 19.5 19.6 19.7 19.9 20.1 20.3 20.4 20.6 20.9 21.2 21.3 21.7 22.0 22.2 22.5 22.9 23.3 23.5 23.9 24.3 24.7 25.1 25.5 25.9 26.3 26.8
1.017 20.5 20.5 20.6 20.8 20.9 21.0 21.2 21.3 21.6 21.7 22.0 22.2 22.5 22.7 23.0 23.3 23.5 23.8 24.2 24.6 24.8 25.2 25.6 26.0 26.4 26.9 27.3 27.7 28.1
1.018 21.7 21.8 22.0 22.1 22.2 22.3 22.5 22.6 22.9 23.0 23.3 23.5 23.8 24.0 24.3 24.6 24.8 25.2 25.5 25.9 26.1 26.5 26.9 27.3 27.7 28.3 28.7 29.0 29.4
1.019 23.0 23.1 23.3 23.4 23.5 23.6 23.8 23.9 24.2 24.3 24.6 24.8 25.1 25.3 25.6 25.9 26.1 26.5 26.8 27.2 27.6 27.8 28.2 28.6 29.0 29.5 30.0 30.4 30.8
1.020 24.3 24.3 24.4 24.6 24.7 24.8 25.1 25.2 25.5 25.6 25.9 26.1 26.4 26.6 26.9 27.2 27.4 27.8 28.2 28.5 28.9 29.2 29.6 30.0 30.4 30.9 31.2 31.6 32.1
1.021 25.6 25.6 25.7 25.9 26.0 26.1 26.4 26.5 26.8 26.9 27.2 27.4 27.7 27.9 28.2 28.5 28.9 29.1 29.5 29.8 30.2 30.6 30.9 31.3 31.7 32.2 32.5 33.0 33.4
1.022 26.8 26.9 27.0 27.2 27.3 27.4 27.7 27.8 28.1 28.2 28.5 28.7 29.0 29.2 29.5 29.8 30.2 30.4 30.8 31.2 31.5 31.9 32.2 32.6 33.0 33.5 33.9 34.3 34.8
1.023 28.1 28.2 28.3 28.5 28.6 28.7 28.9 29.1 29.4 29.5 29.8 30.0 30.3 30.6 30.8 31.2 31.5 31.7 32.1 32.5 32.8 33.2 33.5 33.9 34.4 34.9 35.2 35.6 36.2
1.024 29.4 29.5 29.5 29.8 29.9 30.0 30.2 30.4 30.6 30.8 31.1 31.3 31.6 31.9 32.1 32.5 32.8 33.2 33.4 33.8 34.2 34.5 35.0 35.4 35.7 36.2 36.5 37.1 37.5
1.025 30.6 30.7 30.8 30.9 31.1 31.3 31.5 31.7 31.9 32.1 32.4 32.6 32.9 33.2 33.4 33.8 34.1 34.5 34.7 35.1 35.5 35.9 36.3 36.7 37.1 37.5 37.8 38.4 38.8
1.026 31.9 32.0 32.1 32.2 32.4 32.6 32.8 33.0 33.2 33.4 33.7 33.9 34.2 34.5 34.7 35.1 35.4 35.8 36.0 36.4 36.8 37.2 37.6 38.0 38.4 38.8 39.3 39.7 40.2
1.027 33.2 33.3 33.4 33.5 33.7 33.9 34.1 34.3 34.5 34.7 35.0 35.2 35.5 35.8 36.2 36.4 36.7 37.1 37.5 37.7 38.1 38.5 38.9 39.3 39.8 40.2 40.6 41.0 41.5
1.028 34.5 34.5 34.7 34.8 35.0 35.1 35.4 35.6 35.8 36.0 36.3 36.5 36.8 37.1 37.5 37.7 38.1 38.4 38.8 39.1 39.4 39.9 40.2 40.7 41.1 41.5 41.9 42.5 42.9
1.029 35.6 35.8 35.9 36.2 36.3 36.4 36.7 36.8 37.1 37.3 37.6 37.8 38.1 38.4 38.8 39.0 39.4 39.7 40.1 40.5 40.8 41.2 41.6 42.0 42.4 42.8 43.3 43.8 44.2
1.030 36.9 37.1 37.2 37.3 37.6 37.7 38.0 38.1 38.4 38.6 38.9 39.1 39.4 39.7 40.1 40.3 40.7 41.0 41.4 41.7 42.1 42.6 42.9 43.3 43.8 44.2 44.6 45.1 45.6
1.031 38.2 38.4 38.5 38.6 38.9 39.0 39.3 39.4 39.7 39.9 40.2 40.5 40.7 41.0 41.4 41.8 42.0 42.3 42.7 43.1 43.4 43.9 44.3 44.7 45.1 45.5 45.9 46.5 46.9
1.032 39.5 39.6 39.8 39.9 40.1 40.3 40.6 40.7 41.0 41.2 41.5 41.7 42.0 42.4 42.7 43.0 43.3 43.7 44.1 44.4 44.8 45.2 45.6 46.0 46.5 46.8 47.3 47.8 48.3
1.033 40.8 40.9 41.0 41.2 41.4 41.6 41.9 42.0 42.3 42.5 42.8 43.0 43.3 43.7 44.1 44.3 44.7 45.0 45.4 45.7 46.2 46.6 46.9 47.3 47.8 48.2 48.6 49.2 49.6
1.034 42.0 42.2 42.3 42.4 42.7 42.9 43.2 43.3 43.6 43.8 44.1 44.3 44.6 45.0 45.4 45.6 46.0 46.3 46.7 47.0 47.5 47.9 48.3 48.7 49.2 49.5 50.0 50.5 51.0
1.035 43.3 43.4 43.6 43.8 44.0 44.1 44.4 44.6 44.9 45.1 45.4 45.7 46.0 46.3 46.7 47.0 47.3 47.6 48.0 48.4 48.8 49.2 49.6 50.0 50.5 50.9 51.3 51.9 52.3
1.036 44.5 44.7 44.8 45.0 45.3 45.4 45.7 45.9 46.2 46.4 46.7 47.0 47.3 47.6 48.0 48.3 48.6 49.0 49.4 49.7 50.1 50.6 50.9 51.4 51.8 52.3 52.7 53.2 53.7
1.037 45.8 46.0 46.1 46.3 46.6 46.7 47.0 47.2 47.5 47.7 48.1 48.3 48.6 48.9 49.4 49.6 49.9 50.3 50.7 51.0 51.5 51.9 52.3 52.7 53.2 53.6 54.0 54.6 55.0
1.038 47.1 47.2 47.4 47.6 47.8 48.0 48.3 48.5 48.8 49.0 49.4 49.6 49.9 50.2 50.7 50.9 51.3 51.6 52.0 52.3 52.8 53.2 53.6 54.0 54.5 54.9 55.4 55.9 56.4
1.039 48.3 48.5 48.7 48.9 49.1 49.3 49.6 49.8 50.1 50.3 50.7 50.9 51.2 51.6 52.0 52.2 52.6 52.9 53.3 53.7 54.1 54.6 54.9 55.4 55.9 56.3 56.7 57.2 57.7
1.040 49.6 49.8 49.9 50.1 50.4 50.5 50.9 51.1 51.4 51.6 52.0 52.2 52.5 52.9 53.3 53.5 53.9 54.3 54.7 55.0 55.5 55.9 56.3 56.7 57.2 57.6 58.0 58.6 59.0
1.041 50.9 51.0 51.2 51.4 51.7 51.8 52.2 52.3 52.7 52.9 53.3 53.5 53.8 54.2 54.7 54.9 55.2 55.6 56.0 56.3 56.8 57.2 57.6 58.0 58.5 59.0 59.4 59.9 60.4
1.042 52.1 52.3 52.5 52.7 53.0 53.1 53.5 53.6 54.0 54.2 54.6 54.8 55.1 55.5 56.0 56.2 56.5 56.9 57.3 57.6 58.1 58.6 58.9 59.4 59.9 60.3 60.7 61.3 61.7
1.043 53.4 53.6 53.8 54.0 54.2 54.4 54.7 54.9 55.3 55.5 55.9 56.1 56.4 56.8 57.3 57.5 57.8 58.2 58.6 59.0 59.4 59.9 60.3 60.7 61.2 61.6 62.1 62.6 63.1
1.044 54.7 54.9 55.0 55.3 55.5 55.7 56.0 56.2 56.6 56.8 57.2 57.4 57.7 58.1 58.6 58.8 59.2 59.5 60.0 60.3 60.8 61.2 61.6 62.1 62.6 63.0 63.4 64.0 64.4
1.045 55.9 56.1 56.3 56.5 56.8 57.0 57.3 57.5 57.9 58.1 58.5 58.7 59.1 59.4 60.0 60.1 60.5 60.9 61.3 61.6 62.1 62.6 62.9 63.4 63.9 64.3 64.8 65.3 65.8
1.046 57.2 57.4 57.6 57.8 58.1 58.2 58.6 58.8 59.2 59.4 59.8 60.0 60.4 60.7 61.3 61.4 61.8 62.2 62.6 62.9 63.4 63.9 64.3 64.7 65.2 65.7 66.1 66.7 67.1
1.047 58.5 58.7 58.8 59.1 59.4 59.5 59.9 60.1 60.5 60.7 61.1 61.3 61.7 62.1 62.6 62.8 63.1 63.5 63.9 64.3 64.8 65.2 65.6 66.1 66.6 67.0 67.4 68.0 68.5
1.048 59.7 59.9 60.1 60.4 60.7 60.8 61.2 61.4 61.8 62.0 62.4 62.6 63.0 63.4 63.9 64.1 64.4 64.8 65.3 65.6 66.1 66.6 66.9 67.4 67.9 68.3 68.8 69.4 69.8
1.049 61.0 61.2 61.4 61.6 61.9 62.1 62.5 62.7 63.1 63.3 63.7 63.9 64.3 64.7 65.3 65.4 65.8 66.2 66.6 66.9 67.4 67.9 68.3 68.7 69.3 69.7 70.1 70.7 71.2
1.050 62.2 62.5 62.7 62.9 63.2 63.4 63.8 64.0 64.4 64.6 65.0 65.2 65.6 66.0 66.6 66.7 67.1 67.5 67.9 68.2 68.8 69.2 69.6 70.1 70.6 71.0 71.5 72.1 72.5
34
ESTUARINE
MONITORING
GUIDANCE
MANUAL
TheȱtableȱbelowȱisȱbasedȱonȱoneȱdevelopedȱbyȱProfessorȱBillȱWilliamsȱofȱAdelaideȱUniversity,ȱandȱ
presentedȱatȱtheȱ6thȱInternationalȱSymposiumȱonȱSalineȱLakeȱResearch,ȱBeijing,ȱ1994.ȱItȱisȱforȱbrineȱ
betweenȱ22°Cȱandȱ25°C.ȱTheȱtableȱmayȱbeȱusedȱtoȱconvertȱbetweenȱvariousȱsalinityȱmeasurements.ȱ
Table 3—William's salinity conversion table
Specific
gravity
Brinometer
degrees
Baume
degrees
% salinity
(% NaCl in
brine)
Seawater
salinity %
scale
TDS (g/L or
ppt w/v)
TDS (g/kg or
ppt w/w)
EC (mS/cm)
1.0000
0
0.0
0.000
0
0.0
0
0.0
1.0040
2
0.6
0.528
16
6.6
6
9.0
1.0050
3
0.7
0.704
20
8.2
7
11.0
1.0070
4
1.0
1.056
29
10.9
10
16.0
1.0100
5
1.4
1.452
40
14.9
14
21.8
1.0107
6
1.5
1.544
43
15.1
15
23.2
1.0110
6
1.6
1.584
44
15.5
15
23.8
1.0140
8
2.0
2.020
57
20.2
20
30.2
1.0150
8
2.1
2.112
60
21.8
21
31.6
1.0180
9
2.5
2.482
71
25.4
25
37.1
1.0190
10
2.7
2.640
76
27.1
27
39.0
1.0200
10
2.8
2.772
80
28.6
28
41.0
1.0214
11
3.0
2.956
86
30.6
30
44.0
1.0230
12
3.3
3.167
92
32.9
32
47.0
1.0250
13
3.5
3.540
100
35.8
35
50.7
1.0260
14
3.7
3.695
37.3
36
52.5
1.0286
15
4.0
4.038
41.1
40
57.3
1.0300
16
4.2
4.223
42.4
42
59.8
1.0322
17
4.5
4.513
46.4
45
63.8
1.0340
18
4.8
4.750
49.0
47
66.9
1.0359
19
5.0
5.001
51.7
50
70.1
1.0380
20
5.3
5.279
54.1
53
73.7
1.0395
21
5.5
5.477
55.8
55
76.3
1.0400
21
5.6
5.543
56.4
56
77.0
1.0420
22
5.8
5.807
60.3
58
81.0
1.0431
23
6.0
5.952
62.5
60
82.4
1.0460
24
6.4
6.335
66.7
64
87.0
1.0468
24
6.5
6.441
67.9
65
88.3
1.0500
26
6.9
6.863
70.6
ȱ
ȱ
35
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Mapping your estuary
Understandingȱtheȱmixingȱprocessesȱinȱyourȱestuaryȱrequiresȱanȱ
understandingȱofȱtheȱgeographyȱofȱtheȱestuary.ȱSaltwaterȱandȱ
freshwaterȱmixȱdifferentlyȱdependingȱonȱtheȱshapeȱofȱtheȱ‘container’ȱ
theyȱareȱin.ȱȱ
Toȱdemonstrateȱthis,ȱmixingȱpatternsȱinȱaȱ250–mLȱmeasuringȱ
cylinderȱmayȱbeȱcomparedȱwithȱmixingȱpatternsȱinȱaȱwideȱshallowȱ
bowl.ȱSimplyȱpourȱ100–mLȱofȱthickȱoilȱintoȱtheȱtwoȱcontainers,ȱthenȱ
100–mLȱofȱveryȱthinȱoilȱonȱtop.ȱGentleȱswirlingȱofȱtheȱshallowȱbowlȱ
willȱcauseȱconsiderableȱmixing,ȱwhileȱgentleȱswirlingȱofȱtheȱdeep,ȱ
narrowȱmeasuringȱcylinderȱwillȱhaveȱlittleȱeffectȱatȱall.ȱ
Examinationȱofȱmapsȱofȱyourȱestuaryȱmayȱhelpȱtoȱexplainȱsomeȱofȱ
theȱreadingsȱyouȱobtainȱinȱtheȱfield.ȱMappingȱalsoȱallowsȱyouȱtoȱ
measureȱshorelineȱchangesȱsuchȱasȱerosion,ȱorȱtheȱdevelopmentȱofȱ
sandbanksȱthatȱmayȱchangeȱflowȱpatternsȱwithinȱtheȱestuary.ȱ
Aȱwideȱvarietyȱofȱmapsȱisȱavailable.ȱStandardȱreferencesȱforȱyourȱ
estuaryȱshouldȱincludeȱatȱleastȱoneȱlarge–scaleȱtopographicȱmap.ȱAsȱ
youȱdeepenȱyourȱunderstandingȱofȱyourȱestuary,ȱyouȱmayȱwishȱtoȱ
addȱbathymetricȱmapsȱ(thatȱmapȱtheȱunderwaterȱfeatures),ȱaerialȱ
photography,ȱorthophotoȱmapsȱ(aerialȱphotographsȱthatȱhaveȱbeenȱ
georectifiedȱandȱhaveȱtopographicȱdetailsȱsuperimposedȱonȱthem),ȱ
andȱsatelliteȱimagery.ȱȱ
Activity:
Extension
Age: High school
Time: Variable
Why? The width-to-lengthto-depth ratio of an estuary
has an influence on the
mixing of the fresh and
saline waters within it.
Mapping shoreline changes
over time may allow any
changes in the quantity of
flow, or the effects of
riparian clearing, to be
noted.
Safety: This is a desk-based
activity.
Mapsȱmayȱbeȱpurchasedȱasȱpaperȱproducts,ȱorȱdigitally,ȱonȱCDȱROM.ȱInȱSouthȱAustralia,ȱMaplandȱ
providesȱaȱwideȱrangeȱofȱmappingȱproductsȱforȱareasȱwithinȱtheȱstate,ȱandȱaȱsmallerȱrangeȱforȱotherȱ
partsȱofȱAustralia.ȱ
What you may need:
–
largeȱscaleȱmapsȱorȱaerialȱphotosȱofȱyourȱestuaryȱ(tryȱtoȱgetȱaȱmapȱthatȱincludesȱyourȱestuaryȱonȱ
oneȱsheet—ifȱyouȱhaveȱaȱreallyȱlargeȱestuary,ȱchooseȱtheȱscaleȱthatȱshowsȱyouȱtheȱmostȱdetail,ȱ
andȱpasteȱasȱmanyȱmapsȱtogetherȱasȱyouȱrequire)ȱ
–
tideȱbooksȱ
–
measuringȱtoolsȱsuchȱasȱcallipers,ȱrulersȱandȱcompasses.ȱ
What to do:
Ifȱyouȱneedȱhelpȱinterpretingȱtopographicȱmaps,ȱMaplandȱstockȱaȱrangeȱofȱbooksȱthatȱmayȱassist.ȱTwoȱ
Australianȱbooksȱonȱmapȱreadingȱare:ȱ
Armstrong,ȱPȱ(1987),ȱReadingȱandȱInterpretationȱofȱAustralianȱandȱNewȱZealandȱMaps,ȱ2ndȱedition,ȱ
LongmanȱCheshire,ȱMelbourne.ȱ
StateȱEmergencyȱServiceȱ(1991),ȱMapȱReadingȱHandbook,ȱ2ndȱedition,ȱTASMAP,ȱDeptȱofȱEnvironmentȱ
andȱPlanning,ȱTasmania.ȱ
Usingȱtheȱscaleȱonȱyourȱmapȱasȱaȱguide,ȱworkȱoutȱhowȱlongȱyourȱestuaryȱis.ȱItȱmayȱbeȱtrickyȱ
determiningȱwhereȱtheȱheadȱofȱtheȱestuaryȱis—itȱisȱusuallyȱconsideredȱtoȱbeȱtheȱpointȱfarthestȱupstreamȱ
thatȱstillȱhasȱaȱriseȱandȱfallȱinȱtide.ȱThisȱmayȱnotȱbeȱmarkedȱonȱyourȱmapȱandȱyouȱmayȱneedȱtoȱmakeȱ
someȱfieldȱobservations.ȱ
Takeȱseveralȱmeasurementsȱacrossȱtheȱwidthȱofȱtheȱestuary.ȱWhatȱisȱtheȱaverageȱwidthȱofȱyourȱestuary?ȱ
Doesȱitȱvaryȱmuch?ȱAȱveryȱwideȱestuaryȱmayȱsometimesȱbeȱsubjectȱtoȱCoriolisȱforces,ȱwhichȱpushȱtheȱ
36
ESTUARINE
MONITORING
GUIDANCE
MANUAL
denserȱseawaterȱtoȱoneȱsideȱofȱtheȱestuary,ȱandȱtheȱfreshwaterȱtoȱtheȱother.ȱDoesȱthisȱhappenȱinȱyourȱ
estuary?ȱ
Nowȱtryȱtoȱcalculateȱtheȱareaȱofȱyourȱestuary.ȱYouȱwillȱneedȱthisȱinformationȱtoȱdetermineȱwhetherȱyourȱ
estuaryȱisȱnegativeȱorȱpositiveȱ(seeȱtheȱguidelineȱIsȱyourȱestuaryȱpositiveȱorȱnegative?).ȱMeasuringȱareaȱonȱ
mapsȱthatȱhaveȱaȱgridȱdrawnȱonȱthemȱisȱnotȱdifficult,ȱbutȱitȱmayȱbeȱharderȱonȱaerialȱphotographs.ȱSeeȱtheȱ
guidelineȱUsingȱaerialȱphotographsȱtoȱmapȱhabitatȱchangeȱforȱdetailsȱonȱworkingȱoutȱareas.ȱ
Depthȱisȱanȱimportantȱmeasure.ȱItȱmayȱbeȱavailableȱfromȱbathymetricȱmaps,ȱorȱfromȱyourȱharbourȱ
master.ȱIsȱyourȱestuaryȱdeepȱwithȱsteepȱsides,ȱorȱwideȱandȱshallowȱwithȱdeeperȱchannels?ȱ
Onceȱyouȱknowȱtheȱaverageȱdepth,ȱyouȱcanȱcalculateȱtheȱvolumeȱofȱwaterȱinȱyourȱestuary.ȱForȱaȱveryȱ
roughȱestimate,ȱmultiplyȱtheȱsquareȱmetresȱofȱareaȱbyȱtheȱmetresȱofȱdepth.ȱEachȱresultingȱcubicȱmetreȱisȱ
aȱkilolitreȱofȱwater.ȱToȱgetȱaȱmoreȱaccurateȱmeasure,ȱdivideȱyourȱestuaryȱupȱintoȱdifferentȱzones,ȱandȱ
calculateȱtheȱareaȱandȱvolumeȱforȱeachȱzone.ȱ
Eachȱdayȱtheȱtideȱcomesȱinȱandȱoutȱofȱyourȱestuary.ȱWhenȱtheȱmoonȱisȱfull,ȱtheȱspringȱtidesȱbringȱinȱ
hugeȱamountsȱofȱwater,ȱwhileȱtheȱneapȱtidesȱofȱhalfȬmoonȱhaveȱtheȱsmallestȱtidalȱexchange.ȱByȱlookingȱ
atȱtheȱdifferenceȱinȱheightȱbetweenȱhighȱandȱlowȱtideȱatȱneapsȱandȱsprings,ȱandȱthenȱlookingȱatȱyourȱ
topographicȱandȱbathymetricȱmaps,ȱyouȱmayȱbeȱableȱtoȱgainȱaȱroughȱideaȱofȱtheȱvolumeȱofȱwaterȱthatȱ
movesȱinȱandȱoutȱwithȱtheȱtide.ȱThisȱwater,ȱtheȱtidalȱexchange,ȱhasȱaȱmajorȱinfluenceȱofȱhowȱlongȱitȱ
takesȱforȱpollutantsȱtoȱdisperseȱinȱyourȱestuary.ȱAnȱestuaryȱwithȱaȱsmallȱtidalȱexchangeȱretainsȱtheȱ
pollutantsȱforȱconsiderablyȱlongerȱthanȱaȱsimilarȱestuaryȱwithȱmoreȱexchange.ȱ
Youȱmayȱgainȱquiteȱaȱlotȱofȱinformationȱaboutȱshorelineȱdeposits,ȱerosionalȱareasȱandȱsandȱbarsȱfromȱ
yourȱmaps.ȱBesidesȱusingȱthatȱinformationȱinȱyourȱfieldwork,ȱnoteȱanyȱchangesȱyouȱobserve.ȱLargeȱ
changesȱinȱtheȱshorelineȱorȱinȱdepositionȱareasȱsuchȱasȱsandbanksȱmayȱreflectȱlandȱmanagementȱ
practicesȱinȱtheȱcatchment.ȱ
Theȱinformationȱthatȱyouȱgatherȱinȱthisȱactivityȱwillȱbeȱveryȱusefulȱinȱtheȱactivitiesȱthatȱfollowȱinȱtheȱnextȱ
fewȱpages.ȱ
Ifȱyourȱgroupȱbecomesȱveryȱinterestedȱinȱmapping,ȱyouȱmayȱbeȱpreparedȱtoȱspendȱtheȱtimeȱtoȱlearnȱtheȱ
useȱofȱaȱcomputerisedȱgeographicȱinformationȱsystemȱ(GIS).ȱTheseȱpackagesȱsimplifyȱtheȱ
georectificationȱandȱscalingȱofȱaerialȱphotographs,ȱandȱallowȱyouȱtoȱoverlayȱyourȱfieldȱmeasurementsȱ
ontoȱtopographicȱandȱotherȱbaseȱmaps.ȱTheyȱprovideȱaȱveryȱsophisticatedȱanalysis.ȱFreeȱpublicȱdomainȱ
GISȱpackagesȱareȱavailableȱforȱthoseȱinterestedȱinȱexploringȱthisȱtechnology.ȱMoreȱinformationȱ(andȱtheȱ
software)ȱcanȱbeȱfoundȱatȱtheȱfollowingȱwebȱaddresses:ȱ
—ȱ <www.microimages.com>ȱisȱtheȱsiteȱforȱfreeȱTNTliteȱsoftwareȱ(sizeȱlimitedȱversionȱofȱTNTmips)ȱ
—ȱ <grass.baylor.edu>ȱisȱtheȱsiteȱforȱfree,ȱopenȱsourceȱGRASSȱsoftwareȱdevelopedȱbyȱtheȱUSȱmilitaryȱ
—ȱ <http://www.esri.com/software/arcexplorer/>ȱisȱaȱveryȱbasicȱfreeȱGISȱfromȱtheȱmakersȱofȱArcInfoȱ
—ȱ <www.tiem.utk.edu/~sada/>ȱisȱtheȱfreeȱSpatialȱAnalysisȱandȱDecisionȱAssistanceȱsoftwareȱpageȱ
—ȱ <www.mapmaker.com>ȱisȱtheȱsiteȱtoȱdownloadȱMapmakerȱGratis.ȱ
ȱ
ȱ
37
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Is your estuary positive or negative?
Positiveȱestuariesȱareȱthoseȱwhereȱtheȱamountȱofȱfreshwaterȱthatȱ
naturallyȱentersȱtheȱestuaryȱexceedsȱtheȱamountȱofȱfreshwaterȱlostȱtoȱ
theȱairȱasȱevaporationȱ(seeȱFigureȱ4).ȱSuchȱanȱestuaryȱwillȱhaveȱaȱ
salinityȱgradientȱthatȱisȱfreshȱatȱitsȱheadȱandȱwillȱgraduallyȱincreaseȱ
toȱmarineȱatȱitsȱmouth.ȱ
Inȱcontrast,ȱaȱnegativeȱestuaryȱlosesȱmoreȱfreshwaterȱtoȱevaporationȱ
eachȱdayȱthanȱentersȱtheȱestuary.ȱThisȱtypeȱofȱestuaryȱwillȱhaveȱ
hypersalineȱ(veryȱsaltyȱwater)ȱatȱitsȱhead,ȱandȱtheȱsalinityȱdecreasesȱ
toȱthatȱofȱseawaterȱatȱtheȱmouth.ȱNegativeȱestuariesȱareȱveryȱslowȱatȱ
dispersingȱpollutants–andȱthisȱmayȱbeȱevenȱmoreȱnoticeableȱifȱtidalȱ
exchangeȱisȱlow.ȱ
Activity:
Extension
Age: High school
Time: 3
Why? This factor
determines the types of
salinity patterns in your
estuary.
Safety: This is a desk-based
activity.
InȱSouthȱAustraliaȱmanyȱofȱourȱestuariesȱareȱnegative.ȱThisȱisȱtheȱ
resultȱofȱaȱcombinationȱofȱfactors:ȱtheȱoverallȱaridityȱ(highȱ
evaporationȱandȱlowȱrainfall),ȱandȱtheȱsizeȱofȱourȱriverȱcatchments.ȱ
Onlyȱoneȱofȱourȱriversȱ(theȱMurray)ȱhasȱaȱcatchmentȱthatȱextendsȱintoȱ
wetterȱpartsȱofȱAustralia.ȱ
What you may need:
–
theȱareaȱofȱyourȱestuaryȱ
–
theȱgrossȱannualȱevaporationȱforȱyourȱdistrictȱ
–
theȱannualȱrainfallȱforȱyourȱdistrictȱ
–
aȱtopographicȱmapȱorȱcatchmentȱmapȱforȱyourȱestuaryȱ
–
alternatively,ȱgaugingȱstationȱdataȱforȱtheȱriverȱupstreamȱfromȱtheȱestuaryȱcanȱbeȱusedȱtoȱ
determineȱwaterȱinputȱfromȱupstream.ȱ
ȱ
Figure 4—Water movements in an estuary
What to do:
Forȱaȱsmallȱcatchment:ȱTakeȱyourȱtopographicȱorȱcatchmentȱmapȱandȱdetermineȱwhatȱcatchmentȱareaȱisȱ
coveredȱwithȱurbanȱdevelopmentȱandȱwhatȱareaȱisȱvegetatedȱorȱfarmed.ȱRecordȱtheseȱareasȱasȱ‘urbanȱ
area’ȱandȱ‘ruralȱarea’.ȱȱ
38
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Toȱworkȱoutȱtheȱvolumeȱofȱrainȱthatȱmayȱrunȱoffȱintoȱtheȱriverȱ(andȱestuary)ȱeachȱyearȱfromȱtheȱland,ȱ
multiplyȱeachȱareaȱ(inȱm2)ȱbyȱtheȱannualȱrainfallȱ(inȱmetres),ȱthenȱbyȱaȱrunoffȱcoefficient.ȱWhileȱveryȱ
accurateȱrunoffȱcoefficientsȱhaveȱbeenȱdevelopedȱforȱallȱtypesȱofȱdevelopment,ȱforȱthisȱpurposeȱtwoȱveryȱ
approximateȱfactorsȱareȱused.ȱTheȱrunoffȱcoefficientȱforȱurbanȱareasȱinȱthisȱcalculationȱisȱ0.65,ȱandȱtheȱ
runoffȱcoefficientȱforȱruralȱareasȱisȱ0.12.ȱRecordȱtheȱcubicȱmetresȱofȱwaterȱthatȱrunȱintoȱyourȱestuaryȱforȱ
theȱyearȱasȱinputȱvolume.ȱEachȱcubicȱmetreȱisȱequalȱtoȱaȱkilolitreȱofȱwater,ȱandȱ1000ȱcubicȱmetresȱequalȱaȱ
megalitre.ȱ
Nowȱcalculateȱtheȱamountȱofȱwaterȱthatȱwillȱevaporateȱfromȱtheȱwaterȱsurfaceȱofȱyourȱestuary.ȱForȱthisȱ
youȱneedȱtoȱobtainȱtheȱevaporationȱdataȱforȱyourȱareaȱfromȱtheȱBOMȱwebsite.ȱTheȱevaporationȱthatȱtheȱ
BOMȱprovidesȱisȱusuallyȱinȱtheȱformȱofȱgrossȱevaporation,ȱratherȱthanȱpanȱorȱnetȱevaporation.ȱSubtractȱ
theȱannualȱrainfallȱ(inȱmm)ȱfromȱtheȱgrossȱevaporationȱ(inȱmm)ȱtoȱobtainȱpanȱevaporation.ȱConvertȱthisȱ
figureȱfromȱmillimetresȱtoȱmetres,ȱthenȱmultiplyȱitȱbyȱtheȱareaȱofȱyourȱestuaryȱ(inȱm2).ȱRecordȱtheȱresultȱ
(inȱcubicȱmetres)ȱasȱevaporationȱvolume.ȱ
Whichȱofȱtheseȱfiguresȱisȱtheȱlarger?ȱIfȱtheȱinputȱvolumeȱisȱlargest,ȱyourȱestuaryȱisȱaȱpositiveȱestuary.ȱIfȱ
theȱevaporationȱvolumeȱisȱtheȱlarger,ȱyourȱestuaryȱisȱaȱnegativeȱestuary.ȱ
Forȱaȱlargeȱcatchment:ȱInȱriversȱsuchȱasȱtheȱMurray,ȱthereȱareȱmanyȱsubȬcatchmentsȱthatȱcoverȱhugeȱ
areasȱthatȱhaveȱdifferentȱannualȱrainfallȱandȱevaporation.ȱIfȱyourȱestuaryȱisȱthisȱtypeȱofȱestuary,ȱyouȱcanȱ
stillȱcalculateȱtheȱevaporationȱvolumeȱasȱspecifiedȱabove.ȱ
Toȱcalculateȱtheȱinputȱvolume,ȱyouȱwillȱrequireȱgaugingȱdataȱfromȱweirsȱonȱyourȱriver,ȱasȱcloseȱtoȱtheȱ
estuaryȱasȱpossible.ȱThisȱwillȱtellȱyouȱtheȱvolumeȱofȱwaterȱthatȱpassedȱoverȱtheȱweirȱinȱaȱyear.ȱTheȱdataȱ
mayȱbeȱinȱkilolitresȱorȱmegalitres.ȱȱ
Trapsȱforȱtheȱunwary:ȱInterȬbasinȱwaterȱtransferȱ(forȱexample,ȱfromȱtheȱRiverȱMurrayȱtoȱtheȱTorrensȱandȱ
Onkaparingaȱrivers)ȱmayȱprovideȱanȱunnaturalȱsourceȱofȱfreshwaterȱtoȱyourȱestuary.ȱIfȱyourȱcalculationsȱ
basedȱonȱrunoffȱshowȱthatȱyourȱestuaryȱwouldȱnormallyȱbeȱaȱnegativeȱestuary,ȱbutȱyourȱfieldȱdataȱ
showsȱitȱtoȱbeȱaȱpositiveȱestuary,ȱyouȱmayȱneedȱtoȱconsiderȱwhereȱtheȱextraȱfreshwaterȱisȱcomingȱfrom.ȱ
InterȬbasinȱtransfersȱareȱnotȱalwaysȱobvious.ȱForȱexample,ȱtheȱoutfallȱfromȱaȱsewageȱworksȱisȱmainlyȱ
waterȱthatȱoriginallyȱenteredȱyourȱhouseȱasȱmainsȱwater.ȱAreȱyouȱonȱaȱpipedȱwaterȱscheme?ȱManyȱ
townshipsȱinȱSAȱobtainȱtheirȱpipedȱwaterȱfromȱtheȱRiverȱMurray.ȱ
Reuse:ȱPasturesȱandȱforestsȱhaveȱmuchȱlowerȱrunoffȱratesȱthanȱurbanȱareas,ȱwhichȱhaveȱsealedȱroadsȱ
andȱroofs.ȱWhatȱ(approximately)ȱwouldȱbeȱtheȱrunoffȱfromȱyourȱcatchment,ȱifȱthereȱwereȱnoȱurbanȱ
areas?ȱIsȱitȱveryȱdifferentȱfromȱtheȱcurrentȱrunoff?ȱȱ
Theȱcalculationsȱaboveȱareȱextremelyȱsimplifiedȱformsȱofȱtheȱcomplexȱmodelsȱthatȱnaturalȱresourceȱ
managementȱ(NRM)ȱboardsȱmayȱuseȱtoȱdetermineȱhowȱmuchȱurbanȱstormwaterȱrunoffȱtheyȱmayȱ
responsiblyȱharvestȱandȱstoreȱinȱundergroundȱaquifersȱforȱreuse.ȱAreȱthereȱanyȱaquiferȱstorageȱprojectsȱ
inȱyourȱarea?ȱHowȱmuchȱwaterȱisȱbeingȱinjectedȱintoȱtheȱaquiferȱinȱthoseȱprojects?ȱDon’tȱforgetȱtoȱ
subtractȱthatȱamountȱfromȱyourȱinputȱvolume!ȱ
ȱ
ȱ
39
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Classifying your estuary
GeoscienceȱAustraliaȱhasȱproducedȱaȱCDȱROMȱaboutȱAustralianȱ
estuaries,ȱdesignedȱforȱeducationalȱuse,ȱthatȱincludesȱaȱclassificationȱ
systemȱforȱestuariesȱ(commonlyȱcalledȱtheȱOzEstuariesȱ
classification,ȱdevelopedȱbyȱHeapȱetȱal,ȱ2001).ȱTheȱsystemȱclassifiesȱ
estuariesȱintoȱthreeȱmajorȱtypes,ȱdependingȱonȱwhetherȱtheyȱareȱ
dominatedȱbyȱtheȱtideȱ(mainlyȱfoundȱinȱnorthernȱAustraliaȱwhereȱ
tidesȱareȱlarge),ȱbyȱriversȱ(theseȱareȱdeltaȱestuaries)ȱorȱbyȱwavesȱ
(whereȱaȱsandyȱbarrierȱofȱsomeȱkindȱisȱformedȱbyȱwaves).ȱEachȱofȱ
theseȱgroupsȱcanȱbeȱsubdivided,ȱprovidingȱsixȱsubclasses:ȱtideȱ
dominatedȱdeltas,ȱwaveȱdominatedȱdeltas,ȱwaveȱdominatedȱ
estuaries,ȱstrandȱplains,ȱtideȱdominatedȱestuariesȱandȱtidalȱflats.ȱȱ
What you may need:
–
GeoscienceȱAustraliaȱ(2002)ȱAustralianȱEstuariesȱandȱCoastalȱ
Waterways,ȱaȱCDȱROMȱproducedȱforȱtheȱNationalȱLandȱandȱ
WaterȱResourcesȱAuditȱ(NLWRA),ȱAGSOȱGeoScienceȱ
Australia,ȱCanberraȱ
Activity:
Extension
Age: High school
Time: 2
Why? Different types of
estuaries are very different
in their mixing regimes and
in how pollution is
distributed. Understanding
what type of estuary you
are studying will help you
in understanding why things
happen the way they do in
your estuary.
Safety: This is a desk-based
activity.
–
aȱgoodȱtopographicȱmapȱofȱyourȱestuaryȱ
–
aȱtideȱbookȱ
–
annualȱrainfallȱandȱevaporationȱtotalsȱ
–
accessȱtoȱtheȱinternetȱtoȱexploreȱtheȱOzEstuariesȱdatabaseȱonȱtheȱNLWRAȱwebsiteȱatȱ
<www.ozestuaries.org>.ȱ
What to do:
FirstȱexploreȱtheȱCDȱROM.ȱCanȱyouȱunderstandȱtheȱmethodȱtheȱNLWRAȱuseȱinȱtheirȱclassificationȱofȱ
estuaries?ȱLookingȱatȱyourȱestuary’sȱshapeȱonȱyourȱtopographicȱmap,ȱtheȱrangeȱofȱyourȱtideȱonȱyourȱtideȱ
book,ȱandȱyourȱweatherȱdetails,ȱwhatȱtypeȱofȱestuaryȱdoȱyouȱthinkȱyouȱmayȱbeȱstudying?ȱ
VisitȱtheȱOzEstuariesȱwebsite.ȱIsȱyourȱestuaryȱlistedȱonȱtheȱsite?ȱIfȱitȱis,ȱdidȱtheȱNLWRAȱcomeȱtoȱtheȱ
sameȱclassificationȱasȱyouȱdid?ȱTheȱNLWRAȱonlyȱexaminedȱfairlyȱlargeȱestuaries,ȱsoȱyoursȱmayȱbeȱpartȱ
ofȱanȱ‘amalgamated’ȱestuary.ȱIfȱyourȱestuaryȱisȱlisted,ȱpullȱupȱsomeȱofȱtheȱdetailedȱdataȱthatȱisȱenteredȱonȱ
theȱwebsite.ȱIfȱyourȱestuaryȱwasȱtooȱsmallȱtoȱbeȱincluded,ȱlookȱatȱtheȱdataȱonȱaȱsimilarȱestuaryȱinȱtheȱ
vicinityȱofȱyours.ȱDoesȱitȱhaveȱmuchȱinȱcommonȱwithȱyourȱestuary?ȱ
Theȱdataȱonȱthisȱsiteȱmayȱprovideȱyouȱwithȱlotsȱofȱinformationȱaboutȱyourȱestuary,ȱandȱthisȱmayȱhelpȱ
youȱinȱdecidingȱwhatȱaspectsȱofȱyourȱestuaryȱyouȱwishȱtoȱstudyȱfurther.ȱ
ȱ
ȱ
40
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Mapping the salinity gradient of your
estuary
Manyȱwaterȱqualityȱmonitoringȱprogramsȱareȱbasedȱonȱtakingȱaȱ
waterȱsampleȱregularlyȱatȱtheȱsameȱlocationȱeachȱtime.ȱThisȱ
monitoringȱisȱaȱvalidȱmethodȱofȱensuringȱreplicableȱsampleȱresults,ȱ
althoughȱtheȱsamplesȱmayȱnotȱtellȱyouȱmuchȱaboutȱtheȱrestȱofȱyourȱ
estuary.ȱ
Estuariesȱhaveȱaȱgradientȱofȱsalinityȱalongȱthem,ȱstartingȱwithȱeitherȱ
freshwaterȱ(inȱpositiveȱestuaries)ȱorȱhypersalineȱwaterȱ(inȱnegativeȱ
estuaries)ȱatȱtheȱheadȱofȱtheȱestuary,ȱandȱeitherȱincreasingȱorȱ
decreasingȱinȱsalinityȱuntilȱatȱtheȱmouthȱofȱtheȱestuaryȱtheȱsalinityȱisȱ
thatȱofȱseawaterȱ(eusaline).ȱȱ
Toȱlookȱatȱtheȱsalinityȱgradientȱinȱyourȱestuary,ȱmultipleȱsamplesȱ
needȱtoȱbeȱtakenȱalongȱtheȱestuary–alongȱtheȱedgesȱofȱtheȱestuaryȱȱ
andȱasȱcloseȱtoȱmidstreamȱasȱyouȱcanȱgetȱ(usuallyȱfromȱaȱbridge,ȱorȱ
fromȱaȱjettyȱorȱboat).ȱ
Activity:
3 Extension
Age: High school
Time: 4
Why? Estuaries vary in
salinity from their head to
their mouth.
Safety: Salinity gradient
mapping may require
working over deep water.
What you may need:
–
salinityȱprofileȱandȱgradientȱrecordȱformȱ
–
aȱsamplingȱtubeȱonȱaȱpoleȱ
–
equipmentȱtoȱmeasureȱsalinityȱandȱtemperatureȱ
–
GPSȱtoȱdetermineȱyourȱlocationȱifȱusingȱaȱboat,ȱorȱgoodȱtopographicȱmapȱifȱmeasuringȱfromȱaȱ
jettyȱorȱbridgeȱ
–
samplingȱplatformȱ(seaworthyȱboat,ȱbridge,ȱjetty).ȱ
To ensure good results:
Checkȱyourȱequipmentȱpriorȱtoȱgoingȱoutȱintoȱtheȱfield.ȱSeeȱtheȱmethodȱguidelinesȱMeasuringȱsalinityȱȱ
andȱMeasuringȱtemperatureȱforȱdetails.ȱ
What to do:
Identifyȱyourȱsampleȱlocationȱandȱgetȱthere.ȱRecordȱsiteȱdetailsȱsuchȱasȱlocationȱcoordinatesȱifȱsamplingȱ
fromȱaȱboat.ȱOftenȱaȱseriesȱofȱseveralȱlowȬlevelȱbridgesȱareȱidealȱforȱthisȱactivity,ȱasȱyouȱmayȱsampleȱonȱ
bothȱedgesȱofȱtheȱestuaryȱandȱtheȱmiddle,ȱatȱseveralȱlocationsȱalongȱtheȱestuary.ȱ
Sampleȱwaterȱfromȱaboutȱ200–mmȱbelowȱtheȱsurface.ȱOnceȱsamplesȱareȱcollected,ȱtestȱthemȱforȱsalinityȱ
andȱtemperature.ȱSeeȱtheȱmethodȱguidelinesȱMeasuringȱsalinityȱandȱMeasuringȱtemperatureȱforȱdetails.ȱ
Recordȱtheȱresultsȱforȱeachȱlocation.ȱ
Onȱreturnȱtoȱbase,ȱplotȱtheȱresultsȱonȱaȱmapȱofȱtheȱestuary.ȱ
Thisȱtypeȱofȱinformationȱisȱveryȱusefulȱwhenȱmakingȱmanagementȱorȱmonitoringȱdecisionsȱaboutȱanȱ
estuaryȱ(orȱanyȱcoastalȱwaterȱbody).ȱMoreȱsuitableȱlocationsȱforȱdischargingȱstormwaterȱorȱcleanȱ
saltwaterȱeffluentsȱ(forȱexampleȱfromȱindustrialȱevaporativeȱairȱconditioningȱplants,ȱwaterȱsofteningȱ
plants,ȱandȱreverseȱosmosisȱplants)ȱmayȱbeȱselectedȱbasedȱonȱtheȱsalinityȱgradientȱofȱyourȱestuary.ȱ
41
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Mapping the salinity profile of your
estuary
Manyȱwaterȱqualityȱmonitoringȱprogramsȱareȱbasedȱonȱtakingȱaȱ
waterȱsampleȱregularlyȱatȱtheȱsameȱlocationȱandȱatȱtheȱsameȱdepthȱ
eachȱtime.ȱThisȱmonitoringȱisȱaȱvalidȱmethodȱofȱensuringȱreplicableȱ
sampleȱresults,ȱbutȱmayȱnotȱgiveȱaȱrepresentativeȱresultȱinȱstratifiedȱ
estuaries.ȱ
Stratification,ȱorȱlayering,ȱofȱdifferentȱsalinityȱwatersȱoftenȱoccursȱinȱ
estuaries,ȱparticularlyȱinȱtheȱnegativeȱestuariesȱthatȱareȱsoȱcommonȱinȱ
SouthȱAustralia.ȱHighlyȱsalineȱwaterȱisȱheavierȱthanȱseawater,ȱsoȱ
whenȱtheȱtideȱcomesȱinȱorȱaȱstormwaterȱdischargeȱoccurs,ȱtheȱfresherȱ
waterȱflowsȱoverȱtheȱtopȱofȱtheȱmoreȱsalineȱwater.ȱStratificationȱcanȱ
resultȱinȱreducedȱdissolvedȱoxygenȱlevelsȱinȱtheȱdeeperȱlayers.ȱ
Toȱgetȱaȱrepresentativeȱsampleȱinȱaȱstratifiedȱestuary,ȱmultipleȱ
samplesȱneedȱtoȱbeȱtakenȱatȱaȱrangeȱofȱdepthsȱasȱcloseȱtoȱmidstreamȱ
asȱyouȱcanȱget,ȱusuallyȱfromȱaȱbridge,ȱorȱfromȱaȱjettyȱorȱboat.ȱThisȱ
methodȱisȱcalledȱprofiling.ȱ
Activity:
3 Extension
Age: High school
Time: 3
Why? Stratified estuaries
have quite different water
quality at different depths.
To determine how a
pollutant will be distributed
in an estuary it is necessary
to understand the
stratification pattern.
Safety: Salinity profiling is
conducted in deep water.
Aȱcommonȱrangeȱofȱsamplingȱdepthsȱwouldȱinclude:ȱ200ȱmmȱbelowȱtheȱsurface,ȱoneȱmetre,ȱtwoȱmetresȱ
andȱthenȱeveryȱtwoȱmetresȱafterȱthat,ȱuntilȱtheȱbottomȱofȱtheȱwaterȱbodyȱisȱreached.ȱIfȱyourȱestuaryȱisȱ
particularlyȱshallow,ȱyouȱmayȱlikeȱtoȱmakeȱtheȱsamplingȱdepthsȱcloserȱtogether.ȱOptimallyȱyouȱwouldȱ
takeȱatȱleastȱthreeȱsamplesȱ(bottom,ȱmiddleȱandȱnearȱsurface)ȱfromȱeachȱlocation.ȱSalinity,ȱdissolvedȱ
oxygenȱ(DO),ȱpHȱandȱtemperatureȱreadingsȱareȱtakenȱforȱeachȱsample.ȱȱ
Profilesȱareȱusuallyȱmadeȱatȱaȱnumberȱofȱlocationsȱtoȱproduceȱaȱsalinityȱstratificationȱmapȱofȱtheȱestuary,ȱ
whichȱaidsȱinȱselectingȱtheȱmostȱrepresentativeȱsiteȱforȱregularȱsampling.ȱȱ
What you may need:
–
salinityȱprofileȱandȱgradientȱrecordȱformȱ
–
depthȱsamplingȱdevice,ȱmarkedȱwithȱ500Ȭmmȱintervals–theseȱmayȱbeȱpurchasedȱorȱhomemadeȱ
(seeȱAppendixȱ6ȱforȱusefulȱdesigns)ȱ
–
multipleȱsampleȱbottlesȱwithȱlidsȱ
–
equipmentȱtoȱmeasureȱsalinityȱandȱtemperatureȱ(DOȱandȱpHȱareȱoptional)ȱȱ
–
alternativelyȱyouȱcouldȱreplaceȱtheȱlastȱtwoȱitemsȱwithȱaȱmultiȬparameterȱprobeȱthatȱreadsȱEC,ȱ
DO,ȱpHȱandȱtemperatureȱwithȱaȱsixȬmetreȱcableȱ
–
GPSȱtoȱdetermineȱyourȱlocationȱifȱusingȱaȱboat,ȱorȱgoodȱtopographicȱmapȱifȱmeasuringȱfromȱaȱ
jettyȱorȱbridgeȱ
–
samplingȱplatformȱ(seaworthyȱboat,ȱbridge,ȱjetty).ȱ
To ensure good results:
Tryȱtoȱreachȱyourȱsamplingȱlocationȱwithoutȱdisturbingȱtheȱwaterȱunduly.ȱDisturbingȱtheȱwaterȱmayȱmixȱ
theȱstratificationȱlayers.ȱ
Checkȱyourȱequipmentȱpriorȱtoȱgoingȱoutȱintoȱtheȱfield.ȱSeeȱtheȱmethodȱpagesȱMeasuringȱtemperature,ȱ
MeasuringȱpH,ȱȱMeasuringȱsalinityȱandȱMeasuringȱdissolvedȱoxygenȱforȱdetails.ȱ
What to do:
Identifyȱyourȱsampleȱlocationȱandȱgetȱthere.ȱRecordȱlocationȱdetailsȱsuchȱasȱcoordinates,ȱifȱsamplingȱ
fromȱaȱboat.ȱ
ȱ
ȱ
42
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Useȱyourȱsamplingȱdeviceȱtoȱcollectȱwaterȱsamplesȱatȱseveralȱdepths.ȱMostȱsamplersȱworkȱbyȱremovingȱ
theȱlidȱofȱtheȱbottlesȱafterȱreachingȱpredeterminedȱdepths.ȱSamplersȱmayȱtestȱseveralȱdepthsȱatȱonceȱorȱ
mayȱsampleȱsingleȱbottlesȱatȱaȱtime.ȱInȱtheȱlatterȱcase,ȱrepeatȱtheȱcollectionȱprocessȱuntilȱaȱsampleȱhasȱ
beenȱcollectedȱatȱeachȱdesiredȱdepth.ȱWhenȱtakingȱrepeatedȱsamples,ȱcollectȱtheȱshallowestȱsamplesȱfirst,ȱ
soȱasȱnotȱtoȱdisturbȱtheȱstratification.ȱ
Onceȱsamplesȱareȱcollected,ȱremoveȱthemȱfromȱtheȱwaterȱandȱtestȱtheȱsamplesȱforȱtheȱdesiredȱwaterȱ
qualityȱparametersȱ(salinity,ȱtemperature,ȱandȱmaybeȱpHȱandȱDO).ȱ
Theȱresultsȱwillȱrevealȱifȱthereȱareȱanyȱstratifiedȱlayersȱinȱtheȱwaterȱcolumnȱatȱyourȱsamplingȱlocation.ȱIfȱ
thereȱareȱnoȱobviousȱlayers,ȱitȱshowsȱthatȱyourȱestuaryȱhasȱgoodȱmixingȱatȱthatȱlocation,ȱonȱthatȱday.ȱ
Differencesȱinȱtemperatureȱofȱonlyȱ2°Cȱorȱsalinityȱchangesȱofȱaȱcoupleȱofȱgramsȱperȱlitreȱmayȱbeȱ
sufficientȱtoȱproduceȱaȱstratificationȱlayer.ȱȱ
Lowȱoxygenȱlevelsȱinȱtheȱdeeperȱsamplesȱareȱaȱgoodȱindicatorȱofȱslowȱverticalȱmixing.ȱThisȱmeansȱthatȱ
theȱanimalsȱandȱplantsȱonȱtheȱfloorȱofȱtheȱestuaryȱwillȱbeȱthoseȱthatȱrequireȱlittleȱoxygenȱorȱthoseȱthatȱ
reduceȱsulphurȱcompoundsȱtoȱextractȱoxygen.ȱȱ
Thisȱtypeȱofȱinformationȱisȱveryȱusefulȱwhenȱmakingȱmanagementȱorȱmonitoringȱdecisionsȱaboutȱanȱ
estuaryȱ(orȱanyȱtypeȱofȱcoastalȱwaterȱbody).ȱStratificationȱisȱmoreȱlikelyȱtoȱoccurȱinȱareasȱthatȱhaveȱsmallȱ
tidalȱranges,ȱwhichȱexplainsȱwhyȱstratificationȱisȱsoȱcommonȱinȱSouthȱAustralianȱestuaries.ȱInflowsȱofȱ
freshwaterȱmayȱalsoȱcauseȱtemporaryȱstratificationȱlayers.ȱ
ȱ
ȱ
ȱ
43
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Mapping turbidity plumes
MappingȱturbidityȱplumesȱisȱanȱeventȬbasedȱmonitoringȱactivity.ȱ
EventȬbasedȱmonitoringȱisȱanȱimportant,ȱbutȱlabourȱintensiveȱandȱ
timeȱsensitive.ȱForȱsuccessfulȱturbidityȱplumeȱmapping,ȱpeopleȱneedȱ
toȱrespondȱrapidlyȱandȱbeȱavailableȱatȱaȱmoment’sȱnotice.ȱThisȱtypeȱ
ofȱmonitoringȱisȱdesignedȱtoȱcaptureȱtheȱeffectsȱofȱrunoffȱeventsȱ
(particularlyȱtheȱfirstȱlargeȱeventȱinȱaȱwetȱseason)ȱonȱtheȱestuarineȱ
receivingȱwaters.ȱȱ
Mappingȱofȱaȱturbidityȱplumeȱisȱdoneȱimmediatelyȱafterȱorȱduringȱ
theȱfirstȱmajorȱrunoffȱeventȱforȱtheȱseason.ȱAȱboatȱisȱusedȱtoȱgoȱoutȱ
andȱmapȱtheȱextentȱofȱaȱturbidityȱplumeȱfromȱaȱstormwaterȱ
dischargeȱpointȱorȱtributary.ȱTheȱmajorȱdischargeȱpointȱforȱyourȱ
estuaryȱneedsȱtoȱbeȱidentifiedȱpriorȱtoȱtheȱevent.ȱȱ
WaterȱclarityȱmeasurementsȱtakenȱwithȱaȱSecchiȱdisk,ȱorȱturbidityȱ
measuredȱwithȱaȱmeterȱareȱtheȱonlyȱparametersȱrequiredȱinȱthisȱ
activity.ȱHowever,ȱpH,ȱsalinity,ȱdissolvedȱoxygenȱandȱnutrients,ȱ
particularlyȱofȱtheȱdischarge,ȱcouldȱalsoȱbeȱmeasuredȱifȱyouȱhaveȱtheȱ
time.ȱȱ
Turbidityȱmapsȱareȱveryȱimportantȱwhenȱtryingȱtoȱmanageȱanȱ
estuaryȱandȱitsȱassociatedȱcatchment.ȱTheseȱmapsȱmeasureȱtheȱ
immediateȱdecreaseȱinȱwaterȱclarityȱfromȱaȱrunoffȱevent.ȱInȱ
catchmentsȱwithȱgoodȱlandȱmanagementȱpracticesȱthisȱimpactȱisȱ
generallyȱfairlyȱsmall.ȱTheȱbiggerȱtheȱimpact,ȱtheȱworseȱtheȱlandȱ
managementȱpracticesȱinȱtheȱcatchmentȱgenerallyȱare.ȱȱ
Theȱfineȱsedimentsȱthatȱcauseȱtheȱdecreasedȱwaterȱclarityȱgenerallyȱ
bringȱotherȱpollutantsȱwithȱthem.ȱTheseȱcanȱincludeȱnutrients,ȱheavyȱ
metalsȱandȱhydrocarbons.ȱTheȱfirstȱflushȱofȱfloodwatersȱisȱgenerallyȱ
theȱworst,ȱbutȱisȱoftenȱtheȱhardestȱtoȱcaptureȱwithȱmonitoring.ȱOtherȱ
effectsȱofȱstormwaterȱcanȱbeȱalkalineȱorȱacidȱrunoff,ȱchemicalȱ
pollutantsȱthatȱdepleteȱoxygenȱconcentrationsȱandȱfaecalȱbacteria.ȱByȱ
mappingȱtheȱturbidity,ȱitȱisȱpossibleȱtoȱestimateȱhowȱotherȱpollutantsȱ
fromȱtheȱeventȱwillȱdisperseȱintoȱtheȱestuary.ȱ
Anotherȱturbidityȱmapȱcanȱbeȱcreatedȱaȱcoupleȱofȱdaysȱafterȱtheȱeventȱ
toȱgiveȱanȱideaȱofȱhowȱfastȱtheȱplume,ȱwithȱitsȱassociatedȱpollutants,ȱ
dispersesȱintoȱtheȱecosystem.ȱȱ
What you may need:
Activity:
Age: High school
Time: 4
Why? Turbidity plumes
reveal where the impacts of
stormwater pollution are
likely to be found.
Safety: This activity is
completed either during
rain events or when storm
water is flowing.
Floodwaters can be
dangerous.
Never stand in water above
knee-height if it is flowing
at any speed. Always use
some form of sampling
device if trying to take a
sample in fast-flowing
water, as you can let go of
it if the flow tries to pull
you in. Sample from bridges
or other structures rather
than a boat if the flows are
too great.
Do not go out in lightning
storms, when visibility is
bad or when there is a
heavy weather warning out
for boats in coastal areas.
Check the BOM website to
make sure. IF IN DOUBT—
DON’T GO OUT. Find some
other way to gather the
data, or wait until some
other runoff event.
–
eventȱmonitoringȱformȱ
–
Secchiȱdiskȱ
–
sampleȱbottlesȱandȱtestȱequipmentȱforȱanyȱotherȱparametersȱbeingȱtestedȱȱ
–
seaworthyȱboatȱandȱallȱnecessaryȱsafetyȱequipmentȱ
–
GPSȱforȱlocatingȱsitesȱ
–
atȱleastȱtwoȱpeopleȱinȱtheȱboatȱandȱaȱcoupleȱonȱtheȱshoreȱ
–
aȱgoodȱtopographicȱmapȱorȱaȱbathymetricȱmapȱofȱtheȱestuary.ȱ
44
3 Extension
ESTUARINE
MONITORING
GUIDANCE
MANUAL
To ensure good results:
Identifyȱtheȱmainȱstormwaterȱdrainsȱenteringȱyourȱestuary.ȱYourȱlocalȱcouncilȱmayȱbeȱableȱtoȱhelpȱyou.ȱ
Checkȱyourȱtestȱequipment,ȱpriorȱtoȱgoingȱoutȱonȱsite.ȱSeeȱtheȱmethodȱpageȱMeasuringȱwaterȱclarity.ȱȱ
ȱ
What to do:
Collectȱallȱofȱyourȱgearȱtogetherȱandȱensureȱallȱyourȱtestȱandȱsafetyȱequipmentȱisȱstoredȱinȱtheȱboat.ȱWaitȱ
forȱaȱrainȱevent.ȱIfȱwaterȱisȱrunningȱdownȱtheȱnearbyȱstormwaterȱdrains,ȱitȱwillȱonlyȱbeȱaȱmatterȱofȱ
minutesȱorȱaȱcoupleȱofȱhoursȱatȱmostȱbeforeȱitȱstartsȱtoȱenterȱtheȱestuary.ȱOnceȱwaterȱisȱseenȱrunningȱintoȱ
theȱnearbyȱdrainsȱinȱanyȱquantity,ȱgatherȱtheȱmonitoringȱgroupȱtogetherȱandȱgoȱcheckȱyourȱmajorȱ
stormwaterȱdischargeȱlocation.ȱȱ
Onceȱallȱsafetyȱissuesȱareȱassessedȱandȱaddressed,ȱandȱstormwaterȱisȱcomingȱoutȱofȱtheȱstormwaterȱ
drain,ȱlaunchȱyourȱboatȱandȱgoȱtoȱtheȱdischargeȱpoint.ȱTakeȱSecchiȱdiskȱreadingsȱandȱcollectȱaȱsampleȱ(ifȱ
required)ȱatȱtheȱdischargeȱpoint.ȱȱ
UsingȱyourȱGPSȱasȱaȱguide,ȱmoveȱdirectlyȱoutȱfromȱtheȱdischargeȱpointȱandȱtakeȱanotherȱSecchiȱdepthȱorȱ
turbidityȱreading.ȱContinueȱawayȱfromȱtheȱdischargeȱpoint,ȱtakingȱSecchiȱdepthsȱandȱrecordingȱthemȱ
withȱyourȱGPSȱlocationȱuntilȱtheȱSecchiȱdepthȱstopsȱincreasing.ȱThisȱisȱtheȱextentȱofȱtheȱplume.ȱȱ
Useȱaȱsimilarȱprocedureȱtoȱworkȱoutȱtheȱwidthȱofȱtheȱplume,ȱtakingȱwaterȱsamplesȱifȱyouȱwishȱtoȱdoȱ
chemicalȱanalysesȱofȱthemȱonȱtheȱboatȱorȱlater.ȱȱ
TheȱdepthȱofȱaȱplumeȱinȱveryȱstratifiedȱestuariesȱmayȱbeȱestimatedȱbyȱusingȱaȱmultiȬparameterȱprobeȱonȱ
aȱlongȱcable,ȱthatȱrecordsȱpH,ȱEC,ȱDOȱandȱturbidity.ȱToȱgaugeȱtheȱdepthȱofȱaȱplumeȱmoreȱaccurately,ȱ
sampleȱtheȱwaterȱforȱsuspendedȱsolidsȱusingȱaȱdepthȬsamplingȱdevice.ȱSeeȱMappingȱtheȱsalinityȱprofileȱofȱ
yourȱestuaryȱforȱmoreȱdetailsȱonȱsamplingȱstratifiedȱestuaries.ȱ
DataȱfromȱeventȬbasedȱwaterȱclarityȱorȱturbidityȱmappingȱcanȱbeȱcomparedȱwithȱdataȱcollectedȱduringȱ
normalȱmonthlyȱsampling.ȱThisȱinformationȱwillȱidentifyȱtheȱextentȱthatȱtheȱvaluesȱofȱdifferentȱ
parametersȱmayȱbeȱexpectedȱtoȱchangeȱbetweenȱnormalȱandȱstormȱevents.ȱȱ
ȱ
ȱ
ȱ
45
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Where is the ‘turbidity maximum’?
Inȱestuariesȱtheȱwaterȱinȱtheȱupriverȱpartȱofȱtheȱestuaryȱandȱtheȱwaterȱ
inȱtheȱmarineȱpartȱofȱtheȱestuaryȱareȱusuallyȱfairlyȱclearȱ(exceptȱ
whereȱveryȱturbidȱwaterȱisȱcomingȱfromȱaȱriver,ȱsuchȱasȱtheȱDarlingȱ
RiverȱflowsȱinȱtheȱMurray–Darlingȱsystem).ȱWithinȱtheȱmainȱpartȱofȱ
theȱestuary,ȱhowever,ȱtheȱwaterȱisȱoftenȱveryȱturbid,ȱhighlyȱchargedȱ
withȱsuspendedȱsediment.ȱȱ
Thisȱisȱknownȱasȱtheȱturbidityȱmaximum.ȱTheȱsedimentȱmovesȱupȱ
andȱdownȱtheȱestuaryȱwithȱtheȱdailyȱtide.ȱItȱmayȱbecomeȱdilutedȱ
duringȱhighȱfloodȱeventsȱorȱdisappearȱduringȱstrongȱtidalȱflow,ȱbutȱ
mayȱreformȱduringȱneapȱtidalȱcycles.ȱ
Theȱphenomenonȱoccursȱbecauseȱveryȱfineȱparticlesȱthatȱareȱcarriedȱ
inȱriverȱwaterȱcomeȱintoȱcontactȱwithȱseawaterȱthatȱcontainsȱsaltsȱ
suchȱasȱcarbonates.ȱTheseȱhelpȱtheȱfineȱparticlesȱtoȱaggregate,ȱ
formingȱlarge,ȱsoftȱflocs.ȱTheȱflocsȱareȱheavierȱthanȱtheȱfineȱparticlesȱ
were,ȱandȱtheyȱstartȱtoȱsettleȱtoȱtheȱbottomȱofȱtheȱestuary.ȱHowever,ȱ
theyȱdoȱnotȱformȱsolidȱsedimentsȱonȱtheȱbaseȱofȱtheȱestuary,ȱandȱsoȱ
mayȱbeȱresuspendedȱwithȱtheȱnextȱincomingȱtide.ȱThusȱtheȱzoneȱ
receivesȱaȱcontinuousȱnewȱsupplyȱofȱnewȱsediment,ȱwhileȱ
resuspendingȱsomeȱofȱtheȱsedimentȱalreadyȱpresent.ȱ
Activity:
Extension
Age: High school
Time: 4
Why? The turbidity
maximum in an estuary is
the zone where much of
the sediment from the river
is settled out. The zone
forms an important part of
many estuarine food chains,
but may also be the
location where
accumulations of toxic
metals may occur.
Safety: This may involve
work in deep water.
Theȱturbidityȱmaximumȱforȱaȱgivenȱestuaryȱisȱtheȱareaȱwhereȱmostȱsoftȱsedimentsȱareȱdeposited,ȱandȱ
thisȱisȱtheȱareaȱwhereȱmetals,ȱetc,ȱinȱtheȱriverȱwaterȱwillȱprecipitate.ȱThusȱtheȱturbidityȱmaximaȱofȱ
estuariesȱperformȱanȱessentialȱcleaningȱfunctionȱofȱtheȱriverȱwaterȱbeforeȱitȱentersȱtheȱsea.ȱTheȱzoneȱisȱ
alsoȱaȱrichȱfeedingȱzoneȱforȱsmallȱmacroȱinvertebrates,ȱandȱthereforeȱprovidesȱtheȱbasisȱofȱmanyȱ
estuarineȱfoodȱchains.ȱ
What you may need:
–
eventȱmonitoringȱformȱ
–
Secchiȱdiskȱ
–
seaworthyȱboatȱandȱallȱnecessaryȱsafetyȱequipmentȱ
–
GPSȱforȱlocatingȱsitesȱ
–
atȱleastȱtwoȱpeopleȱinȱtheȱboatȱandȱaȱcoupleȱonȱtheȱshoreȱ
–
aȱgoodȱtopographicȱmapȱorȱaȱbathymetricȱmapȱofȱtheȱestuary,ȱandȱpossiblyȱanȱaerialȱphotograph.ȱ
To ensure good results:
Onlyȱconductȱthisȱactivityȱinȱcalmȱconditionsȱwithȱlowȱtidalȱflowsȱ(neapȱtides).ȱAtȱthisȱtime,ȱtheȱturbidityȱ
maximumȱwillȱbeȱmoreȱpronouncedȱandȱeasierȱtoȱdetect.ȱ
Checkȱyourȱtestȱequipment,ȱpriorȱtoȱgoingȱoutȱonȱsite.ȱ
What to do:
Reviewȱyourȱtopographicȱmaps,ȱbathymetricȱmapsȱandȱaerialȱphotographs.ȱYouȱmayȱbeȱableȱtoȱpickȱtheȱ
roughȱlocationȱofȱtheȱturbidityȱmaximumȱfromȱturbidityȱvisibleȱinȱtheȱaerialȱphotograph.ȱUseȱyourȱotherȱ
mapsȱtoȱlookȱforȱareasȱofȱdepositionȱ(sandbanksȱonȱtheȱbathymetricȱmaps,ȱinȬstreamȱsandyȱislandsȱonȱ
theȱtopographicȱmaps),ȱandȱtheȱchannelsȱaroundȱtheseȱareas.ȱ
Collectȱallȱofȱyourȱgearȱandȱensureȱallȱyourȱtestȱandȱsafetyȱequipmentȱisȱstoredȱinȱtheȱboat.ȱWaitȱforȱcalmȱ
weatherȱandȱaȱneapȱtide.ȱOnceȱyouȱareȱsureȱtheȱconditionsȱareȱstable,ȱgatherȱtheȱmonitoringȱgroupȱandȱ
goȱoutȱintoȱtheȱestuary.ȱȱ
46
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Startȱfromȱtheȱmarineȱendȱofȱtheȱestuary,ȱorȱatȱleastȱwellȱonȱtheȱmarineȱsideȱofȱtheȱareaȱthatȱyouȱhaveȱ
decidedȱmayȱcontainȱyourȱturbidityȱmaximum.ȱTakeȱSecchiȱdiskȱreadingsȱatȱregularȱintervalsȱasȱyouȱ
progressȱupstream,ȱrecordingȱeachȱlocationȱusingȱyourȱGPS.ȱTheȱguidelineȱMeasuringȱwaterȱclarityȱ
containsȱdetailsȱaboutȱusingȱtheȱSecchiȱdisk.ȱ
Theȱturbidityȱmaximumȱwillȱbeȱrevealedȱasȱaȱseriesȱofȱlowȱclarityȱreadings.ȱ
Identifyingȱtheȱlocationȱofȱyourȱestuary’sȱturbidityȱmaximumȱassistsȱenvironmentalȱmanagersȱwhoȱmayȱ
beȱstudyingȱpollutantȱaccumulationȱinȱtheȱestuary.ȱTheȱcomplexȱflocsȱthatȱareȱformedȱinȱthisȱzoneȱareȱaȱ
mixtureȱofȱorganicȱandȱinorganicȱmaterials,ȱandȱsoȱthisȱzoneȱmayȱalsoȱcontainȱaȱlargeȱpopulationȱofȱ
macroȱinvertebrates.ȱStudentsȱworkingȱonȱestuarineȱmacroȱinvertebratesȱmayȱfindȱthatȱknowingȱtheȱ
locationȱofȱestuarineȱturbidityȱmaximaȱprovidesȱthemȱwithȱfurtherȱunderstandingȱaboutȱtheȱ
distributionsȱofȱcertainȱspeciesȱwithinȱestuaries.ȱ
ȱ
ȱ
ȱ
47
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Effect of tidal restrictions on wetlands
Studyingȱtheȱeffectȱofȱtidalȱrestrictionsȱonȱtheȱwetlandsȱthatȱsurroundȱ
yourȱestuaryȱisȱaȱfascinatingȱwayȱofȱdiscoveringȱestuarineȱprocesses.ȱ
Estuarineȱwetlandsȱdevelopȱtheirȱcharacterȱfromȱtheȱhydrologicalȱ
regimeȱofȱtheȱestuary.ȱMonitoringȱtheȱgroundȱandȱsurfaceȱwaterȱ
qualityȱandȱquantityȱcanȱprovideȱanȱinsightȱintoȱtheȱhealthȱandȱlongȬȱ
termȱchangesȱinȱtheseȱwetlands.ȱȱ
Tidalȱrestrictionsȱmayȱcauseȱaȱwideȱrangeȱofȱbiological,ȱecological,ȱ
chemicalȱandȱphysicalȱeffects.ȱAreasȱwithȱnaturalȱorȱanthropogenicȱ
restrictionsȱonȱtidalȱmovementȱoftenȱhaveȱhigherȱsalinitiesȱorȱsalinityȱ
rangesȱthanȱareasȱthatȱhaveȱfreeȱtidalȱflushing.ȱIfȱthereȱisȱaȱlargeȱ
regularȱfreshwaterȱinputȱtoȱaȱtidallyȱrestrictedȱareaȱtheȱlackȱofȱtidalȱ
flushingȱmayȱresultȱinȱreducedȱsalinity.ȱWhenȱsalinityȱlevelsȱfallȱ
belowȱ20ȱg/Lȱorȱ2%,ȱopportunisticȱbrackishȱplantsȱsuchȱasȱPhragmitesȱ
australisȱ(commonȱreed)ȱmayȱstartȱtoȱtakeȱoverȱtheȱsamphireȱareas.ȱ
ManyȱhistoricȱdevelopmentsȱinȱSouthȱAustraliaȱdidȱnotȱconsiderȱtheȱ
impactsȱofȱtidalȱrestriction.ȱ
Tideȱrestrictionsȱmayȱblockȱtheȱpassageȱofȱestuarineȱinvertebratesȱ
andȱfishȱintoȱtheȱupperȱestuary.ȱRestrictedȱareasȱmayȱalsoȱsufferȱfromȱ
aȱconcentrationȱofȱsediments,ȱorganicȱmatterȱandȱwaterȱpollutantsȱinȱ
theȱmarshes,ȱsoȱtheyȱbecomeȱanoxicȱandȱsmelly.ȱ
SedimentsȱthatȱwereȱonceȱregularlyȱsubmergedȱinȱsulphateȬrichȱ
seawaterȱmayȱsinkȱrapidlyȱwhenȱtheȱseawaterȱisȱdrainedȱoffȱandȱtheȱ
sedimentsȱareȱexposedȱtoȱair.ȱThisȱisȱbecauseȱmanyȱmarineȱsedimentsȱ
containȱlargeȱquantitiesȱofȱshellȱgritȱ(calciumȱcarbonate).ȱSulphateȱ
compoundsȱleftȱbehindȱbyȱtheȱseawaterȱareȱconvertedȱtoȱhydrogenȱ
sulphideȱbyȱsulphurȬreducingȱbacteria.ȱHydrogenȱsulphideȱmayȱ
convertȱtoȱsulphuricȱacidȱinȱcontactȱwithȱtheȱair,ȱandȱthisȱrapidlyȱ
reactsȱwithȱtheȱcalciumȱcarbonateȱinȱtheȱshellȱgrit.ȱThisȱresultsȱinȱ
carbonȱdioxideȱoffȬgassingȱfromȱtheȱsoilȱandȱcalciumȱsulphateȱ
enteringȱtheȱgroundwater,ȱeffectivelyȱremovingȱsolidȱmatterȱfromȱtheȱ
soil.ȱ
Knowledgeȱofȱtideȱrestrictions,ȱtheirȱtypeȱandȱpotentialȱeffectsȱisȱ
essentialȱforȱcomprehensiveȱsaltmarshȱmonitoringȱandȱassessment.ȱ
Tidalȱinfluenceȱisȱanȱimportantȱparameterȱtoȱmeasure,ȱalongȱwithȱ
tidalȱrangeȱandȱsalinity.ȱTheseȱthreeȱattributesȱcanȱprovideȱaȱveryȱ
goodȱunderstandingȱofȱtheȱeffectȱofȱtideȱrestrictionsȱonȱtheȱphysicalȱ
andȱchemicalȱnatureȱofȱsaltmarshes.ȱ
Thisȱactivityȱoutlinesȱtheȱbasicȱmethodsȱusedȱtoȱmonitorȱtidalȱ
restrictions.ȱItȱisȱenvisagedȱthatȱcommunityȱgroupsȱundertakingȱ
restorationȱorȱrecoveryȱprogramsȱinȱaffectedȱestuariesȱwillȱfindȱtheȱ
methodsȱusefulȱisȱassessingȱtheȱprogressȱofȱtheirȱprojects.ȱȱ
Activity:
3 Extension
Age: High school
Time: 4 (initially, then 2 to
monitor)
Why? Estuarine wetlands
develop their character
(saltmarsh, melaleuca
wetland, mangrove, or
freshwater-tidal wetland)
from the hydrological
regime. Monitoring the
ground and surface water
quantity and quality can
provide insight into the
health of, and reasons for
long-term change in, these
wetlands.
Safety: Saltmarshes contain
rough terrain and ill–
defined waterways.
Participants should wear
sturdy shoes, long pants
and a hat. Participants
should take care when
walking so that they do not
fall down undercut
embankments or slide over
in muddy sections. Working
in pairs will help avoid and
deal with any injuries that
may occur in saltmarshes.
Areas where tidal
movement is restricted may
have strong currents
passing through channels or
culverts. Care should be
taken to avoid these, and
avoid wading in fast flowing
water.
Theȱmethodsȱusedȱinȱthisȱactivityȱmeasureȱtheȱareaȱofȱtidalȱinfluence,ȱaverageȱtidalȱranges,ȱsalinityȱ
concentrationsȱandȱpHȱchangesȱinȱareasȱthatȱhaveȱbeenȱaffectedȱbyȱtidalȱrestrictions.ȱThisȱisȱdoneȱbyȱ
installingȱdepthȱgaugesȱinȱsamphireȱpondsȱandȱinȱtheȱunrestrictedȱwaterway,ȱasȱwellȱasȱpiezometersȱinȱ
theȱsamphireȱuplandsȱ(highȱmarsh).ȱ
Staffȱgaugesȱareȱessentiallyȱlargeȱrulersȱstakedȱinȱaȱfixedȱposition,ȱandȱareȱusedȱtoȱmeasureȱwaterȱlevels.ȱ
Youȱcanȱconstructȱstaffȱgaugesȱfromȱaȱvarietyȱofȱmaterials,ȱandȱtheȱonlyȱrequirementsȱareȱthatȱtheyȱbeȱ
durable,ȱrustproofȱandȱappropriateȱforȱtheȱsiteȱlocation,ȱbudget,ȱandȱneedsȱofȱtheȱinvestigators.ȱ
48
ESTUARINE
MONITORING
GUIDANCE
MANUAL
GroundwaterȱisȱsampledȱfromȱverticallyȱinstalledȱoneȬmetreȱlongȱPVCȱpipesȱknownȱasȱpiezometers.ȱ
Theseȱareȱusedȱforȱmonitoringȱtheȱdepth,ȱsalinityȱandȱpHȱofȱtheȱgroundwaterȱtable.ȱGroundwaterȱinȱ
saltmarshesȱisȱusuallyȱmonitoredȱonlyȱduringȱdryȱperiods,ȱalthoughȱsamplingȱduringȱwetȱperiodsȱmayȱ
beȱinterestingȱfromȱaȱsalinityȱandȱpHȱperspective.ȱDuringȱwetȱperiodsȱtheȱgroundwaterȱwillȱusuallyȱbeȱ
at,ȱorȱnear,ȱtheȱsurface.ȱȱ
Theȱaverageȱtidalȱrangeȱisȱestimatedȱbyȱtakingȱregularȱobservationsȱofȱaȱsurveyedȱdepthȱorȱstaffȱgaugeȱ
overȱaȱtidalȱperiodȱ(approximatelyȱsixȱhours)ȱatȱleastȱonceȱaȱyearȱduringȱaȱspringȱtide.ȱMonitoringȱ
severalȱtimesȱaȱyearȱisȱpreferable.ȱȱ
Theȱareaȱofȱtidalȱinfluenceȱisȱmeasuredȱbyȱobservingȱseveralȱdepthȱgaugesȱoverȱaȱtidalȱperiodȱtoȱ
determineȱhowȱfarȱtheȱtideȱmovesȱintoȱtheȱsaltmarsh.ȱTheȱtidalȱinfluenceȱonȱgroundȱwaterȱcanȱalsoȱbeȱ
measuredȱbyȱtakingȱseveralȱdepthȱobservationsȱdownȱpiezometersȱoverȱaȱtidalȱperiodȱorȱoverȱaȱday.ȱ
Excellentȱreferenceȱbooksȱonȱtidalȱmarshȱrestorationȱare:ȱ
Coultas,ȱCLȱ&ȱHsieh,ȱYȱ(eds)ȱ(1997),ȱEcologyȱandȱManagementȱofȱTidalȱMarshes—AȱModelȱfromȱtheȱGulfȱ
ofȱMexico,ȱStȱLucieȱPress,ȱDelrayȱBeach,ȱFlorida.ȱ
Packham,ȱJRȱ&ȱWillis,ȱAJȱ(1997),ȱEcologyȱofȱDunes,ȱSaltmarshȱandȱShingle.ȱChapmanȱandȱHall,ȱLondon.ȱ
Purinton,ȱTAȱ&ȱMountain,ȱDCȱ(1997),ȱTidalȱCrossingȱHandbook—AȱVolunteerȱGuideȱtoȱAssessingȱTidalȱ
Restrictions,ȱParkerȱRiverȱCleanȱWaterȱAssociation,ȱMassachesetts.ȱThisȱbookȱmayȱbeȱdownloadedȱ
fromȱtheȱInternetȱfromȱ<www.parkerȬriver.org>.ȱ
Zedler,ȱJB(ed)ȱ(2001),ȱHandbookȱforȱRestoringȱTidalȱWetlands,ȱCRCȱPress,ȱBocaȱRaton,ȱFlorida.ȱ
What you may need:
F or ȱ installing ȱst a ffȱg aug es ȱ
–
betweenȱtwoȱandȱsevenȱstaffȱgaugesȱ
–
aȱsurveyorȱorȱsurveyingȱequipmentȱ
–
largeȱsledgehammerȱorȱmallet.ȱ
F or ȱm on it oring ȱs u r f ac eȱt id a lȱm ov eme nt ȱ
–
installedȱstaffȱgaugesȱ
–
hydrologyȱfieldȱdatasheetsȱandȱpencilsȱȱ
–
clockȱorȱwatchȱwithȱstopwatchȱȱ
–
clipboard.ȱȱ
F or ȱc on struc t ing ȱ and ȱ installingȱp iez o met er s ȱ
–
tapeȱmeasureȱ
–
50–75ȱmmȱPVCȱpipeȱ(oneȱmetreȱperȱpiezometer)ȱ
–
smallȱgardenȱstakeȱwithȱflagȱorȱbrightȱpaintȱ
–
drillȱwithȱaȱ0.5ȱtoȱ10–mmȱdrillȱbitȱ
–
twoȱendȬcapsȱperȱpiezometerȱtoȱfitȱtheȱPVCȱpipeȱ
–
someȱkneeȬhighȱstockingsȱ(twoȱperȱpiezometer)ȱ
–
GPSȱand/orȱaȱdetailedȱtopographicȱmapȱ
–
augurȱorȱpost–holeȱdiggerȱforȱboringȱaȱholeȱgreaterȱthanȱ100–mmȱȱ
–
bucketȱofȱcoarseȱsandȱorȱgravelȱ&ȱbucketȱofȱbentoniteȱȱ
–
smallȱamountȱofȱquicksetȱconcrete.ȱ
49
ESTUARINE
MONITORING
GUIDANCE
MANUAL
F or ȱgroundwaterȱ mon itoring ȱw o r kȱ
–
plopperȱorȱbeeperȱ(instructionsȱforȱmakingȱtheseȱareȱinȱAppendixȱ6),ȱorȱaȱthinȱstraightȱdryȱȱ
woodenȱstakeȱlongerȱthanȱ1.3ȱmȱforȱeachȱpiezometerȱȱ
–
sampleȱflaskȱ&ȱtestȱequipmentȱandȱguidelinesȱforȱmeasuringȱforȱpHȱandȱsalinityȱȱ
–
balerȱorȱpetrolȱsiphonȱwithȱfoot–valveȱforȱremovingȱwaterȱfromȱtheȱwellȱȱ
–
distilledȱwaterȱtoȱcleanȱbaler(s)ȱȱ
–
measuringȱtape.ȱ
What to do:
Installing ȱ st a ffȱg aug esȱȱ
Staffȱgaugesȱareȱgraduated,ȱmeaningȱthatȱunitsȱ(metres)ȱareȱclearlyȱwrittenȱonȱtheȱstaffȱsoȱthatȱtheȱwaterȱ
levelȱcanȱbeȱrecordedȱbyȱsimplyȱlookingȱatȱtheȱgaugeȱ(Figureȱ5).ȱTheseȱgaugesȱshouldȱbeȱconstructedȱofȱ
rustproofȱmaterialsȱthatȱcanȱwithstandȱwindȱandȱwaterȱcurrents.ȱȱ
ItȱisȱcommonȱtoȱuseȱPVCȱpipeȱtoȱconstructȱgauges,ȱwithȱunitsȱmarkedȱ
byȱetchingȱtheȱpipeȱthenȱfillingȱtheȱetchingsȱwithȱpaint.ȱAnotherȱ
methodȱisȱtoȱuseȱaȱsheetȱofȱplasticȱorȱmelamineȱwithȱblackȱandȱwhiteȱ
layers,ȱsoȱthatȱtheȱmarksȱmayȱbeȱetchedȱintoȱtheȱwhiteȱsideȱsoȱthatȱtheȱ
blackȱlayerȱshowsȱthrough.ȱTheseȱareȱbestȱforȱinstallingȱdirectlyȱontoȱaȱ
culvertȱorȱfenceȱpost,ȱandȱtheyȱwithstandȱdamageȱfromȱvandals.ȱ
ȱ
Figure 5—Staff gauge
ȱ
Findingȱaȱsuitableȱlocationȱforȱtheȱstaffȱgaugesȱisȱsometimesȱaȱ
challenge.ȱVisitingȱtheȱstudyȱsiteȱatȱdifferentȱtidalȱstagesȱwillȱassistȱ
you.ȱPlaceȱtheȱgaugesȱwhereȱthereȱisȱusuallyȱonlyȱaȱsmallȱamountȱofȱ
water,ȱbutȱwhereȱyouȱcanȱeasilyȱreadȱthemȱwhenȱtheȱtideȱisȱhigh.ȱAȱ
suggestedȱsetȱofȱlocationsȱforȱstaffȱgaugesȱisȱillustratedȱinȱtheȱexampleȱ
siteȱplanȱbelowȱ(Figureȱ6).ȱȱ
Toȱgaugeȱaȱrestriction,ȱyouȱshouldȱinstallȱstaffȱgaugesȱnoȱfurtherȱthanȱ
15ȱmȱfromȱtheȱtidalȱrestrictionȱonȱbothȱsidesȱofȱtheȱrestrictionȱ(egȱonȱ
theȱrestrictedȱsideȱandȱtheȱunrestrictedȱside).ȱOther,ȱadditional,ȱ
gaugesȱmayȱbeȱplacedȱinȱaȱtidalȱmarshȱtoȱmapȱtheȱareaȱofȱinundation.ȱ
ȱ
Figure 6—Staff gauge locations and piezometer transects
50
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Gaugesȱonȱfreestandingȱpostsȱshouldȱnotȱbeȱplacedȱwhereȱstrongȱcurrentsȱoccurȱasȱtheyȱmayȱwashȱaway.ȱ
Also,ȱitȱisȱdifficultȱtoȱreadȱtheȱwaterȱlevelȱifȱtheȱcurrentȱisȱcreatingȱlargeȱeddiesȱaroundȱtheȱpost.ȱInȱareasȱ
subjectȱtoȱfrequentȱvandalism,ȱattachȱgaugesȱtoȱpreȬexistingȱimmovableȱobjectsȱwhereȱpossible,ȱforȱ
exampleȱculvertsȱorȱrockȱembankments.ȱȱ
Ifȱyouȱareȱinstallingȱfreestandingȱgauges,ȱtwoȱpeopleȱmayȱbeȱnecessaryȱtoȱinstallȱtheȱgauges–oneȱtoȱholdȱ
theȱgaugeȱpostȱwhileȱtheȱotherȱpoundsȱitȱintoȱtheȱsubstrateȱwithȱaȱsledgehammerȱorȱmallet.ȱToȱbeȱsureȱ
youȱaccuratelyȱplaceȱtheȱgauge,ȱinstallȱtheȱpost,ȱthenȱattachȱtheȱstaffȱmarkingȱplate.ȱBeȱsureȱtoȱpositionȱ
theȱstaffȱgaugeȱsoȱthatȱtheȱheightȱmarksȱareȱreadilyȱvisibleȱbyȱtheȱobserver.ȱ
Yourȱlocalȱcouncilȱmayȱbeȱpreparedȱtoȱassistȱyouȱsurveyȱstaffȱgaugeȱlocationsȱandȱinstallȱthem,ȱasȱaȱ
surveyorȱ(orȱatȱleastȱtheirȱequipment)ȱisȱrequiredȱtoȱplaceȱtheȱmarkersȱatȱaȱknownȱheightȱrelativeȱtoȱ
AHDȱ(AustralianȱHeightȱDatum).ȱGaugesȱshouldȱbeȱinstalledȱatȱleastȱaȱdayȱorȱtwoȱbeforeȱtheȱsamplingȱ
dateȱtoȱensureȱtheyȱareȱinȱaȱsuitableȱlocation.ȱȱ
Measuringȱtid alȱm ov e men tȱu s ingȱ st affȱg aug es ȱ
Theȱnextȱstepȱisȱtoȱcollectȱtheȱtidalȱrangeȱdata.ȱTheȱstaffsȱareȱmeasuredȱbyȱrecordingȱtheȱlevelȱtheȱwaterȱ
reachesȱonȱtheȱstaff.ȱAȱtorchȱorȱpairȱofȱbinocularsȱmayȱbeȱneededȱtoȱhelpȱyouȱseeȱtheȱmarksȱonȱtheȱstaff.ȱȱ
Thisȱmonitoringȱrequiresȱsomeoneȱtoȱbeȱonȱsiteȱtoȱrecordȱwaterȱlevelsȱ(tidalȱheightȱinȱAHD)ȱonȱallȱtheȱ
staffȱgaugesȱeveryȱ15ȱtoȱ30ȱminutes,ȱoverȱtheȱperiodȱofȱoneȱorȱseveralȱtides.ȱTheȱregularȱreadingsȱareȱ
noted,ȱalongȱwithȱtheȱtimeȱofȱeachȱmeasurement,ȱonȱtheȱfieldȱdatasheet.ȱTheȱmonitoringȱisȱusuallyȱdoneȱ
overȱaȱperiodȱofȱatȱleastȱsixȱhoursȱsoȱthatȱbothȱaȱhighȱandȱlowȱtideȱisȱcoveredȱforȱtheȱevent.ȱNamesȱofȱ
investigators,ȱdateȱofȱsampling,ȱandȱtimeȱofȱhighȱtideȱwillȱalsoȱneedȱtoȱbeȱrecorded.ȱThisȱactivityȱshouldȱ
beȱconductedȱatȱthatȱtimeȱofȱtheȱmonthȱwhereȱtheȱtidalȱvariationȱisȱgreatest—theȱmonthlyȱspringȱtides.ȱ
Additionalȱsamplingȱatȱtheȱneapȱtidesȱ(theȱperiodȱmidȬmonthȱwhenȱtheȱrangeȱisȱtheȱsmallest)ȱmayȱalsoȱ
beȱuseful,ȱbutȱisȱnotȱessential.ȱ
Workingȱinȱshiftsȱwithȱdifferentȱpeopleȱtoȱtakeȱtheȱreadingsȱmayȱreduceȱtheȱtimeȱresourcesȱrequiredȱ
fromȱeachȱperson.ȱȱ
Lessȱintenseȱmonitoringȱmayȱbeȱdoneȱbyȱgoingȱoutȱonȱsiteȱonlyȱatȱhighȱandȱlowȱtides,ȱorȱatȱsetȱtimesȱeachȱ
day,ȱandȱtakingȱtheseȱreadingsȱoverȱaȱlongerȱperiodȱofȱtime,ȱperhapsȱsixȱreadingsȱoverȱ12ȱhoursȱorȱtwoȱ
readingsȱaȱdayȱforȱaȱweekȱorȱmonth.ȱTheȱintensityȱofȱtheȱmonitoringȱprogramȱdependsȱentirelyȱonȱtheȱ
aimsȱofȱtheȱprogram,ȱandȱthisȱwillȱneedȱtoȱbeȱdecidedȱbyȱyourȱresourceȱlimitationsȱandȱinȱconsultationȱ
withȱyourȱWaterwatchȱcoordinator.ȱȱ
Installing ȱpiezometers ȱ
Priorȱtoȱgoingȱoutȱintoȱtheȱfieldȱtoȱinstallȱyourȱpiezometers,ȱitȱisȱimportantȱthatȱyouȱdetermineȱhowȱmanyȱ
piezometersȱyouȱwillȱrequire,ȱroughlyȱwhereȱtheyȱwillȱgoȱandȱwhatȱtheȱsurveyedȱgroundȱlevelsȱareȱforȱ
thoseȱsites.ȱȱ
Siteȱselectionȱisȱbestȱdoneȱduringȱdryȱperiodsȱwhenȱtheȱwetlandȱisȱmostȱaccessible.ȱSelectingȱsitesȱatȱaȱ
moderateȱhighȱtideȱwillȱgiveȱyouȱanȱideaȱofȱwhereȱtheȱtideȱcomesȱtoȱinȱyourȱsaltmarsh,ȱandȱallȱ
piezometersȱshouldȱbeȱplacedȱaboveȱthisȱmark.ȱȱ
Usingȱanȱaerialȱphotograph,ȱdetermineȱtwoȱorȱthreeȱtransectȱlinesȱrunningȱfromȱtheȱhighȱtideȱmarkȱ
throughȱtoȱtheȱhighestȱpointȱinȱyourȱsaltmarsh.ȱTheyȱshouldȱformȱaȱstraightȱlineȱperpendicularȱtoȱtheȱ
tideȱline,ȱasȱthisȱwillȱhelpȱshowȱtidalȱinfluencesȱonȱgroundwaterȱandȱtheȱzonationȱofȱplants.ȱItȱmayȱbeȱ
worthwhileȱplacingȱaȱcoupleȱofȱpiezometersȱinȱaȱreferenceȱsite,ȱwhichȱisȱsimilarȱinȱhabitatȱorȱgeography,ȱ
butȱdoesȱnotȱhaveȱtidalȱrestrictions.ȱ
Placingȱtheȱtransectsȱatȱdifferentȱdistancesȱfromȱtheȱtidalȱrestriction,ȱforȱexampleȱ50ȱmȱandȱ100ȱm,ȱwillȱ
giveȱyouȱanȱideaȱofȱtheȱeffectsȱofȱtidalȱrestrictionȱfurtherȱintoȱtheȱsaltmarsh.ȱPlacingȱyourȱpiezometersȱinȱ
differentȱsaltmarshȱhabitatsȱwillȱalsoȱgiveȱyouȱsomeȱinterestingȱandȱusefulȱdata.ȱ
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Placeȱyourȱtwoȱtoȱfourȱpiezometerȱsitesȱalongȱeachȱtransectȱwithȱatȱleastȱoneȱatȱeachȱend,ȱwithȱanyȱothersȱ
spacedȱinȱbetween.ȱExamplesȱofȱsuitableȱpiezometerȱsitesȱareȱshownȱinȱtheȱexampleȱsiteȱplanȱprovidedȱinȱ
theȱstaffȱgaugeȱsectionȱabove.ȱȱ
Itȱmayȱbeȱadvisableȱtoȱdigȱaȱtestȱholeȱatȱtheȱhighestȱandȱlowestȱpointsȱtoȱworkȱoutȱhowȱlongȱyourȱ
piezometersȱwillȱneedȱtoȱbe,ȱsoȱthatȱtheyȱareȱinȱaȱzoneȱofȱgroundwaterȱflow.ȱThisȱisȱdeterminedȱbyȱ
diggingȱaȱsmallȱholeȱwithȱaȱshovelȱorȱpostholeȱdiggerȱuntilȱyouȱreachȱaȱpointȱwhereȱtheȱsoilȱisȱsaturatedȱ
andȱtheȱbottomȱofȱtheȱholeȱstartsȱtoȱgatherȱwater.ȱAȱmaximumȱdepthȱofȱoneȱmetreȱbelowȱtheȱground,ȱ
withȱ300ȱmmȱofȱpipeȱaboveȱgroundȱlevelȱisȱadvised,ȱasȱpiezometersȱlongerȱthanȱthisȱ(1.3ȱm)ȱbecomeȱ
difficultȱtoȱhandle.ȱȱ
Aȱsurveyorȱorȱsurveyingȱequipmentȱwillȱbeȱneededȱtoȱdetermineȱtheȱheightȱofȱtheȱgroundȱatȱeachȱofȱ
yourȱselectedȱpiezometerȱsites.ȱOnceȱeachȱpointȱhasȱbeenȱsurveyed,ȱmarkȱeachȱsiteȱwithȱaȱgardenȱstakeȱ
andȱtakeȱaȱGPSȱlocationȱtoȱensureȱthatȱtheȱsiteȱcanȱbeȱfoundȱagain.ȱTheȱpiezometersȱshouldȱthenȱbeȱmadeȱ
andȱinstalledȱasȱsoonȱasȱpossible,ȱtoȱminimiseȱtheȱchanceȱthatȱaȱlocationȱwillȱbeȱlost.ȱȱ
Theȱpiezometersȱareȱmadeȱbyȱcuttingȱtheȱrequiredȱlengthsȱofȱpipeȱsoȱthatȱatȱleastȱ100–mmȱofȱtheȱpipeȱ
willȱbeȱinȱtheȱsaturatedȱzoneȱofȱtheȱsoil.ȱTheȱpipeȱwillȱneedȱtoȱbeȱlongȱenoughȱsoȱthatȱitȱsticksȱoutȱofȱtheȱ
soilȱbyȱapproximatelyȱ300ȱmmȱsoȱthatȱtheȱpiezometersȱmayȱbeȱseenȱfromȱaȱdistance,ȱwithoutȱbeingȱ
overlyȱobvious.ȱȱ
Forȱaȱstandardȱpiezometer,ȱtheȱconstructionȱmethodȱisȱoutlinedȱbelow.ȱ
– cutȱaȱoneȬmetreȱsectionȱofȱPVCȱpipeȱ
–
drillȱsmallȱholesȱ(5ȱmm)ȱapproximatelyȱ20ȱmmȱapartȱintoȱtheȱlowerȱthirdȱofȱtheȱpipeȱ
–
alternativelyȱaȱhandsawȱcouldȱbeȱusedȱtoȱcutȱslotsȱacrossȱtheȱpipeȱinstead,ȱifȱdrillingȱisȱtooȱtimeȱ
consumingȱ
–
drillȱaȱventȱholeȱ100ȱmmȱfromȱtheȱtopȱofȱtheȱpipeȱ
–
fitȱanȱendȬcapȱoverȱtheȱtopȱopeningȱofȱtheȱpipe,ȱbeingȱcarefulȱnotȱtoȱcoverȱtheȱventȱholeȱ
–
fitȱanȱendȬcapȱwithȱaȱfewȱholesȱdrilledȱintoȱitȱoverȱtheȱbottomȱopeningȱofȱtheȱpipeȱ
–
pullȱatȱleastȱtwoȱstockingsȱoverȱtheȱlowerȱendȱofȱtheȱpipe,ȱincludingȱtheȱopeningȱandȱallȱofȱtheȱ
drillȱholesȱ
–
—ȱȱȱsecureȱtheȱstockingȱfabricȱwithȱductȱtape.ȱ
ȱ
Installationȱisȱaȱsimpleȱprocedureȱonceȱtheȱsitesȱhaveȱbeenȱ
identifiedȱandȱsurveyedȱ(Figureȱ7).ȱAȱpostholeȱaugerȱisȱusedȱtoȱ
digȱaȱsmallȱholeȱatȱleastȱ100ȱmmȱacrossȱandȱ50ȱmmȱdeeperȱthanȱ
theȱintendedȱdepthȱofȱtheȱpiezometer.ȱȱ
Thisȱholeȱisȱfilledȱwithȱapproximatelyȱ50–mmȱofȱcoarseȱgravelȱ
orȱsand,ȱthenȱtheȱpiezometerȱisȱplacedȱintoȱtheȱholeȱandȱtheȱ
spaceȱaroundȱitȱpackedȱwithȱfurtherȱcoarseȱgravelȱorȱsandȱtoȱ
justȱaboveȱtheȱdrillȱholes.ȱTheȱspaceȱaboveȱtheȱdrillȱholesȱisȱ
thenȱpackedȱtightȱwithȱbentonite,ȱorȱnativeȱclay,ȱandȱcappedȱ
withȱaȱsmallȱamountȱofȱquicksetȱconcreteȱ(ifȱavailable).ȱȱ
ȱ
Figure 7—Installing a piezometer
T h e seȱ sm a llȱg roundw aterȱ monitoring ȱst at ion sȱn eed ȱt oȱ be ȱ
l e f tȱt oȱ sett leȱ for ȱa tȱ le a stȱa ȱw ee kȱ be fore ȱth eȱm on it o r ing ȱ
c om me nc es. ȱT h eȱd epthȱ ofȱ eachȱp iez om et erȱ fromȱth eȱt opȱ
o fȱth eȱ sta nd pi p e, ȱthe ȱh e ig h tȱ o fȱe a chȱ st andp ipe ȱa b ov eȱth eȱ
g round ȱ su r fa c eȱ andȱth eȱg round ȱ levelȱ atȱ e achȱ s it e ȱn eed sȱ
t oȱ be ȱr ec orde dȱo nȱy ou rȱ fie ld ȱdatasheet.ȱ These ȱw il lȱ b eȱ
u sed ȱ la te rȱto ȱh e lp ȱc a lc u l a t e ȱthe ȱgroundwaterȱ lev elȱandȱ
w i l lȱh e lpȱy ou ȱrepairȱy ou rȱp iez om ete r sȱ ifȱ anyȱ a re ȱ
d amaged. ȱ ȱ
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Measuringȱg roundw ater ȱ lev e lȱ
TheȱfirstȱparameterȱtoȱbeȱmeasuredȱwhenȱdoingȱgroundwaterȱmonitoringȱisȱtheȱStandingȱWaterȱLevelȱ
(SWL)ȱofȱtheȱpiezometer.ȱThisȱmayȱbeȱdeterminedȱusingȱaȱvarietyȱofȱequipment.ȱȱ
Theȱsimplestȱ(andȱcheapest)ȱwayȱisȱbyȱgentlyȱinsertingȱ(soȱasȱnotȱtoȱdamageȱtheȱbottomȱofȱtheȱwell)ȱaȱ
thinȱdryȱwoodenȱorȱbambooȱstakeȱintoȱtheȱpipeȱuntilȱitȱcanȱgoȱnoȱfurther.ȱOnceȱitȱisȱwithdrawnȱtheȱdepthȱ
ofȱwaterȱfromȱtheȱbottomȱofȱtheȱwellȱmayȱbeȱmeasuredȱasȱtheȱwetȱsectionȱofȱtheȱstake,ȱorȱtheȱdistanceȱtheȱ
wetȱareaȱisȱfromȱtheȱtopȱofȱtheȱstandpipeȱmayȱbeȱmeasured.ȱThisȱmethodȱhasȱitsȱdrawbacks–itȱcanȱbeȱ
difficultȱandȱpotentiallyȱdangerousȱcarryingȱlargeȱnumbersȱofȱlongȱstakes,ȱandȱifȱitȱrainsȱonȱthemȱorȱtheyȱ
becomeȱwetȱinȱsomeȱotherȱwayȱthereȱisȱnoȱwayȱofȱdeterminingȱwhereȱtheȱwaterȱlevelsȱare.ȱȱ
Professionalȱgroundwaterȱmonitoringȱgroupsȱuseȱeitherȱaȱplopperȱorȱbeeper,ȱdependingȱonȱtheȱdepthȱofȱ
theȱwellsȱthatȱtheyȱareȱmonitoringȱandȱtheȱfinancialȱresourcesȱofȱtheȱgroup.ȱInstructionsȱforȱmakingȱ
ploppersȱandȱbeepersȱareȱincludedȱinȱAppendixȱ6.ȱ
AȱplopperȱisȱsimplyȱaȱcupȬshapedȱtinȱobject,ȱwhichȱisȱattachedȱtoȱaȱstringȱandȱloweredȱfaceȱdownȱintoȱ
theȱpipe.ȱWhenȱtheȱcupȱhitsȱtheȱwater,ȱtheȱforceȱmakesȱaȱ‘plop’ȱsound.ȱThisȱcanȱbeȱdoneȱseveralȱtimesȱ
andȱtheȱaverageȱpointȱwhereȱthisȱsoundȱisȱmadeȱcanȱbeȱmarkedȱonȱtheȱstring,ȱandȱtheȱgroundwaterȱ
depthȱisȱcalculatedȱasȱtheȱdepthȱfromȱtheȱtopȱofȱtheȱstandpipe,ȱminusȱtheȱheightȱofȱtheȱstandpipeȱaboveȱ
theȱground.ȱȱ
Aȱbeeperȱisȱtheȱeasiestȱtoȱuseȱandȱmostȱaccurateȱmethod,ȱparticularlyȱforȱdeepȱpiezometersȱorȱwhereȱtheȱ
piezometersȱrequireȱaȱlongȱwalkȱthroughȱtheȱsamphires.ȱItȱcomprisesȱaȱsmallȱelectronicȱcircuit,ȱwhichȱisȱ
attachedȱtoȱaȱlong,ȱtwoȬcoredȱelectricalȱcableȱwithȱbothȱtheȱwiresȱexposedȱatȱoneȱend.ȱTheȱcircuitȱisȱ
normallyȱanȱopenȱcircuitȱasȱthereȱisȱnothingȱjoiningȱtheȱtwoȱcoresȱofȱtheȱcable.ȱWhenȱtheȱcableȱisȱloweredȱ
downȱaȱgroundwaterȱwellȱitȱeventuallyȱcomesȱintoȱcontactȱwithȱwater.ȱWaterȱconductsȱelectricityȱsoȱitȱ
completesȱtheȱcircuit.ȱThisȱallowsȱelectricityȱtoȱflowȱbetweenȱtheȱtwoȱwiresȱandȱtheȱbuzzerȱ(heldȱinȱyourȱ
hand)ȱbeepsȱandȱaȱlightȱcomesȱon.ȱTheȱwireȱcanȱbeȱjiggledȱupȱandȱdownȱtoȱidentifyȱtheȱexactȱwaterȱlevelȱ
fromȱtheȱtopȱofȱtheȱstandpipe.ȱȱ
Theȱnextȱstepȱinȱgroundwaterȱmonitoringȱisȱmeasuringȱ
theȱpHȱandȱsalinity.ȱToȱdoȱthisȱtheȱcontentsȱofȱtheȱwellȱ
needȱtoȱbeȱcompletelyȱremoved,ȱpreferablyȱtoȱtwiceȱtheȱ
well’sȱvolume,ȱandȱtheȱwellȱshouldȱbeȱallowedȱtoȱfillȱ
againȱtoȱensureȱuncontaminatedȱgroundwaterȱisȱbeingȱ
measured.ȱTheȱwellȱmayȱbeȱemptiedȱusingȱaȱbalingȱ
device,ȱandȱsomeȱexamplesȱofȱtheseȱareȱshownȱinȱȱȱȱȱȱȱȱȱȱȱ
Figureȱ8.ȱ
ȱ
Figure 8—Assorted groundwater monitoring
equipment
AȱpetrolȱsiphonȱwithȱaȱoneȬwayȱvalveȱonȱtheȱbaseȱisȱ
probablyȱtheȱeasiestȱdeviceȱtoȱobtain.ȱTheȱpipeȱisȱjiggledȱ
upȱandȱdownȱwithȱtheȱvalveȱinȱtheȱwater,ȱuntilȱwaterȱ
pumpsȱoutȱtheȱtopȱofȱtheȱpipe.ȱContinueȱjigglingȱtheȱpipeȱ
upȱandȱdownȱuntilȱnoȱmoreȱwaterȱcomesȱoutȱorȱatȱleastȱ
1.8ȱlitresȱhaveȱbeenȱremovedȱfromȱtheȱstandpipe.ȱȱ
Moveȱonȱtoȱtheȱnextȱpiezometer,ȱrinsingȱtheȱbalingȱdeviceȱ
withȱdistilledȱwaterȱbeforeȱrepeatingȱtheȱprocess.ȱOnceȱallȱtheȱpiezometersȱhaveȱbeenȱemptied,ȱtheȱfirstȱ
oneȱshouldȱhaveȱrecharged.ȱThisȱmayȱtakeȱupȱtoȱanȱhour.ȱReturnȱtoȱtheȱfirstȱpiezometerȱandȱextractȱaȱ
200–300ȱmLȱwaterȱsampleȱfromȱitȱforȱsalinityȱandȱpHȱmeasurement.ȱȱ
TestȱyourȱgroundwaterȱsamplesȱinȱaccordanceȱwithȱtheȱguidelinesȱMeasuringȱpHȱandȱMeasuringȱsalinity.ȱ
Disposeȱofȱtheȱremainingȱsampleȱbackȱdownȱtheȱpiezometerȱitȱcameȱfrom,ȱandȱcapȱtheȱpiezometer.ȱ
RecordȱtheȱsalinityȱandȱpHȱmeasurements.ȱȱ
Groundwaterȱlevelȱreadingsȱshouldȱbeȱtakenȱmonthlyȱforȱtheȱdryȱperiodsȱofȱyourȱyear,ȱegȱSeptemberȱ
throughȱtoȱApril,ȱwithȱoccasionalȱmonitoringȱduringȱwetterȱmonthsȱifȱaccessȱisȱpossibleȱwithoutȱcausingȱ
undueȱdamage.ȱOptimally,ȱsamplesȱfromȱtheȱpiezometersȱwouldȱbeȱcollectedȱforȱsalinityȱandȱpHȱ
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measurementȱmonthlyȱfromȱOctoberȱthroughȱtoȱMarch.ȱAnȱannualȱorȱbiannualȱreadingȱwouldȱsufficeȱifȱ
monitoringȱaȱnaturalȱarea.ȱAdditionalȱcollectionȱofȱgroundwaterȱlevelȱmeasurementsȱatȱhighȱandȱlowȱ
tidesȱisȱinformative,ȱasȱlongȱasȱthereȱisȱnoȱsurfaceȱwaterȱonȱtheȱsaltmarshȱnearȱtheȱwells.ȱ
Piezometersȱareȱeasilyȱdamagedȱorȱdestroyedȱbyȱfire,ȱfloodsȱorȱvandalism.ȱKeepȱanȱeyeȱonȱyourȱ
piezometersȱandȱrepairȱthemȱimmediatelyȱifȱtheyȱareȱdamaged.ȱReplacingȱtheȱcapȱifȱitȱgoesȱmissingȱandȱ
ensuringȱthatȱtheȱpiezometersȱareȱkeptȱcappedȱatȱallȱtimesȱwhenȱnotȱbeingȱusedȱisȱimportant.ȱRainȱ
contaminationȱofȱtheȱgroundwaterȱmayȱcreateȱsodicȱsoilsȱaroundȱtheȱpiezometerȱifȱtheȱcapȱisȱleftȱoff.ȱȱ
I nte rpr et ingȱt id a lȱ movementȱd at a ȱ
Bothȱtheȱtideȱandȱgroundwaterȱdataȱneedsȱtoȱbeȱinterpretedȱusingȱgraphsȱandȱcolouredȱmapsȱshowingȱ
allȱyourȱresults.ȱTheseȱgraphsȱandȱmapsȱcouldȱbeȱcomparedȱtoȱresultsȱfromȱreferenceȱsitesȱifȱyouȱhaveȱ
anyȱavailable.ȱTheȱlocalȱharbourȱauthorityȱmayȱhaveȱlocalȱtidalȱdata,ȱwhileȱtheȱMiningȱBranchȱofȱPIRSAȱ
mayȱbeȱableȱtoȱprovideȱinformationȱonȱgroundwaterȱinȱyourȱdistrict.ȱ
Whenȱinterpretingȱtidalȱmovementȱdataȱitȱisȱimportantȱtoȱplotȱtheȱdataȱfromȱeachȱsiteȱontoȱaȱgraphȱ
showingȱtimeȱandȱdepth.ȱTheseȱgraphsȱcanȱthenȱbeȱcomparedȱtoȱeachȱotherȱtoȱidentifyȱdifferencesȱisȱ
shapeȱorȱtidalȱrange.ȱ
Anȱunrestrictedȱtidalȱgraphȱwillȱlookȱlikeȱaȱ‘bellȱcurve’ȱorȱ‘sineȱwave’.ȱItȱwillȱbeȱsmoothȱandȱeven.ȱAsȱtheȱ
severityȱofȱtheȱtidalȱrestrictionȱincreases,ȱsoȱwillȱtheȱdifferenceȱinȱtidalȱrangeȱandȱshapeȱofȱtheȱgraphȱ
betweenȱyourȱunrestrictedȱandȱrestrictedȱsites.ȱȱ
Theȱtidalȱrange,ȱorȱtheȱdifferenceȱinȱlevelȱbetweenȱhighȱandȱlowȱtide,ȱisȱoneȱofȱtheȱmostȱimportantȱ
ecologicalȱaspectsȱtoȱmonitorȱinȱaȱsaltmarsh.ȱItȱdeterminesȱtheȱareasȱsuitableȱforȱdifferentȱhabitats,ȱsuchȱ
asȱseagrass,ȱmangrove,ȱlowȱmarsh,ȱhighȱmarshȱandȱgrassland.ȱȱ
Theȱdataȱalsoȱprovideȱtheȱobserverȱwithȱanȱideaȱofȱtheȱtidalȱflushingȱthatȱoccurs.ȱAreasȱthatȱareȱregularlyȱ
inundatedȱareȱflushedȱofȱexcessȱsalts,ȱwhereasȱthoseȱthatȱareȱonlyȱoccasionallyȱfloodedȱbecomeȱveryȱ
saline.ȱIfȱtheȱareaȱbeingȱstudiedȱhasȱexperiencedȱsoilȱshrinkageȱdueȱtoȱtidalȱrestrictionsȱcausingȱacidȱ
sulphateȱsoils,ȱandȱisȱundergoingȱremediation,ȱtheȱstaffȱgaugeȱdataȱcanȱalsoȱindicateȱifȱtooȱmuchȱ
tidewaterȱisȱenteringȱtheȱreopenedȱestuary.ȱMangrovesȱorȱotherȱmarineȱemergentȱvegetationȱwillȱrapidlyȱ
coloniseȱareasȱthatȱreceiveȱdailyȱinundation.ȱAreasȱthatȱareȱonlyȱinundatedȱaȱcoupleȱofȱtimesȱaȱmonthȱ
willȱbeȱmoreȱappropriateȱforȱuplandȱsamphires,ȱwhileȱareasȱthatȱareȱinundatedȱonlyȱseveralȱtimesȱaȱyearȱ
areȱlikelyȱtoȱsupportȱsaltbushȱcommunities.ȱ
P u t ti n g i t t o g e t h e r
Theȱgroundwaterȱdataȱisȱusedȱinȱconjunctionȱwithȱtheȱstaffȱgaugeȱdataȱtoȱdetermineȱifȱsufficientȱtidalȱ
flushingȱisȱoccurring.ȱIfȱinsufficientȱtidalȱflushingȱisȱoccurringȱinȱaȱsamphireȱswamp,ȱtheȱfollowingȱtwoȱ
scenariosȱcouldȱdevelop:ȱ
–
inȱaridȱareasȱtheȱgroundwaterȱwillȱshowȱincreasingȱsalinityȱandȱdecreasingȱpHȱoverȱaȱperiodȱofȱ
severalȱmonths.ȱAcidȱdischargeȱcouldȱoccurȱafterȱrain.ȱSaltȱscaldsȱmayȱappearȱonȱtheȱsurface,ȱandȱ
theȱsaltbushȱcommunityȱwillȱstartȱtoȱinvadeȱtheȱsamphireȱzone.ȱ
–
Inȱareasȱwhereȱfreshwaterȱcontinuouslyȱdischargesȱintoȱtheȱtidallyȱrestrictedȱareaȱtheȱ
groundwaterȱwillȱgraduallyȱbecomeȱfresh.ȱAreasȱofȱsodicȱsoilsȱmayȱappear.ȱGrasslandȱplantsȱmayȱ
invadeȱtheȱuplandȱmarshȱandȱreedsȱmayȱinvadeȱtheȱlowerȱmarsh.ȱ
Anȱareaȱwithȱsufficientȱflushingȱshouldȱshowȱaȱmonthlyȱsalinityȱcycleȱduringȱneapȱtidesȱandȱdecreasedȱ
salinityȱimmediatelyȱafterȱaȱspringȱtide.ȱSeasonalȱvariationsȱwillȱalsoȱbeȱexperiencedȱdependingȱonȱ
rainfallȱandȱevaporation.ȱȱ
Atȱleastȱ12ȱmonthsȱofȱdataȱneedsȱtoȱbeȱcollectedȱbeforeȱseasonalȱtrendȱinȱ
dataȱcanȱbeȱidentified.ȱTheseȱseasonalȱtrendsȱwillȱalsoȱactȱasȱaȱbaseline,ȱ
whichȱwillȱallowȱcomparisonsȱwithȱdataȱfromȱotherȱsitesȱorȱoverȱtime.ȱ
ȱ
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Chemical assessments
ȱ
ȱ
ȱ
ȱ
ȱ
ȱ
ȱ
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Measuring dissolved oxygen
Dissolvedȱoxygenȱ(DO)ȱmeasuresȱtheȱamountȱofȱoxygenȱdissolvedȱ
inȱtheȱwater,ȱandȱhenceȱavailableȱtoȱaquaticȱplantsȱandȱanimalsȱforȱ
breathing.ȱWhenȱdissolvedȱoxygenȱlevelsȱdrop,ȱaquaticȱlifeȱstartsȱ
toȱdie.ȱSomeȱorganismsȱneedȱmoreȱoxygen,ȱandȱsoȱdieȱfirst.ȱFishȱ
comingȱtoȱtheȱsurfaceȱforȱairȱisȱoneȱofȱtheȱfirstȱsignsȱofȱlowȱDOȱ
levels.ȱȱ
Someȱanimalsȱhaveȱadaptationsȱthatȱallowȱthemȱtoȱdealȱwithȱlowȱ
dissolvedȱoxygen.ȱMosquitoesȱhaveȱtubesȱtheyȱbreatheȱthrough,ȱ
veryȱmuchȱlikeȱsnorkels.ȱOtherȱorganismsȱsuchȱasȱmusselsȱandȱ
pipisȱmayȱshutȱtheirȱshellsȱandȱ‘hibernate’.ȱȱ
Aȱrangeȱofȱnaturalȱandȱhumanȱrelatedȱfactorsȱaffectsȱtheȱ
concentrationȱofȱDOȱinȱwater.ȱNaturalȱfactorsȱincludeȱ
temperature,ȱtimeȱofȱdayȱandȱlightȱintensity.ȱHumanȬrelatedȱ
factorsȱincludeȱpollutionȱwithȱchemicalsȱthatȱdecreaseȱtheȱlevelsȱofȱ
oxygen,ȱincreasedȱnutrientȱloads,ȱandȱtemperatureȱchangesȱthatȱ
raiseȱorȱlowerȱtheȱDOȱsaturationȱpoint.ȱȱ
Highȱnutrientsȱincreaseȱtheȱgrowthȱofȱalgaeȱinȱtheȱwater.ȱAlgaeȱareȱ
plants,ȱusingȱoxygenȱatȱnightȱviaȱrespirationȱandȱcreatingȱoxygenȱ
duringȱtheȱdayȱviaȱphotosynthesis.ȱInȱcleanȱwatersȱwithȱlowȱ
nutrients,ȱtheȱnightȱtoȱdayȱchangesȱinȱDOȱcontentȱareȱminimal.ȱInȱ
nutrientȬrichȱwatersȱtheȱamountȱofȱalgaeȱinȱtheȱwaterȱincreases,ȱ
andȱtheȱnight/dayȱDOȱchangeȱmayȱbecomeȱextreme.ȱȱ
Oxygenȱmayȱbeȱmeasuredȱusingȱeitherȱaȱdissolvedȱoxygenȱtestȱkitȱ
orȱaȱdissolvedȱoxygenȱmeter.ȱTestȱkitsȱareȱcheapȱbutȱtakeȱ
considerableȱtime.ȱDissolvedȱoxygenȱmetersȱprovideȱhighlyȱ
accurateȱresultsȱandȱtakeȱveryȱlittleȱtime.ȱDOȱmetersȱareȱcommonlyȱȱ
soldȱasȱcombinationȱmeters,ȱwhichȱalsoȱmeasureȱpH,ȱtemperatureȱȱ
andȱconductivity.ȱTheseȱmetersȱareȱcostlyȱandȱrequireȱregularȱȱ
calibrationȱtoȱmaintainȱaccuracy.ȱȱ
Activity:
3 Core
Age: All
Time: 3
Why? Most aquatic
organisms require at least
3 – 5 mg/L of dissolved
oxygen to survive. The
concentration in the water
varies depending on
salinity, temperature and
time of day. Below 3 mg/L
indicates hypoxia, and
below 0.5 mg/L indicates
anoxia.
Safety: Dispose of all
sample and reagent mixes
appropriately. The test kit
uses chemicals that can be
dangerous if handled
incorrectly. Read the
instructions provided with
the chemicals and
equipment. Also check first
aid procedures.
What you may need:
–
siteȱrecordȱformȱ
–
safetyȱglassesȱandȱdisposableȱglovesȱ
–
sampleȱbottleȱwithȱscrewȱtopȱcapȱȱ
–
oxygenȱtestȱkitȱ(modifiedȱWinklerȱmethod).ȱ
To ensure good results:
Checkȱtheȱexpiryȱdatesȱofȱreagentsȱpriorȱtoȱuse.ȱ
Getȱtwoȱpeopleȱtoȱeachȱanalyseȱaȱseparateȱsample,ȱandȱaverageȱtheȱresults.ȱ
What to do:
Rinseȱbottleȱwithȱsampleȱwaterȱandȱsubmergeȱitȱinȱtheȱwaterȱtoȱaboutȱ200–mmȱbelowȱtheȱsurface,ȱuntilȱ
filled.ȱWhenȱfull,ȱtapȱtheȱbottleȱsidesȱtoȱremoveȱairȱbubblesȱandȱreplaceȱlidȱwhilstȱstillȱunderȱwater.ȱȱ
Immediatelyȱcompleteȱtheȱtestȱprocedureȱasȱoutlinedȱinȱtheȱinstructionsȱprovidedȱwithȱyourȱtestȱkit.ȱBeȱ
sureȱtoȱfollowȱsafetyȱinstructionsȱandȱwearȱsafetyȱequipment.ȱRecordȱtheȱresultȱonȱyourȱsiteȱrecordȱformȱ
asȱDOȱmg/L.ȱ
56
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Bothȱtheȱtemperatureȱandȱtheȱsalinityȱofȱwaterȱaffectȱtheȱsolubilityȱofȱoxygen.ȱSeawaterȱcanȱonlyȱholdȱaȱ
littleȱmoreȱthanȱhalfȱtheȱoxygenȱthatȱfreshwaterȱcanȱholdȱatȱtheȱsameȱtemperature.ȱȱ
Manyȱgroupsȱstudyingȱestuariesȱreportȱtheȱdissolvedȱoxygenȱcontentȱasȱtheȱpercentȱsaturation,ȱasȱthisȱ
takesȱintoȱaccountȱtheȱtemperatureȱandȱsalinityȱeffectsȱandȱgivesȱaȱmoreȱimmediateȱideaȱofȱtheȱhealthȱofȱ
yourȱwaterȱbody,ȱinȱcomparisonȱtoȱotherȱwaterȱbodies.ȱToȱcalculateȱtheȱpercentȱsaturationȱyouȱneedȱtoȱ
knowȱtheȱtemperatureȱandȱsalinityȱofȱtheȱwater.ȱȱ
Valuesȱaboveȱ100%ȱsaturationȱareȱusuallyȱindicativeȱofȱnutrientȱenrichment,ȱoftenȱinȱtheȱformȱofȱsewageȱ
orȱfertilisers.ȱTheseȱpollutantsȱcauseȱanȱovergrowthȱinȱplanktonicȱalgaeȱthatȱproduceȱoxygenȱinȱtheȱ
daytime.ȱTheȱdownsideȱisȱtheȱamountȱofȱoxygenȱtheyȱuseȱatȱnight,ȱwhenȱtheȱalgaeȱmayȱremoveȱtooȱ
muchȱoxygenȱfromȱtheȱwater,ȱkillingȱfish.ȱ
Valuesȱbelowȱapproximatelyȱ60%ȱareȱoftenȱindicativeȱofȱorganicȱpollution.ȱBacteriaȱbreakȱdownȱmostȱ
organicȱpollutants,ȱandȱtheseȱrequireȱoxygen.ȱThereforeȱorganicȱwastesȱareȱoftenȱdescribedȱbyȱtheirȱ
biochemicalȱoxygenȱdemandȱ(BOD).ȱThisȱisȱtheȱamountȱofȱoxygenȱinȱmg/Lȱthatȱaȱsolutionȱofȱtheȱwasteȱ
wouldȱdemandȱfromȱtheȱenvironment.ȱ
P e r ce n t s a t u ra ti o n ca l cu l a t i o n
Ifȱyouȱwouldȱlikeȱtoȱknowȱtheȱapproximateȱpercentȱdissolvedȱoxygenȱsaturationȱofȱyourȱsample,ȱyouȱcanȱ
useȱtheȱroughȱconversionȱinȱTableȱ4.ȱAȱmoreȱaccurateȱconversionȱisȱavailableȱusingȱaȱspreadsheet,ȱwhichȱ
yourȱWaterwatchȱcoordinatorȱwillȱhave.ȱȱ
Toȱundertakeȱthisȱcalculationȱyouȱwillȱneedȱtoȱtestȱsalinity,ȱtemperatureȱandȱdissolvedȱoxygen.ȱTheseȱ
willȱneedȱtoȱbeȱreportedȱas;ȱ
–
salinityȱasȱTDSȱ(g/L)ȱȱ
–
waterȱtemperatureȱinȱ°Cȱȱ
–
theȱmeasuredȱDOȱinȱmg/Lȱ(withoutȱtemperatureȱcorrection).ȱȱ
Useȱyourȱtemperatureȱandȱsalinityȱreadingsȱtoȱestablishȱtheȱpotentialȱdissolvedȱoxygenȱbasedȱonȱtheȱ
tablesȱinȱTchobanoglousȱ&ȱBurtonȱ(1991).ȱȱ
Firstȱdetermineȱwhatȱconcentrationȱofȱoxygenȱisȱequivalentȱtoȱ100%ȱsaturationȱinȱyourȱwater.ȱInȱtheȱtableȱ
belowȱlocateȱtheȱclosestȱsalinityȱreadingȱacrossȱtheȱtopȱandȱtheȱclosestȱtemperatureȱreadingȱfromȱtheȱleftȱ
column.ȱScrollȱacrossȱtheȱrowȱandȱdownȱtheȱcolumnȱtoȱfindȱtheȱpotentialȱsaturationȱoxygenȱcontentȱforȱ
yourȱwater.ȱȱ
Table 4—Potential saturation oxygen concentrations
0 g/L TDS
0 °C
10 g/L
14.6
20 g/L TDS
30 g/L TDS
13.6
12.7
11.9
40 g/L
11.1
45 g/L
10.7
5 °C
12.8
11.9
11.2
10.5
9.8
9.5
10 °C
11.3
10.6
9.9
9.3
8.8
8.5
15 °C
10.1
9.5
8.9
8.4
7.9
7.7
20 °C
9.1
8.6
8.1
7.6
7.2
7.0
25 °C
8.2
7.8
7.4
7.0
6.6
6.4
30 °C
7.5
7.1
6.8
6.4
6.1
5.9
35 °C
6.9
6.6
6.2
5.9
5.6
5.5
Onceȱyouȱhaveȱdeterminedȱtheȱpotentialȱsaturation,ȱapplyȱtheȱformulaȱbelowȱtoȱcalculateȱtheȱpercentȱ
saturationȱforȱyourȱwaterȱbody:ȱȱ
Percent saturation =
Measured DO
Potential DO x 100
57
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring sulphide
Sulphurȱisȱanȱimportantȱpartȱofȱestuarineȱecosystems.ȱBacteriaȱreduceȱ
sulphurȱcompoundsȱtoȱcreateȱenergy.ȱSulphurȱisȱanȱimportantȱ
componentȱofȱtheȱheavyȱmetalȱandȱnutrientȱcycles.ȱTheȱoxidisedȱformȱ
ofȱsulphur,ȱsulphate,ȱisȱaȱmajorȱcomponentȱsaltȱofȱmarineȱwater.ȱItȱisȱ
usuallyȱassociatedȱwithȱcalciumȱandȱmagnesium.ȱȱ
Sulphideȱisȱtheȱreducedȱformȱofȱsulphur.ȱItȱisȱregularlyȱpresentȱinȱ
lowȱconcentrationȱunderȱtheȱsurfaceȱofȱestuarineȱsediments,ȱbutȱitȱisȱ
rarelyȱpresentȱinȱsurfaceȱwater.ȱProblemsȱoccurȱwhenȱsulphideȱ
migratesȱintoȱsurfaceȱwater.ȱThisȱchemicalȱisȱhighlyȱreactive,ȱandȱ
quicklyȱconsumesȱallȱoxygenȱinȱtheȱwaterȱcolumn.ȱItȱmayȱoxidiseȱintoȱ
acid,ȱwhichȱaffectsȱtheȱpHȱofȱtheȱwaterway.ȱȱ
Anyȱsulphideȱpresentȱinȱtheȱwaterȱcolumn,ȱparticularlyȱnearȱtheȱ
surface,ȱisȱanȱindicatorȱthatȱyourȱwaterwayȱhasȱbeen,ȱisȱorȱisȱaboutȱtoȱ
becomeȱanoxicȱ(noȱdissolvedȱoxygen)ȱorȱhypoxicȱ(lowȱinȱoxygen).ȱȱ
What you may need:
–
siteȱrecordȱformȱ
–
sulphideȱtestȱkitȱ
–
pHȱstripsȱ
–
disposableȱglovesȱandȱsafetyȱglassesȱ
–
liddedȱcontainerȱwithȱkittyȱlitterȱ
–
sampleȱbottleȱorȱcontainer.ȱ
Activity:
3 Extension
Age: All
Time: 3
Why? The presence of
sulphide in the water
column may be used as a
surrogate for measuring
dissolved oxygen. There
should be no sulphide
present in the free surface
water of an estuary.
Safety: Sulphide test kits
often contain concentrated
acid or corrosive chemicals.
Use care when handling the
reagents, and read the
safety instructions provided
with the kit. Wear
disposable gloves and eye
protection.
To ensure good results:
Sulphideȱfieldȱtestȱkitsȱareȱnotȱasȱpreciseȱorȱaccurateȱasȱlaboratoryȱmethods,ȱbutȱtheȱkitsȱrecommendedȱ
byȱWaterwatchȱSAȱareȱaccurateȱenoughȱforȱbasicȱecologicalȱassessment,ȱparticularlyȱwhenȱcombinedȱ
withȱdissolvedȱoxygenȱreadings.ȱȱ
ManyȱsmallȱtestȱkitsȱhaveȱaȱuseȬbyȱdate.ȱCheckȱyourȱsulphideȱkitȱbeforeȱgoingȱoutȱintoȱtheȱfield.ȱ
What to do:
Collectȱaȱsampleȱaccordingȱtoȱtheȱsampleȱcollectionȱsectionȱofȱtheseȱguidelines.ȱDoȱnotȱundulyȱshakeȱorȱ
aerateȱtheȱsampleȱpriorȱtoȱtestingȱasȱoxygenȱ(presentȱinȱair)ȱmayȱoxidiseȱtheȱsulphideȱinȱtheȱsample.ȱȱ
TestȱtheȱpHȱofȱtheȱsample,ȱusingȱtheȱmethodȱoutlinedȱinȱtheȱguidelineȱMeasuringȱpH.ȱRecordȱitȱonȱyourȱ
sampleȱsheet.ȱ
Theȱsulphideȱtestȱkitȱcomesȱcompleteȱwithȱinstructionsȱonȱhowȱtoȱuseȱit.ȱAsȱkitsȱvaryȱbetweenȱ
manufacturers,ȱpleaseȱreadȱtheȱtestȱmethodsȱcarefullyȱandȱfollowȱthemȱasȱcloselyȱasȱyouȱcan.ȱRecordȱtheȱ
resultsȱimmediatelyȱonȱyourȱfieldȱdatasheet.ȱ
Disposeȱofȱliquidȱwastesȱdirectlyȱintoȱtheȱcontainerȱfilledȱwithȱkittyȱlitter.ȱOnceȱtheȱkittyȱlitterȱisȱfullyȱ
used,ȱdisposeȱofȱitȱinȱaȱsealedȱrubbishȱbagȱtoȱgeneralȱwaste.ȱCleanȱallȱequipmentȱwithȱdistilledȱwaterȱ
onceȱfinished,ȱasȱyourȱnextȱresultsȱmayȱotherwiseȱbeȱaffected.ȱAllowȱtheȱequipmentȱtoȱairȱdryȱbeforeȱ
storingȱit.ȱ
Ifȱyouȱcan’tȱunderstandȱyourȱsulphideȱtestȱkitȱinstructions,ȱpleaseȱcontactȱyourȱWaterwatchȱcoordinator.ȱ
Theȱsulphideȱconcentrationȱisȱreportedȱasȱmilligramsȱperȱlitreȱofȱsulphideȱ(mg/LȱS2Ȭ).ȱReportȱanyȱpositiveȱ
sulphideȱreadingsȱatȱyourȱsiteȱtoȱyourȱWaterwatchȱcoordinator.ȱȱ
58
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring orthophosphate
Theȱimportanceȱofȱnutrientsȱinȱtheȱestuarineȱenvironmentȱisȱ
discussedȱinȱseveralȱsectionsȱofȱthisȱmanual.ȱOrthophosphateȱisȱaȱ
solubleȱinorganicȱformȱofȱphosphorus,ȱwhichȱmeansȱthatȱitȱisȱeasilyȱ
availableȱtoȱaquaticȱplantsȱandȱanimals.ȱȱ
Phosphorusȱ(inȱanyȱofȱitsȱaccessibleȱforms)ȱisȱcriticalȱforȱmetabolicȱ
processes,ȱwhichȱinvolveȱtheȱtransferȱofȱenergy.ȱWithoutȱ
phosphorusȱanimalsȱandȱplantsȱwouldȱbeȱunableȱtoȱlive.ȱ
Phosphorusȱexistsȱinȱtheȱwaterȱinȱseveralȱotherȱforms—mainlyȱ
organicȱphosphates,ȱandȱpolyphosphatesȱfromȱdetergents.ȱTotalȱ
phosphorusȱcanȱalsoȱbeȱmeasured,ȱbutȱitȱrequiresȱdigestionȱatȱhighȱ
temperatures.ȱ
Nutrientȱconcentrationsȱvaryȱaccordingȱtoȱsurroundingȱlandȱuse,ȱ
seasonȱandȱgeology.ȱNitrogenȱandȱphosphorusȱareȱtwoȱofȱtheȱmostȱ
importantȱnutrientsȱforȱtheȱgrowthȱofȱaquaticȱplants.ȱTheirȱ
concentrationsȱinȱtheȱenvironmentȱhaveȱincreasedȱdramaticallyȱ
sinceȱEuropeanȱsettlement.ȱ
Orthophosphateȱinȱwaterȱcomesȱfromȱfertilisersȱandȱisȱtheȱformȱ
commonlyȱmeasured,ȱasȱitȱdetectsȱpoorȱagriculturalȱorȱlandȱ
managementȱpracticesȱinȱtheȱcatchment.ȱItȱalsoȱindicatesȱsewageȱ
pollutionȱfurtherȱfromȱtheȱpointȱofȱdischargeȱthanȱdoesȱnitrogen.ȱ
Excessȱphosphatesȱmayȱalsoȱenterȱanȱestuaryȱfromȱsoil,ȱanimalȱ
feedlotȱoperationsȱandȱlawns.ȱPhosphatesȱmayȱattachȱtoȱsoilȱ
particlesȱandȱbeȱtransportedȱtoȱtheȱestuaryȱwithȱerodedȱsoil.ȱVeryȱ
highȱphosphorusȱloadsȱareȱoftenȱdeliveredȱbyȱlargeȱstormwaterȱ
dischargesȱorȱfromȱoverȱirrigation.ȱ
BlueȬgreenȱalgaeȱbloomsȱareȱlimitedȱbyȱtheȱavailabilityȱofȱ
phosphorusȱratherȱthanȱnitrogen,ȱasȱtheyȱcanȱfixȱtheirȱownȱnitrogenȱ
fromȱtheȱair.ȱHighȱlevelsȱofȱavailableȱphosphorusȱinȱtheȱwaterȱwillȱ
enableȱlargeȱnumbersȱofȱblueȬgreenȱalgaeȱtoȱbloom.ȱSomeȱofȱtheseȱ
bloomsȱareȱtoxicȱandȱmayȱcauseȱfishȱkills.ȱ
Activity:
3 Core
Age: All
Time: 2
Why? Total ortho-P includes
soluble ortho-P and the
more easily reacted
particulate P that may be
loosely bound to clay
particles or incorporated in
algae. These forms of P are
rapidly taken up by algae.
The presence of high
concentrations of ortho-P is
frequently an indicator of
fertiliser or other nutrient
runoff.
Safety: The orthophosphate
test kit contains
concentrated chemicals,
including acids and alkalis.
Use care when handling
them, and read the safety
instructions provided with
the kit. Wear disposable
gloves and eye protection.
Dispose of all samples
and reagents responsibly.
Theȱkeyȱtoȱeffectiveȱnutrientȱmonitoringȱisȱtoȱsampleȱasȱoftenȱasȱpossibleȱatȱasȱmanyȱsitesȱasȱpossible,ȱtoȱ
accountȱforȱtheȱhighȱvariabilityȱofȱestuarineȱecosystems.ȱSamplingȱduringȱwinterȱmayȱbeȱdecreased,ȱasȱ
manyȱaquaticȱplantsȱareȱdormantȱandȱtheȱeffectsȱofȱhighȱphosphorusȱlevelsȱareȱnotȱsoȱobvious.ȱSitesȱmayȱ
beȱselectedȱtoȱreflectȱtheirȱproximityȱtoȱaȱdischargeȱlocation,ȱorȱbecauseȱofȱtheirȱrelativelyȱpristineȱnature.ȱȱ
Becauseȱnutrientȱlevelsȱoftenȱvaryȱwithȱdepth,ȱespeciallyȱduringȱsummerȱwhenȱtheȱestuaryȱmayȱbeȱ
stratified,ȱWaterwatchȱgroupsȱmayȱwishȱtoȱcollectȱsamplesȱatȱdifferentȱdepths.ȱConstructingȱdepthȱ
samplersȱisȱdiscussedȱinȱAppendixȱ6.ȱȱ
What you may need:
–
siteȱrecordȱformȱ
–
orthophosphateȱtestȱkitȱ
–
containerȱforȱsamplingȱ
–
fieldȱdatasheetȱ
–
distilledȱorȱde–ionisedȱwaterȱ
–
liddedȱcontainerȱfilledȱwithȱkittyȱlitterȱ
–
safetyȱequipmentȱincludingȱglassesȱandȱdisposableȱgloves.ȱ
59
ESTUARINE
MONITORING
GUIDANCE
MANUAL
To ensure good results:
Orthophosphateȱfieldȱtestȱkitsȱareȱnotȱasȱpreciseȱorȱaccurateȱasȱmethodsȱusedȱbyȱlaboratories,ȱ
particularlyȱwhenȱnutrientȱconcentrationsȱareȱlow.ȱTheȱkitsȱrelyȱonȱaȱcolourȱcomparison:ȱmatchȱtheȱ
colourȱofȱaȱpreparedȱwaterȱsampleȱtoȱoneȱonȱaȱcolourȱcard.ȱTheȱsubjectivityȱofȱeachȱvolunteer’sȱdecision,ȱ
asȱwellȱasȱambientȱlightȱlevels,ȱmayȱinfluenceȱyourȱresults.ȱDoingȱtestsȱatȱaȱsimilarȱtimeȱofȱday,ȱandȱ
averagingȱseveralȱpeople’sȱresultsȱ(duplicateȱanalyses)ȱwillȱensureȱmoreȱconsistentȱresults.ȱ
OrthophosphateȱkitȱreagentsȱoftenȱhaveȱaȱuseȬbyȱdate.ȱCheckȱthisȱbeforeȱgoingȱoutȱintoȱtheȱfield.ȱ
Theȱphosphateȱtestȱkitsȱ(molybdenumȱblue–acsorbateȱmethod)ȱrecommendedȱbyȱWaterwatchȱforȱuseȱinȱ
estuariesȱareȱcompatibleȱwithȱwaterȱupȱtoȱaboutȱtwiceȱseawaterȱsalinity.ȱIfȱtheȱwaterȱyouȱareȱtestingȱisȱ
tooȱsalty,ȱitȱwillȱshowȱupȱcloudyȱinȱtheȱsolution.ȱRetestingȱafterȱdilutionȱofȱtheȱsampleȱwithȱdistilledȱ
waterȱovercomesȱtheȱproblem.ȱ
Recordȱtheȱunitsȱmeasured,ȱandȱtheȱspeciesȱofȱphosphateȱmeasured,ȱonȱyourȱresultsȱsheet.ȱ
What to do:
Collectȱaȱsampleȱaccordingȱtoȱtheȱinstructionsȱinȱtheȱsampleȱcollectionȱsectionȱofȱthisȱmanual.ȱTestȱtheȱ
sampleȱasȱsoonȱasȱpossible.ȱ
Theȱorthophosphateȱtestȱkitȱcomesȱwithȱinstructions.ȱAsȱtheȱmethodȱvariesȱbetweenȱmanufacturers,ȱ
pleaseȱreadȱtheȱtestȱmethodsȱcarefullyȱandȱfollowȱthemȱasȱcloselyȱasȱyouȱcan.ȱRecordȱtheȱresultsȱ
immediatelyȱonȱyourȱfieldȱdatasheet.ȱ
Theȱrangeȱofȱorthophosphateȱconcentrationsȱcoveredȱbyȱtheȱkitȱisȱrelativelyȱsmall,ȱinȱorderȱtoȱdetectȱveryȱ
smallȱchangesȱinȱtheȱwaterȱquality.ȱIfȱyouȱareȱtestingȱwaterȱthatȱisȱvisiblyȱpolluted,ȱdiluteȱtheȱsampleȱ
withȱdeȬionisedȱorȱdistilledȱwaterȱifȱtheȱconcentrationȱisȱhigherȱthanȱthoseȱshownȱonȱtheȱcolourȱcardȱ
suppliedȱwithȱtheȱkit.ȱ
Disposeȱofȱliquidȱwastesȱdirectlyȱintoȱtheȱcontainerȱfilledȱwithȱkittyȱlitter.ȱOnceȱtheȱkittyȱlitterȱisȱfullyȱ
used,ȱdisposeȱofȱitȱinȱaȱsealedȱrubbishȱbagȱtoȱgeneralȱwaste.ȱCleanȱallȱequipmentȱwithȱdistilledȱwaterȱ
onceȱfinished,ȱotherwiseȱtheȱcurrentȱresultsȱwillȱaffectȱyourȱnextȱtest.ȱAllowȱtheȱequipmentȱtoȱairȱdryȱ
beforeȱstoringȱit.ȱ
Ifȱtheȱkitȱinstructionsȱareȱnotȱclear,ȱpleaseȱcontactȱyourȱWaterwatchȱcoordinator.ȱ
Theȱinterpretationȱofȱnutrientȱconcentrationȱdataȱmustȱbeȱdoneȱwithȱcare.ȱHighȱnutrientȱconcentrationsȱ
oftenȱsuggestȱtheȱpotentialȱforȱexplosiveȱalgalȱgrowth.ȱHowever,ȱlowȱlevelsȱdoȱnotȱnecessarilyȱmeanȱtheȱ
estuaryȱisȱreceivingȱlessȱnutrientȱinput.ȱȱ
Phytoplanktonȱandȱalgaeȱgrowȱveryȱquickly,ȱsoȱlargeȱquantitiesȱofȱnutrientsȱmayȱhaveȱenteredȱtheȱ
estuaryȱandȱhaveȱalreadyȱbeenȱtakenȱupȱbyȱvegetativeȱgrowth.ȱInȱthisȱcase,ȱalthoughȱwaterȱnutrientȱ
concentrationsȱareȱlow,ȱtheȱquantityȱofȱnutrientsȱtiedȱupȱinȱbiomassȱisȱhigh.ȱObservationȱofȱplanktonȱ
bloomsȱandȱwaterȱclarityȱreadingsȱmayȱhelpȱdetermineȱifȱthisȱisȱtheȱcase.ȱChlorophyllȬaȱanalysisȱorȱ
phytoplanktonȱcountsȱmayȱbeȱneededȱifȱyouȱwishȱtoȱquantifyȱtheȱphytoplanktonȱbiomass.ȱ
Orthophosphateȱcanȱbeȱexpressedȱasȱmg/Lȱofȱphosphateȱ(PO4)ȱorȱtheȱmassȱofȱelementalȱphosphorusȱperȱ
litreȱ(PO4–P).ȱTheȱlatterȱmethodȱisȱtheȱmostȱcommon.ȱCheckȱyourȱkitȱtoȱseeȱwhichȱunitsȱitsȱresultsȱareȱin.ȱȱ
AlwaysȱrecordȱtheȱunitȱandȱspeciesȱofȱPȱonȱyourȱrecordȱsheet.ȱIfȱyourȱtestȱkitȱprovidesȱresultsȱasȱȱ
mg/LȱPO4,ȱandȱyouȱwouldȱlikeȱtoȱconvertȱtheȱresult,ȱmultiplyȱtheȱresultȱbyȱ0.32ȱtoȱgiveȱyouȱtheȱresultȱinȱȱ
mg/LȱPO4–P.ȱ
60
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring ammonium
Nutrientsȱareȱessentialȱtoȱallȱecosystems.ȱTheyȱareȱtheȱchemicalsȱthatȱ
provideȱbuildingȱblocksȱforȱplantȱandȱanimalȱgrowth.ȱAustralianȱ
estuariesȱnaturallyȱcontainȱveryȱlowȱlevelsȱofȱnutrients,ȱparticularlyȱ
nitrogen.ȱTheseȱlowȱlevelsȱlimitȱplantȱandȱanimalȱgrowth,ȱandȱnativeȱ
floraȱandȱfaunaȱhaveȱadaptedȱtoȱlowȱnutrientȱlevels.ȱȱ
Manyȱindustrial,ȱagriculturalȱandȱstormwaterȱdischargesȱcontainȱ
largeȱamountsȱofȱtheseȱnutrients,ȱwhichȱunbalanceȱourȱfragileȱ
estuarineȱecosystems.ȱMeasuringȱtheȱconcentrationȱofȱnutrientsȱgivesȱ
usȱanȱindicationȱofȱhowȱbadlyȱaffectedȱtheȱestuaryȱis.ȱ
Theȱmostȱcommonlyȱmeasuredȱnutrientsȱareȱphosphorusȱandȱ
nitrogen.ȱAmmoniumȱ(NH4+)ȱisȱaȱcompoundȱofȱnitrogen.ȱNitrogenȱ
comesȱinȱmanyȱdifferentȱcompounds,ȱdependingȱonȱwhatȱotherȱ
chemicalsȱtheȱnitrogenȱatomȱisȱattachedȱto.ȱTheȱmostȱcommonȱformsȱ
ofȱnitrogenȱinȱestuariesȱareȱammonium,ȱnitrate,ȱnitrite,ȱureaȱandȱ
insolubleȱorganicȱnitrogen.ȱȱ
Plantsȱuseȱnitrogenȱinȱphotosynthesis.ȱExcessiveȱnitrogenȱcanȱcauseȱ
hugeȱgreenȱalgalȱbloomsȱandȱdinoflagellateȱblooms.ȱHighȱnitrogenȱ
levelsȱdoȱnotȱusuallyȱcauseȱblueȬgreenȱalgaeȱblooms,ȱasȱtheseȱ
cyanobacteriaȱcanȱfixȱtheirȱownȱnitrogenȱfromȱtheȱairȱorȱwater.ȱHighȱ
nutrientȱconcentrationsȱinȱgeneralȱhaveȱbeenȱlinkedȱtoȱharmfulȱorȱ
nuisanceȱphytoplanktonȱbloomsȱsuchȱasȱredȱtides,ȱwhichȱcanȱ
produceȱharmfulȱtoxins,ȱinȱparticularȱAlexandrinumȱminutum,ȱwhichȱ
canȱcauseȱparalyticȱshellfishȱpoisoning.ȱHighȱlevelsȱofȱammoniumȱ
mayȱcauseȱfishȱkills.ȱ
Activity:
3 Core
Age: All
Time: 2
Why? High levels of
ammonium are toxic to
fish. SA EPA considers <0.05
mg/L indicates good water
quality for ammonium in an
estuary, and that 0.5 mg/L
indicates poor water
quality.
Safety: The ammonium test
kit contains concentrated
chemicals, including acids
and alkalis. Use care when
handling them, and read
the safety instructions
provided with the kit. Wear
disposable gloves and eye
protection.
It is important to use a nonNessler test, as Nessler’s
reagent contains mercury.
Dispose of all sample and
Measuringȱtheȱconcentrationȱofȱtotalȱnitrogenȱisȱdifficult,ȱasȱitȱ
reagent mixes
requiresȱdigestionȱatȱhighȱtemperaturesȱandȱaȱlotȱofȱfairlyȱexpensiveȱ
appropriately.
laboratoryȱequipment.ȱManyȱcommunityȱgroupsȱandȱscientificȱ
surveysȱmeasureȱtheȱindividualȱformsȱofȱnitrogenȱinstead,ȱasȱsomeȱofȱ
theseȱareȱsimplerȱtoȱmeasureȱandȱtheyȱmayȱgiveȱindicationsȱofȱtheȱsourceȱofȱanyȱexcessȱnitrogen.ȱȱ
Nutrientȱconcentrationȱvariesȱaccordingȱtoȱsurroundingȱlandȱuse,ȱseasonȱandȱgeology.ȱTheȱtidalȱflushingȱ
ofȱtheȱestuary,ȱwaterȱtemperature,ȱbiologicalȱactivityȱandȱsurroundingȱlandȱmanagementȱmethodsȱmayȱ
alsoȱhaveȱanȱeffect.ȱȱ
Ammoniumȱwasȱselectedȱforȱthisȱactivityȱasȱitȱisȱeasyȱtoȱmeasureȱinȱseawaterȱandȱisȱindicativeȱofȱlowȱ
oxygenȱlevels,ȱsewerageȱoutfalls,ȱanimalȱfeedlotȱeffluentsȱorȱcausticȱplantȱoutfalls.ȱTheseȱpollutionȱ
sourcesȱcommonlyȱdischargeȱintoȱSouthȱAustralianȱestuaries.ȱȱ
Theȱkeyȱtoȱeffectiveȱnutrientȱmonitoringȱisȱtoȱsampleȱasȱoftenȱasȱpossibleȱatȱasȱmanyȱsitesȱasȱpossibleȱtoȱ
accountȱforȱtheȱhighȱvariabilityȱofȱestuarineȱecosystems.ȱSamplingȱduringȱwinterȱmayȱbeȱdecreasedȱasȱ
manyȱaquaticȱplantsȱareȱdormantȱandȱtheȱeffectsȱofȱhighȱnitrogenȱlevelsȱareȱnotȱsoȱobvious.ȱSitesȱmayȱbeȱ
selectedȱbasedȱonȱtheirȱproximityȱtoȱdischargeȱlocationsȱorȱbecauseȱofȱtheirȱrelativelyȱpristineȱnature.ȱȱ
Becauseȱnutrientȱlevelsȱoftenȱvaryȱwithȱdepth,ȱespeciallyȱduringȱtheȱsummerȱwhenȱtheȱestuaryȱmayȱbeȱ
stratified,ȱWaterwatchȱgroupsȱmayȱwishȱtoȱcollectȱsamplesȱatȱdifferentȱdepths.ȱConstructingȱdepthȱ
samplersȱisȱdiscussedȱinȱAppendixȱ6.ȱȱ
61
ESTUARINE
MONITORING
GUIDANCE
MANUAL
What you may need:
–
siteȱrecordȱformȱ
–
ammoniumȱtestȱkitȱ
–
containerȱforȱsamplingȱ
–
distilledȱorȱdeionisedȱwaterȱ
–
liddedȱcontainerȱfilledȱwithȱkittyȱlitterȱ
–
safetyȱequipmentȱincludingȱglassesȱandȱdisposableȱgloves.ȱ
To ensure good results:
Ammoniumȱfieldȱtestȱkitsȱareȱnotȱasȱpreciseȱorȱasȱaccurateȱasȱmanyȱotherȱmethodsȱusedȱbyȱlaboratories,ȱ
particularlyȱwhenȱnutrientȱlevelsȱareȱlow.ȱGetȱtheȱbestȱresultsȱpossibleȱbyȱobservingȱtheȱfollowingȱ
recommendations.ȱ
Ammoniumȱkitsȱhaveȱaȱuse–byȱdate.ȱCheckȱthisȱbeforeȱgoingȱoutȱintoȱtheȱfield.ȱFreshȱreagentsȱareȱanȱ
essentialȱpartȱofȱaccurateȱresults.ȱ
Theȱkitsȱrelyȱonȱaȱcolourȱcomparison:ȱmatchȱtheȱcolourȱofȱaȱpreparedȱwaterȱsampleȱtoȱaȱcolourȱonȱaȱ
colourȱcard.ȱTheȱsubjectivityȱofȱeachȱvolunteer’sȱdecision,ȱasȱwellȱasȱtheȱambientȱlightȱlevels,ȱwillȱ
influenceȱtheȱresultsȱtoȱsomeȱdegree.ȱDoingȱtestsȱatȱaȱsimilarȱtimeȱofȱday,ȱandȱgettingȱseveralȱpeopleȱtoȱ
testȱsamplesȱ(duplicateȱanalysis)ȱwillȱensureȱmoreȱreliableȱresults.ȱ
Recordȱtheȱunitsȱmeasuredȱandȱtheȱspeciesȱofȱnitrogenȱmeasuredȱonȱyourȱresultsȱsheet.ȱ
What to do:
Collectȱaȱsampleȱaccordingȱtoȱtheȱinstructionsȱinȱtheȱsampleȱcollectionȱsectionȱofȱthisȱmanual.ȱDoȱnotȱ
shakeȱorȱaerateȱtheȱsampleȱpriorȱtoȱtestingȱasȱammoniumȱrapidlyȱoff–gasses.ȱTestȱtheȱsampleȱasȱsoonȱasȱ
possible.ȱ
Theȱammoniumȱtestȱkitȱcomesȱcompleteȱwithȱinstructionsȱonȱhowȱtoȱuseȱit.ȱAsȱtestȱkitȱmethodsȱvaryȱ
betweenȱmanufacturers,ȱpleaseȱreadȱtheȱtestȱmethodsȱcarefullyȱandȱfollowȱthemȱasȱcloselyȱasȱyouȱcan.ȱ
Recordȱtheȱresultsȱimmediatelyȱonȱyourȱfieldȱdatasheet.ȱ
Theȱrangeȱofȱammoniumȱconcentrationsȱcoveredȱbyȱtheȱkitȱisȱrelativelyȱsmall,ȱasȱveryȱlowȱconcentrationsȱ
affectȱtheȱenvironment.ȱIfȱyouȱareȱtestingȱnearȱaȱpollutedȱoutfall,ȱdiluteȱtheȱsampleȱwithȱde–ionisedȱorȱ
distilledȱwaterȱifȱtheȱammoniumȱconcentrationȱisȱhigherȱthanȱthatȱshownȱonȱtheȱcolourȱcardȱsuppliedȱ
withȱtheȱkit.ȱ
Disposeȱofȱliquidȱwastesȱdirectlyȱintoȱtheȱcontainerȱfilledȱwithȱkittyȱlitter.ȱOnceȱtheȱkittyȱlitterȱisȱfullyȱ
used,ȱdisposeȱofȱitȱinȱaȱsealedȱrubbishȱbagȱtoȱgeneralȱwaste.ȱCleanȱallȱequipmentȱwithȱdistilledȱwaterȱ
onceȱfinished,ȱotherwiseȱtheȱcurrentȱresultsȱwillȱaffectȱyourȱnextȱtest.ȱAllowȱtheȱequipmentȱtoȱairȱdryȱ
beforeȱstoringȱit.ȱ
Ifȱtheȱkitȱinstructionsȱareȱnotȱclear,ȱpleaseȱcontactȱyourȱWaterwatchȱcoordinator.ȱ
Theȱinterpretationȱofȱnutrientȱconcentrationȱdataȱmustȱbeȱdoneȱwithȱcare.ȱHighȱnutrientȱconcentrationsȱ
oftenȱsuggestȱtheȱpotentialȱforȱexplosiveȱalgalȱgrowth;ȱlowȱlevelsȱdoȱnotȱnecessarilyȱmeanȱtheȱestuaryȱisȱ
receivingȱlessȱnutrientȱinput.ȱPhytoplanktonȱandȱalgaeȱgrowȱveryȱquickly,ȱsoȱlargeȱquantitiesȱofȱ
nutrientsȱmayȱhaveȱcomeȱintoȱtheȱestuaryȱandȱhaveȱalreadyȱbeenȱtakenȱupȱbyȱvegetativeȱgrowth.ȱȱ
Inȱthisȱcase,ȱalthoughȱwaterȱnutrientȱconcentrationsȱareȱlow,ȱtheȱquantityȱofȱnutrientsȱtiedȱupȱinȱbiomassȱ
isȱhigh.ȱObservationsȱofȱplanktonȱbloomsȱandȱwaterȱclarityȱreadingsȱwillȱhelpȱdetermineȱifȱthisȱisȱtheȱ
case.ȱChlorophyll–aȱanalysisȱorȱphytoplanktonȱcountsȱareȱneededȱifȱyouȱwishȱtoȱquantifyȱtheȱ
phytoplanktonȱbiomass.ȱ
62
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring chlorophyll-a
PhytoplanktonȱareȱautotrophicȱsingleȬcelledȱmicroȬorganismsȱthatȱ
liveȱinȱwater.ȱPhytoplanktonȱoccurȱnaturallyȱinȱallȱwatersȱofȱtheȱ
worldȱthatȱareȱregularlyȱexposedȱtoȱsunlight.ȱTheȱabundanceȱofȱtheseȱ
organismsȱdependsȱonȱtheȱamountȱofȱlightȱtheyȱreceiveȱandȱtheȱ
quantityȱofȱnutrientsȱinȱtheȱwater.ȱȱ
Anȱincreaseȱinȱtheȱconcentrationȱofȱnutrientsȱ(includingȱcarbon,ȱsilica,ȱ
phosphateȱandȱnitrogen)ȱinȱtheȱwaterȱrapidlyȱcausesȱanȱincreaseȱinȱ
theȱpopulationȱofȱphytoplankton.ȱTherefore,ȱtheirȱpresenceȱandȱ
biomassȱisȱanȱindicatorȱofȱtheȱnutrientȱloadȱinȱtheȱestuary.ȱTheȱ
biomassȱofȱphytoplanktonȱcanȱbeȱdeterminedȱbyȱidentifyingȱthemȱ
andȱcountingȱthemȱunderȱaȱmicroscope.ȱThisȱtakesȱexpensiveȱ
equipmentȱandȱconsiderableȱexperience.ȱChlorophyllȬaȱisȱtheȱgreenȱ
pigmentȱusedȱbyȱplantsȱduringȱphotosynthesis.ȱMeasuringȱ
chlorophyllȬaȱisȱanotherȱwayȱofȱestimatingȱbiomass,ȱasȱthereȱisȱaȱ
wellȬacceptedȱrelationshipȱbetweenȱchlorophyll–aȱandȱbiomass.ȱȱ
Activity:
3 Extension
Age: Adult groups
Time: 4
Why? Chlorophyll is the
green pigment in plants and
so is a good measure of the
amount of plankton present
in the water, and therefore
reflects the trophic status
of the estuary. This is a
surrogate test for nutrients.
ToȱmeasureȱchlorophyllȬa,ȱaȱsampleȱofȱwaterȱisȱfiltered,ȱtoȱtrapȱallȱtheȱphytoplanktonȱonȱtheȱfilterȱpad.ȱInȱ
theȱlaboratoryȱchemicalsȱareȱusedȱtoȱdestroyȱtheȱcellsȱandȱdissolveȱtheȱchlorophyllȬa.ȱThisȱisȱthenȱputȱ
intoȱaȱspectrophotometerȱtoȱdetermineȱtheȱconcentrationȱofȱtheȱpigment.ȱMostȱgroupsȱmonitoringȱthisȱ
parameterȱneedȱtoȱsendȱtheirȱsampleȱawayȱtoȱaȱspecialisedȱlaboratory,ȱasȱthereȱisȱnoȱwayȱtoȱdoȱthisȱinȱtheȱ
field.ȱ
Thisȱguidelineȱoutlinesȱtheȱmethodȱrequiredȱtoȱcollect,ȱstoreȱandȱprepareȱaȱchlorophyllȬaȱsampleȱforȱ
laboratoryȱanalysis.ȱ
What you may need:
–
siteȱrecordȱformȱ
–
twoȬlitreȱsamplingȱbottleȱwithȱlidȱ
–
500ȬmLȱmeasuringȱcontainerȱȱ
–
aȱvacuumȱpumpȱwithȱgaugeȱforȱuseȱinȱtheȱfield,ȱorȱaȱsampleȱlocationȱcloseȱtoȱaȱlaboratoryȱwithȱaȱ
suitableȱpumpȱȱ
–
500ȬmLȱvacuumȱflaskȱtoȱfitȱgaugeȱȱ
–
47Ȭmmȱglassȱfibreȱ(GF/C)ȱfilterȱpaperȱȱ
–
forcepsȱ
–
sealableȱairtight,ȱlabelledȱsmallȱplasticȱcontainers–eachȱcontainerȱneedsȱtoȱbeȱlabelled,ȱwithȱspaceȱ
toȱrecordȱtheȱsiteȱlocation,ȱdateȱandȱtimeȱofȱcollectionȱandȱamountȱofȱwaterȱfilteredȱȱ
–
aluminiumȱfoilȱtoȱwrapȱsmallȱcontainersȱinȱ
–
smallȱplasticȱsnapȱlockȱbagsȱforȱsmallȱcontainersȱȱ
–
oneȱsmallȱeskyȱwithȱiceȱorȱrapidȱaccessȱtoȱaȱfreezer.ȱ
To ensure good results:
Doȱnotȱexceedȱ400Ȭmmȱmercuryȱvacuumȱwhenȱpumpingȱasȱchlorophyllȱmayȱbeȱforcedȱthroughȱtheȱfilter.ȱ
Filterȱtheȱsampleȱandȱfreezeȱitȱasȱsoonȱasȱpossible.ȱ
Itȱisȱeasierȱtoȱcentreȱtheȱfilterȱpaperȱonȱtheȱfilterȱholderȱifȱtheȱfilterȱisȱslightlyȱwet.ȱ
Itȱisȱbestȱtoȱfilterȱasȱmuchȱwaterȱasȱpossibleȱ(upȱtoȱtwoȱlitres).ȱHowever,ȱitȱisȱalsoȱimportantȱnotȱtoȱclogȱ
theȱfilter,ȱasȱallȱwaterȱinȱtheȱfilteringȱapparatusȱmustȱbeȱfiltered.ȱTheȱbestȱwayȱtoȱmakeȱsureȱofȱthisȱisȱtoȱ
onlyȱputȱaȱsmallȱamountȱofȱwaterȱintoȱtheȱfilteringȱreservoirȱatȱaȱtime.ȱIfȱtheȱfilterȱstartsȱtoȱclogȱ(theȱflowȱ
63
ESTUARINE
MONITORING
GUIDANCE
MANUAL
ofȱwaterȱthroughȱtheȱfilterȱslowsȱdown),ȱceaseȱfilteringȱasȱsoonȱasȱtheȱsmallȱamountȱyouȱhaveȱinȱtheȱfilterȱ
reservoirȱhasȱfiltered,ȱandȱrecordȱtheȱvolumeȱfilteredȱonȱyourȱdatasheet.ȱȱ
Ifȱtheȱfilterȱbecomesȱcompletelyȱcloggedȱbeforeȱallȱtheȱwaterȱinȱtheȱfilteringȱcontainerȱcanȱbeȱfiltered,ȱtheȱ
testȱwillȱneedȱtoȱbeȱredone.ȱȱ
TheȱquantityȱofȱchlorophyllȬaȱpresentȱmayȱbeȱreportedȱbyȱtheȱlaboratoryȱinȱseveralȱforms;ȱusuallyȱitȱisȱinȱ
Pg/Lȱ(microgramsȱperȱlitre),ȱbutȱitȱisȱwiseȱtoȱcheckȱcarefully.ȱȱ
Someȱlaboratoriesȱmayȱpreferȱthatȱtheȱsampleȱisȱgivenȱtoȱthemȱinȱanȱunfilteredȱform;ȱifȱso,ȱaskȱthemȱhowȱ
theȱsampleȱisȱtoȱbeȱhandledȱandȱhowȱquicklyȱtheȱsampleȱmustȱreachȱtheȱlaboratory.ȱ
What to do:
CollectȱaȱtwoȬlitreȱsampleȱfromȱtheȱwaterȱbodyȱ200ȱmmȱbelowȱtheȱsurface.ȱPourȱ500ȬmLȱofȱtheȱsampleȱ
intoȱtheȱmeasuringȱflask,ȱreadyȱforȱfiltering.ȱ
Placeȱtheȱfilterȱpaperȱinȱtheȱfilter,ȱensuringȱthatȱtheȱwrinkledȱsideȱofȱtheȱpaperȱfacesȱupwards.ȱPlaceȱ250Ȭ
mLȱfromȱtheȱmeasuringȱflaskȱintoȱtheȱtopȱofȱtheȱfilterȱdeviceȱandȱuseȱtheȱpumpȱtoȱcreateȱaȱvacuumȱinȱtheȱ
flask.ȱKeepȱtheȱwaterȱlevelȱaboveȱtheȱfilterȱdeviceȱsemiȬfullȱusingȱwaterȱfromȱtheȱ500ȬmLȱflask,ȱbutȱbeȱ
carefulȱnotȱtoȱblockȱtheȱfilter.ȱȱ
Onceȱtheȱ500ȬmLȱflaskȱhasȱbeenȱemptied,ȱrefillȱtoȱtheȱ500ȬmLȱlineȱandȱcontinueȱfiltering.ȱAfterȱallȱwaterȱ
hasȱbeenȱfiltered,ȱorȱtheȱfilterȱhasȱstartedȱtoȱblockȱup,ȱandȱtheȱfilteringȱdeviceȱisȱempty,ȱleaveȱtheȱfilterȱinȱ
placeȱforȱaȱseveralȱsecondsȱtoȱensureȱtheȱfilterȱpaperȱhasȱbeenȱsuckedȱdry.ȱ
Recordȱtheȱvolumeȱofȱwaterȱthatȱwasȱfiltered.ȱRemoveȱtheȱfilterȱpaperȱfromȱtheȱfilterȱscreenȱgentlyȱusingȱ
theȱforceps,ȱensuringȱthatȱtheȱupperȱsurfaceȱofȱtheȱfilterȱpaperȱ(whichȱcontainsȱtheȱchlorophyllȬa)ȱ
remainsȱuntouched.ȱFoldȱtheȱpaperȱ(upperȱsurfaceȱonȱtheȱinside)ȱoverȱtwiceȱthenȱplaceȱintoȱaȱsmall,ȱ
labelledȱcontainer.ȱȱ
Recordȱtheȱsiteȱlocation,ȱdate,ȱtimeȱsampled,ȱandȱvolumeȱofȱwaterȱfilteredȱonȱtheȱlabelȱandȱonȱyourȱ
datasheet.ȱ
WrapȱtheȱcontainersȱcompletelyȱwithȱaluminiumȱfoilȱtoȱstopȱlightȱfromȱdegradingȱtheȱchlorophyllȬaȱthenȱ
placeȱintoȱaȱplasticȱbagȱinȱtheȱeskyȱorȱfreezer.ȱFreezeȱtheȱsamplesȱimmediately.ȱȱ
Arrangeȱtoȱtransferȱtheȱsamplesȱfromȱtheȱstorageȱareaȱtoȱtheȱlaboratoryȱthatȱwillȱcompleteȱtheȱanalysis.ȱ
Frozenȱsamplesȱmayȱbeȱkeptȱinȱstorageȱforȱupȱtoȱaȱmonthȱbeforeȱbeingȱtransportedȱtoȱtheȱlaboratoryȱforȱ
analysis,ȱalthoughȱtheȱtemperatureȱmustȱnotȱexceedȱ0°C.ȱȱ
ChlorophyllȬaȱconcentrationsȱvaryȱdependingȱonȱtheȱtimeȱofȱyearȱandȱweatherȱconditions.ȱPlanktonȱ
countsȱ(andȱthereforeȱchlorophyll)ȱtendȱtoȱbeȱhigherȱduringȱsunnyȱwarmȱmonthsȱandȱlowerȱduringȱcoldȱ
darkȱmonths.ȱRecordingȱtemperature,ȱrecentȱweatherȱandȱdateȱofȱsamplingȱisȱimportantȱwhenȱtakingȱ
chlorophyllȬaȱreadings.ȱȱ
Phytoplanktonȱdoȱnotȱgrowȱsoȱwellȱinȱwaterȱwithȱlowȱclarityȱasȱtheyȱrequireȱsunlight.ȱThereforeȱtakingȱ
Secchiȱdepthȱorȱturbidityȱreadingsȱatȱtheȱsameȱtimeȱasȱtheȱsampleȱisȱcollectedȱisȱadvisable.ȱAnotherȱ
variableȱthatȱinfluencesȱtheȱquantityȱofȱphytoplanktonȱcellsȱinȱtheȱwaterȱisȱtheȱamountȱofȱflowȱorȱtidalȱ
flushing.ȱAreasȱwithȱlowȱflowȱorȱflushingȱwillȱhaveȱhigherȱreadingsȱthanȱotherȱareas.ȱ
64
ESTUARINE
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GUIDANCE
MANUAL
Measuring alkalinity
Totalȱalkalinityȱ(alsoȱknownȱasȱbufferȱcapacity)ȱmeasuresȱtheȱ
capacityȱofȱwaterȱtoȱneutraliseȱacids.ȱAlkalineȱcompoundsȱsuchȱasȱ
bicarbonates,ȱcarbonates,ȱandȱhydroxidesȱremoveȱhydrogenȱionsȱandȱ
lowerȱtheȱacidityȱofȱtheȱwaterȱ(therebyȱincreasingȱpH).ȱȱ
Alkalinity,ȱacidity,ȱpHȱandȱhardnessȱareȱallȱrelatedȱandȱareȱpartȱofȱ
theȱcarbonȱcycleȱofȱtheȱestuary.ȱTotalȱalkalinityȱisȱmeasuredȱbyȱ
measuringȱtheȱamountȱofȱacidȱ(forȱexample,ȱsulphuricȱacid)ȱneededȱ
toȱbringȱtheȱsampleȱtoȱaȱpHȱofȱ4.2.ȱAtȱthisȱpH,ȱallȱtheȱalkalineȱ
compoundsȱinȱtheȱsampleȱareȱusedȱup.ȱȱ
Manyȱthings,ȱsuchȱasȱtheȱsurroundingȱsoil,ȱsaltsȱleachingȱintoȱtheȱ
waterway,ȱplantȱgrowthȱandȱindustrialȱwastewaterȱdischarges,ȱ
influenceȱtheȱalkalinityȱofȱanȱestuary.ȱ
Alkalinityȱisȱimportantȱforȱdeterminingȱtheȱestuary’sȱabilityȱtoȱ
neutraliseȱacidicȱpollutionȱfromȱrainfall,ȱacidȱgroundwaterȱorȱ
wastewater.ȱTheȱmeasureȱgivesȱenvironmentalȱmanagersȱanȱ
indicationȱofȱtheȱchemicalȱmakeȬupȱofȱtheȱwaterȱcontainedȱinȱyourȱ
estuaryȱandȱanyȱlongȬtermȱtrendsȱthatȱmayȱbeȱoccurring.ȱȱ
Thisȱbufferingȱcapacityȱofȱwater,ȱorȱitsȱabilityȱtoȱresistȱpHȱchange,ȱisȱ
criticalȱtoȱaquaticȱlife.ȱTheȱestuary’sȱcapacityȱtoȱneutraliseȱacidsȱwillȱ
varyȱbetweenȱtheȱfreshwaterȱreachesȱofȱtheȱestuaryȱandȱtheȱportionsȱ
withȱhigherȱsalinity.ȱ
Activity:
3 Core
Age: All
Time: 2
Why? Alkalinity measures
the water’s ability to
neutralise acidity. Fresh
water varies from 30 to
90 mg/L CaCO3, while
seawater has around
116 mg/L.
Safety: The alkalinity test
kit contains concentrated
acid. Use care when
handling the reagents, and
read the safety instructions
provided with the kit.
Wear disposable gloves and
eye protection.
Dispose of all
reagent/sample mixes
appropriately.
What you may need:
–
siteȱrecordȱformȱ
–
alkalinityȱtestȱkitȱ
–
disposableȱglovesȱandȱsafetyȱglassesȱ
–
liddedȱcontainerȱwithȱkittyȱlitterȱ
–
sampleȱbottleȱorȱcontainer.ȱ
To ensure good results:
Alkalinityȱtestȱkitsȱareȱnotȱasȱpreciseȱorȱaccurateȱasȱmethodsȱusedȱinȱlaboratories,ȱparticularlyȱasȱtheȱ
dropsȱneedȱtoȱbeȱcountedȱmanually,ȱthereforeȱduplicateȱanalysesȱareȱrecommended.ȱ
Alkalinityȱkitsȱhaveȱaȱuse–byȱdate.ȱCheckȱthisȱbeforeȱgoingȱoutȱintoȱtheȱfield.ȱ
What to do:
Collectȱaȱsampleȱaccordingȱtoȱtheȱinstructionsȱprovidedȱinȱtheȱsampleȱcollectionȱsectionȱofȱthisȱmanual.ȱ
Doȱnotȱundulyȱshakeȱorȱaerateȱtheȱsampleȱpriorȱtoȱtestingȱasȱcarbonȱdioxideȱ(presentȱinȱair)ȱhasȱanȱeffectȱ
onȱalkalinity.ȱȱ
Theȱalkalinityȱtestȱkitȱcomesȱcompleteȱwithȱinstructionsȱonȱhowȱtoȱuseȱit.ȱAsȱtheȱmethodȱmayȱvaryȱ
betweenȱmanufacturers,ȱpleaseȱreadȱtheȱtestȱmethodsȱcarefullyȱandȱfollowȱthemȱasȱcloselyȱasȱyouȱcan.ȱ
Recordȱtheȱresultsȱimmediatelyȱonȱyourȱfieldȱdatasheet.ȱ
Disposeȱofȱliquidȱwastesȱdirectlyȱintoȱtheȱcontainerȱfilledȱwithȱkittyȱlitter.ȱOnceȱtheȱkittyȱlitterȱisȱfullyȱ
used,ȱdisposeȱofȱitȱinȱaȱsealedȱrubbishȱbagȱtoȱgeneralȱwaste.ȱCleanȱallȱequipmentȱwithȱdistilledȱwaterȱ
onceȱfinished;ȱotherwiseȱtheȱcurrentȱresultsȱwillȱaffectȱyourȱnextȱtest.ȱAllowȱtheȱequipmentȱtoȱairȱdryȱ
beforeȱstoringȱit.ȱ
Ifȱtheȱkitȱinstructionsȱareȱnotȱclear,ȱpleaseȱcontactȱyourȱWaterwatchȱcoordinator.ȱȱ
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Theȱresultsȱareȱreportedȱasȱmilligramsȱperȱlitreȱofȱcalciumȱcarbonateȱ(mg/LȱCaCO3).ȱ
AȱhighȱalkalinityȱreadingȱdoesȱnotȱmeanȱthatȱtheȱwaterwayȱisȱalkalineȱorȱhasȱaȱhighȱpH.ȱSomeȱwaterȱcanȱ
testȱasȱacid,ȱorȱhaveȱaȱlowȱpH,ȱyetȱstillȱhaveȱaȱhighȱalkalinity.ȱThisȱmeansȱthatȱwhileȱtheȱwaterȱmightȱbeȱ
acidic,ȱitȱstillȱhasȱaȱcapacityȱtoȱbufferȱorȱneutralise,ȱacids.ȱ
AȱlowȱbufferingȱabilityȱmeansȱthatȱtheȱpHȱofȱtheȱwaterȱwillȱfluctuateȱconsiderably,ȱandȱonlyȱplantsȱorȱ
animalsȱthatȱcanȱtolerateȱlargeȱpHȱrangesȱwillȱsurvive.ȱȱ
Totalȱalkalinityȱinȱseawaterȱaveragesȱ116ȱmg/L.ȱThisȱisȱgreaterȱthanȱthatȱofȱfreshwater,ȱwhichȱrangesȱ
fromȱ30ȱtoȱ90ȱmg/Lȱdependingȱonȱtheȱwatershed.ȱEstuarineȱwaterȱshouldȱhaveȱaȱtotalȱalkalinityȱbetweenȱ
theseȱvalues.ȱ
ȱ
ȱ
ȱ
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Measuring total suspended solids
Suspendedȱsolidsȱinȱwaterȱareȱtheȱsolidsȱthat,ȱonceȱpickedȱupȱbyȱtheȱ
water,ȱdoȱnotȱsettleȱout.ȱTheyȱareȱveryȱfineȱparticlesȱofȱorganicȱ
matter,ȱpollutantsȱandȱsoilȱthatȱareȱheldȱsuspendedȱinȱtheȱwaterȱ
column.ȱTheseȱparticlesȱinterfereȱwithȱwaterȱclarity,ȱcausingȱturbidityȱ
andȱblockingȱtheȱpassageȱofȱlightȱtoȱtheȱanimalsȱandȱplantsȱinȱtheȱ
benthicȱzone.ȱȱ
Highȱloadingsȱofȱsuspendedȱsolidsȱcanȱcauseȱstarvationȱinȱfilterȱ
feedersȱsuchȱasȱmusselsȱandȱseaȱanemones,ȱasȱwellȱasȱblockingȱtheȱ
gillsȱofȱfish.ȱ
Suspendedȱsolidsȱareȱmeasuredȱbyȱfilteringȱaȱsampleȱthroughȱaȱfineȱ
glassȱfibreȱfilterȱ(GDȱ120),ȱwhichȱcapturesȱallȱsolidsȱoverȱ2.7ȱΐmȱ
(2.7ȱmicron)ȱandȱallowsȱfinerȱparticulatesȱandȱcleanȱwaterȱthrough.ȱȱ
What you may need:
Activity:
3 Extension
Age: High school
Time: 4
Why? Suspended solids is
related to turbidity and
indicates how many solid
particles are in the water.
These fine particles can
clog fish gills and foul
benthic filter feeders.
Safety: Heat risks apply as
TSS is dried in an oven.
–
siteȱrecordȱformȱȱ
–
oneȬlitreȱsamplingȱbottleȱwithȱlidȱ
–
500ȬmLȱmeasuringȱcontainerȱȱ
–
aȱvacuumȱpumpȱforȱuseȱinȱtheȱfield,ȱorȱaccessȱtoȱaȱlaboratoryȱwithȱaȱsuitableȱpumpȱȱ
–
500ȬmLȱvacuumȱflaskȱtoȱfitȱpumpȱ
–
47Ȭmmȱglassȱfibreȱ(GDȬ120)ȱfilterȱpaperȱ
–
bottleȱofȱdistilledȱorȱdemineralisedȱwaterȱȱ
–
forcepsȱȱ
–
smallȱsquareȱtraysȱmadeȱofȱaluminiumȱfoil,ȱmarkedȱwithȱsampleȱnumbersȱ(oneȱperȱsample)ȱ
–
dryingȱovenȱ
–
heatproofȱorȱheatȱresistantȱglovesȱ
–
laboratoryȱscalesȱaccurateȱtoȱ0.0002ȱgȱ
–
aȱdesiccatorȱorȱaȱflat,ȱliddedȱcontainerȱcontainingȱsilicaȱdryingȱcrystals.ȱ
To ensure good results:
Doȱnotȱexceedȱ400–mmȱmercuryȱvacuumȱwhenȱpumping,ȱorȱtheȱfilterȱpaperȱmayȱbreakȱdownȱorȱ
sedimentȱmayȱbeȱforcedȱthroughȱtheȱfilter.ȱ
Itȱisȱeasierȱtoȱcentreȱtheȱfilterȱpaperȱonȱtheȱfilterȱholderȱifȱtheȱfilterȱisȱslightlyȱwet.ȱ
Continuousȱstirringȱorȱshakingȱofȱtheȱsampleȱnotȱyetȱinȱtheȱfilteringȱapparatusȱisȱrecommended.ȱ
Itȱisȱbestȱtoȱfilterȱasȱmuchȱwaterȱasȱpossibleȱ(upȱtoȱoneȱlitre).ȱItȱisȱalsoȱimportantȱnotȱtoȱclogȱtheȱfilter,ȱasȱ
allȱwaterȱinȱtheȱfilteringȱapparatusȱmustȱbeȱfiltered.ȱTheȱbestȱwayȱtoȱmakeȱsureȱofȱthisȱisȱtoȱonlyȱputȱ
smallȱamountsȱofȱwaterȱinȱtheȱfilteringȱcontainerȱatȱaȱtime.ȱȱ
Ifȱtheȱfilterȱstartsȱtoȱbecomeȱclogged,ȱorȱtheȱflowȱofȱwaterȱthroughȱtheȱfilterȱslowsȱdown,ȱceaseȱfilteringȱasȱ
soonȱasȱpossibleȱandȱrecordȱtheȱvolumeȱfilteredȱonȱyourȱdatasheet.ȱIfȱtheȱfilterȱbecomesȱcompletelyȱ
cloggedȱbeforeȱallȱtheȱwaterȱinȱtheȱfilteringȱcontainerȱcanȱbeȱfilteredȱthenȱtheȱtestȱwillȱneedȱtoȱbeȱredone.ȱ
Beforeȱdryingȱandȱweighing,ȱtheȱfilterȱpaperȱneedsȱtoȱbeȱthoroughlyȱrinsedȱwithȱdistilledȱwaterȱtoȱ
removeȱanyȱdissolvedȱsaltsȱthatȱmayȱbeȱcaughtȱinȱtheȱfibres.ȱYouȱareȱonlyȱmeasuringȱsolids,ȱnotȱsolubleȱ
salts.ȱ
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What to do:
CollectȱaȱoneȬlitreȱsampleȱofȱtheȱwaterȱbody,ȱfromȱ200Ȭmmȱbelowȱtheȱsurface.ȱ
Usingȱforcepsȱplaceȱaȱfilterȱpaperȱontoȱanȱaluminiumȱtrayȱandȱweighȱthem.ȱRecordȱtheȱweightȱtoȱtheȱlastȱ
decimalȱplaceȱonȱyourȱdatasheet.ȱȱ
Pourȱ200–mLȱofȱtheȱfirstȱsampleȱintoȱtheȱmeasuringȱflask.ȱPlaceȱtheȱfilterȱpaperȱinȱtheȱfilter,ȱensuringȱthatȱ
theȱwrinkledȱsideȱofȱtheȱpaperȱfacesȱupwards.ȱPourȱ100ȬmLȱfromȱtheȱmeasuringȱflaskȱintoȱtheȱtopȱofȱtheȱ
filterȱdeviceȱandȱuseȱtheȱpumpȱtoȱcreateȱaȱvacuumȱinȱtheȱflask.ȱKeepȱtheȱfilterȱpaperȱwetȱorȱimmersedȱ
usingȱwaterȱfromȱtheȱflask,ȱbutȱbeȱcarefulȱnotȱtoȱblockȱtheȱfilter.ȱȱ
Onceȱtheȱflaskȱhasȱbeenȱemptiedȱrefillȱtoȱ200ȬmLȱlineȱandȱcontinueȱfiltering.ȱȱ
Afterȱallȱwaterȱhasȱbeenȱfilteredȱorȱtheȱfilterȱhasȱstartedȱtoȱblockȱupȱandȱtheȱfilteringȱdeviceȱisȱempty,ȱ
pourȱ100–200ȱmLȱofȱdistilledȱwaterȱintoȱtheȱfilterȱdeviceȱtoȱrinseȱanyȱsaltȱoutȱofȱtheȱfilter.ȱOnceȱtheȱrinseȱ
waterȱhasȱbeenȱfiltered,ȱpourȱorȱsprayȱdistilledȱwaterȱontoȱtheȱwallsȱofȱtheȱfilteringȱdeviceȱtoȱensureȱthatȱ
allȱsedimentȱhasȱbeenȱwashedȱontoȱtheȱfilter.ȱȱ
Afterȱtheȱfilterȱpaperȱhasȱbeenȱsuckedȱdry,ȱrecordȱtheȱvolumeȱofȱsampleȱthatȱwasȱfiltered.ȱTheȱcolourȱofȱ
theȱsedimentȱonȱtheȱfilterȱmayȱalsoȱbeȱrecorded.ȱ
Usingȱtheȱforceps,ȱgentlyȱremoveȱtheȱfilterȱpaperȱfromȱtheȱfilterȱscreen,ȱensuringȱthatȱtheȱupperȱsurfaceȱ
ofȱtheȱfilterȱpaperȱremainsȱuntouched.ȱPlaceȱtheȱfilterȱonȱitsȱlabelledȱaluminiumȱtray.ȱȱ
Placeȱtheȱfilterȱandȱitsȱtrayȱintoȱtheȱdryingȱovenȱatȱ100°Cȱforȱoneȱhour.ȱ
Wearingȱheatproofȱgloves,ȱremoveȱtheȱtrayȱandȱfilterȱfromȱtheȱoven.ȱAllowȱthemȱtoȱcoolȱinȱtheȱdesiccatorȱ
untilȱtheyȱareȱatȱroomȱtemperatureȱthenȱweighȱthemȱcarefully.ȱȱ
Recordȱtheȱweightȱonȱtheȱdataȱsheet.ȱȱ
Calculateȱtheȱconcentrationȱofȱsuspendedȱsolidsȱperȱlitreȱusingȱtheȱformulaȱbelow:ȱ
SS = B-A x (1000/C) x 1000
where:
SS = Suspended solids in mg/L
A = Unused (starting) filter paper and tray (g)
B = Used filter (ending) paper and tray (g)
C = Volume of sample filtered (mL)
Theȱdataȱisȱpresentedȱasȱmg/Lȱsuspendedȱsolids.ȱIfȱmultipleȱsitesȱareȱvisited,ȱaȱmapȱofȱtheȱsuspendedȱ
solidsȱconcentrationsȱinȱtheȱestuaryȱmayȱbeȱmadeȱusingȱaȱtopographicȱmapȱandȱsomeȱcolouredȱpencils.ȱ
Ifȱyouȱregularlyȱtestȱforȱsuspendedȱsolidsȱoverȱaȱperiodȱofȱtimeȱatȱoneȱlocation,ȱyouȱmayȱbeȱableȱtoȱ
correlateȱthemȱwithȱrainȱorȱotherȱeventsȱthatȱmayȱraiseȱtheȱsuspendedȱsolidȱconcentrationȱinȱyourȱ
estuaryȱorȱatȱyourȱsite.ȱȱ
Ifȱwaterȱclarityȱorȱturbidityȱareȱmeasuredȱatȱtheȱsameȱsiteȱandȱtimeȱasȱtheȱsuspendedȱsolids,ȱaȱ
relationshipȱbetweenȱtheseȱmeasurementsȱcouldȱbeȱdeterminedȱforȱyourȱsite(s).ȱ
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Mass balances to estimate pollutants
TheȱNationalȱPollutantȱInventoryȱ(NPI)ȱisȱAustralia’sȱnationalȱ
databaseȱofȱpollutantȱemissions.ȱInȱ2006,ȱtheȱonlineȱdatabaseȱheldȱ
emissionȱdataȱforȱmoreȱthanȱ3700ȱfacilities,ȱinȱ29ȱcatchmentsȱaroundȱ
Australia.ȱLargeȱindustriesȱprovideȱinformationȱtoȱtheȱgovernmentȱ
onȱtheirȱemissionsȱtoȱair,ȱlandȱandȱwaterȱusingȱaȱtechniqueȱreferredȱ
toȱasȱmassȱbalance.ȱLocalȱandȱstateȱgovernmentsȱprovideȱadditionalȱ
dataȱtoȱtheȱNPIȱthatȱincludesȱtheȱmoreȱdiffuseȱpollutionȱsources,ȱ
suchȱasȱstormwaterȱrunoff.ȱ
IndividualsȱmayȱaccessȱtheȱNPIȱdatabaseȱonlineȱtoȱexamineȱareasȱofȱ
interestȱtoȱthem.ȱByȱcallingȱupȱaȱmapȱofȱyourȱestuaryȱyouȱcanȱseeȱ
thoseȱfacilitiesȱlargeȱenoughȱtoȱbeȱrequiredȱtoȱreportȱtoȱtheȱNPI,ȱandȱ
obtainȱstatisticsȱonȱtheȱemissionȱloadsȱtheyȱdischargeȱtoȱland,ȱairȱorȱ
water.ȱȱ
Inȱthisȱwayȱyouȱmayȱestimateȱtheȱtotalȱloadsȱofȱpollutantsȱthatȱareȱ
dischargedȱintoȱtheȱwaterway.ȱTheȱfirstȱactivityȱinȱthisȱsectionȱ
showsȱyouȱhowȱtoȱaccessȱtheȱNPIȱdatabase.ȱ
Theȱmassȱbalanceȱtechniqueȱisȱaȱsimpleȱmethodȱthatȱcanȱbeȱappliedȱ
toȱallȱtypesȱofȱdevelopments,ȱnotȱjustȱlargeȱindustries.ȱTheȱmethodȱ
mayȱbeȱappliedȱtoȱyourȱhome,ȱschoolȱorȱlocalȱsmallȱbusinesses.ȱReadȱ
theȱsectionȱbelowȱthatȱdescribesȱhowȱtoȱperformȱaȱmassȱbalance.ȱOneȱ
ofȱtheȱbenefitsȱofȱaȱmassȱbalanceȱisȱthatȱtheȱmethodȱhighlightsȱareasȱ
whereȱwasteȱisȱbeingȱproduced.ȱȱ
Activity:
Extension
Age: High School
Time: 4
Why? Many contaminants
that end up in estuaries are
toxic to marine life. These
activities describe how to
calculate the overall load
of contaminants entering
into an estuary, and how to
determine what
contaminants may be
coming from a single
facility.
Safety: This is a desk-based
activity.
Thinkȱaboutȱwasteȱforȱaȱmoment.ȱIsn’tȱaȱwasteȱsomethingȱyouȱhaveȱpaidȱmoneyȱforȱoriginally,ȱbutȱareȱ
nowȱthrowingȱaway?ȱIfȱyouȱreduceȱwaste,ȱyouȱreduceȱyourȱupȬfrontȱcosts,ȱsavingȱyourselfȱmoneyȱasȱ
wellȱasȱreducingȱimpactsȱonȱtheȱenvironment.ȱMaybeȱtheȱmassȱbalanceȱyouȱundertakeȱwillȱshowȱyouȱaȱ
wayȱthatȱyourȱgroupȱcouldȱreduceȱwaste,ȱsaveȱmoneyȱandȱhelpȱtheȱenvironment.ȱ
What you may need:
TheȱNPIȱwebsiteȱatȱ<www.npi.gov.au>,ȱandȱvisitȱtheȱ‘Makeȱaȱmap’ȱlink.ȱȱ
What to do:
Lookȱatȱtheȱoverallȱpollutantȱloadsȱgoingȱintoȱyourȱestuary.ȱGoȱtoȱtheȱNPIȱwebsiteȱatȱ<www.npi.gov.au>ȱ
andȱclickȱonȱtheȱbuttonȱthatȱwillȱopenȱtheȱ‘MakeȱaȱMap’ȱwindow.ȱAȱmapȱofȱAustraliaȱwithȱmanyȱblueȱ
squaresȱmarkingȱindustriesȱthatȱareȱreportingȱtoȱtheȱNPIȱwillȱbeȱdisplayed.ȱAtȱtheȱtopȱofȱtheȱmapȱisȱaȱ
rowȱofȱ‘tools’.ȱTheȱfirstȱtoolȱisȱaȱ‘+’ȱsymbol.ȱClickȱonȱthisȱsymbol,ȱthenȱuseȱyourȱmouseȱtoȱdrawȱaȱ‘box’ȱ
aroundȱtheȱareaȱthatȱinterestsȱyou.ȱTheȱmapȱwillȱredraw,ȱandȱyouȱwillȱbeȱcloserȱtoȱoutliningȱtheȱareaȱofȱ
yourȱestuary.ȱContinueȱenlargingȱtheȱmapȱuntilȱjustȱyourȱestuaryȱisȱcontainedȱinȱtheȱmapȱpage.ȱ
Onȱtheȱtoolbarȱyouȱwillȱseeȱaȱselectionȱofȱgreenȱcirclesȱwithȱdottedȱoutlinesȱinȱthem.ȱTheseȱareȱselectionȱ
tools.ȱTheyȱenableȱyouȱtoȱselectȱfacilitiesȱtoȱexamine.ȱChooseȱtheȱshapeȱ(circle,ȱrectangleȱorȱirregularȱ
polygon)ȱthatȱwillȱallowȱyouȱtoȱcaptureȱallȱtheȱfacilitiesȱthatȱmayȱcontributeȱtoȱtheȱestuaryȱpollutionȱ
loads,ȱandȱdrawȱyourȱselectionȱontoȱtheȱmap.ȱ
Thisȱtimeȱtheȱprogramȱwillȱopenȱaȱwindowȱthatȱtellsȱyouȱhowȱmanyȱfacilitiesȱareȱinȱtheȱareaȱyouȱ
selected.ȱIfȱyouȱclickȱyourȱmouseȱonȱtheȱwordȱ‘Facilities’ȱyouȱwillȱbeȱprovidedȱwithȱaȱlistȱofȱfacilitiesȱandȱ
aȱlinkȱtoȱeachȱofȱtheirȱpollutantȱloadȱreports.ȱTheȱtablesȱshowȱwhetherȱaȱpollutantȱisȱreleasedȱtoȱland,ȱairȱ
orȱwater.ȱTheȱfacilitiesȱdoȱnotȱreportȱanythingȱthatȱtheyȱsendȱtoȱsewerȱorȱlandfill,ȱasȱtheseȱpollutantsȱwillȱ
beȱrecordedȱasȱtransfersȱbyȱthoseȱfacilities.ȱHenceȱanyȱpollutantȱrecordedȱasȱdischargingȱtoȱwater,ȱmayȱ
beȱdischargingȱintoȱtheȱestuary.ȱ
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Totalȱupȱallȱtheȱfacilities’ȱdischargesȱtoȱwater.ȱThisȱisȱtheȱminimumȱtotalȱloadȱofȱpollutantsȱthatȱyourȱ
estuaryȱreceivesȱinȱanyȱgivenȱyear.ȱSo,ȱisȱthisȱloadȱaȱbigȱload,ȱorȱaȱlittleȱload?ȱThatȱisȱaȱdifficultȱquestion.ȱ
TheȱNPIȱranksȱtheȱloads,ȱsoȱaȱfacilityȱwithȱaȱloadȱrankȱofȱ100ȱisȱtheȱlargestȱproducerȱofȱthatȱwasteȱinȱtheȱ
country,ȱwhileȱaȱrankingȱofȱ1ȱshowsȱthatȱtheȱfacilityȱisȱinȱtheȱ1%ȱofȱsmallestȱproducersȱofȱthatȱwaste.ȱTheȱ
rankingȱisȱrelative,ȱnotȱbasedȱonȱfixedȱquantities.ȱȱ
Additionally,ȱaȱlargeȱestuary,ȱwithȱlargeȱtidesȱandȱaȱpositiveȱriverȱflowȱmayȱbeȱableȱtoȱacceptȱmuchȱ
largerȱloadsȱthanȱaȱsmall,ȱmicrotidalȱestuaryȱwithȱlittleȱfreshwaterȱinput,ȱbeforeȱenvironmentalȱimpactsȱ
becomeȱobvious.ȱ
Conduct ing ȱ aȱ s im p l eȱmassȱ ba lan ce :ȱ ȱ
Chooseȱaȱsmallȱfacilityȱtoȱdevelopȱaȱmassȱbalanceȱfor.ȱItȱmayȱbeȱyourȱhome,ȱschoolȱorȱaȱsmallȱlocalȱ
business.ȱIfȱtheȱlatter,ȱrememberȱthatȱanyȱinformationȱaȱlocalȱbusinessȱsharesȱwithȱyouȱisȱconfidential.ȱ
Localȱbusinessesȱareȱoftenȱinterestedȱinȱimprovingȱtheirȱenvironmentalȱperformance,ȱandȱaȱlackȱofȱ
discretionȱonȱtheȱgroup’sȱpartȱmayȱbeȱcounterproductive.ȱȱ
Aȱmassȱbalanceȱassumesȱthatȱeverythingȱthatȱentersȱtheȱfrontȱgateȱofȱaȱfacilityȱ(rawȱmaterials,ȱenergy,ȱ
fuel)ȱgoesȱsomewhere.ȱTheȱmaterialsȱeitherȱbecomeȱpartȱofȱtheȱproduct,ȱareȱconvertedȱtoȱsomethingȱelseȱ
(heat,ȱsmoke,ȱsteam)ȱorȱareȱexpelledȱfromȱtheȱsiteȱbyȱsomeȱotherȱmeansȱ(downȱsewersȱandȱdrains,ȱorȱinȱ
theȱgarbageȱcan).ȱ
Inȱaȱhugeȱfactory,ȱtrackingȱallȱtheȱthingsȱthatȱenterȱtheȱsiteȱmayȱbeȱextremelyȱcomplex.ȱHowever,ȱ
businessesȱhaveȱoneȱadvantage—theirȱaccountsȱrevealȱwhatȱtheyȱboughtȱin,ȱandȱtheȱfeesȱpertainingȱtoȱatȱ
leastȱsomeȱofȱtheirȱdisposalȱcosts,ȱalongȱwithȱtheȱquantitiesȱofȱproductȱsold.ȱTypicallyȱauditorsȱdoingȱaȱ
massȱbalanceȱwillȱaskȱquestionsȱsuchȱasȱ‘Whyȱdoȱ100ȱtonnesȱofȱwoodchipȱonlyȱproduceȱ80ȱtonnesȱofȱ
fibreboard?’ȱtoȱfindȱoutȱwhereȱwasteȱisȱformed.ȱ
Inȱaȱsmallȱoperation,ȱitȱisȱeasierȱtoȱseeȱwhatȱhappensȱtoȱmaterials,ȱbutȱhouseholdȱmassȱbalancesȱareȱ
complicatedȱbyȱtheȱfactȱthatȱfewȱhouseholdsȱkeepȱaccounts,ȱsoȱyouȱneedȱtoȱtakeȱestimatesȱforȱthingsȱlikeȱ
howȱmuchȱfood,ȱdetergentȱorȱpetrolȱisȱpurchasedȱeachȱyear.ȱ
Theȱdiagramȱ(Figureȱ9)ȱshowsȱaȱmaterialȱflowȱinȱaȱfishȱandȱchipȱoperation.ȱByȱputtingȱfiguresȱonȱtheȱ
inputsȱandȱoutputs,ȱyouȱwouldȱbeȱableȱtoȱdetermineȱtheȱamountȱofȱeachȱwasteȱandȱitsȱdestination.ȱ
ȱ
Figure 9—Material flow in a fish and chip shop
70
ESTUARINE
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MANUAL
Measuring soil salinity and soil pH
SoilȱsalinityȱandȱpHȱareȱtwoȱimportantȱindicatorsȱofȱsaltmarshȱ
ecologicalȱhealth,ȱparticularlyȱinȱareasȱthatȱhaveȱpotentialȱacidȱ
sulphateȱsoilsȱorȱsalinityȱproblems.ȱSalinityȱreadingsȱareȱalsoȱusefulȱ
forȱstudentsȱdoingȱhydrologicalȱstudiesȱonȱsaltmarshesȱandȱ
supratidalȱorȱintertidalȱestuarineȱecosystems.ȱChangesȱtoȱtheȱ
hydrologicalȱregimeȱmayȱgreatlyȱinfluenceȱbothȱsoilȱsalinityȱandȱpH.ȱȱ
Soilȱsalinityȱisȱstronglyȱinfluencedȱbyȱtidalȱflushing,ȱevaporationȱandȱ
rainfall.ȱTheȱsupratidalȱareasȱareȱtheȱmostȱsalineȱdueȱtoȱinfrequentȱ
tidalȱflushingȱcombinedȱwithȱevaporation.ȱAreasȱthatȱreceiveȱgreaterȱ
tidalȱflushingȱareȱlessȱsaline.ȱȱ
SoilȱsalinityȱandȱsoilȱpHȱareȱmeasuredȱusingȱsimilarȱmethods,ȱandȱ
bothȱmayȱbeȱdoneȱtogetherȱinȱoneȱsampleȱorȱindividually.ȱTheseȱ
factorsȱareȱnotȱoftenȱmeasuredȱinȱisolation,ȱbutȱasȱpartȱofȱanȱoverallȱ
collectionȱofȱinformationȱwhenȱdoingȱvegetationȱassessmentsȱorȱ
hydrologicalȱstudies.ȱȱ
Theȱmethodȱgivenȱbelowȱusesȱaȱ1:5ȱsoil–waterȱsolutionȱwithȱfieldȱ
equipment.ȱMoreȱaccurateȱresultsȱcanȱbeȱobtainedȱusingȱlaboratoryȱ
equipment,ȱalthoughȱtheȱequipmentȱspecifiedȱwillȱgiveȱaȱreasonableȱ
result.ȱTheȱ1:5ȱsolutionȱmethodȱwasȱselectedȱforȱitsȱwidespreadȱuseȱ
andȱeaseȱofȱmeasurement.ȱ
What you may need:
–
saltmarshȱrecordȱformȱ
–
topographicȱmapȱ(orȱGPS)ȱ
–
smallȱhandȱtrowelȱȱ
–
smallȱflatȱtraysȱorȱboxesȱforȱdryingȱsoilȱȱ
–
glassȱscrew–toppedȱcontainerȱmarkedȱatȱ300ȱmLȱȱ
–
distilledȱwaterȱȱ
–
hydrometer(s),ȱthermometerȱandȱpHȱstripsȱ
–
pocketȱscalesȱaccurateȱtoȱ0.2ȱgȱwithȱaȱmaximumȱmassȱofȱ100ȱgȱ
–
batteryȱoperatedȱtimerȱ
–
mechanicalȱstirringȱdeviceȱ(optional)ȱ
–
tubeȱforȱhydrometerȱreadings.ȱ
Activity:
3 Extension
Age: High school
Time: 2 or 3
Why? The salinity and pH of
saltmarsh soils determines
the types of vegetation that
will develop. These
parameters may change
rapidly after tidal gates or
impoundments are placed
in intertidal areas, resulting
in large changes to the
vegetation. In some cases
there may be releases of
acid from the oxidized soil
into the main estuary.
Safety: Glass equipment
needs to be handled gently.
Use a sharps container for
broken glass. Dispose of all
reagent/sample mixes
appropriately. Saltmarshes
may contain rough terrain
and ill-defined waterways.
To ensure good results:
Checkȱyourȱequipmentȱbeforeȱgoingȱoutȱintoȱtheȱfield.ȱBackȱatȱbase,ȱcheckȱyourȱreagentsȱandȱequipmentȱ
beforeȱtestingȱtheȱsoilȱsamples.ȱSeeȱMeasuringȱpHȱandȱMeasuringȱsalinityȱforȱmoreȱdetails.ȱ
Cleanȱyourȱsamplingȱequipmentȱ(trowel)ȱbetweenȱsamplesȱtoȱpreventȱcontaminationȱofȱtheȱnextȱsample.ȱ
What to do:
Decideȱwhereȱyouȱwillȱtestȱtheȱsoil—youȱmayȱobtainȱmoreȱusefulȱinformationȱifȱyouȱmakeȱaȱtraverseȱ
awayȱfromȱtheȱwaterwayȱtowardsȱhighȱland,ȱsamplingȱatȱintervals.ȱRecordȱyourȱsamplingȱlocationsȱonȱaȱ
topographicȱmapȱorȱbyȱusingȱaȱGPS.ȱ
Atȱeachȱsamplingȱlocation,ȱuseȱtheȱhandȱtrowelȱtoȱcollectȱaȱsmallȱsoilȱsampleȱfromȱaboutȱ100ȱmmȱbelowȱ
theȱsurface.ȱAroundȱaȱhandfulȱwillȱdo.ȱPlaceȱitȱinȱaȱlabelledȱplasticȱbag.ȱRepeatȱthisȱforȱasȱmanyȱsamplesȱ
asȱyouȱareȱtesting.ȱOnceȱallȱsamplesȱareȱcollected,ȱreturnȱtoȱyourȱbaseȱandȱplaceȱeachȱsampleȱinȱaȱ
71
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MANUAL
separateȱdryingȱtrayȱinȱaȱwarmȱspotȱ(butȱ<40°C)ȱuntilȱallȱtheȱsamplesȱareȱdryȱandȱcrumbly.ȱThisȱusuallyȱ
takesȱatȱleastȱ24ȱhours.ȱIfȱtheȱsoilȱisȱdryȱtoȱtouchȱpriorȱtoȱairȬdrying,ȱtestingȱcanȱcommenceȱimmediately,ȱ
inȱtheȱfield,ȱbutȱthisȱisȱunusualȱinȱsaltmarshȱareas.ȱȱ
Fillȱtheȱliddedȱglassȱcontainerȱtoȱtheȱ300ȬmLȱmarkȱwithȱdistilledȱwater.ȱWeighȱ60gȱofȱsoilȱandȱplaceȱinȱ
theȱdistilledȱwaterȱandȱscrewȱtheȱlidȱonȱwell.ȱȱ
Eitherȱshakeȱvigorouslyȱforȱtwoȱminutesȱeveryȱ15ȱminutesȱforȱtwoȱhoursȱ(aȱtotalȱofȱ16ȱminutesȱofȱ
shaking)ȱorȱplaceȱonȱtheȱmechanicalȱstirrerȱforȱoneȱhour.ȱȱ
Leaveȱsampleȱtoȱsettleȱforȱ20ȱminutesȱandȱtakeȱaȱpHȱreadingȱaccordingȱtheȱMeasuringȱpHȱguideline.ȱ
RecordȱtheȱpHȱvalueȱonȱyourȱrecordȱsheet.ȱ
Decantȱtheȱclearȱ(orȱsemiȬclear)ȱliquidȱintoȱtheȱtubeȱusedȱforȱhydrometerȱreadings.ȱAtȱleastȱ200ȱmLȱisȱ
needed.ȱUseȱtheȱhydrometer(s)ȱtoȱtakeȱaȱspecificȱgravityȱreadingȱaccordingȱtheȱMeasuringȱsalinityȱȱ
guideline.ȱRecordȱtheȱtemperatureȱofȱtheȱliquidȱtoȱenableȱyouȱtoȱmakeȱaȱtemperatureȱcorrectionȱlater.ȱ
Theȱ1:5ȱsoil–waterȱmethodȱofȱanalysisȱdoesȱnotȱprovideȱtheȱtrueȱsoilȱsalinityȱorȱpHȱreadingȱthatȱaȱplantȱ
wouldȱencounterȱinȱtheȱactualȱenvironment.ȱHowever,ȱtheȱmethodȱdoesȱprovideȱaȱwellȱrecognisedȱ
indicationȱofȱsoilȱconditions.ȱThereȱareȱseveralȱsoilȱsalinityȱandȱpHȱmeasurementȱmethods.ȱEachȱmethodȱ
hasȱitsȱmeritsȱandȱisȱusedȱforȱdifferentȱreasons.ȱTheȱ1:5ȱsoil–waterȱsolutionȱmethodȱisȱtheȱmostȱ
commonlyȱusedȱinȱAustralia,ȱandȱthereȱisȱaȱlargeȱdatabaseȱofȱplantȱsalinityȱtolerancesȱforȱthisȱmethod.ȱ
EnsureȱthatȱanyȱdataȱyouȱrecordȱorȱuseȱaboutȱsoilȱsalinityȱorȱpHȱstatesȱtheȱmethodȱused.ȱTheȱstandardȱ
protocolȱisȱtoȱreportȱtheȱmethodȱasȱaȱsubscript.ȱSoilȱpHȱmayȱbeȱreportedȱas:ȱpH(1:5)ȱ=ȱ6.9,ȱforȱexample.ȱ
Potential,ȱandȱactual,ȱacidȱsulphateȱsoilsȱareȱfoundȱinȱmanyȱcoastalȱdepositionalȱenvironmentsȱsuchȱasȱ
areasȱofȱmangroveȱandȱsaltmarsh.ȱManagingȱtheseȱareasȱsoȱasȱnotȱtoȱincreaseȱtheȱchanceȱofȱoxidisingȱtheȱ
soilsȱandȱcausingȱacidȱgenerationȱisȱimportant.ȱInȱ2003ȱtheȱSouthȱAustralianȱCoastȱProtectionȱBoardȱ
producedȱanȱissueȱofȱtheirȱnewsletterȱCoastlineȱthatȱdiscussesȱcoastalȱacidȱsulphateȱsoils.ȱCoastlineȱ33ȱmayȱ
beȱobtainedȱfromȱtheȱCoastȱandȱMarineȱBranchȱofȱtheȱDepartmentȱforȱEnvironmentȱandȱHeritage,ȱorȱ
downloadedȱfromȱtheirȱwebsiteȱ<www.environment.sa.gov.au/coasts/pub.html>.ȱ
ȱ
ȱ
ȱ
72
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E
MONITORING
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MANUAL
Looking at the vegetation and habitat
ȱ
ȱ
ȱ
ȱ
73
ESTUARINE
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MANUAL
Keeping a visual record of plankton
blooms
Inȱtheȱestuarineȱenvironment,ȱjustȱasȱinȱourȱownȱbodies,ȱthereȱisȱsuchȱaȱ
thingȱasȱtooȱmuchȱofȱaȱgoodȱthing.ȱEvenȱthoughȱnutrientsȱareȱessentialȱ
forȱgrowthȱandȱsurvival,ȱtooȱmuchȱofȱthemȱwillȱresultȱinȱbloomsȱofȱ
planktonicȱalgae.ȱ
Activity:
3 Core
Age: All
Theseȱbloomsȱmayȱaffectȱtheȱestuaryȱinȱseveralȱways.ȱWaterȱcloudedȱ
byȱplanktonȱdoesȱnotȱallowȱsunlightȱtoȱpenetrateȱtoȱtheȱbenthicȱzone.ȱ
Seagrassesȱandȱotherȱsubmergedȱplantsȱthatȱrequireȱlightȱmayȱdieȱifȱ
theȱwaterȱisȱpermanentlyȱturbid.ȱ
Time: 1
Whileȱinȱtheȱdaylight,ȱplanktonȱproduceȱoxygenȱbyȱphotosynthesis,ȱinȱ
theȱdarkȱtheyȱuseȱitȱtoȱrespire.ȱWhenȱthereȱisȱaȱlargeȱbloomȱthereȱisȱaȱ
hugeȱswingȱeachȱday/nightȱcycleȱinȱtheȱamountȱofȱdissolvedȱoxygenȱ
(DO)ȱinȱtheȱwater.ȱIfȱtheȱDOȱfallsȱfarȱenough,ȱtheȱwaterȱbecomesȱ
hypoxicȱ(lowȱinȱoxygen),ȱputtingȱmassiveȱstressȱonȱallȱlifeȱinȱtheȱwater.ȱ
Onceȱtheȱwaterȱofȱanȱestuaryȱhasȱlessȱthanȱ4ȱmg/LȱDO,ȱfishȱmayȱstartȱ
toȱdie.ȱ
Safety: Algal blooms may
be toxic. Do not get into
water that has a dense
bloom and use gloves while
collecting samples.
Why? Plankton blooms are
often the result of high
nutrient concentrations.
Planktonȱbloomsȱareȱoftenȱmadeȱupȱofȱcertainȱgroupsȱofȱplanktonicȱalgaeȱthatȱbelongȱtoȱtheȱ
dinoflagellateȱgroup.ȱThisȱisȱbecauseȱtheȱwasteȱstreamsȱthatȱprovideȱsoȱmuchȱnitrogenȱandȱphosphorusȱ
areȱoftenȱshortȱofȱotherȱelementsȱsuchȱasȱsilica,ȱwhichȱisȱrequiredȱbyȱmanyȱvaluableȱplanktonȱsuchȱasȱ
diatoms.ȱThisȱleadsȱtoȱaȱsituationȱwhereȱonlyȱcertainȱtypesȱofȱphytoplanktonȱsuchȱasȱtheȱdinoflagellatesȱ
canȱgrow.ȱTheseȱbloomsȱareȱoftenȱcalledȱredȱtidesȱandȱbrownȱtidesȱandȱsomeȱofȱtheseȱalgaeȱproduceȱ
toxinsȱthatȱmayȱkillȱfishȱorȱaccumulateȱinȱshellfish,ȱpoisoningȱpeople.ȱ
InȱSouthȱAustralia,ȱtheȱPortȱRiverȱsupportsȱregularȱbloomsȱofȱtheȱtoxicȱdinoflagellateȱAlexandriumȱ
minutum.ȱ
What you may need:
–
siteȱrecordȱformȱ
–
Mitrovic,ȱSȱ(1995),ȱWhatȱScumȱisȱThat?,ȱWaterȱQualityȱServicesȱUnit,ȱDepartmentȱofȱLandȱ&ȱWaterȱ
Conservation,ȱSydney.ȱ
What to do:
Onȱarrivalȱatȱyourȱsite,ȱlookȱforȱanyȱred,ȱbrownȱorȱyellowȱcolourȱinȱtheȱwater,ȱorȱanyȱscumȱfloatingȱonȱ
theȱsurface.ȱIfȱthereȱisȱaȱslightȱcolourationȱonly,ȱrecordȱtheȱcolourȱonȱyourȱsiteȱrecordȱform.ȱ
Ifȱthereȱisȱanȱobviousȱbloomȱorȱscum,ȱattemptȱtoȱdescribeȱitȱorȱphotographȱit.ȱUsingȱaȱreferenceȱsuchȱasȱ
WhatȱScumȱisȱThat?ȱtryȱtoȱdetermineȱwhatȱtypeȱofȱeventȱmayȱbeȱoccurring.ȱCollectȱasȱmuchȱdetailȱasȱyouȱ
canȱfromȱtheȱsite—whatȱkindȱofȱareaȱcanȱyouȱseeȱaffected,ȱisȱtheȱbloomȱdeepȱinȱtheȱwaterȱcolumnȱorȱisȱitȱ
floatingȱonȱtheȱsurface?ȱȱ
YouȱmayȱwishȱtoȱcollectȱaȱsampleȱtoȱprovideȱtoȱyourȱWaterwatchȱcoordinator,ȱwhoȱmayȱbeȱableȱtoȱ
identifyȱtheȱalgaeȱresponsible.ȱIfȱyouȱdoȱattemptȱtoȱcollectȱaȱsample,ȱrememberȱthatȱalgalȱbloomsȱmayȱbeȱ
toxic—wearȱdisposableȱglovesȱwhileȱcollectingȱyourȱsample,ȱrinseȱoffȱtheȱoutsideȱofȱtheȱsampleȱbottleȱ
withȱcleanȱwaterȱandȱensureȱyouȱwashȱyourȱhandsȱthoroughlyȱafterȱtheȱactivity.ȱ
74
ESTUARINE
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Getting to know phytoplankton with a
net tow
PhytoplanktonȱareȱsingleȬcelledȱplantsȱthatȱoccurȱinȱmostȱnaturalȱ
waterȱbodies.ȱTheyȱfloatȱfreelyȱasȱindividuals,ȱcoloniesȱorȱinȱropeȬlikeȱ
strands.ȱTheyȱdoȱnotȱattachȱthemselvesȱtoȱsurfaces.ȱAȱmicroscopeȱisȱ
neededȱtoȱseeȱthem,ȱasȱtheyȱareȱoftenȱonlyȱaȱfewȱ10sȱofȱmicronsȱ
(thousandthsȱofȱmillimetre)ȱlong.ȱȱ
Aȱsingleȱdropȱofȱestuarineȱwaterȱmayȱhaveȱhundredsȱofȱtheseȱ
microscopicȱplantsȱinȱit.ȱTheseȱplantsȱareȱtheȱfoundationȱstoneȱforȱ
ecologicalȱhealth.ȱPhytoplanktonȱdirectlyȱandȱindirectlyȱsupportȱ
muchȱofȱourȱmarineȱlife,ȱincludingȱlargeȱanimalsȱlikeȱwhalesȱandȱ
sharks.ȱUnfortunatelyȱsomeȱspeciesȱproduceȱtoxinsȱthatȱmayȱkillȱ
humansȱorȱanyȱotherȱanimalȱthatȱconsumesȱenoughȱofȱthem.ȱRedȱ
tidesȱareȱcausedȱbyȱaȱselectionȱofȱdinoflagellateȱspecies,ȱsomeȱofȱ
whichȱproduceȱtoxinsȱandȱsomeȱthatȱareȱharmless.ȱȱ
Activity:
3 Extension
Age: High school
Time: 3
ThisȱactivityȱintroducesȱtheȱuseȱofȱaȱveryȱfineȱplanktonȱtowȬnetȱandȱ
someȱbasicȱidentificationȱmethodsȱtoȱhelpȱyouȱcollectȱandȱbecomeȱ
familiarȱwithȱsomeȱofȱtheȱphytoplanktonȱfoundȱinȱyourȱestuary.ȱ
Why? Different types of
plankton are always present
in the water. The dominant
types vary depending on
the conditions. For
example, diatoms require a
source of silica (usually
present in riverine water
entering the estuary) as
well as nutrients, while
dinoflagellates only require
nutrients. Plankton
‘blooms’ are often the
result of high nutrient
concentrations in shallow
estuarine waters.
Ifȱyouȱwouldȱlikeȱtoȱcompleteȱaȱmoreȱdetailedȱassessmentȱofȱyourȱ
estuarineȱphytoplankton,ȱfeelȱfreeȱtoȱcompleteȱtheȱactivitiesȱgivenȱinȱ
theȱguidelineȱCountingȱplanktonȱinȱaȱwaterȱsample.ȱ
Safety: Net tows may be
conducted in deep or fastflowing waters.
Overabundanceȱofȱphytoplanktonȱmayȱcauseȱbigȱswingsȱinȱdissolvedȱ
oxygenȱconcentrationsȱinȱtheȱwater,ȱleadingȱtoȱaȱconditionȱcalledȱ
hypoxia,ȱwhereȱtheȱlowȱoxygenȱconcentrationsȱmayȱcauseȱfishȱkills.ȱ
What you may need:
–
50–100ȱmicronȱphytoplanktonȱtowȱnetȱȱ
–
plasticȱcollectionȱbottleȱwithȱlidȱ
–
100–200×ȱmicroscopeȱ(preferablyȱwithȱphaseȱcontrast)ȱ
–
microscopeȱslidesȱandȱcoverȱslipsȱ
–
dropperȱorȱpipetteȱ
–
alcohol,ȱmethylatedȱspritsȱorȱglycerineȱ(optional)ȱ
–
drawingȱbookȱforȱrecordingȱyourȱphytoplankton,ȱorȱdigitalȱcamera.ȱ
What to do:
Obtainingȱaȱphytoplanktonȱsampleȱfromȱyourȱestuaryȱisȱrelativelyȱeasy.ȱAllȱitȱrequiresȱisȱforȱyouȱtoȱ
attachȱyourȱcollectionȱbottleȱ(withoutȱitsȱlid)ȱtoȱtheȱbaseȱofȱtheȱplanktonȱnet,ȱusingȱaȱscrewȱmountȱorȱaȱ
wormȬdriveȱhoseȱclampȱtoȱensureȱtheȱbottleȱstaysȱinȱplace.ȱȱ
Theȱnetȱisȱthenȱloweredȱoffȱtheȱendȱofȱaȱjettyȱorȱoverȱtheȱsideȱofȱaȱbridgeȱdirectlyȱintoȱtheȱmainȱflowȱofȱ
theȱestuary.ȱThisȱisȱbestȱdoneȱjustȱafterȱhighȱtideȱwhenȱtheȱoutgoingȱflowȱisȱrelativelyȱstrong.ȱTieȱtheȱnetȱ
ropeȱontoȱtheȱstructureȱandȱleaveȱitȱthereȱforȱapproximatelyȱ15ȱminutes.ȱAlternatively,ȱyouȱmayȱtowȱtheȱ
netȱbehindȱaȱseaworthyȱboatȱatȱaȱslowȱspeed.ȱ
Pullȱtheȱnetȱverticallyȱoutȱofȱtheȱwaterȱsoȱthatȱanyȱphytoplanktonȱonȱtheȱsidesȱofȱtheȱnetȱwashȱdownȱintoȱ
theȱbottle.ȱOnceȱtheȱnetȱisȱonshore,ȱwashȱanythingȱleftȱonȱtheȱsidesȱofȱtheȱnetȱintoȱtheȱcollectionȱbottleȱ
usingȱseawater.ȱCarefullyȱremoveȱtheȱcollectionȱbottleȱwithoutȱspillingȱit,ȱremoveȱanyȱlargeȱvisibleȱ
objectsȱandȱscrewȱtheȱlidȱon.ȱThisȱbottleȱwillȱneedȱtakingȱbackȱtoȱtheȱlaboratoryȱimmediatelyȱtoȱexamineȱ
underȱtheȱmicroscope.ȱȱ
75
ESTUARINE
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Backȱinȱtheȱlaboratory,ȱtakeȱaȱsmallȱsampleȱofȱ
theȱphytoplanktonȱandȱplaceȱaȱfewȱdropsȱontoȱaȱ
microscopeȱslideȱusingȱaȱpipetteȱorȱdropper.ȱ
Placeȱtheȱcoverȱslipȱonȱtopȱofȱtheȱwater.ȱȱ
Ifȱyouȱhaveȱneverȱusedȱaȱmicroscopeȱhaveȱaȱ
lookȱatȱaȱtypicalȱoneȱ(Figureȱ10).ȱOnceȱyouȱhaveȱ
familiarisedȱyourselfȱwithȱyourȱmicroscope,ȱ
placeȱyourȱslideȱandȱcoverȱslipȱonȱtheȱstage.ȱȱ
Rotateȱnosepieceȱsoȱthatȱtheȱ10×ȱobjectiveȱisȱinȱ
use,ȱthisȱgivesȱyouȱ100×ȱmagnification.ȱStartȱ
withȱtheȱobjectiveȱdownȱnearȱtheȱslideȱandȱ
coarselyȱfocusȱupwardsȱbyȱturningȱtheȱfocusȱ
controlȱtowardsȱtheȱoperator.ȱBeȱcarefulȱifȱtryingȱ
toȱfocusȱdownwardsȱasȱtheȱobjectiveȱcouldȱ
smashȱintoȱtheȱslide.ȱȱ
Useȱtheȱfineȱfocusȱcontrolȱtoȱgainȱtheȱclearestȱ
image.ȱAdjustȱtheȱeyepiecesȱtoȱsuitȱyourȱeyes.ȱ
Theȱeyepiecesȱadjustȱbothȱforȱdistanceȱbetweenȱ
pupilsȱandȱindividualȱfocus.ȱȱ
Itȱisȱoftenȱeasierȱtoȱlookȱthroughȱaȱbinocularȱ
microscopeȱifȱyouȱdonȇtȱactuallyȱtouchȱtheȱ
eyepiecesȱwithȱyourȱface,ȱbutȱviewȱdownȱtheȱ
eyepiecesȱfromȱaȱslightȱdistance.ȱȱȱ
ȱ
Figure 10—A typical microscope
Closeȱtheȱcondenserȱirisȱjustȱenoughȱtoȱgiveȱtheȱspecimenȱsomeȱcontrast.ȱItȱshouldȱbeȱaboutȱoneȱthirdȱ
closed.ȱTooȱmuchȱclosureȱresultsȱinȱaȱdecreasedȱdepthȱofȱfield.ȱ
Whatȱdoȱyouȱnowȱseeȱdownȱyourȱmicroscope?ȱDidȱyouȱnoticeȱthatȱsomeȱplantsȱswim?ȱIfȱtheȱplanktonȱ
areȱmovingȱtooȱfastȱforȱyouȱtoȱfocusȱonȱthem,ȱtakeȱtheȱslideȱoutȱandȱplaceȱaȱdropȱofȱglycerineȱontoȱtheȱ
slide.ȱThisȱwillȱmakeȱtheȱwaterȱthickerȱandȱharderȱforȱtheȱphytoplanktonȱtoȱswimȱthrough.ȱȱ
Alcoholȱorȱmethylatedȱspiritsȱmayȱbeȱaddedȱtoȱtheȱwholeȱsampleȱifȱyouȱfindȱitȱeasierȱtoȱlookȱatȱdeadȱ
specimens,ȱalthoughȱyouȱloseȱtheȱdifferentȱmovementȱmethods,ȱwhichȱmayȱhelpȱyouȱidentifyȱsomeȱ
speciesȱorȱgroupsȱofȱplankton.ȱȱ
Youȱcouldȱnowȱtryȱandȱdrawȱtheȱplanktonȱyouȱseeȱunderȱtheȱscope,ȱorȱtryȱandȱmatchȱthemȱupȱtoȱtheȱ
picturesȱshownȱinȱFigureȱ11ȱofȱsomeȱphytoplanktonȱfoundȱinȱestuarineȱwetlandsȱnearȱAdelaide.ȱ
Aȱdigitalȱcameraȱplacedȱonȱtheȱeyepieceȱmayȱbeȱableȱtoȱtakeȱphotographsȱofȱtheȱfieldȱofȱview,ȱandȱtheseȱ
photographsȱmayȱbeȱdownloadedȱontoȱyourȱcomputer.ȱTheseȱcouldȱbeȱidentifiedȱbyȱaȱspecialistȱorȱbyȱ
usingȱspecialistȱidentificationȱmaterials.ȱȱ
Youȱmayȱwishȱtoȱprepareȱaȱlistȱofȱtheȱtypesȱofȱphytoplanktonȱpresentȱinȱyourȱsample,ȱalongȱwithȱanyȱofȱ
theȱphotographsȱyouȱtookȱorȱtheȱdrawingsȱthatȱyouȱdid.ȱDisplayingȱthisȱisȱaȱpublicȱplaceȱhelpsȱraiseȱ
publicȱawarenessȱofȱtheȱrangeȱofȱorganismsȱthatȱliveȱinȱyourȱestuarineȱwaterways.ȱȱ
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ȱ
ȱ
Key to some plankton of South Australian estuaries
ȱ
ȱ
Figure 11—Examples of phytoplankton
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Counting plankton in a water sample
PhytoplanktonȱareȱsingleȬcelledȱplantsȱthatȱoccurȱinȱmostȱnaturalȱ
waterȱbodies.ȱTheyȱfloatȱfreelyȱasȱindividuals,ȱcoloniesȱorȱinȱropeȬlikeȱ
strands.ȱTheyȱdoȱnotȱattachȱthemselvesȱtoȱsurfaces.ȱAȱmicroscopeȱisȱ
neededȱtoȱseeȱthem,ȱasȱtheyȱareȱoftenȱonlyȱaȱfewȱtensȱofȱmicronsȱ
(thousandthsȱofȱmillimetre)ȱlong.ȱȱ
Aȱsingleȱdropȱofȱestuarineȱwaterȱmayȱhaveȱhundredsȱofȱtheseȱ
microscopicȱplantsȱinȱit.ȱTheseȱplantsȱareȱtheȱfoundationȱstoneȱforȱ
ecologicalȱhealth.ȱPhytoplanktonȱdirectlyȱandȱindirectlyȱsupportȱ
muchȱofȱourȱmarineȱlife,ȱincludingȱlargeȱanimalsȱlikeȱwhalesȱandȱ
sharks.ȱUnfortunatelyȱsomeȱspeciesȱproduceȱtoxinsȱthatȱmayȱkillȱ
humansȱorȱanyȱotherȱanimalȱthatȱconsumesȱenoughȱofȱthem.ȱRedȱ
tidesȱareȱcausedȱbyȱaȱselectionȱofȱdinoflagellateȱspecies,ȱsomeȱofȱ
whichȱproduceȱtoxinsȱandȱsomeȱthatȱareȱharmless.ȱ
Activity:
3 Extension
Age: Adult groups
Time: 4
Why? The number of
plankton cells present in a
water sample, as well as
their type, provides
information on the health
of the estuary.
Safety: Sample/reagent
mixes should be disposed of
appropriately.
Thisȱactivityȱusesȱaȱcondensedȱwaterȱsampleȱandȱaȱbasicȱflowchartȱtoȱ
helpȱyouȱidentifyȱandȱcountȱtheȱcommonȱphytoplanktonȱphyla.ȱ
Theseȱareȱveryȱcoarseȱclassifications,ȱbutȱtheȱproportionsȱofȱoneȱphylumȱtoȱanotherȱmayȱprovideȱanȱ
insightȱintoȱtheȱwaterȱqualityȱofȱtheȱestuary,ȱandȱtheȱriskȱofȱtoxicȱdinoflagellateȱorȱblueȬgreenȱblooms.ȱ
Ifȱyouȱwouldȱlikeȱtoȱcompleteȱaȱmoreȱdetailedȱassessmentȱofȱyourȱestuarineȱphytoplankton,ȱfeelȱfreeȱtoȱ
lookȱatȱsomeȱofȱtheȱotherȱidentificationȱaidsȱreferencedȱinȱthisȱguideline,ȱorȱtryȱtoȱobtainȱotherȱ
informationȱfromȱyourȱlocalȱuniversityȱlibrary.ȱȱ
What you may need:
–
200–500ȱmLȱcollectionȱbottleȱwithȱlidȱ
–
100–200×ȱmicroscopeȱ(preferablyȱwithȱphaseȱcontrast)ȱ
–
250ȬmLȱmeasuringȱcylinderȱ
–
haemocytometerȱandȱcoverȱslipsȱ
–
dropperȱorȱpipetteȱ
–
0.5ȱmLȱofȱLugol’sȱmediaȱperȱsampleȱ
–
aȱfineȱpieceȱofȱclearȱflexibleȱplasticȱpipingȱtoȱuseȱasȱaȱsiphonȱ
–
liddedȱbucketȱcontainingȱkittyȱlitterȱ
–
aȱplanktonȱcountȱdatasheet.ȱ
To ensure good results:
Identifyingȱphytoplanktonȱcanȱbeȱdifficult,ȱinȱfactȱdistinguishingȱphytoplanktonȱ(microscopicȱfloatingȱ
plants)ȱfromȱzooplanktonȱ(microscopicȱswimmingȱanimals)ȱmayȱbeȱveryȱdifficult,ȱasȱthereȱareȱmanyȱ
singleȬcelledȱclearȱanimalsȱthatȱfeedȱonȱphytoplankton,ȱandȱtheirȱfoodȱitemsȱareȱvisibleȱthroughȱtheirȱcellȱ
walls.ȱȱ
Withoutȱaȱgreatȱdealȱofȱexperienceȱyouȱcan’tȱbeȱentirelyȱsureȱofȱwhatȱyouȱareȱlookingȱatȱallȱtheȱtime.ȱ
Evenȱidentificationȱguidesȱareȱnotȱfoolproof,ȱasȱonlyȱaȱsmallȱportionȱofȱplanktonȱhaveȱbeenȱdescribedȱinȱ
theȱscientificȱliterature.ȱExpectȱtoȱmakeȱaȱfewȱmistakes,ȱandȱaskȱsomeoneȱelseȱtheirȱopinionȱifȱyouȱareȱnotȱ
sure.ȱȱ
Aȱtaxonomicȱsuretyȱsystemȱisȱcommonlyȱusedȱwhenȱtryingȱtoȱidentifyȱhowȱconfidentȱyouȱareȱofȱyourȱ
data.ȱTheseȱsystemsȱgenerallyȱinvolveȱplacingȱaȱnumberȱbetweenȱ1ȱandȱ3ȱafterȱyourȱidentification.ȱ
Numberȱ1ȱmeansȱthatȱyou,ȱandȱmaybeȱaȱcoupleȱofȱotherȱpeople,ȱareȱveryȱhappyȱwithȱyourȱidentification.ȱ
Numberȱ2ȱmeansȱthatȱyouȱareȱreasonablyȱsure,ȱbutȱhaveȱnotȱhadȱsomeoneȱelse’sȱopinion,ȱorȱtheyȱareȱnotȱ
entirelyȱsure.ȱNumberȱ3ȱmeansȱthatȱyouȱareȱnotȱsureȱatȱall,ȱbutȱthisȱwasȱtheȱclosestȱidentificationȱyouȱ
couldȱcomeȱupȱwith.ȱȱ
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Beȱentirelyȱhonestȱwhenȱgivingȱtheseȱratings.ȱIfȱtheȱdataȱisȱusedȱforȱmanagementȱofȱyourȱestuary,ȱitȱisȱ
betterȱthatȱtheȱdecisionȬmakerȱknowsȱhowȱconfidentȱyouȱareȱofȱyourȱdata.ȱTakingȱaȱphotographȱofȱanyȱ
thatȱyouȱgiveȱaȱratingȱ3ȱtoȱwouldȱmeanȱthatȱtheseȱidentificationsȱcouldȱbeȱcheckedȱfurtherȱatȱaȱlaterȱdate.ȱ
Anȱalternativeȱisȱtoȱsimplyȱcallȱallȱplanktonȱyouȱareȱunsureȱaboutȱ‘unidentifiedȱplankton’,ȱwhichȱwillȱ
allowȱyouȱtoȱstillȱcountȱtheȱnumberȱpresent.ȱ
What to do:
Obtainingȱaȱquantitativeȱphytoplanktonȱsampleȱisȱusuallyȱdoneȱatȱtheȱsameȱtimeȱasȱcollectionȱofȱwaterȱ
samplesȱforȱotherȱmeasurements.ȱAȱ200–500–mLȱsampleȱbottleȱisȱfilledȱwithȱwater,ȱobtainedȱfromȱ200ȱ
mmȱbelowȱtheȱwaterȱsurface.ȱThisȱisȱbestȱdoneȱatȱtheȱendȱofȱaȱjettyȱorȱotherȱstructure.ȱȱ
Thisȱsampleȱisȱreturnedȱtoȱtheȱlaboratoryȱasȱsoonȱasȱpossible,ȱwhereȱ200ȱmLȱisȱpouredȱintoȱaȱ250ȬmLȱ
measuringȱcylinder.ȱApproximatelyȱ0.5ȱmLȱofȱLugol’sȱmediaȱisȱaddedȱandȱtheȱsampleȱisȱwellȱshakenȱorȱ
stirred.ȱThisȱisȱthenȱleftȱtoȱsettleȱovernight.ȱȱ
Theȱtopȱ180ȱmLȱisȱthenȱdecantedȱoffȱcarefully,ȱ
usingȱaȱgravityȱsiphon,ȱsoȱthatȱtheȱbottomȱ
20ȱmLȱisȱleftȱundisturbed.ȱThisȱisȱthenȱshakenȱ
upȱandȱaȱdropȱofȱtheȱliquidȱisȱplacedȱonȱeachȱ
halfȱofȱaȱhaemocytometerȱslideȱandȱaȱcoverȱslipȱ
isȱplacedȱoverȱtheȱslide.ȱ
ȱ
Figure 12—Haemocytometer, general arrangement
Theȱhaemocytometerȱisȱaȱglassȱslideȱnormallyȱ
usedȱtoȱcountȱbloodȱcells.ȱItȱcanȱbeȱusedȱtoȱ
countȱalgalȱcellsȱinȱtheȱsameȱmanner,ȱasȱ
discussedȱinȱthisȱguideline.ȱTheȱgeneralȱ
structureȱofȱaȱhaemocytometerȱisȱprovidedȱinȱ
Figureȱ12.ȱ
Placeȱtheȱhaemocytometerȱunderȱtheȱ
microscopeȱandȱuseȱtheȱfineȱfocusȱcontrolȱtoȱ
gainȱtheȱclearestȱimage.ȱDetailsȱonȱhowȱtoȱdoȱ
thisȱareȱgivenȱinȱtheȱguidelineȱGettingȱtoȱknowȱ
phytoplanktonȱwithȱaȱnetȱtowȱ(pageȱ75).ȱȱ
ȱ
Theȱhaemocytometerȱhasȱtwoȱmainȱcountingȱ
areasȱ(Figureȱ12).ȱAȱmoreȱdetailedȱdiagramȱofȱaȱ
singleȱcountingȱareaȱisȱshownȱarrangementȱinȱ
Figureȱ13.ȱEachȱcountingȱareaȱisȱdividedȱintoȱ
nineȱequalȱportionsȱofȱoneȱmillimetreȱbyȱ
oneȱmillimetre.ȱTheseȱportionsȱareȱreferredȱtoȱasȱ
cells.ȱThereȱareȱ18ȱcells.ȱȱ
ȱ
Figure 13—Counting area of a haemocytometer
Theȱalgaeȱpresentȱinȱtheȱcountingȱareasȱareȱ
identifiedȱtoȱphylumȱlevelȱwithȱtheȱaidȱofȱtheȱ
chartȱprovidedȱinȱFigureȱ14ȱ(aȱlargerȱversionȱisȱ
providedȱinȱAppendixȱ4),ȱtheȱpicturesȱprovidedȱ
inȱtheȱGettingȱtoȱknowȱphytoplanktonȱwithȱaȱnetȱ
towȱguidelineȱandȱanyȱotherȱliteratureȱorȱ
photographsȱthatȱyouȱhaveȱaccessȱto.ȱ
Theȱchartȱidentifiesȱmarineȱorȱestuarineȱphytoplanktonȱtoȱphyla.ȱThisȱisȱaȱveryȱcoarseȱlevelȱofȱ
identification,ȱbutȱthereȱareȱmanyȱveryȱdifferentȱphytoplanktonȱspecies,ȱandȱidentifyingȱthemȱpastȱ
phylumȱlevelȱrequiresȱaccessȱtoȱspecialisedȱliterature.ȱUsingȱtheȱflowȱchartȱisȱveryȱeasy.ȱStartingȱatȱtheȱ
top,ȱyouȱlookȱatȱtheȱstatementsȱonȱeachȱofȱtheȱpaths.ȱWhichȱoneȱdoesȱtheȱorganismȱyouȱareȱlookingȱatȱ
matchȱbest?ȱMoveȱalongȱthatȱbranchȱandȱrepeatȱtheȱprocessȱuntilȱaȱnameȱisȱgiven.ȱCompareȱyourȱobjectȱ
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toȱtheȱpicturesȱinȱtheȱchart.ȱDoȱtheyȱlookȱanythingȱlikeȱyourȱspecimen?ȱIfȱyouȱcannotȱmakeȱupȱyourȱmindȱ
recordȱtheȱorganismȱasȱ‘unidentifiedȱplankton’ȱonȱyourȱdatasheet.ȱ
Ifȱthereȱareȱtooȱmanyȱalgaeȱpresentȱtoȱcountȱinȱallȱ18ȱcells,ȱcountȱaȱsmallerȱnumberȱofȱcountingȱcells.ȱInȱ
casesȱwhereȱthereȱisȱaȱveryȱhighȱdensityȱofȱalgae,ȱonlyȱoneȱcountingȱareaȱ(comprisingȱnineȱcells),ȱorȱinȱ
extremeȱcasesȱonlyȱoneȱcell,ȱneedsȱtoȱbeȱcounted.ȱ
Theȱnumberȱandȱtypeȱofȱalgalȱcellsȱinȱeachȱhaemocytometerȱcellȱisȱrecordedȱonȱyourȱdatasheet.ȱTheȱ
numberȱofȱcountingȱcellsȱyouȱcountedȱisȱwrittenȱinȱtheȱneighbouringȱcolumn.ȱWhenȱallȱtheȱsamplesȱhaveȱ
beenȱcounted,ȱtheȱremainingȱsampleȱbrinesȱshouldȱbeȱdisposedȱofȱbyȱpouringȱthemȱintoȱtheȱbucketȱ
containingȱkittyȱlitter.ȱOnceȱtheȱabsorbentȱmaterialȱcanȱcontainȱnoȱmoreȱliquid,ȱitȱshouldȱbeȱbaggedȱandȱ
placedȱinȱtheȱwasteȱbinȱforȱdisposalȱtoȱlandfill.ȱȱȱ
D at aȱ in t e rpr et at i on ȱ
TheȱdataȱfromȱthisȱtypeȱofȱactivityȱisȱoftenȱpresentedȱasȱtheȱnumberȱofȱplanktonȱpresentȱinȱoneȱmLȱofȱ
water,ȱorȱtheȱnumberȱofȱplanktonȱfromȱeachȱphylumȱpresentȱinȱoneȱmLȱofȱsample.ȱToȱcalculateȱtheȱ
numberȱofȱphytoplanktonȱperȱmLȱorȱtheȱnumberȱofȱeachȱtypeȱperȱmLȱyouȱneedȱtoȱapplyȱtheȱformulaȱ
below:ȱ
plankton count =
no of plankton × 103
no of cells (squares) counted
Planktonȱdataȱisȱusuallyȱpresentedȱinȱlistȱorȱgraphȱform,ȱwithȱtheȱclassificationȱlistedȱdownȱoneȱsideȱandȱ
theȱcountsȱonȱtheȱotherȱside.ȱComparisonsȱbetweenȱtheȱnumberȱofȱplanktonȱinȱeachȱphylumȱpresentȱ
providesȱanȱinformativeȱpictureȱofȱtheȱwaterȱqualityȱinȱyourȱestuary.ȱȱ
Theȱtotalȱnumberȱofȱphytoplanktonȱandȱtheȱratiosȱbetweenȱtheȱphylaȱareȱtheȱmostȱusefulȱfigures.ȱAȱhighȱ
totalȱcountȱindicatesȱaȱhighȱbiomass,ȱthereforeȱaȱhighȱoxygenȱdemandȱandȱlargeȱamountsȱofȱnutrientsȱinȱ
theȱwater.ȱLargeȱnumbersȱofȱblueȬgreenȱalgaeȱsuggestȱthatȱthereȱareȱhighȱconcentrationsȱofȱphosphateȱinȱ
theȱwater.ȱLargeȱnumbersȱofȱdiatomsȱsuggestȱthatȱtheȱwaterȱisȱrichȱinȱsilicaȱandȱnutrients.ȱ
Playȱaroundȱwithȱtheȱdataȱandȱcombineȱitȱwithȱdataȱfromȱotherȱsitesȱorȱtests.ȱItȱisȱfascinatingȱtoȱseeȱwhatȱ
trendsȱorȱcorrelationsȱmayȱbeȱfoundȱthisȱway.ȱ
ȱ
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Figure 14—Plankton identification flow chart
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Monitoring a seaweed bed
Seaweedsȱareȱmacroalgae,ȱmeaningȱthatȱtheyȱformȱlargeȱplantsȱ
visibleȱtoȱtheȱnakedȱeye.ȱTheyȱcanȱbeȱred,ȱgreenȱorȱbrown.ȱTheyȱhaveȱ
noȱroots,ȱbutȱoftenȱhaveȱholdfasts,ȱaȱcupȬshapedȱappendageȱthatȱ
fastensȱontoȱsolidȱsurfaces,ȱincludingȱrocksȱorȱjettyȱpylons.ȱȱ
Seaweedȱandȱseaweedȱdistributionȱareȱgoodȱindicatorsȱofȱwaterȱ
qualityȱinȱanȱestuary.ȱAsȱseaweedsȱareȱalgae,ȱtheyȱcanȱgrowȱandȱdieȱ
offȱveryȱquickly.ȱTheȱcommonȱindicatorsȱofȱestuarineȱhealth—
nutrients,ȱpH,ȱturbidity,ȱdissolvedȱoxygenȱandȱsalinity—allȱhaveȱ
hugeȱandȱrapidlyȱidentifiableȱimpactsȱonȱseaweedȱcommunities.ȱ
Temperatureȱalsoȱhasȱanȱeffectȱonȱtheseȱplants.ȱȱ
Inȱcommonȱwithȱmostȱbiologicalȱindicators,ȱtheȱdegreeȱofȱ
identificationȱrequiredȱforȱthisȱactivityȱdependsȱonȱwhatȱyouȱwantȱtoȱ
useȱtheȱdataȱfor.ȱTheȱeffectsȱofȱlongȬtermȱturbidityȱorȱnutrientsȱmayȱ
oftenȱbeȱseenȱbyȱsimplyȱidentifyingȱtheȱseaweedsȱtoȱtheirȱcolour,ȱthenȱ
estimatingȱtheȱapproximateȱamountsȱofȱeachȱcolourȱatȱyourȱsite.ȱȱ
Activity:
3 Extension
Age: High school
Time: 3
Why? The more complex
types of brown seaweed
(macroalgae) may respond
to disturbance by
disappearing from seaweed
beds.
Safety: Conducted over
deep water (jetty, bridge,
boat or wharf)
Moreȱdetailedȱidentificationsȱmayȱgiveȱyouȱmoreȱdetailedȱinformation.ȱCatastrophicȱeventsȱsuchȱasȱanȱ
anoxicȱeventȱcanȱkillȱentireȱalgalȱcommunities.ȱTheȱstructureȱofȱeachȱplantȱmayȱprovideȱyouȱwithȱanȱ
indicationȱofȱhowȱlongȱtheȱcommunityȱhasȱbeenȱgrowing,ȱandȱthereforeȱhowȱlongȱitȱhasȱbeenȱsinceȱoneȱ
ofȱtheseȱevents.ȱFlatȱsheetȬlikeȱalgaeȱsuchȱasȱUlvaȱstartȱtoȱgrowȱonȱaȱsiteȱalmostȱimmediatelyȱtheȱeventȱisȱ
over.ȱComplexȱalgae,ȱsuchȱasȱCodiumȱspeciesȱorȱtheȱcomplexȱbrownsȱlikeȱkelp,ȱneedȱaȱconsiderableȱtimeȱ
afterȱtheȱeventȱbeforeȱtheyȱcoloniseȱtheȱsite.ȱȱ
Thisȱactivityȱleavesȱtheȱchoiceȱofȱidentificationȱresolutionȱtoȱtheȱgroup.ȱTheȱguidelineȱdiscussesȱcreatingȱ
aȱherbariumȱorȱcollectionȱofȱpressingsȱbeforeȱcommencingȱmonitoring,ȱasȱthisȱallowsȱyouȱtoȱidentifyȱ
howȱtimeȱconsumingȱ(orȱnot)ȱdetailedȱidentificationsȱmayȱbeȱatȱyourȱlocation.ȱThisȱpartȱofȱtheȱactivityȱ
mayȱneedȱaȱpermitȱfromȱtheȱNPWSȱorȱPIRSA—checkȱbeforeȱstartingȱtheȱproject.ȱ
Onceȱpressedȱandȱdried,ȱtheȱspecimensȱcouldȱbeȱtakenȱintoȱtheȱStateȱHerbariumȱ(atȱtheȱAdelaideȱBotanicȱ
Gardens)ȱorȱtoȱaȱseaweedȱexpertȱinȱyourȱareaȱforȱdetailedȱidentification.ȱThisȱwouldȱallowȱyouȱtoȱsimplyȱ
matchȱtheȱplantsȱyouȱseeȱinȱtheȱfieldȱwithȱthoseȱonȱyourȱnamedȱpressings,ȱwhichȱwouldȱmakeȱregularȱ
detailedȱidentificationȱmuchȱquickerȱthanȱotherwise.ȱȱ
Severalȱtypesȱofȱequipmentȱforȱmonitoringȱseaweedȱbedsȱareȱsuggested—selectȱtheȱmostȱsuitableȱforȱ
yourȱgroupȱandȱmonitoringȱlocation.ȱ
What you may need:
F or ȱpreparing ȱthe ȱh e r ba r iu m ȱ
–
bathersȱandȱmaskȱorȱaȱpoleȱwithȱaȱhookȱandȱnetȱatȱoneȱendȱ
–
bucketȱwithȱwaterproofȱlidȱ
–
permit(s)ȱfromȱtheȱappropriateȱauthoritiesȱ
–
sinkȱwithȱplugȱandȱfreshwaterȱ
–
A3ȱsheetsȱofȱpaper,ȱoneȱorȱtwoȱperȱsampleȱ
–
severalȱwadsȱofȱnewspaperȱ
–
waxedȱpaperȱ
–
woodenȱboardȱaȱlittleȱlargerȱthanȱanȱA3ȱsheetȱ
–
A3ȱplasticȱsleevesȱ
–
A3ȱarchȬleverȱfolder.ȱ
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F or ȱdoingȱth eȱm on it or ing ȱ
–
GPSȱandȱdetailedȱtopographicȱmapȱ
–
underwaterȱcamera,ȱnormalȱcameraȱwithȱpolarisingȱlens,ȱorȱcameraȱinȱaȱglassȱaquariumȱȱ
–
500Ȭmmȱquadratȱ(optional)ȱ
–
measuringȱtapeȱ
–
siteȱherbariumȱ(optional)ȱ
–
clearȱtransparencyȱfilmȱ
–
transparencyȱfilmȱmarkedȱwithȱaȱgridȱȱ
–
permanentȱmarkersȱinȱaȱfewȱcolours.ȱ
What to do:
S it eȱ selection ȱ
Sitesȱareȱselectedȱonȱtheȱbasisȱthatȱtheȱseaweedȱbedsȱshouldȱbeȱobviousȱfromȱtheȱsurface,ȱeasilyȱ
accessibleȱandȱfreeȱfromȱanyȱdangerousȱcurrentsȱorȱdeepȱwater.ȱTheȱseaweedȱbedȱmayȱbeȱpresentȱonȱaȱ
jettyȱpylon,ȱonȱaȱrockyȱoutcropȱorȱanyȱotherȱhardȱstableȱsurface.ȱȱ
Siteȱselectionȱisȱbestȱdoneȱonȱaȱfineȱday.ȱVisitȱeachȱjettyȱandȱpylonȱwithinȱyourȱestuaryȱorȱyourȱsectionȱofȱ
theȱestuary.ȱIsȱthereȱanywhereȱthatȱmeetsȱtheȱcriteriaȱabove?ȱIfȱthereȱareȱsites,ȱtakeȱGPSȱlocationsȱandȱ
selectȱyourȱfavouriteȱsite.ȱMarkȱtheȱsiteȱclearlyȱonȱyourȱtopographicȱmapȱofȱtheȱarea.ȱIfȱthereȱareȱnoȱsitesȱ
meetingȱtheȱaboveȱcriteria,ȱthenȱperhapsȱaȱdifferentȱactivityȱmayȱbeȱmoreȱappropriate.ȱȱ
P r ep a r ingȱ aȱh er b ar i umȱ
Preparingȱaȱherbariumȱisȱanȱimportantȱstepȱinȱtheȱprocessȱofȱgettingȱtoȱknowȱyourȱseaweedsȱandȱanȱ
essentialȱpartȱofȱseaweedȱmonitoring.ȱȱ
Selectȱaȱfine,ȱwarm,ȱstillȱdayȱtoȱcollectȱtheȱherbariumȱsamples.ȱTheȱcollectionȱmayȱbeȱdoneȱinȱoneȱofȱtwoȱ
ways.ȱSamplesȱcouldȱbeȱcutȱfreeȱofȱtheirȱsubstrateȱandȱcaughtȱinȱaȱsmallȱnetȱusingȱaȱpoleȱwithȱaȱhookȱandȱ
netȱattached,ȱorȱtheyȱmayȱbeȱcollectedȱbyȱhandȱwhenȱswimmingȱorȱsnorkelling.ȱȱ
Collectingȱbyȱhandȱgivesȱyouȱbetterȱsamples,ȱbutȱtheȱhookȱandȱnetȱmethodȱisȱsaferȱifȱmembersȱofȱyourȱ
teamȱdon’tȱknowȱhowȱtoȱswim,ȱtheȱwaterȱqualityȱisȱinappropriateȱforȱswimming,ȱorȱinȱareasȱthatȱareȱ
deepȱorȱmayȱexperienceȱstrongȱcurrents.ȱ
Onceȱinȱtheȱfield,ȱcollectȱatȱleastȱoneȱsampleȱofȱeachȱseaweedȱyouȱsee.ȱTryȱnotȱtoȱtakeȱtheȱsamplesȱ
directlyȱfromȱtheȱsiteȱyouȱintendȱtoȱmonitor.ȱYouȱmayȱneedȱmoreȱthanȱoneȱsampleȱtoȱcomplyȱwithȱyourȱ
permitȱconditions.ȱPlaceȱtheseȱsamplesȱintoȱaȱbucketȱcontainingȱaȱlittleȱseawaterȱandȱkeepȱthemȱcool.ȱȱ
Onceȱallȱtheȱspecimensȱhaveȱbeenȱcollected,ȱplaceȱtheȱlidȱonȱtheȱbucketȱandȱtakeȱthemȱbackȱtoȱwhereȱyouȱ
planȱtoȱpressȱthem,ȱgenerallyȱyourȱhome,ȱmeetingȱhallȱorȱschool.ȱȱ
Backȱatȱbase,ȱrinseȱeachȱofȱtheȱsamplesȱoff,ȱremovingȱallȱsand,ȱsaltȱorȱanimalsȱfromȱtheȱfrondsȱandȱfollowȱ
theȱprocedureȱbelow:ȱ
–
plugȱtheȱsinkȱandȱplaceȱaȱsheetȱofȱA3ȱpaperȱinȱitȱȱ
–
addȱcoolȱwaterȱuntilȱitȱisȱaboutȱ20ȱmmȱdeepȱ
–
placeȱtheȱfirstȱsampleȱinȱtheȱwaterȱandȱarrangeȱitȱsoȱthatȱitȱlooksȱniceȱandȱrelativelyȱnaturalȱonȱtheȱ
pageȱȱ
–
ensureȱthatȱholdfasts,ȱtheȱshapeȱofȱtheȱfrondsȱandȱanyȱotherȱpossibleȱidentifyingȱcharacteristicsȱ
areȱvisibleȱȱ
–
carefullyȱliftȱaȱcornerȱorȱtheȱpageȱandȱpartiallyȱunplugȱtheȱsink,ȱsoȱthatȱtheȱwaterȱslowlyȱdrainsȱ
outȱȱ
–
ensureȱthatȱtheȱseaweedȱisȱstillȱarrangedȱhowȱyouȱputȱitȱthenȱcarefullyȱliftȱtheȱpaper,ȱwithȱtheȱ
algaeȱonȱit,ȱoutȱofȱtheȱsinkȱandȱontoȱaȱfewȱsheetsȱofȱnewspaperȱȱ
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–
ifȱtheȱpaperȱrips,ȱredoȱtheȱactivityȱ
–
allowȱthisȱsampleȱtoȱdryȱinȱtheȱshadeȱwhileȱtheȱrestȱofȱtheȱsamplesȱareȱpreparedȱ
–
placeȱaȱsheetȱofȱwaxedȱpaperȱonȱtopȱofȱeachȱsampleȱandȱplaceȱnewȱnewspaperȱaboveȱandȱbelowȱ
themȱȱ
–
stackȱtheȱsamplesȱandȱplaceȱaȱwoodenȱboardȱandȱsomeȱphoneȱbooksȱonȱtopȱ
–
changeȱtheȱnewspaperȱwheneverȱitȱgetsȱwetȬprobablyȱbeȱeveryȱfewȱhoursȱinitiallyȱthenȱeveryȱ
coupleȱofȱdaysȱȱ
–
onceȱallȱtheȱsamplesȱareȱdry,ȱdustȱanyȱsandȱoffȱȱ
–
checkȱthatȱtheȱseaweedsȱareȱallȱstuckȱtoȱtheirȱpages,ȱtheyȱhaveȱnotȱdiscolouredȱtheȱpaperȱandȱareȱ
relativelyȱflatȱȱ
–
ifȱtheȱpaperȱisȱdiscoloured,ȱcarefullyȱliftȱoffȱorȱcutȱoutȱtheȱsampleȱandȱstickȱitȱontoȱaȱnewȱsheetȱofȱ
paperȱȱ
–
ifȱtheȱsamplesȱareȱaȱlittleȱloose,ȱstickȱthemȱbackȱontoȱtheirȱpaperȱwithȱacidȬfreeȱglueȱ
–
onceȱyouȱhaveȱfinished,ȱplaceȱeachȱsheetȱintoȱaȱplasticȱsleeveȱandȱputȱthemȱintoȱaȱlargeȱfolder.ȱ
Thisȱwillȱbeȱusedȱregularlyȱduringȱtheȱrestȱofȱthisȱactivity,ȱsoȱensureȱtheȱfolderȱisȱrigid.ȱȱ
Identifyingȱeachȱofȱtheȱseaweedsȱinȱtheȱfolderȱisȱanȱimportantȱpartȱofȱthisȱactivity,ȱalthoughȱ
identificationȱtoȱspeciesȱisȱnotȱrequired.ȱAskingȱaȱspecialistȱorȱusingȱidentificationȱaidsȱtoȱhelpȱyouȱ
identifyȱtheȱspecimensȱtoȱgenusȱlevelȱwouldȱbeȱmoreȱthanȱsufficient.ȱAlternatively,ȱcontactȱReefȱWatchȱ
orȱlookȱatȱtheirȱwebsiteȱatȱ<www.reefwatch.asn.au>ȱ
M on it or i ngȱm et h od ȱ
Monitoringȱyourȱseaweedȱbedȱisȱrelativelyȱsimpleȱonceȱyourȱherbariumȱhasȱbeenȱpreparedȱandȱ
identifiedȱtoȱaȱlevelȱyouȱareȱcomfortableȱwith.ȱȱ
Selectȱanȱareaȱbetweenȱ0.5–1.0ȱmȱwideȱandȱtheȱsameȱdimensionsȱlengthwise.ȱRecordȱtheȱlocationȱofȱthisȱ
usingȱaȱGPSȱandȱmarkȱitȱonȱyourȱtopographicȱmap.ȱWriteȱaȱdescriptionȱofȱtheȱsiteȱonȱtheȱbottomȱofȱtheȱ
map.ȱPlaceȱtheȱquadratȱorȱsomeȱotherȱdeviceȱofȱknownȱlengthȱcloseȱtoȱtheȱareaȱyouȱplanȱtoȱphotographȱ
andȱtakeȱaȱpictureȱatȱlowȱtideȱfromȱaȱdistance,ȱsoȱthatȱlandmarksȱ(egȱbigȱbouldersȱorȱjettyȱpylons)ȱareȱ
visibleȱaroundȱtheȱseaweedȱbed.ȱThisȱphotographȱisȱtoȱhelpȱyouȱfindȱtheȱlocationȱnextȱtimeȱyouȱcomeȱ
back.ȱȱ
HammeringȱinȱaȱwoodenȱstakeȱorȱsprayȬpaintingȱsomeȱlocatingȱmarksȱmayȱalsoȱbeȱpossible,ȱdependingȱ
onȱyourȱlocation.ȱBeȱcarefulȱnotȱtoȱdamageȱtheȱareaȱtoȱbeȱmonitoredȱorȱcreateȱvisualȱpollution.ȱ
Onceȱyouȱhaveȱlocatedȱtheȱarea,ȱplaceȱtheȱquadratȱorȱsomethingȱofȱknownȱlengthȱ(aȱscalingȱobject)ȱ
immediatelyȱnextȱtoȱit.ȱTakeȱaȱpictureȱofȱtheȱmonitoringȱareaȱandȱtheȱscalingȱobject,ȱensuringȱthatȱtheȱ
monitoringȱareaȱandȱtheȱobjectȱtakeȱupȱtheȱentireȱviewingȱareaȱofȱtheȱcamera.ȱȱ
Theȱpictureȱcanȱbeȱtakenȱinȱoneȱofȱthreeȱways:ȱ
1
Aȱdisposableȱwaterproofȱcameraȱmayȱbeȱusedȱwithȱitsȱlensȱrestingȱonȱtheȱwaterȱsurfaceȱorȱ
submergedȱbelowȱit.ȱ
2
Aȱstandardȱcameraȱfittedȱwithȱaȱpolarisingȱlensȱisȱused.ȱStandingȱonȱaȱjettyȱdirectlyȱaboveȱtheȱ
site,ȱcarefullyȱadjustȱtheȱpolarisingȱlensȱsoȱthatȱyouȱcanȱseeȱtheȱmonitoringȱareaȱclearly.ȱȱ
3
Aȱstandardȱcameraȱmayȱbeȱplacedȱinȱaȱglassȱaquarium,ȱwhichȱisȱheldȱpartiallyȱinȱtheȱwater.ȱTheȱ
pictureȱisȱtakenȱthroughȱtheȱglassȱbottom.ȱBeȱcarefulȱnotȱtoȱwetȱyourȱcameraȱifȱyouȱuseȱthisȱ
method.ȱ
Theȱlastȱtwoȱoptionsȱwillȱprobablyȱrequireȱaȱzoomȱlensȱofȱsomeȱvariety,ȱdependingȱonȱtheȱsizeȱofȱyourȱ
monitoringȱareaȱandȱtheȱgeographyȱofȱyourȱsampleȱlocation.ȱȱ
Theȱmainȱaimȱofȱthisȱexerciseȱisȱtoȱgetȱaȱclearȱphotographȱofȱexactlyȱtheȱsameȱareaȱonȱaȱregularȱbasis.ȱ
Withȱthisȱaimȱinȱmind,ȱselectȱtheȱphotographicȱmethodȱmostȱappropriateȱforȱyourȱgroupȱandȱyourȱsite.ȱȱ
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I nte rpr et ingȱy ou rȱ re su lt s ȱ
Onceȱtheȱphotographsȱhaveȱbeenȱprocessed,ȱtheyȱcanȱbeȱanalysedȱusingȱtheȱmethodsȱoutlinedȱinȱtheȱ
guidelineȱUsingȱaerialȱphotographsȱtoȱmapȱhabitatȱchange.ȱTheȱphotographsȱtakenȱareȱbasicallyȱhomemadeȱ
aerialȱphotographsȱandȱtheyȱwillȱyieldȱaȱsimilarȱrangeȱofȱdata.ȱȱ
Classificationȱofȱtheȱseaweedsȱmayȱbeȱasȱsimpleȱasȱtheȱpercentageȱofȱgreen,ȱredȱorȱbrownȱalgae,ȱorȱyouȱ
mayȱattemptȱtoȱidentifyȱtheȱalgaeȱinȱtheȱphotographsȱtoȱgenus,ȱusingȱyourȱidentifiedȱherbariumȱ
specimensȱorȱotherȱreferenceȱmaterials.ȱȱ
TheȱmostȱstableȱareasȱtendȱtoȱbeȱdominatedȱbyȱcomplexȱbrownȱalgaeȱsuchȱasȱSargassumȱandȱEcklonia.ȱ
IntermittentlyȱdisturbedȱareasȱmayȱhaveȱCodiumȱ(aȱcomplexȱgreenȱalgae),ȱwhileȱtheȱfilamentousȱandȱ
sheetȬtypeȱgreenȱalgaeȱsuchȱasȱEnteromorphaȱandȱUlvaȱareȱrapidȱcolonisersȱafterȱaȱdisturbanceȱorȱindicateȱ
highȱnutrientȱconcentrations.ȱRightȱafterȱaȱmajorȱdisturbanceȱaȱfewȱveryȱtiny,ȱfineȱbrownȱfurryȱalgaeȱ
suchȱasȱGiffordiaȱmayȱbeȱseen.ȱ
Onceȱyouȱhaveȱfinishedȱdoingȱanyȱanalysisȱyouȱwishȱtoȱdoȱonȱtheȱphotographs,ȱsendȱaȱlistȱofȱtheȱ
herbariumȱidentifications,ȱaȱcopyȱofȱtheȱphotographsȱandȱtheȱresultsȱofȱanyȱanalysisȱtoȱyourȱWaterwatchȱ
coordinatorȱandȱtoȱanyȱagenciesȱthatȱissuedȱpermitsȱforȱtheȱactivity.ȱTheseȱitemsȱofȱdataȱmayȱbeȱ
comparedȱwithȱthoseȱcollectedȱbyȱotherȱgroupsȱinȱotherȱlocations,ȱorȱatȱotherȱtimes.ȱȱ
Thisȱactivityȱshouldȱbeȱundertakenȱregularly.ȱItȱdependsȱonȱtheȱresourcesȱofȱyourȱgroupȱandȱtheȱaimsȱofȱ
theȱprogram,ȱbutȱannuallyȱisȱprobablyȱsufficient.ȱEnsuringȱthatȱtheȱmonitoringȱisȱdoneȱinȱtheȱsameȱ
seasonȱeachȱyearȱwillȱreduceȱtheȱeffectȱofȱseasonalȱvariationȱonȱyourȱdata,ȱasȱtheȱopportunisticȱgreenȱ
algaeȱinȱparticular,ȱhaveȱwideȱseasonalȱvariationsȱinȱabundance.ȱ
U s e f u l r e f e r e n ce s
Christianson,ȱIG,ȱClayton,ȱMNȱ&ȱAllender,ȱBMȱ(1981)ȱSeaweedsȱofȱAustralia,ȱReedȱBooks,ȱSydney.ȱ
ȱ
ȱ
ȱ
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Monitoring an intertidal SAM bed
Intertidalȱsubmergedȱaquaticȱmacrophytesȱ(SAMs)ȱareȱvascularȱ
plants,ȱwithȱmodifiedȱflowers,ȱseeds,ȱroots,ȱstemsȱandȱleaves.ȱ
EstuarineȱSAMsȱincludeȱseagrasses,ȱwidgeonȱgrassesȱandȱwatermats.ȱ
Theyȱareȱaquaticȱversionsȱofȱourȱterrestrialȱfloweringȱplants.ȱ
MeasuringȱtheȱpercentȱcoverȱofȱSAMȱquantifiesȱtheȱamountȱofȱ
macrophytesȱinȱanȱarea,ȱandȱallowsȱchangesȱinȱmacrophyteȱcoverȱtoȱ
beȱdetectedȱoverȱtime.ȱTheȱmeasureȱgivesȱanȱindicationȱofȱtheȱstatusȱ
andȱstageȱofȱdevelopmentȱofȱaȱmacrophyteȱmeadow.ȱȱ
Aȱmacrophyteȱmeadowȱwithȱaȱhighȱpercentageȱofȱcoverȱthatȱdisplaysȱ
littleȱvariationȱoverȱtimeȱorȱspaceȱindicatesȱaȱstableȱcommunityȱthatȱisȱ
wellȱdeveloped.ȱIfȱchangesȱinȱcoverȱareȱidentified,ȱorȱanȱincreasedȱ
amountȱofȱcoatingȱalgaeȱorȱencrustingȱanimalsȱareȱdetectedȱonȱtheȱ
leavesȱofȱtheȱplants,ȱtheȱSAMȱbedȱmayȱbeȱsubjectȱtoȱnaturalȱorȱhumanȱ
inducedȱstress.ȱȱ
Activity:
3 Extension
Age: High school
Time: 3
Why? SAM (submerged
aquatic macrophytes) beds
are an essential habitat in
estuaries, and are fish
nursery areas. Most SAM
beds require high light
levels to survive, and
appropriate inundation,
temperature and salinity
regimes.
Thisȱactivityȱusesȱ500Ȭmmȱquadratsȱplacedȱatȱregularȱintervalsȱalongȱ
threeȱtransectsȱwithinȱanȱintertidalȱmacrophyteȱcommunity.ȱAȱrapidȱ
assessmentȱofȱmacrophyteȱcoverȱisȱmade.ȱTheȱdominantȱspeciesȱareȱ
alsoȱidentified.ȱȱ
Safety: Do not use steel
star droppers. They corrode
and may also be a health
and safety problem to
people and boats.
Dependingȱonȱtheȱlocationȱyouȱwishȱtoȱstudy,ȱaȱpermitȱfromȱtheȱ
NativeȱVegetationȱCouncil,ȱTransportȱSAȱorȱPIRSAȱmayȱbeȱrequiredȱ
toȱcompleteȱthisȱactivity,ȱparticularlyȱifȱyouȱareȱplanningȱtoȱleaveȱ
permanentȱmarkersȱforȱtheȱtransects.ȱȱ
Use suncream for this
activity, particularly on the
back of the neck. Ensure
that hats and suitable shoes
are worn by all
participants.
What you may need:
–
twoȱbrightlyȱpaintedȱgardenȱstakesȱ
–
rubberȱmalletȱ
–
quadratȱlabelsȱ
–
cameraȱwithȱpolarisingȱfilterȱȱ
–
50Ȭmȱmeasuringȱtape(s),ȱpreferablyȱmadeȱofȱfibreglassȱȱ
–
compassȱ
–
GPSȱȱ
–
500ȱmmȱ×ȱ500ȱmmȱquadratȱ(mayȱbeȱsubdividedȱintoȱ100Ȭmmȱsquaresȱwithȱstring)ȱ
–
aerialȱphotograph,ȱtopographicȱorȱothophotographicȱmapȱ
–
identificationȱsheetsȱshowingȱlocalȱSAMȱspeciesȱ(theseȱareȱavailableȱforȱsomeȱareasȱfromȱReefȱ
WatchȱorȱtheȱCoastȱandȱMarineȱConservationȱBranchȱofȱtheȱDepartmentȱforȱConservationȱandȱ
Heritage).ȱ
Only undertake this activity
at low tide.
To ensure good results:
Seagrassȱmeadowsȱexperienceȱseasonalȱandȱclimaticȱtrendsȱinȱtheirȱpercentageȱcover.ȱAtȱleastȱthreeȱyearsȱ
ofȱdataȱ(preferablyȱmore)ȱareȱrequiredȱtoȱtrackȱunusualȱchanges.ȱ
What to do:
Selectȱaȱ50mȱ×ȱ50ȱmȱsiteȱusingȱanȱaerialȱphotograph,ȱorthophotographicȱmapȱorȱbyȱwalkingȱacrossȱtheȱ
site.ȱTheȱsiteȱneedsȱtoȱbeȱrelativelyȱhomogenousȱwithȱnoȱobviousȱsandbanksȱorȱchanges.ȱEnsureȱthatȱitȱ
appearsȱtoȱbeȱrepresentativeȱofȱtheȱSAMȱcommunityȱatȱthatȱlocationȱandȱisȱnotȱdifficultȱtoȱrevisit.ȱȱ
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OnceȱaȱsiteȱisȱselectedȱrecordȱitsȱpositionȱusingȱaȱGPSȱandȱbyȱtakingȱcompassȱbearingsȱfromȱprominentȱ
landȱfeatures.ȱRecordȱtheseȱmeasurementsȱandȱplotȱtheȱlocationȱonȱtheȱaerialȱphotographȱorȱtopographicȱ
map.ȱThisȱwillȱassistȱwithȱfindingȱtheȱsiteȱwhenȱrevisiting.ȱȱ
Threeȱtransectsȱareȱrequired.ȱEachȱtransectȱshouldȱrunȱperpendicularȱtoȱtheȱseaȱandȱbeȱ50Ȭmȱlong.ȱAllȱ
quadratsȱshouldȱbeȱplacedȱonȱtheȱrightȬhandȱsideȱofȱtheȱtransects,ȱsoȱonlyȱwalkȱonȱtheȱleftȱhandȱside.ȱ
Markȱtheȱmiddleȱtransectȱbyȱdrivingȱaȱgardenȱstakeȱintoȱtheȱgroundȱatȱeitherȱend,ȱleavingȱapproximatelyȱ
100ȱmmȱstickingȱout.ȱTakeȱaȱGPSȱreadingȱatȱeachȱpegȱandȱattachȱaȱsiteȱmarkerȱtagȱtoȱeachȱmarker.ȱȱ
Theȱotherȱtwoȱtransectsȱshouldȱrunȱparallelȱto,ȱbutȱ25Ȭmȱtoȱtheȱleftȱandȱrightȱof,ȱtheȱmiddleȱtransect.ȱ
Theseȱshouldȱbeȱunmarked,ȱandȱwillȱneedȱmeasuringȱeachȱvisit,ȱorȱGPSȱlocationsȱrecordedȱtoȱlocateȱtheirȱ
startȱandȱfinishȱpoints.ȱȱ
Alwaysȱstartȱmonitoringȱanȱhourȱorȱsoȱbeforeȱlowȱtide.ȱAtȱtheȱbeginningȱofȱtheȱfirstȱquadrat,ȱplaceȱaȱ500ȱ
mmȱ×ȱ500ȱmmȱquadratȱtoȱtheȱrightȱhandȱsideȱofȱtheȱtransect.ȱPlaceȱaȱquadratȱlabelȱnextȱtoȱtheȱquadratȱ
andȱphotographȱtheȱquadratȱsoȱthatȱminimalȱglareȱinterferesȱwithȱtheȱphotographȱ(turnȱtheȱpolarisingȱ
filterȱuntilȱyouȱgetȱnoȱreflectionsȱfromȱtheȱwater).ȱȱ
Youȱmayȱestimateȱtheȱpercentageȱcoverȱofȱmacrophytesȱinȱtheȱfieldȱorȱatȱyourȱdeskȱonceȱtheȱphotosȱhaveȱ
beenȱdeveloped.ȱThisȱmayȱbeȱeasierȱifȱyouȱsubdivideȱyourȱquadrat.ȱOnceȱyouȱhaveȱobtainedȱanȱestimateȱ
ofȱmacrophyteȱcover,ȱrecordȱyourȱresultȱontoȱtheȱdataȱsheet.ȱȱ
Onceȱtheȱphotographȱhasȱbeenȱtaken,ȱidentifyȱandȱrecordȱtheȱspeciesȱofȱmacrophyteȱpresentȱinȱtheȱ
quadrat.ȱIfȱthereȱisȱmoreȱthanȱoneȱspeciesȱpresent,ȱanȱestimateȱofȱhowȱmuchȱofȱtheȱtotalȱcoverȱeachȱ
speciesȱcontributesȱwillȱbeȱrequired.ȱIfȱyouȱareȱunableȱtoȱidentifyȱtheȱmacrophyteȱspecies,ȱtakeȱaȱ
specimenȱ(ifȱyouȱhaveȱtheȱappropriateȱpermit)ȱorȱtakeȱaȱphotographȱofȱit.ȱȱ
Repeatȱtheȱaboveȱprocedureȱatȱtheȱbeginning,ȱmiddleȱandȱendȱofȱallȱthreeȱtransects.ȱThisȱactivityȱshouldȱ
beȱrepeatedȱannuallyȱatȱtheȱsameȱtimeȱofȱyear,ȱtoȱminimiseȱtheȱimpactȱofȱseasonalȱvariations.ȱȱ
Dataȱfromȱthisȱactivityȱmayȱbeȱpresentedȱasȱaverageȱpercentageȱcoverȱforȱtheȱsite,ȱorȱdominantȱspeciesȱ
forȱeachȱsite.ȱPresentingȱtheȱdataȱasȱaȱgraphȱorȱseriesȱofȱgraphsȱisȱaȱgoodȱmethodȱforȱassessingȱtrendsȱ
overȱtimeȱatȱtheȱsiteȱorȱbetweenȱsites.ȱSAMȱbedsȱexperienceȱseasonalȱandȱclimaticȱtrendsȱinȱtheirȱ
percentageȱcover.ȱAtȱleastȱthreeȱyearsȱofȱdataȱ(preferablyȱmore)ȱareȱrequiredȱtoȱtrackȱunusualȱchanges.ȱ
ȱ
ȱ
ȱ
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Monitoring submerged SAM beds
InȱshelteredȱestuariesȱthatȱsupportȱSAMȱ(submergedȱaquaticȱ
macrophyte)ȱbeds,ȱaȱstableȱpopulationȱofȱtheseȱplantsȱisȱtheȱhallmarkȱ
ofȱaȱhealthyȱestuary.ȱȱ
SAMȱbedsȱcontributeȱtoȱtheȱestuaryȱinȱseveralȱways.ȱTheyȱprovideȱ
foodȱforȱseveralȱtypesȱofȱwaterfowlȱandȱaȱnurseryȱforȱjuvenileȱfish.ȱInȱ
death,ȱtheȱplantsȱprovideȱhugeȱquantitiesȱofȱdecomposedȱmatterȱasȱ
leavesȱdie,ȱandȱsomeȱaquaticȱinvertebratesȱuseȱthisȱdetritusȱasȱtheirȱ
mainȱfoodȱsource.ȱDuringȱtheȱwarmerȱgrowingȱseason,ȱSAMsȱsupplyȱ
oxygenȱtoȱtheȱwater.ȱTheȱSAMȱbedsȱlockȱupȱnutrientsȱduringȱtheȱ
summer,ȱandȱasȱtheyȱdieȱoffȱinȱautumnȱtheyȱslowlyȱreleaseȱtheseȱbackȱ
intoȱcolderȱwaterȱthatȱwillȱnotȱsupportȱlargeȱplanktonȱblooms.ȱ
SAMȱbedsȱrequireȱhighȱlightȱlevelsȱtoȱsurvive,ȱandȱappropriateȱ
inundation,ȱtemperatureȱandȱsalinityȱregimes.ȱ
InȱSouthȱAustraliaȱtheȱCoastȱandȱMarineȱBranchȱofȱtheȱDepartmentȱ
forȱEnvironmentȱandȱHeritageȱhasȱdevelopedȱmapsȱofȱsubmergedȱ
SAMȱbeds,ȱderivedȱfromȱanalysingȱaerialȱsurveys.ȱTheseȱareȱ
availableȱforȱmanyȱpartsȱofȱtheȱstate,ȱfromȱtheȱSouthȱAustralianȱnodeȱ
ofȱtheȱCoastalȱAtlas,ȱaccessedȱthroughȱtheȱinternetȱonȱ
<www.atlas.sa.gov.au>.ȱȱ
Activity:
3 Extension
Age: Adult groups
Time: 4
Why? SAM (submerged
aquatic macrophytes) beds
are an essential habitat in
estuaries, and are fish
nursery areas. Most SAM
beds require high light
levels to survive, and
appropriate inundation,
temperature and salinity
regimes.
Safety: This is a deep water
activity.
Itȱisȱnotȱalwaysȱeasyȱtoȱseparateȱsomeȱtypesȱofȱseaweedȱ(algae)ȱfromȱSAMs,ȱandȱaerialȱsurveysȱmayȱmissȱ
smallȱbeds.ȱToȱimproveȱtheȱaccuracyȱofȱtheseȱmaps,ȱgroundtruthingȱisȱused,ȱwhereȱtheȱsitesȱidentifiedȱ
fromȱtheȱaerialȱphotographsȱareȱvisited,ȱandȱsampled,ȱtoȱconfirmȱthatȱtheyȱareȱindeedȱSAMȱbeds.ȱ
GroundtruthingȱsubmergedȱSAMȱbedsȱinȱyourȱestuaryȱprovidesȱusersȱofȱyourȱdataȱwithȱinformationȱonȱ
theȱaccuracyȱofȱtheȱlargerȱscaleȱaerialȱmapping,ȱasȱwellȱasȱprovidingȱinformationȱonȱtheȱlocationȱofȱ
smallerȱbeds.ȱȱ
IfȱyouȱwishȱtoȱsampleȱSAMȱbeds,ȱyouȱmayȱneedȱaȱpermitȱtoȱcollectȱnativeȱvegetationȱfromȱtheȱNativeȱ
VegetationȱCouncil.ȱTheseȱpermitsȱareȱissuedȱbyȱtheȱNPWS.ȱ
What you may need:
–
seaworthyȱboatȱwithȱadequateȱsafetyȱandȱrunningȱequipmentȱ
–
GPSȱ
–
mapȱshowingȱlocationsȱofȱSAMȱbedsȱinȱyourȱestuaryȱ
–
aȱlongȬhandledȱrakeȱ
–
identificationȱsheetsȱshowingȱlocalȱSAMȱspeciesȱ(theseȱareȱavailableȱforȱsomeȱareas,ȱfromȱReefȱ
WatchȱorȱtheȱCoastȱandȱMarineȱBranch)ȱ
–
plasticȱzipȱbagsȱforȱspecimens,ȱwithȱaȱmarkerȱpenȱtoȱlabelȱthemȱ
–
polarisedȱsunglasses,ȱswimmingȱgogglesȱorȱaȱclearȬbottomedȱcontainerȱforȱviewingȱtheȱSAMȱ
bedsȱ
–
groundtruthingȱdatasheet.ȱ
To ensure good results:
Goȱoutȱonȱtheȱcalmestȱdayȱyouȱcan,ȱatȱaȱreasonablyȱlowȱtide.ȱThisȱwillȱallowȱyouȱtoȱseeȱintoȱtheȱwaterȱ
moreȱclearly.ȱ
Undertakeȱthisȱactivityȱatȱaȱsimilarȱtimeȱofȱyearȱ(preferablyȱsummer)ȱtoȱminimiseȱtheȱimpactȱofȱseasonalȱ
variationȱifȱyouȱvisitȱtheȱsitesȱrepeatedlyȱtoȱmonitorȱtheirȱhealth.ȱSomeȱspeciesȱofȱSAMsȱdieȱbackȱinȱ
winter.ȱȱ
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What to do:
Beforeȱgoingȱoutȱinȱtheȱboat,ȱmarkȱtheȱlocationsȱyouȱwishȱtoȱvisitȱonȱyourȱmap,ȱandȱwriteȱtheirȱmapȱ
coordinatesȱnextȱtoȱthem.ȱRecordȱtheȱproposedȱlocationsȱonȱyourȱdatasheetȱasȱwell.ȱ
Proceedȱtoȱtheȱfirstȱlocationȱonȱyourȱsheet.ȱOnȱapproachingȱaȱSAMȱbed,ȱSLOWȱDOWN.ȱEnsureȱyouȱwillȱ
notȱdamageȱtheȱbedȱwithȱyourȱpropellerȱitselfȱorȱfromȱtheȱperturbationȱitȱmayȱcause.ȱAreȱyouȱatȱtheȱ
locationȱyouȱwereȱheadingȱtowards,ȱorȱhaveȱyouȱfoundȱaȱsmallȱbedȱthatȱisȱnotȱmarkedȱonȱyourȱmap?ȱ
FloatȱoverȱtheȱSAMȱbedȱinȱyourȱboat.ȱYouȱwillȱgetȱaȱclearerȱviewȱbyȱusingȱpolarisedȱsunglasses,ȱorȱbyȱ
puttingȱonȱyourȱswimmingȱmaskȱandȱsubmergingȱyourȱheadȱ(beȱcarefulȱnotȱtoȱfallȱinȱtheȱwater),ȱorȱbyȱ
lookingȱthroughȱaȱclearȬbottomedȱcontainerȱ(oldȱaquariumȱorȱsimilar).ȱ
Recordȱyourȱlocation,ȱandȱtheȱsizeȱandȱshapeȱofȱtheȱSAMȱbed.ȱSlowlyȱcircumnavigateȱtheȱbedȱandȱtakingȱ
readingsȱfromȱtheȱGPSȱtoȱdetermineȱtheȱshape.ȱ
CanȱyouȱidentifyȱtheȱtypeȱofȱSAM?ȱIfȱyouȱareȱunsureȱofȱtheȱspecies,ȱuseȱyourȱrakeȱtoȱGENTLYȱfishȱupȱaȱ
smallȱspecimen,ȱbagȱit,ȱlabelȱit,ȱandȱreturnȱitȱtoȱshoreȱforȱidentification.ȱIfȱyouȱcanȱseeȱwhatȱspeciesȱitȱis,ȱ
justȱrecordȱtheȱspeciesȱonȱtheȱdatasheet.ȱ
HowȱhealthyȱdoesȱtheȱSAMȱappear?ȱIfȱyouȱhaveȱvisitedȱthisȱbedȱbefore,ȱisȱitȱanyȱdifferent?ȱNoteȱtheȱ
locationȱofȱanyȱerosionȱscarpsȱorȱblowoutsȱusingȱtheȱGPS.ȱRecordȱwhetherȱthereȱisȱmuchȱepiphyticȱ
growthȱ(visibleȱasȱaȱsoftȱbrownishȱfuzz)ȱonȱtheȱbladesȱofȱtheȱSAM.ȱ
Proceedȱtoȱtheȱnextȱbedȱandȱrepeatȱtheȱprocess.ȱ
Onȱyourȱreturnȱtoȱbase,ȱidentifyȱallȱsamples,ȱorȱcontactȱyourȱWaterwatchȱcoordinatorȱtoȱhelpȱyouȱfindȱ
someoneȱwhoȱcanȱidentifyȱthemȱforȱyou.ȱOnȱyourȱSAMȱbedȱmapȱorȱaȱtopographicȱmap,ȱtryȱtoȱdrawȱinȱ
anyȱnewȱbedȱlocations,ȱorȱanyȱotherȱchangesȱasȱaccuratelyȱasȱyouȱcan.ȱȱ
IfȱyouȱnoticeȱaȱregularȱreductionȱinȱtheȱsizeȱofȱSAMȱbeds,ȱorȱincreasingȱnumbersȱofȱblowoutsȱandȱ
propellerȱscarsȱoverȱseveralȱyears,ȱtalkȱtoȱyourȱWaterwatchȱcoordinator,ȱwhoȱcanȱputȱyouȱinȱcontactȱwithȱ
theȱappropriateȱpeople.ȱ
ȱ
ȱ
ȱ
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How continuous is the fringing
vegetation?
Riparianȱvegetationȱisȱimportantȱinȱestuarineȱsituations.ȱRiparianȱ
vegetationȱgrowsȱalongsideȱtidalȱwatercoursesȱaboveȱtheȱhighȬtideȱ
mark,ȱwhereȱonlyȱkingȱtides,ȱfloodwatersȱorȱrunoffȱregularlyȱ
inundateȱit.ȱInȱtheȱupperȱtidalȱfreshwaterȱreachesȱthisȱvegetationȱisȱ
oftenȱdistinctlyȱdifferentȱfromȱtheȱsurroundingȱvegetation,ȱoftenȱ
includingȱemergentȱmacrophytesȱdueȱtoȱtheȱbetterȱavailabilityȱofȱ
freshwater.ȱHowever,ȱfurtherȱdownȱtheȱestuaryȱtheȱvegetationȱ
becomesȱlessȱdistinctȱfromȱtheȱsupratidalȱvegetation,ȱwithȱtheȱ
vegetationȱbandsȱoftenȱcomprisingȱvariousȱtypesȱofȱsamphire.ȱȱ
Riparianȱvegetationȱaidsȱinȱpreventingȱerosion,ȱprovidesȱhabitatȱforȱ
smallȱbirdsȱorȱotherȱanimals,ȱandȱcleansȱstormwaterȱrunoffȱbeforeȱitȱ
reachesȱtheȱestuarineȱsystem.ȱȱ
MuchȱofȱAustralia’sȱriparianȱvegetationȱisȱdegraded.ȱPreviousȱ
clearingȱforȱurban,ȱindustrialȱandȱagriculturalȱdevelopmentȱhasȱ
reducedȱtheȱqualityȱofȱriparianȱvegetationȱwhileȱweedȱandȱferalȱ
animalȱinvasionsȱhaveȱtakenȱoverȱtheȱareasȱstillȱleftȱinȱtheirȱnaturalȱ
state.ȱȱ
Considerableȱcommunityȱandȱgovernmentȱeffortȱhasȱbeenȱspentȱ
tryingȱtoȱrestoreȱtheseȱestuarineȱriparianȱzonesȱoverȱtheȱpastȱ10ȱtoȱ20ȱ
years.ȱSomeȱAdelaideȱcouncilsȱhaveȱbuiltȱlargeȱareasȱofȱartificialȱ
wetlandsȱtoȱhelpȱrecreateȱaȱsmallȱportionȱofȱthisȱhabitat,ȱandȱtheseȱareȱ
usedȱtoȱtreatȱstormwaterȱbeforeȱitȱentersȱtheȱBarkerȱInletȱandȱtheȱPortȱ
Riverȱestuary.ȱȱ
Activity:
3 Extension
Age: High school
Time: 2
Why? Width and continuity
of riparian vegetation is
related to water quality,
particularly water clarity.
Other important indicators
examined in this activity
are weediness and erosion.
Safety: Winter months are
normally the best time of
the year to conduct
assessments as the climate
is milder and the risks of
encountering snakes is
lower.
Always ensure that boots,
long pants and a hat are
worn by all participants.
Water bottles or regular
refreshment stops are also
recommended.
Thisȱactivityȱaimsȱtoȱprovideȱaȱrapidȱassessmentȱofȱriparianȱ
vegetationȱalongȱaȱ100Ȭmȱstretchȱofȱestuarineȱcreekȱandȱgiveȱanȱ
overviewȱofȱtheȱconditionȱofȱremainingȱriparianȱvegetationȱwithinȱtheȱtidalȱarea.ȱTheȱactivityȱusesȱaerialȱ
photosȱtoȱselectȱhomogenousȱstretchesȱofȱriparianȱvegetationȱtoȱhelpȱreduceȱtheȱamountȱofȱfieldwork.ȱ
Representativeȱsitesȱonȱtheȱgroundȱareȱassessed.ȱFiveȱkeyȱindicatorsȱofȱriparianȱvegetationȱdisturbanceȱ
areȱexaminedȱtoȱprovideȱanȱindexȱscoreȱofȱriparianȱhealth.ȱȱ
What you may need:
–
currentȱaerialȱphotosȱofȱareaȱtoȱbeȱexaminedȱinȱanȱappropriateȱscaleȱȱ
–
topographicȱmapȱofȱtheȱareaȱinȱaȱsimilarȱscaleȱtoȱtheȱphotographsȱȱ
–
50Ȭmȱtapeȱmeasureȱ
–
oneȬmetreȱmeasuringȱstickȱorȱsimilarȱobjectȱȱ
–
cameraȱ
–
riparianȱvegetationȱdatasheet.ȱ
What to do:
Thisȱactivityȱcanȱbeȱperformedȱonȱjustȱyourȱregularȱsampleȱsite,ȱaȱnumberȱofȱsites,ȱaȱsingleȱtidalȱcreekȱorȱ
onȱtheȱentireȱestuary.ȱTheȱactivityȱdescribedȱhereȱdetailsȱhowȱyouȱwouldȱassessȱtheȱriparianȱvegetationȱ
ofȱtheȱentireȱlengthȱofȱaȱtidalȱcreek.ȱHowever,ȱitȱisȱsimpleȱtoȱcutȱitȱdownȱtoȱaȱ100Ȭmȱsiteȱbyȱperformingȱ
theȱfieldworkȱsectionȱonȱyourȱregularȱwaterȱsamplingȱlocations,ȱorȱtoȱgraduallyȱassessȱdifferentȱsitesȱ
untilȱyouȱhaveȱcoveredȱyourȱentireȱestuary.ȱȱ
Homogenousȱstreamȱunitsȱareȱsectionsȱofȱstreamȱthatȱhaveȱconsistentȱcharacteristicsȱalongȱtheirȱlength.ȱ
Thisȱmethodȱassumesȱthatȱthereȱisȱlittleȱvariationȱinȱtheȱstructureȱofȱtheȱriparianȱvegetationȱwithinȱeachȱ
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unit.ȱThisȱmeansȱthatȱanȱassessmentȱofȱtheȱentireȱriparianȱzoneȱmayȱbeȱmadeȱbyȱvisitingȱoneȱsiteȱwithinȱ
eachȱunit.ȱȱ
Theȱnumberȱofȱhomogenousȱstreamȱunitsȱforȱeachȱstreamȱwillȱvaryȱconsiderably,ȱdependingȱonȱtheȱ
natureȱofȱtheȱstreamȱandȱitsȱvegetation.ȱUsingȱaerialȱphotosȱandȱtopographicȱmap,ȱdivideȱyourȱestuaryȱ
banksȱintoȱhomogenousȱunitsȱusingȱtheȱfollowingȱmethod:ȱȱ
1
Divideȱtheȱestuaryȱatȱeachȱbendȱandȱatȱanyȱtributaryȱjunctionsȱ
2
Divideȱtheseȱsectionsȱfurtherȱwhereȱtheȱwidthȱofȱtheȱriparianȱzoneȱchangesȱorȱdiscontinuesȱ
3
Ifȱlandȱusesȱchange,ȱdivideȱtheȱcurrentȱsectionsȱfurtherȱsoȱdifferentȱlandȱusesȱareȱinȱdifferentȱ
unitsȱ
4
Ensureȱthatȱeachȱofȱtheȱdivisionsȱisȱmarkedȱontoȱtheȱtopographicȱmapȱorȱaȱtransparencyȱsheetȱ
tapedȱontoȱit.ȱȱ
Eachȱstreamȱunitȱneedsȱtoȱbeȱgreaterȱthanȱ300ȱmȱlong.ȱSelectȱaȱrepresentativeȱ100Ȭmȱlengthȱofȱeachȱ
streamȱunitȱthatȱisȱaccessibleȱtoȱyourȱgroup.ȱȱ
Theȱremainingȱpartȱofȱthisȱactivityȱcomprisesȱtheȱfieldworkȱthatȱisȱconductedȱonȱeachȱ100Ȭmȱstretch.ȱ
Eachȱstretchȱneedsȱtoȱbeȱvisited,ȱandȱtheȱfollowingȱparametersȱassessed.ȱAlwaysȱobtainȱpermissionȱfromȱ
landholdersȱifȱtravellingȱonȱprivateȱpropertyȱisȱrequired.ȱ
Markȱoutȱaȱ100Ȭmȱstretchȱofȱriparianȱvegetationȱfromȱaȱpointȱthatȱisȱeasyȱtoȱrelocateȱonȱfutureȱvisits.ȱ
MeasureȱtheȱwidthȱofȱtheȱriparianȱvegetationȱonȱtheȱbankȱbyȱrunningȱaȱtapeȱmeasureȱfromȱtheȱhighȬ
waterȱmarkȱtoȱtheȱouter,ȱorȱlandward,ȱedgeȱofȱtheȱriparianȱvegetation.ȱRecordȱthisȱonȱyourȱdatasheet.ȱIfȱ
mangrovesȱareȱpresent,ȱmeasureȱtheȱwidthȱofȱtheȱmangroveȱcommunityȱseparatelyȱandȱrecordȱonȱtheȱ
dataȱsheet.ȱȱ
Lookȱatȱtheȱextentȱofȱtheȱremainingȱriparianȱvegetationȱandȱestimateȱtheȱpercentȱremainingȱbyȱwalkingȱ
alongȱtheȱlandwardȱedgeȱofȱtheȱvegetationȱandȱlookingȱtowardsȱtheȱestuary.ȱIfȱaȱbankȱhasȱaȱwellȬ
vegetatedȱriparianȱzoneȱthatȱisȱcontinuousȱandȱconsistent,ȱitȱhasȱexcellentȱcontinuity.ȱAreȱthereȱanyȱgapsȱ
inȱtheȱvegetation,ȱorȱisȱitȱoneȱlongȱbelt?ȱRecordȱtheȱnumberȱandȱwidthȱofȱbreaksȱinȱtheȱriparianȱ
vegetationȱandȱuseȱthisȱinformationȱtoȱcalculateȱpercentageȱcover.ȱNoteȱgrazingȱorȱploughingȱofȱtheȱ
riparianȱvegetation.ȱDescribeȱtheȱexistingȱvegetationȱandȱidentifyȱit,ȱifȱyouȱcan.ȱ
Lookȱaroundȱforȱweedȱspecies.ȱAreȱtheȱplantsȱmainlyȱweedsȱorȱareȱtheyȱnatives?ȱWhatȱnoxiousȱweedȱ
speciesȱareȱpresent?ȱNoteȱyourȱobservationsȱonȱyourȱdatasheet.ȱ
Assessȱtheȱseverityȱofȱerosionȱonȱtheȱbank.ȱCircleȱtheȱcategoryȱonȱtheȱdatasheetȱthatȱbestȱdescribesȱtheȱ
extentȱofȱtheȱerosionȱatȱthisȱsite.ȱȱ
Takeȱaȱphotoȱofȱtheȱriparianȱvegetationȱbyȱstandingȱatȱoneȱendȱofȱyourȱtransectȱonȱtheȱlandwardȱside,ȱ
lookingȱalongȱyourȱtransect.ȱEnsureȱaȱmeasuringȱstickȱisȱplacedȱinȱanȱeasilyȱrepeatableȱlocationȱ(nextȱtoȱaȱ
distinctȱtree,ȱforȱexample).ȱRepeatedȱphotosȱfromȱthisȱpointȱmayȱbeȱscaledȱagainstȱtheȱmeasuringȱstickȱ
andȱanyȱchangesȱwillȱbeȱeasyȱtoȱobserve.ȱ
Recordȱanyȱotherȱvisibleȱsignsȱofȱdegradationȱincludingȱlitterȱorȱdumping.ȱDescribeȱtheȱpresenceȱandȱ
extentȱofȱrevegetationȱeffortsȱorȱotherȱenvironmentalȱworksȱandȱtheȱpresenceȱandȱlocationȱofȱdrainageȱ
outletsȱorȱotherȱmanȱmadeȱstructures.ȱ
Theȱdatasheetȱprovidesȱaȱmethodȱofȱscoringȱeachȱsite.ȱThisȱisȱanȱindexȱscoreȱforȱtheȱhealthȱofȱtheȱ
vegetation,ȱbasedȱonȱtheȱamountȱofȱhumanȱdisturbance.ȱTheseȱscoresȱmayȱbeȱcomparedȱwithȱscoresȱfromȱ
otherȱsitesȱtoȱhelpȱdetermineȱwhereȱtheȱmostȱorȱleastȱdegradedȱsitesȱare.ȱȱ
Ifȱyourȱgroupȱassessesȱanȱentireȱtidalȱcreek,ȱaȱmapȱcouldȱbeȱdevelopedȱshowingȱtheȱlocationsȱofȱhigherȱ
andȱlowerȱscoredȱareas.ȱSuchȱaȱmapȱwouldȱprovideȱlocalȱLandcareȱgroupsȱorȱtheȱlocalȱcouncilȱwithȱ
assistanceȱinȱidentifyingȱandȱprioritisingȱanyȱenvironmentalȱimprovementȱprogramsȱtheyȱmayȱbeȱ
planning.ȱTheȱphotopointȱphotographsȱtakenȱoverȱseveralȱyearsȱareȱalsoȱusefulȱinȱtrackingȱtheȱprogressȱ
ofȱrevegetationȱefforts.ȱ
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Monitoring mangrove leaf/twig litter
production
InȱSouthȱAustralia,ȱonlyȱoneȱspeciesȱofȱmangroveȱoccurs.ȱThisȱisȱ
Avicenniaȱmarinaȱ(itsȱnameȱrefersȱtoȱitsȱseaȬgoingȱhabit).ȱItȱisȱ
commonlyȱcalledȱtheȱWhiteȱ(orȱGrey)ȱMangrove,ȱdueȱtoȱtheȱcolourȱofȱ
theȱundersideȱofȱitsȱleaves.ȱItȱisȱtheȱmostȱcoldȱtolerantȱofȱallȱ
mangroves,ȱandȱisȱalsoȱoneȱofȱtheȱfastestȱcolonisingȱspecies.ȱȱ
Tropicalȱareas,ȱsuchȱasȱtheȱNorthernȱTerritory,ȱmayȱhaveȱupȱtoȱ36ȱ
speciesȱofȱmangroveȱinȱlargeȱmangalsȱorȱmangroveȱforests.ȱȱ
Mangroveȱlitterȱproductionȱrefersȱtoȱtheȱsheddingȱofȱleaves,ȱtwigs,ȱ
flowers,ȱseedsȱorȱotherȱvegetativeȱmatterȱbyȱaȱmangroveȱtree.ȱThisȱ
mayȱbeȱcausedȱbyȱage,ȱstressȱorȱmechanicalȱfactorsȱ(egȱwind,ȱtidesȱorȱ
floods).ȱȱ
Measuringȱtheȱlitterȱproductionȱofȱindividualȱtreesȱmayȱmonitorȱtheȱ
healthȱofȱaȱmangroveȱforest.ȱAȱhealthyȱsystemȱshouldȱhaveȱaȱhighȱ
and/orȱstableȱmonthlyȱlitterȱproduction,ȱalthoughȱthisȱmayȱhaveȱlargeȱ
seasonalȱvariationsȱ(May,ȱ1999).ȱDecliningȱleafȱlitterȱproductionȱoverȱ
aȱperiodȱofȱyears,ȱorȱsuddenȱcopiousȱlitterȱproductionȱmayȱindicateȱ
thatȱtheȱcommunityȱisȱunderȱstress.ȱȱ
Theȱamountȱofȱreproductiveȱmaterialȱmayȱalsoȱbeȱusedȱasȱaȱmeasureȱ
ofȱhealth,ȱasȱreproductionȱeffortȱchangesȱifȱplantsȱareȱstressed.ȱ
PropagulesȱfromȱtheȱWhiteȱMangroveȱtakeȱupȱtoȱtwoȱyearsȱtoȱform,ȱ
thenȱfallȱfromȱtheȱparentȱplant,ȱdependingȱonȱclimate,ȱsoȱaȱ
downwardȱtrendȱinȱtheȱnumbersȱofȱpropagulesȱmayȱtakeȱmanyȱyearsȱ
toȱdetect.ȱȱ
Litterȱfallȱfromȱmangroveȱtreesȱrepresentsȱaȱsignificantȱpartȱofȱtheȱnetȱ
primaryȱproductivityȱofȱaȱmangroveȱforest,ȱalthoughȱaȱconsiderableȱ
amountȱofȱextraȱdetritusȱisȱbroughtȱinȱwithȱeachȱtide.ȱȱ
Activity:
3 Extension
Age: High school
Time: 3
Why? Leaf and flower
production is an indicator
of mangrove health. The
litter from mangroves is an
important part of the
detrital cycle and a
reduction may affect fauna.
Safety: Snakes may pose
danger during the summer
months, especially the drier
approaches to the
mangroves. Always wear
suitable clothing (strong
shoes and long trousers)
and work in pairs to
minimise the risk.
Keep a careful eye on the
litter when drying it in the
oven, to ensure it does not
catch alight.
Heat risks apply.
Litterȱfallȱisȱmeasuredȱbyȱinstallingȱleafȱlitterȱtrapsȱalongȱaȱtransectȱinȱaȱmangroveȱcommunity.ȱTrappedȱ
litterȱisȱcollectedȱandȱsortedȱintoȱdifferentȱcategories,ȱovenȱdriedȱandȱthenȱweighed.ȱTheȱdryȱweightȱofȱ
eachȱcategoryȱprovidesȱaȱmeasureȱofȱtheȱoverallȱlitterȱproductivityȱofȱtheȱmangal.ȱȱ
AȱpermitȱfromȱPIRSAȱwillȱbeȱrequiredȱforȱthisȱactivity.ȱIfȱanyȱaquacultureȱorȱminingȱleasesȱareȱheldȱoverȱ
theȱlandȱyouȱareȱworkingȱon,ȱyouȱwillȱalsoȱneedȱpermissionȱfromȱtheȱleaseholder.ȱItȱisȱbetterȱtoȱaccessȱ
mangrovesȱthroughȱaȱboardwalk,ȱwhereȱtheseȱexist,ȱtoȱminimiseȱyourȱimpactȱonȱtheȱforest.ȱ
What you may need:
–
GPSȱandȱtopographicȱmapȱorȱmapȱofȱtheȱboardwalkȱyouȱareȱaccessingȱ
–
50Ȭmȱmeasuringȱtapeȱ
–
aȱmetalȱtapeȱȱ
–
leafȱtrapsȱ(500ȱmmȱ×ȱ500ȱmm)ȱtaggedȱwithȱuniqueȱnumbersȱȱ
–
heavyȬdutyȱnylonȱcord,ȱpreferablyȱinȱaȱbrightȱcolourȱȱ
–
aȱlargeȱplasticȱbagȱforȱeachȱtrapȱȱ
–
sixȱsmallerȱplasticȱbagsȱforȱeachȱtrapȱ
–
labȱscalesȱ(accurateȱtoȱ0.01ȱg)ȱȱ
–
accessȱtoȱdryingȱovensȱ
–
litterȱrecordȱform.ȱ
92
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GUIDANCE
MANUAL
To ensure good results:
Leafȱlitterȱvariesȱconsiderablyȱbetweenȱtrees,ȱdependingȱmainlyȱonȱtheȱsizeȱofȱtheȱtreesȱandȱtheirȱlocationȱ
inȱrelationȱtoȱtheȱtide.ȱManyȱtransectsȱwouldȱbeȱrequiredȱtoȱallowȱaȱcomparisonȱofȱsites,ȱbutȱfewerȱ
locationsȱareȱrequiredȱtoȱmonitorȱoneȱsiteȱoverȱtime.ȱEnsureȱyouȱselectȱaȱrangeȱofȱsimilarȱsizedȱtreesȱ
throughȱtheȱwidthȱofȱtheȱforest,ȱandȱmarkȱthoseȱtreesȱsoȱthatȱyouȱmayȱuseȱthemȱagainȱinȱsubsequentȱ
years.ȱ
What to do:
Selectȱaȱsurveyȱareaȱwithinȱtheȱtallestȱpartȱofȱtheȱforest.ȱTheȱstuntedȱlandwardȱedgesȱofȱtheȱforestȱwillȱnotȱ
provideȱrepresentativeȱsamples.ȱDetermineȱtheȱapproximateȱcanopyȱheightȱusingȱaȱmetalȱtapeȱandȱ
recordȱthisȱonȱyourȱlitterȱrecordȱform.ȱȱ
Ifȱyouȱareȱusingȱaȱboardwalkȱtoȱaccessȱtheȱmangroveȱforest,ȱtrapsȱmayȱbeȱinstalledȱatȱregularȱintervalsȱ
alongȱtheȱboardwalk,ȱthroughȱtheȱcentralȱportionȱofȱtheȱforest.ȱAlternatively,ȱsetȱyourȱtrapsȱsoȱthatȱeachȱ
trapȱisȱaȱsimilarȱdistanceȱfromȱtheȱlowȱorȱhighȱtideȱlines.ȱTheȱnumberȱofȱtrapsȱusedȱisȱentirelyȱupȱtoȱtheȱ
resourcesȱofȱtheȱgroup,ȱalthoughȱmoreȱthanȱoneȱisȱrequiredȱtoȱaccountȱforȱvariabilityȱbetweenȱplants.ȱ
Eightȱorȱmoreȱprovideȱaȱreasonableȱnumberȱifȱtheȱgroupȱhasȱsufficientȱresources.ȱȱ
Toȱinstallȱaȱtrap,ȱattachȱaȱnylonȱcordȱtoȱeachȱcornerȱofȱtheȱtrapȱandȱtieȱitȱontoȱtheȱmangroveȱbranchesȱsoȱ
thatȱtheȱtrapȱhangsȱfairlyȱlevel.ȱMakeȱsureȱthatȱtheȱbottomȱofȱtheȱtrapȱisȱaboveȱtheȱhighȱtideȱmark,ȱwhichȱ
isȱoftenȱvisibleȱinȱaȱmangroveȱforestȱasȱaȱlineȱofȱdebrisȱcaughtȱinȱtheȱbranches.ȱȱ
Mangroveȱlitterȱtrapsȱneedȱtoȱbeȱemptiedȱfortnightly,ȱasȱAvicenniaȱmarinaȱleavesȱhaveȱsaltȱinȱthem,ȱandȱ
thisȱattractsȱmoisture,ȱcausingȱthemȱtoȱdecomposeȱquickly.ȱEmptyȱtheȱtrapȱbyȱremovingȱanyȱlargeȱsticksȱ
andȱplacingȱthemȱinȱplasticȱbagȱmarkedȱwithȱtheȱtrapȱnumber.ȱNextȱyouȱplaceȱtheȱbagȱunderȱtheȱtrapȱ
chute,ȱuntieȱtheȱchuteȱandȱemptyȱtheȱtrapȱcontents.ȱRetieȱtheȱchuteȱsecurelyȱthenȱmoveȱonȱtoȱtheȱnextȱ
trap.ȱ
Shouldȱaȱlargeȱstormȱorȱkingȱtideȱdisruptȱyourȱmonitoringȱbyȱstrippingȱlargeȱamountsȱofȱleavesȱorȱfillingȱ
theȱtrapȱwithȱdebris,ȱemptyȱtheȱtrapȱontoȱtheȱforestȱfloorȱandȱexamineȱitȱforȱdamage.ȱRecordȱthatȱtheȱ
dataȱwasȱlostȱforȱthisȱtrapȱduringȱthisȱperiod.ȱResetȱtheȱtrapȱandȱcontinueȱmonitoring.ȱȱ
Backȱatȱyourȱbase,ȱsortȱleafȱlitterȱcontentsȱfromȱeachȱtrapȱintoȱtheȱfollowingȱgroups:ȱleaves,ȱflowers,ȱbarkȱ
(includeȱwood),ȱpropagulesȱandȱ‘other’ȱ(oftenȱdriedȱseagrassȱorȱalgaeȱthatȱmayȱhaveȱblownȱintoȱtheȱtrapȱ
fromȱnearbyȱbranches).ȱDoȱnotȱmixȱtheȱcontentsȱofȱoneȱtrapȱwithȱmaterialȱfromȱotherȱtraps.ȱForȱeachȱ
trap,ȱcountȱtheȱnumberȱofȱpartsȱinȱeachȱcategoryȱ(ifȱpossible)ȱandȱrecordȱtheseȱnumbersȱonȱtheȱdatasheet.ȱȱ
Placeȱtheȱsortedȱcontentsȱintoȱlabelledȱsmallerȱbagsȱandȱplaceȱtheseȱbagsȱtogetherȱintoȱtheȱoriginalȱ
labelledȱplasticȱbagȱforȱstorageȱuntilȱdrying.ȱIfȱthereȱisȱtooȱmuchȱlitterȱtoȱdryȱatȱonce,ȱorȱtheȱovensȱareȱnotȱ
immediatelyȱavailable,ȱlitterȱmayȱbeȱrefrigeratedȱforȱupȱtoȱaȱweekȱbeforeȱbeingȱdried.ȱȱ
Theȱlitterȱshouldȱbeȱdriedȱinȱitsȱseparateȱcategoriesȱandȱtrapȱnumbersȱatȱ70°Cȱforȱthreeȱfullȱdays.ȱTheȱ
litterȱisȱdryȱwhenȱitȱisȱbrittleȱandȱtheȱleavesȱareȱeasilyȱcrumbledȱbetweenȱyourȱfingers.ȱIfȱtheȱweatherȱisȱ
hotȱandȱdryȱitȱmayȱbeȱpossibleȱtoȱdry,ȱorȱpartiallyȱdry,ȱtheȱlitterȱinȱaȱshelteredȱplaceȱinȱtheȱsun,ȱunderȱ
glassȱorȱbehindȱaȱwindow.ȱKeepȱaȱcarefulȱeyeȱonȱtheȱlitterȱtoȱensureȱitȱdoesȱnotȱburn.ȱTheȱpropagulesȱ
manyȱnotȱdryȱcompletely,ȱsoȱcountsȱareȱimportantȱtoȱsupplementȱtheȱweights.ȱȱ
Onceȱtheȱlitterȱisȱdry,ȱuseȱlabȱscalesȱtoȱseparatelyȱweighȱtheȱcontentsȱfromȱeachȱcategoryȱandȱeachȱtrap.ȱ
Recordȱeachȱofȱtheȱweightsȱ(inȱgramsȱtoȱtwoȱdecimalȱplaces)ȱonȱtheȱdatasheet.ȱDisposeȱofȱlitterȱbackȱtoȱ
whereȱitȱwasȱcollectedȱorȱintoȱmunicipalȱwaste.ȱȱ
Theȱdataȱfromȱthisȱactivityȱisȱexpressedȱasȱg/m2/fortnight,ȱforȱeachȱevent.ȱIfȱyouȱwishȱtoȱlookȱatȱ
productionȱannually,ȱexpressȱtheȱdataȱasȱaȱrangeȱofȱvaluesȱperȱmonth,ȱegȱx–yȱg/m2/month,ȱorȱpresentȱtheȱ
dataȱasȱaȱgraphȱshowingȱeachȱsamplingȱevent.ȱȱ
Significantȱdeclinesȱorȱsuddenȱincreasesȱinȱleafȱlitterȱfallȱorȱreproductiveȱeffortȱmayȱindicateȱthatȱtheȱ
communityȱisȱunderȱstress.ȱSeekȱadviceȱifȱsuchȱtrendsȱoccur.ȱȱ
93
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MANUAL
Monitoring mangrove expansion
Wetȱcoastalȱecosystemsȱcontainingȱhabitatsȱsuchȱasȱmangrovesȱandȱ
saltmarshesȱareȱseralȱcommunitiesȱ(Chapman,ȱ1960).ȱTheȱ
distributionȱofȱtheȱdifferentȱhabitatsȱisȱgovernedȱbyȱsedimentȱ
supply,ȱtidalȱregime,ȱwindȬwaveȱclimateȱandȱtheȱrelativeȱmovementȱ
ofȱlocalȱseaȱlevelȱ(PackhamȱandȱWillis,ȱ1997).ȱȱ
Forȱtheȱdevelopmentȱofȱmangalsȱandȱsaltmarshes,ȱsandȱorȱmudȱflatsȱ
mustȱaccumulateȱuntilȱtheirȱlevelȱisȱhighȱenoughȱtoȱallowȱ
colonisationȱbyȱplants.ȱThisȱcanȱonlyȱoccurȱwhereȱthereȱisȱsufficientȱ
sedimentȱsupplyȱ(eitherȱfromȱlandȱorȱoffshore)ȱandȱwhereȱtheȱwaterȱ
flowsȱareȱofȱlowȱenergy.ȱConstructionȱofȱembankments,ȱdeathȱofȱ
offshoreȱbenthicȱfloraȱsuchȱasȱseagrassȱbedsȱandȱchannellingȱofȱ
stormwaterȱflowsȱmayȱinfluenceȱbankȱformationȱbyȱchangingȱtheȱ
tidalȱregime,ȱwaterȱflowȱratesȱorȱwaveȱaction.ȱ
Changesȱinȱtheseȱcommunitiesȱoccurȱreasonablyȱquickly,ȱandȱ
simpleȱphotographicȱmonitoringȱmayȱdetectȱtheȱchangesȱwithinȱaȱ
fewȱyears.ȱOneȱparticularlyȱusefulȱwayȱofȱassessingȱthisȱchangeȱisȱtoȱ
establishȱaȱphotopointȱatȱaȱboatȱrampȱthatȱtraversesȱtheȱwidthȱofȱaȱ
mangroveȱforest.ȱ
Activity:
3 Extension
Age: High school
Time: 2
Why? Regular examination
of the seaward and
landward edges of a
mangrove forest can
determine whether the
forest is expanding or
retreating landward. This
may indicate local sea-level
change, or sediment
availability.
What you may need:
–
cameraȱ
–
fixedȱlocationsȱforȱtakingȱphotographsȱ(mayȱbeȱpaintȱmarksȱonȱaȱboatȱramp,ȱaboveȱwhichȱyouȱ
standȱyourȱcameraȱtripod,ȱaȱmarkedȱjettyȱrailȱorȱsomethingȱsimilar)ȱ
–
aȱmetreȱruleȱorȱotherȱmeasuringȱstickȱwithȱtheȱdateȱmarkedȱonȱaȱsheetȱattachedȱtoȱit.ȱ
To ensure good results:
Chooseȱaȱramp,ȱwharfȱorȱotherȱlocationȱwhereȱyouȱcanȱseeȱalongȱbothȱtheȱseawardȱandȱlandwardȱedgesȱ
ofȱaȱmangroveȱforest.ȱEnsureȱthatȱyouȱcanȱaccessȱbothȱareasȱtoȱplaceȱyourȱmetreȱruleȱagainstȱaȱtree.ȱ
What to do:
Thisȱactivityȱisȱbestȱconductedȱannually,ȱtoȱrecordȱtheȱexpansionȱorȱretreatȱofȱtheȱedgesȱofȱtheȱmangroveȱ
forest.ȱȱ
Establishȱaȱlocationȱthatȱisȱeasyȱtoȱmarkȱandȱcloseȱtoȱtheȱseawardȱedgeȱofȱtheȱmangrovesȱfromȱwhichȱtoȱ
takeȱyourȱphotographs.ȱPlaceȱyourȱmetreȱruleȱagainstȱaȱmangroveȱtreeȱthatȱwillȱbeȱinȱtheȱforegroundȱofȱ
theȱphotograph.ȱTakeȱaȱshotȱthatȱlooksȱalongȱtheȱseawardȱedgeȱandȱthatȱincludesȱyourȱmetreȱruleȱasȱaȱ
scaleȱandȱdate.ȱȱ
Moveȱinlandȱuntilȱyouȱreachȱaȱpointȱwhereȱyouȱcanȱseeȱalongȱtheȱlandwardȱedgeȱofȱtheȱforest.ȱRepeatȱ
theȱactivityȱoutlinedȱabove.ȱ
Onceȱyouȱhaveȱcollectedȱseveralȱyearsȱofȱphotographsȱyouȱmayȱwishȱtoȱscanȱtheȱprints,ȱandȱenlargeȱorȱ
reduceȱthemȱsoȱthatȱtheȱmetreȱruleȱisȱtheȱsameȱsizeȱinȱallȱofȱthem.ȱMostȱimageȱeditingȱsoftwareȱwillȱallowȱ
youȱdoȱthis,ȱandȱtoȱoverlayȱtheȱphotographsȱsoȱthatȱyouȱcanȱseeȱtheȱdifference.ȱAlternatively,ȱyouȱcouldȱ
scaleȱtheȱprintsȱusingȱaȱphotocopier,ȱthenȱplaceȱaȱgridȱoverȱtheȱscaledȱphotographsȱtoȱestimateȱtheȱ
change,ȱasȱdescribedȱinȱtheȱguidelineȱUsingȱaerialȱphotographsȱtoȱmapȱhabitatȱchange.ȱ
Isȱyourȱmangroveȱforestȱexpanding,ȱretreatingȱorȱmovingȱinland?ȱ
94
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Studying saltmarsh plants
SaltmarshesȱinȱSouthȱAustraliaȱhaveȱchangedȱextensivelyȱsinceȱ
Europeanȱsettlement.ȱDrainsȱandȱdykesȱhaveȱbeenȱusedȱtoȱconvertȱ
marshȱareasȱintoȱagriculturalȱlands,ȱandȱembankmentsȱhaveȱchangedȱ
theȱhydrologyȱsignificantly.ȱȱ
Thereȱisȱevidenceȱtoȱsuggestȱthat,ȱinȱtheȱPortȱAdelaideȱarea,ȱ
saltmarshȱcommunitiesȱareȱdecliningȱdueȱtoȱaȱlandwardȱexpansionȱofȱ
mangroveȱcommunities.ȱThisȱisȱdueȱtoȱaȱcombinationȱofȱsoilȱ
subsidenceȱ(aȱresultȱofȱembankmentȱworksȱinȱtheȱ1890s)ȱandȱseaȱlevelȱ
rise.ȱȱ
Healthyȱsaltmarshȱcommunitiesȱshowȱaȱzonationȱfromȱtheȱlowerȱ
marshȱtoȱtheȱupperȱmarsh.ȱInȱSouthȱAustralia,ȱsaltmarshesȱareȱ
samphireȬdominated.ȱSpeciesȱinȱtheȱlowerȱmarshȱmayȱincludeȱ
Sarcocornia,ȱthenȱthereȱareȱbandsȱofȱSclerostegia,ȱHalosarcia,ȱMaireanaȱ
andȱAtriplex,ȱandȱthenȱatȱtheȱhighestȱzoneȱaȱbandȱofȱgrassesȱmayȱbeȱ
found.ȱ
Thisȱactivityȱlooksȱatȱtheȱpercentȱcoverȱandȱspeciesȱdominanceȱofȱ
saltmarshȱspeciesȱalongȱaȱlineȱintersectȱtransect.ȱTheȱtransectȱcanȱrunȱ
eitherȱperpendicularȱtoȱ(fromȱlandȱtoȱtheȱmangroveȱfringe),ȱorȱ
parallelȱto,ȱtheȱtidalȱgradient.ȱSamphiresȱmayȱbeȱveryȱdenseȱandȱ
growȱoverȱhighlyȱunevenȱterrain,ȱandȱsoȱitȱisȱpreferableȱtoȱworkȱfromȱ
aȱboardwalk.ȱIfȱyouȱhaveȱaccessȱtoȱaȱboardwalk,ȱyouȱmayȱconsiderȱitȱ
toȱbeȱtheȱtransectȱlineȱandȱassessȱtheȱplantsȱtoȱoneȱsideȱofȱtheȱwalk.ȱȱ
Theȱpresenceȱandȱdistributionȱofȱspeciesȱoverȱtimeȱisȱaȱsimpleȱbutȱ
usefulȱindicatorȱofȱecosystemȱfunctionȱoverȱtime,ȱwithȱtheirȱlossȱorȱ
declineȱindicatingȱpotentialȱenvironmentalȱstressȱ(Zedler,ȱ2001).ȱ
Vegetationȱpatternsȱmayȱchangeȱinȱresponseȱto,ȱandȱmayȱindicate,ȱ
changingȱsoilȱsalinitiesȱorȱpH,ȱtidalȱflushingȱregimesȱorȱclimaticȱ
patterns.ȱThereforeȱthisȱactivityȱisȱaȱusefulȱoneȱforȱassessingȱtheȱ
progressȱofȱsaltmarshȱrehabilitationȱprojectsȱthatȱinvolveȱchangedȱ
tidalȱregimesȱ(ieȱafterȱfloodgatesȱhaveȱbeenȱremovedȱorȱmodified).ȱȱ
Activity:
3 Extension
Age: High school
Time: 3
Why? Saltmarsh areas are
valuable wader habitat and
fish nurseries. Saltmarshes
are very vulnerable to
hydrological change, which
may be revealed by a
change in the vegetation.
Safety: Saltmarshes are
home to snakes and other
small creatures. They also
have large numbers of
hidden creeks or overhangs
which are easy to fall
down. Look where you are
walking and ensure that all
members of the group are
wearing long pants and
covered shoes.
Saltmarsh environments
have no shade and can
become extremely hot.
Wear a hat, take a bottle of
water and try to work in
the cooler parts of the day.
What you may need:
–
50–100ȱmȱtapeȱmeasureȱȱ
–
saltmarshȱidentificationȱguidesȱ
–
compassȱandȱGPSȱ
–
topographicȱorȱsiteȱmapȱ
–
plasticȱorȱpaintedȱwoodenȱstakesȱȱ
–
malletȱorȱhammerȱ
–
saltmarshȱvegetationȱrecordȱform.ȱ
To ensure good results:
Doȱnotȱmonitorȱimmediatelyȱafterȱaȱveryȱhighȱstormȱtide.ȱTheȱsaltmarshesȱareȱlikelyȱtoȱbeȱflattened,ȱ
whichȱwillȱbiasȱresults.ȱ
95
ESTUARINE
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MANUAL
What to do:
S it eȱ selection ȱ
Closelyȱexamineȱaerialȱphotographsȱofȱtheȱmarshȱyouȱwishȱtoȱmonitor.ȱIfȱthereȱisȱaȱboardwalkȱorȱ
walkingȱpathȱthroughȱtheȱmarsh,ȱtakeȱaȱwalkȱalongȱit.ȱObserveȱtheȱspeciesȱcomposition,ȱcoverȱandȱ
canopyȱheightȱofȱtheȱsaltmarshȱandȱtheȱextentȱofȱeachȱofȱtheȱhabitats.ȱȱ
Itȱisȱimportantȱtoȱselectȱaȱmonitoringȱsiteȱthatȱisȱeasyȱtoȱaccess.ȱWalkingȱacrossȱsaltmarshesȱdamagesȱ
them,ȱandȱtheyȱmayȱtakeȱaȱlongȱtimeȱtoȱrecover.ȱTheȱharderȱtheȱsiteȱisȱtoȱaccess,ȱtheȱmoreȱdamageȱ
accessingȱitȱwillȱdo.ȱUsingȱtheȱedgeȱofȱaȱboardwalkȱorȱwalkingȱpathȱasȱtheȱtransectȱlineȱisȱprobablyȱbestȱ
forȱminimisingȱdamageȱandȱmakingȱthisȱactivityȱeasierȱonȱparticipants.ȱȱ
Theȱnextȱmostȱimportantȱpointȱisȱtoȱensureȱthatȱtheȱsiteȱappearsȱtoȱbeȱrepresentativeȱofȱtheȱstateȱofȱ
saltmarshesȱinȱtheȱarea.ȱ
E st a b l ish ingȱ aȱt r an sec tȱ or ȱ l in eȱ o fȱ in te rc ept ȱ
Theȱdirectionȱandȱlengthȱofȱtheȱlineȱintersectȱtransectȱdependsȱonȱtheȱobjectivesȱofȱtheȱmonitoringȱ
program,ȱsiteȱcharacteristicsȱandȱaccess.ȱȱ
Intersectȱlinesȱthatȱrunȱfromȱtheȱmangroveȱedgeȱtoȱtheȱhighestȱpointȱinȱtheȱmarshȱwillȱgenerallyȱcaptureȱ
theȱfullestȱrangeȱofȱhabitatȱgradients.ȱHowever,ȱlinesȱrunningȱparallelȱtoȱtheȱtideȱwillȱgiveȱyouȱtheȱlargestȱ
sampleȱofȱoneȱhabitatȱtype.ȱȱ
Eachȱtransectȱshouldȱbeȱ50ȱtoȱ100ȱmȱlong.ȱIfȱyouȱareȱrunningȱtheȱtransectȱlineȱacrossȱtheȱmarsh,ȱmeasureȱ
thisȱoutȱandȱlayȱtheȱmeasuringȱtapeȱalongȱtheȱground.ȱAtȱtheȱstartȱpointȱofȱtheȱline,ȱhammerȱaȱsmallȱ
stakeȱinȱ(withȱtheȱpermissionȱofȱtheȱlandholder).ȱRecordȱtheȱlocationȱusingȱaȱGPSȱorȱyourȱsiteȱmap.ȱ
Hammerȱanotherȱstakeȱinȱatȱtheȱotherȱendȱandȱrecordȱitsȱlocation.ȱAttachȱtheȱmeasuringȱtapeȱtoȱeachȱ
stakeȱsoȱthatȱitȱisȱrelativelyȱstraightȱandȱlevel.ȱ
Ifȱyouȱareȱusingȱaȱboardwalkȱasȱaȱtransect,ȱsimplyȱmarkȱtheȱstartȱandȱendȱpointsȱwithȱaȱdabȱofȱpaintȱonȱ
theȱboards,ȱandȱrecordȱtheirȱlocationsȱusingȱyourȱGPSȱorȱmap.ȱ
Itȱisȱrecommendedȱthatȱ100–300ȱmȱofȱtransectȱisȱestablishedȱinȱeachȱareaȱofȱsaltmarshȱthatȱyouȱwishȱtoȱ
monitor,ȱalthoughȱthisȱwillȱdependȱonȱyourȱresourcesȱandȱtimeȱavailability.ȱ
M on it or i ngȱth eȱm ar sh ȱ
Startingȱatȱtheȱbeginningȱofȱyourȱtransectȱandȱlookȱatȱtheȱplantsȱthatȱintersectȱit.ȱWhatȱisȱgrowingȱ
directlyȱbelowȱtheȱmeasuringȱtape,ȱorȱrightȱnextȱtoȱtheȱboardwalk?ȱUseȱyourȱguidesȱtoȱidentifyȱitȱtoȱ
eitherȱgenusȱorȱspeciesȱlevel.ȱIfȱyouȱcan’tȱidentifyȱit,ȱtakeȱaȱpictureȱorȱdescribeȱit.ȱAȱfewȱgoodȱ
identificationȱbooksȱareȱlistedȱatȱtheȱendȱofȱthisȱguideline.ȱHowȱmuchȱofȱtheȱfirstȱmetreȱofȱtransectȱlineȱ
doesȱeachȱspeciesȱcover?ȱȱ
Recordȱtheȱdistanceȱalongȱyourȱtransectȱthisȱspeciesȱcovers.ȱForȱexample,ȱyouȱmayȱhaveȱaȱtwoȱmetreȬ
wideȱswatheȱofȱSarcocorniaȱquinqueflora.ȱItȱisȱnotȱnecessaryȱtoȱrecordȱbareȱmudȱifȱtheȱpatchesȱareȱlessȱthanȱ
200ȱmmȱacross.ȱBareȱareasȱlargerȱthanȱthisȱneedȱtoȱbeȱrecorded.ȱȱ
Lookȱatȱeachȱmetreȱalongȱtheȱtransectȱlineȱandȱmakeȱaȱsimilarȱassessment.ȱIfȱyouȱgetȱlongȱlengthsȱofȱtheȱ
sameȱthing,ȱjustȱrecordȱthisȱasȱoneȱentryȱandȱdrawȱbracketsȱenclosingȱtheȱareaȱitȱcovers.ȱ
Whenȱyouȱgetȱtoȱtheȱendȱofȱtheȱfirstȱtransectȱworkȱoutȱtheȱtotalȱamountȱofȱeachȱspeciesȱinȱlinearȱmetresȱ
orȱpercentage.ȱRecordȱtheȱunitȱthatȱyouȱuse.ȱRepeatȱthisȱprocedureȱforȱeachȱofȱyourȱtransects.ȱȱ
Theȱinformationȱyouȱobtainȱwillȱtellȱyouȱaboutȱspeciesȱdominance,ȱtheȱpercentageȱcoverȱofȱsaltmarshȱ
speciesȱandȱtheȱpercentageȱcoverȱofȱweedȱspecies.ȱAȱcopyȱofȱyourȱfieldȱsheetȱandȱcalculationsȱforȱtheȱ
figuresȱmentionedȱaboveȱshouldȱbeȱsentȱtoȱyourȱWaterwatchȱcoordinator.ȱȱ
Thisȱactivityȱdetectsȱchangesȱthatȱoccurȱoverȱaȱlongȱperiodȱandȱthatȱmayȱnotȱbeȱnoticeableȱtoȱtheȱeye.ȱAnȱ
annualȱmeasurementȱatȱtheȱsameȱseasonȱmayȱbeȱrequiredȱforȱthreeȱyearsȱorȱmore,ȱbeforeȱyouȱcanȱdetectȱ
slowȱdegradation.ȱTwoȱmeasurementsȱaȱyearȱapartȱmayȱpickȱupȱanyȱrapidȱimprovementȱthatȱoccursȱonȱ
remediatedȱsites.ȱAȱonceȬonlyȱmeasurementȱwillȱtellȱyouȱquiteȱaȱlotȱaboutȱtheȱtypeȱofȱsaltmarshȱyouȱareȱ
96
ESTUARINE
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MANUAL
monitoring,ȱbutȱwillȱnotȱtellȱyouȱmuchȱaboutȱanyȱenvironmentalȱimpactsȱthatȱmayȱbeȱoccurring,ȱapartȱ
fromȱtheȱpresenceȱandȱquantityȱofȱweeds.ȱȱ
Someȱareas,ȱsuchȱasȱtheȱhighȱmarshȱareasȱnearȱPortȱPirieȱthatȱabutȱnaturalȱsabkhasȱ(giantȱmudȱorȱsaltȱ
flats),ȱwillȱnaturallyȱhaveȱaȱlowȱpercentageȱcover,ȱandȱwillȱbeȱdominatedȱbyȱaȱveryȱfewȱspecies.ȱOtherȱ
areas,ȱparticularlyȱlowȱmarshes,ȱwillȱhaveȱaȱhighȱpercentageȱcoverȱandȱwillȱalsoȱhaveȱhighȱnumberȱofȱ
species.ȱNeitherȱofȱtheseȱareȱmore,ȱorȱless,ȱhealthyȱthanȱtheȱother.ȱȱ
Aȱusefulȱpurposeȱofȱsaltmarshȱmonitoringȱisȱtoȱperformȱaȱ‘beforeȱandȱafter’ȱassessmentȱforȱregenerationȱ
projectsȱorȱhydrologicalȱchangesȱonȱtheȱsite.ȱIfȱtheȱmonitoringȱisȱbeingȱusedȱforȱthisȱpurpose,ȱcontrolȱ
sitesȱshouldȱbeȱestablishedȱtoȱdetermineȱifȱtheȱdetectedȱchangesȱareȱsiteȱspecificȱorȱareȱtheȱresultȱofȱmoreȱ
widespreadȱvariationsȱsuchȱasȱtheȱweather.ȱȱ
Dataȱonȱsoilȱsalinity,ȱpH,ȱsoilȱelevationȱandȱtidalȱflushingȱregimesȱwouldȱalsoȱbeȱusefulȱwhenȱ
interpretingȱtheȱsaltmarshȱspeciesȱdata.ȱGuidelinesȱonȱmeasuringȱtheseȱparametersȱareȱavailableȱinȱ
earlierȱsectionsȱofȱthisȱmanual.ȱȱ
U s e f u l r e f e r e n ce s
Dashorst,ȱGȱ&ȱJessop,ȱJȱ(1998),ȱPlantsȱofȱtheȱAdelaideȱPlainsȱ&ȱHills,ȱ2ndȱedition,ȱSouthȱAustralianȱStateȱ
Herbarium,ȱFinsburyȱPress.ȱȱ
Datson,ȱBȱ(2002),ȱSamphiresȱinȱWesternȱAustralia:ȱAȱFieldȱGuideȱtoȱChenopodiaceaeȱTribeȱSalicorniae,ȱ
DepartmentȱofȱConservationȱandȱLandȱManagement,ȱPerth.ȱȱ
George,ȱAȱ(ed)(1984),ȱFloraȱofȱAustralia:ȱVolumeȱ4—PhytolaccaceaeȱtoȱChenpodiaceae,ȱCommonwealthȱofȱ
Australia,ȱGriffinȱPress,ȱSouthȱAustralia.ȱȱ
Jessop,ȱJȱ&ȱToelken,ȱHȱ(1986),ȱFloraȱofȱSouthȱAustralia.ȱPartsȱI—IV,ȱ4thȱedition,ȱSouthȱAustralianȱStateȱ
Herbarium,ȱSouthȱAustralianȱGovernmentȱPress,ȱAdelaide.ȱȱ
Zedler,ȱJBȱ(2001),ȱHandbookȱforȱrestoringȱtidalȱwetlands,ȱCRCȱPress,ȱBocaȱRaton,ȱFlorida.ȱ
ȱ
ȱ
97
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Monitoring Melaleuca leaf/twig litter
production
InȱwetterȱareasȱofȱSouthȱAustralia,ȱMelaleucaȱorȱTeaȬTreeȱswampsȱ
oftenȱreplaceȱmangrovesȱatȱtheȱfresherȱendȱofȱestuaries.ȱȱ
‘Litterȱproduction’ȱmeansȱtheȱsheddingȱofȱleaves,ȱtwigs,ȱflowers,ȱ
seedsȱorȱotherȱvegetativeȱmatterȱbyȱaȱplant.ȱThisȱmayȱbeȱcausedȱbyȱ
age,ȱstressȱorȱmechanicalȱfactorsȱsuchȱasȱwindȱorȱfloods.ȱȱ
TheȱhealthȱofȱaȱMelaleucaȱswampȱmayȱbeȱassessedȱbyȱmeasuringȱtheȱ
litterȱproductionȱofȱitsȱmajorȱplantȱspecies.ȱAȱhealthyȱsystemȱwillȱ
haveȱaȱhighȱand/orȱstableȱmonthlyȱleafȱlitterȱasȱtheȱolderȱleavesȱareȱ
shedȱwhenȱtheȱplantȱproducesȱnewerȱones,ȱalthoughȱthereȱmayȱbeȱ
largeȱseasonalȱvariations.ȱDecliningȱleafȱlitterȱproductionȱoverȱseveralȱ
yearsȱmayȱindicateȱthatȱtheȱcommunityȱisȱunderȱstress.ȱTheȱquantityȱ
ofȱreproductiveȱmaterialȱmayȱalsoȱbeȱusedȱasȱaȱmeasureȱofȱhealthȱasȱ
reproductionȱeffortȱchangesȱifȱplantsȱareȱstressed.ȱȱ
LitterȱfallȱfromȱMelaleucaȱspeciesȱrepresentsȱaȱsignificantȱpartȱofȱtheȱ
netȱprimaryȱproductivityȱofȱaȱsupratidalȱMelaleucaȱswamp.ȱExamplesȱ
ofȱtheseȱtypesȱofȱswampsȱcanȱbeȱfoundȱinȱestuariesȱthroughoutȱtheȱ
southeastȱofȱSouthȱAustralia.ȱȱ
Litterȱfallȱisȱmeasuredȱbyȱinstallingȱleafȱlitterȱtrapsȱalongȱaȱtransectȱinȱ
aȱMelaleucaȱcommunity.ȱTrappedȱlitterȱisȱcollectedȱandȱsortedȱintoȱ
differentȱcategories,ȱovenȱdriedȱandȱthenȱweighed.ȱTheȱdryȱweightȱofȱ
eachȱcategoryȱprovidesȱaȱmeasureȱofȱtheȱlitterȱproductivityȱofȱtheȱ
Melaleucaȱcommunity.ȱThisȱmethodȱshouldȱonlyȱbeȱattemptedȱifȱ
groupsȱcanȱobtainȱaccessȱtoȱdryingȱovens.ȱȱ
Activity:
3 Extension
Age: High school
Time: 3
Why? In SA, Melaleuca
halmaturorum fringing
wetlands are often present
in the estuarine parts of
swampy watercourses.
These freshwater-intertidal
wetlands are an important
filter system for
floodwaters, and also
attenuate the progression
of floods into the more
marine parts of the
estuary.
Safety: Snakes may pose
danger during the summer
months, especially in long
grass. Always wear suitable
clothing (strong shoes and
long trousers) and work in
pairs to minimise the risk.
Aȱpermitȱmayȱbeȱrequiredȱforȱthisȱactivity.ȱAttemptȱtoȱfindȱoutȱwhoȱ
ownsȱtheȱlandȱyouȱplanȱtoȱcollectȱlitterȱfrom.ȱIfȱprivatelyȱowned,ȱgetȱ
writtenȱpermissionȱfromȱtheȱowner.ȱIfȱtheȱlandȱisȱownedȱbyȱtheȱ
Crown,ȱaȱpermitȱtoȱtakeȱnativeȱvegetationȱ(availableȱfromȱtheȱNPWS)ȱ
mayȱbeȱrequired.ȱȱ
Keep a careful eye on the
litter when drying it to
ensure it does not catch
alight, and ensure no other
flammables are near the
litter.
What you may need:
Heat risks apply when
working with ovens.
–
GPSȱandȱtopographicȱmapȱ
–
50Ȭmȱmeasuringȱtapeȱ
–
steelȱmeasuringȱtapeȱ
–
leafȱtrapsȱ(500ȱ×ȱ500ȱmm)ȱtaggedȱuniqueȱnumbersȱȱ
–
fourȱwoodenȱgardenȱstakesȱforȱeachȱtrapȱ
–
heavyȬdutyȱnylonȱcord,ȱpreferablyȱinȱaȱbrightȱcolourȱȱ
–
aȱlargeȱplasticȱbagȱforȱeachȱtrapȱȱ
–
sixȱsmallerȱplasticȱbagsȱforȱeachȱtrapȱ
–
labȱscalesȱ(accurateȱtoȱ0.01ȱg)ȱȱ
–
accessȱtoȱdryingȱovensȱ
–
litterȱrecordȱform.ȱ
To ensure good results:
Selectȱyourȱsurveyȱsiteȱsoȱthatȱitȱisȱcompletelyȱcontainedȱinȱhabitatȱthatȱappearsȱhomogenous.ȱIfȱtheȱ
habitatȱchanges,ȱthenȱlitterȱcollectionȱwillȱalsoȱvary.ȱ
98
ESTUARINE
MONITORING
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MANUAL
What to do:
Recordȱtheȱdominantȱspeciesȱpresent,ȱandȱuseȱtheȱsteelȱtapeȱtoȱapproximateȱtheȱcanopyȱheightȱofȱyourȱ
site.ȱRecordȱthisȱonȱyourȱlitterȱrecordȱform.ȱȱ
Trapsȱmayȱeitherȱbeȱinstalledȱatȱregularȱintervalsȱalongȱaȱtransectȱorȱlocatedȱrandomlyȱinȱaȱ20ȱmȱ×ȱ20ȱmȱ
grid.ȱTheȱnumberȱofȱtrapsȱusedȱisȱentirelyȱupȱtoȱtheȱresourcesȱofȱtheȱgroup.ȱHowever,ȱmoreȱthanȱoneȱisȱ
requiredȱtoȱaccountȱforȱvariabilityȱbetweenȱplants.ȱEightȱorȱmoreȱisȱaȱgoodȱnumberȱifȱtheȱgroupȱhasȱ
sufficientȱresources.ȱȱ
Toȱinstallȱeachȱtrap,ȱhammerȱfourȱstakesȱintoȱtheȱgroundȱuntilȱaboutȱoneȱmetreȱhigh.ȱPlaceȱthemȱinȱaȱ
squareȱpatternȱjustȱoverȱ500Ȭmmȱapart.ȱAttachȱtheȱtrapȱtoȱtheȱstakesȱwithȱheavyȬdutyȱcord,ȱensuringȱthatȱ
theȱchuteȱisȱoffȱtheȱground.ȱTheȱtrapȱisȱnotȱgenerallyȱsecuredȱtoȱtheȱtree,ȱasȱMelaleucaȱbranchesȱsnapȱ
easily.ȱEnsureȱthatȱtheȱchutesȱareȱsecurelyȱtied.ȱȱ
IfȱyourȱareaȱofȱMelaleucaȱswampȱisȱregularlyȱinundated,ȱlocateȱtheȱtrapsȱinȱtheȱhigherȱareasȱofȱtheȱ
wetland,ȱdiscontinueȱmonitoringȱduringȱfloodȱperiodsȱorȱplaceȱtheȱtrapsȱhighȱenoughȱaboveȱtheȱgroundȱ
toȱpreventȱinundation.ȱȱ
Ifȱtrapsȱbecomeȱfloodedȱduringȱwetȱperiodsȱdiscontinueȱleafȱcollectingȱfromȱthisȱtrapȱuntilȱtheȱfloodȱhasȱ
dispersed.ȱWhenȱtheȱwaterȱisȱgone,ȱreturnȱtoȱtrapȱandȱemptyȱitȱontoȱtheȱground.ȱThisȱlitterȱwillȱhaveȱ
rottedȱorȱhaveȱbeenȱcontaminatedȱwithȱsediment,ȱsoȱisȱnotȱuseful.ȱRecordȱthatȱtheȱdataȱwasȱlostȱforȱthisȱ
period.ȱResetȱtheȱtrapȱtoȱcontinueȱmonitoring.ȱȱ
Trapsȱneedȱtoȱbeȱemptiedȱeveryȱmonth.ȱThisȱisȱtoȱpreventȱleafȱdecayȱandȱtoȱhelpȱdetermineȱmonthlyȱorȱ
seasonalȱtrends.ȱEmptyȱtheȱtrapȱbyȱremovingȱanyȱlargeȱsticksȱandȱthenȱplaceȱthemȱinȱaȱplasticȱbagȱ
markedȱwithȱtheȱtrapȱnumber.ȱNextȱyouȱplaceȱtheȱbagȱunderȱtheȱchute,ȱuntieȱtheȱchuteȱandȱemptyȱtheȱ
trapȱcontents.ȱRetieȱtheȱchuteȱsecurelyȱthenȱmoveȱonȱtoȱtheȱnextȱtrap.ȱȱ
Onceȱbackȱatȱyourȱbase,ȱsortȱleafȱlitterȱcontentsȱfromȱeachȱtrapȱintoȱtheȱfollowingȱgroups:ȱleaves,ȱflowers,ȱ
barkȱ(includeȱwood),ȱseeds,ȱotherȱspeciesȱ(nonȱMelaleuca)ȱandȱweeds.ȱDoȱnotȱmixȱcontentsȱofȱoneȱtrapȱ
withȱmaterialȱfromȱotherȱtraps.ȱCountȱtheȱnumberȱofȱpartsȱinȱeachȱcategoryȱ(ifȱpossible)ȱandȱrecordȱtheseȱ
numbersȱonȱtheȱdatasheet.ȱȱ
Placeȱtheȱsortedȱcontentsȱintoȱsmallerȱbagsȱandȱtheȱsmallerȱbagsȱbackȱintoȱtheȱoriginalȱlabelledȱplasticȱ
bagȱforȱstorageȱuntilȱdryingȱcanȱbeȱattempted.ȱIfȱthereȱisȱtooȱmuchȱlitterȱtoȱdryȱatȱonce,ȱorȱtheȱovensȱareȱ
notȱimmediatelyȱavailable,ȱlitterȱcontentsȱmayȱbeȱrefrigeratedȱforȱupȱtoȱaȱweek.ȱȱ
Theȱlitterȱshouldȱbeȱdriedȱinȱtheirȱseparateȱcategoriesȱandȱtrapȱnumbersȱatȱ70°Cȱforȱthreeȱfullȱdays.ȱTheȱ
litterȱisȱdryȱwhenȱitȱisȱbrittleȱandȱtheȱleavesȱareȱeasilyȱcrumbledȱbetweenȱyourȱfingers.ȱIfȱtheȱweatherȱisȱ
hotȱandȱdryȱitȱmayȱbeȱpossibleȱtoȱdry,ȱorȱpartiallyȱdry,ȱtheȱlitterȱinȱaȱshelteredȱplaceȱinȱtheȱsun,ȱunderȱ
glassȱorȱbehindȱaȱwindow.ȱKeepȱaȱcarefulȱeyeȱonȱtheȱlitterȱtoȱensureȱitȱdoesȱnotȱburn.ȱȱ
Onceȱtheȱlitterȱisȱdry,ȱuseȱlabȱscalesȱtoȱseparatelyȱweighȱtheȱcontentsȱfromȱeachȱcategoryȱandȱeachȱtrap.ȱ
Recordȱeachȱofȱtheȱweightsȱ(inȱgramsȱtoȱtwoȱdecimalȱplaces)ȱontoȱtheȱdatasheet.ȱDisposeȱofȱleafȱlitterȱ
backȱtoȱwhereȱitȱwasȱcollectedȱorȱintoȱmunicipalȱwaste.ȱȱ
Theȱdataȱforȱeachȱsamplingȱeventȱisȱexpressedȱasȱg/m2/month.ȱShouldȱyouȱwishȱtoȱlookȱatȱanȱannualȱ
figure,ȱexpressȱtheȱdataȱasȱrangesȱofȱvaluesȱperȱmonth,ȱegȱx–yȱg/m2/month,ȱorȱgraphȱtheȱyear’sȱevents.ȱȱ
Significantȱdeclinesȱinȱleafȱlitterȱfallȱorȱreproductiveȱeffortȱmayȱindicateȱthatȱtheȱcommunityȱisȱunderȱ
stress.ȱSeekȱadviceȱifȱsuchȱtrendsȱoccur.ȱȱ
99
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Using aerial photographs to map habitat
change
Theȱfirstȱtimeȱaeroplanesȱwereȱusedȱtoȱphotographȱaȱlargeȱsectionȱofȱ
SouthȱAustraliaȱwasȱinȱ1949.ȱThisȱareaȱincludedȱAdelaideȱandȱitsȱ
surroundingȱplains.ȱTheȱphotosȱwereȱinȱblackȱandȱwhite,ȱbutȱtheȱ
qualityȱwasȱexceptionalȱforȱtheȱtime.ȱ
Inȱtheȱlastȱ54ȱyearsȱtheseȱaerialȱphotographsȱareȱtakenȱonȱaȱregularȱ
basis.ȱTheȱAdelaideȱmetropolitanȱareaȱisȱphotographedȱatȱleastȱ
everyȱyear.ȱOtherȱlowlyȱpopulatedȱareasȱareȱphotographedȱlessȱ
frequently.ȱȱ
Theseȱphotographsȱwereȱinitiallyȱtakenȱforȱplanningȱreasons,ȱasȱ
theyȱareȱusedȱtoȱcreateȱupȬtoȬdateȱorthophotoȱmapsȱinȱtheȱ1:20,000,ȱ
1:10,000,ȱ1:5000ȱandȱ1:2500ȱscales.ȱEnvironmentalȱscientists,ȱ
managersȱandȱgeologistsȱquicklyȱfoundȱusesȱforȱaerialȱphotographs,ȱ
asȱtheyȱareȱplentifulȱsourcesȱofȱdata.ȱAerialȱphotographyȱisȱnowȱ
commonlyȱavailableȱinȱblackȱandȱwhite,ȱcolour,ȱfalseȱcolourȱandȱ
digitalȱformats.ȱȱ
Activity:
Extension
Age: High school
Time: 3
Why? This activity measures
the changes in coastal
habitats that occur over a
long period of time.
Safety: This is a desk-based
activity.
Forȱthisȱactivityȱcurrentȱorȱhistoricȱorthophotoȱmapsȱorȱaerialȱphotographsȱmayȱbeȱused.ȱWhereȱ
available,ȱtheseȱareȱtheȱtwoȱcheapestȱsourcesȱofȱspatialȱdataȱonȱyourȱestuary.ȱObtainedȱinȱanȱappropriateȱ
scale,ȱusuallyȱbetweenȱ1:10,000ȱandȱ1:2500,ȱtheseȱmapsȱandȱphotographsȱcanȱbeȱusedȱtoȱidentifyȱlandȱ
managementȱchanges,ȱnewȱareasȱofȱdevelopment,ȱchangesȱinȱvegetationȱorȱpollutionȱdischargeȱareas.ȱȱ
Currentȱaerialȱphotos,ȱsatelliteȱimagery,ȱtopographicȱmapsȱandȱorthophotoȱmapsȱareȱproducedȱbyȱandȱ
canȱbeȱpurchasedȱfromȱtheȱStateȱGovernment,ȱthroughȱMaplandȱSAȱatȱ(08)ȱ8463ȱ3999ȱorȱ
<www.mapland.sa.gov.au>.ȱThisȱgroupȱalsoȱproducesȱCDȱROMsȱofȱaerialȱphotographsȱforȱdifferentȱ
partsȱofȱtheȱstate,ȱandȱtheseȱareȱaȱveryȱeconomicalȱwayȱtoȱpurchaseȱlargeȱareasȱofȱcoverage.ȱ
Thisȱactivityȱisȱsimplestȱtoȱcompleteȱifȱallȱtheȱdataȱsourcesȱareȱobtainedȱinȱsimilarȱscales,ȱasȱitȱmakesȱ
comparisonȱeasier;ȱscalingȱcanȱbeȱdoneȱlaterȱifȱrequired.ȱTheȱpersonnelȱatȱMaplandȱorȱanyȱotherȱretailȱ
outletȱshouldȱbeȱableȱtoȱassistȱyouȱinȱselectingȱtheȱrightȱscaleȱforȱthisȱactivity.ȱIfȱinȱdoubt,ȱaskȱtoȱlookȱatȱ
anȱexampleȱofȱyourȱareaȱinȱeachȱofȱtheȱdifferentȱscalesȱandȱpickȱtheȱoneȱyouȱfeelȱbestȱfitsȱyourȱ
requirements.ȱȱ
What you may need:
–
aerialȱphotosȱofȱyourȱestuaryȱarea,ȱbothȱhistoricȱandȱrecentȱȱ
–
latitudeȱandȱlongitude,ȱAustralianȱMapȱGridȱorȱUniversalȱMapȱGridȱcoordinatesȱforȱaȱrangeȱofȱ
landmarksȱsurroundingȱorȱinȱyourȱestuaryȱ(theseȱmayȱbeȱobtainedȱfromȱaȱgoodȱqualityȱ
topographicȱmap)ȱ
–
clearȱtransparencyȱfilmȱ
–
blackȬlinedȱgraphȱpaper,ȱphotocopiedȱontoȱtransparencyȱfilmȱ
–
fineȬtippedȱpermanentȱmarkersȱȱ
–
topographicȱmapȱwithȱaȱsimilarȱscaleȱtoȱtheȱphotographȱ
–
rulerȱȱ
–
paperȱclips,ȱpinsȱorȱblueȱtackȱ
–
calculatorȱȱ
–
goodȱlight.ȱ
ȱ
100
ESTUARINE
MONITORING
GUIDANCE
MANUAL
To ensure good results:
Useȱatȱleastȱthree,ȱandȱpreferablyȱfour,ȱreferenceȱpointsȱtoȱcheckȱtheȱscaleȱofȱyourȱaerialȱphotographȱandȱ
rememberȱtoȱgroundtruth—checkȱyourȱinterpretationȱbyȱvisitingȱtheȱsites.ȱ
What to do:
I nte rpr et ingȱ map sȱ andȱa e r ia l s:ȱ o r ie n t at i on ȱ
Layȱyourȱphotographsȱandȱmapsȱoutȱinȱfrontȱofȱyou.ȱLocateȱlandmarksȱthatȱyouȱhaveȱvisitedȱonȱtheȱ
ground.ȱCanȱyouȱfindȱany?ȱDoȱtheyȱlookȱdifferentȱfromȱhowȱyouȱthoughtȱtheyȱwouldȱlook?ȱȱ
Layȱaȱtransparentȱsheetȱoverȱtheȱphotographsȱandȱmarkȱtheȱlandmarksȱwithȱaȱpermanentȱmarker.ȱWriteȱ
theȱcoordinatesȱnextȱtoȱtheȱlandmarksȱonȱtheȱacetateȱsheet,ȱthenȱlayȱitȱoverȱaȱmapȱofȱtheȱsameȱscale.ȱIfȱ
youȱdoȱnotȱhaveȱaȱmapȱofȱtheȱsameȱscale,ȱyouȱmayȱreduceȱorȱincreaseȱtheȱsizeȱofȱyourȱtransparencyȱonȱaȱ
photocopier.ȱȱ
Doȱtheȱlandmarksȱonȱtheȱtransparencyȱlineȱupȱwithȱthoseȱmarkedȱonȱtheȱmap?ȱHowȱfarȱoutȱareȱthey?ȱ
Aerialȱphotosȱareȱdistortedȱdueȱtoȱtheȱcurveȱofȱtheȱearthȱandȱtheȱangleȱtheȱplaneȱwasȱatȱwhenȱtheȱphotoȱ
wasȱtaken.ȱHowȱdistortedȱareȱyourȱphotos?ȱ
I nte rpr et ingȱ map sȱ andȱa e r ia l s:ȱ tracing ȱobjectsȱo fȱ int er e st ȱ
Placeȱaȱtransparentȱsheetȱontoȱyourȱaerialȱphoto.ȱSelectȱtheȱobjectsȱthatȱyouȱwishȱtoȱmap.ȱExamplesȱcouldȱ
beȱvegetationȱtypes,ȱhousingȱandȱindustrialȱareas,ȱareaȱofȱtheȱestuaryȱorȱtheȱlocationȱofȱtheȱshoreline.ȱUseȱ
yourȱfineȱtippedȱpermanentȱmarkersȱtoȱtraceȱaroundȱeachȱofȱtheȱobjectsȱofȱinterest,ȱusingȱaȱdifferentȱ
colourȱifȱyouȱwantȱtoȱshowȱseveralȱthingsȱonȱtheȱsameȱsheet.ȱForȱinstance,ȱmangrovesȱcouldȱbeȱoutlinedȱ
inȱoneȱcolourȱandȱsamphiresȱinȱanother.ȱ
Beȱcareful,ȱwhenȱtracing,ȱtoȱbeȱasȱaccurateȱasȱpossible,ȱotherwiseȱyourȱdataȱwillȱnotȱbeȱofȱveryȱgoodȱ
quality.ȱItȱisȱgenerallyȱrecommendedȱthatȱtheȱoutsideȱofȱyourȱmarkerȱlineȱmatchesȱtheȱoutsideȱofȱtheȱ
objectȱorȱareaȱyouȱareȱmapping,ȱandȱthatȱtheȱlineȱisȱasȱfineȱasȱpossible.ȱȱ
Ifȱmappingȱtheȱchangesȱthatȱoccurȱoverȱtimeȱinȱhabitats,ȱtraceȱeachȱofȱtheȱdifferentȱdatedȱaerialȱ
photographsȱontoȱdifferentȱtransparentȱsheets.ȱȱ
I nte rpr et ingȱ map sȱ andȱa e r ia l s:ȱworking ȱ out ȱa rea ȱ
Onceȱyouȱhaveȱfinishedȱtracingȱallȱtheȱobjects,ȱreduceȱorȱenlargeȱthemȱonȱyourȱphotocopierȱuntilȱtheyȱareȱ
allȱtoȱtheȱsameȱscale.ȱOnceȱyouȱareȱhappyȱwithȱthem,ȱphotocopyȱthemȱontoȱfilmȱthatȱhasȱgraphȱpaperȱ
markingsȱonȱit,ȱorȱoverlayȱtwoȱbitsȱofȱfilmȱandȱstickȱthemȱtogether.ȱȱ
Determineȱtheȱareaȱofȱeachȱofȱtheȱsquaresȱonȱtheȱfilm.ȱCountȱtheȱnumberȱofȱsquaresȱthatȱfallȱcompletelyȱ
withinȱeachȱofȱtheȱtracedȱobjectsȱandȱestimateȱtheȱnumberȱofȱpartialȱsquares.ȱCalculateȱtheȱtotalȱareaȱ(onȱ
theȱfilm)ȱofȱeachȱofȱtheȱtracedȱobjects.ȱMultiplyȱthisȱbyȱtheȱappropriateȱscaleȱtoȱgetȱtheȱareaȱofȱeachȱofȱtheȱ
objectsȱonȱtheȱland.ȱȱ
I nte rpr et ingȱ map sȱ andȱa e r ia l s:ȱ c omp ar ing ȱch ang e ȱ
Changeȱcanȱbeȱmeasuredȱinȱaȱnumberȱofȱways.ȱItȱmayȱbeȱmeasuredȱasȱchangesȱinȱarea,ȱorȱitȱmayȱbeȱ
measuredȱasȱchangesȱinȱlocation.ȱCompareȱyourȱtracingsȱandȱyourȱareaȱcalculations.ȱHasȱanyȱobjectȱorȱ
landȱcoverȱtypeȱchangedȱsignificantlyȱinȱitsȱtotalȱarea?ȱAreȱtheȱindividualȱareasȱofȱvegetationȱsmallerȱorȱ
larger?ȱȱ
Layȱtheȱtracingsȱonȱtopȱofȱeachȱother.ȱHasȱanyȱobjectȱorȱlandȱcoverȱtypeȱchangedȱsignificantlyȱinȱ
location?ȱIfȱsoȱhasȱitȱmovedȱinlandȱorȱseaward?ȱandȱbyȱhowȱmuch?ȱȱ
Theseȱfiguresȱprovideȱveryȱusefulȱinformationȱforȱenvironmentalȱmanagers.ȱForȱexample,ȱinȱtheȱ
Adelaideȱarea,ȱmuchȱofȱtheȱcoastalȱareaȱaroundȱPortȱAdelaideȱandȱGillmanȱhasȱpotentialȱacidȱsulphateȱ
soils.ȱInȱtheȱ1890sȱseawallsȱwereȱputȱin,ȱtoȱkeepȱtheȱtideȱoutȱofȱlargeȱareasȱsouthȱofȱStȱKilda,ȱsoȱtheȱlandȱ
couldȱbeȱusedȱforȱgrazing.ȱThisȱplanȱwasȱnotȱveryȱsuccessful,ȱandȱbyȱtheȱlateȱ1930sȱtheȱseawallsȱwereȱ
breachedȱtoȱallowȱtheȱseaȱbackȱin.ȱHowever,ȱtheȱseaȱdidȱnotȱjustȱcomeȱbackȱinȱtoȱwhereȱitȱhadȱoriginally:ȱ
inȱtheȱtimeȱitȱhadȱbeenȱkeptȱdry,ȱtheȱsoilȱhadȱoxidised,ȱgeneratingȱacid.ȱThisȱhadȱdissolvedȱmuchȱofȱtheȱ
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MANUAL
carbonateȱ(shelly)ȱdepositsȱinȱtheȱsoil,ȱandȱtheȱlandȱhadȱshrunk.ȱItȱwasȱnowȱmuchȱlowerȱthanȱitȱhadȱbeenȱ
whenȱtheȱseawallsȱwereȱfirstȱinstalled.ȱAsȱaȱresultȱtheȱmangroveȱzoneȱhasȱmovedȱinlandȱbyȱseveralȱ
hundredȱmetresȱinȱsomeȱareas.ȱAcidȱsulphateȱsoilsȱareȱnotȱrestrictedȱtoȱtheȱAdelaideȱarea,ȱtheyȱoccurȱinȱ
depositionalȱcoastalȱenvironmentsȱaroundȱtheȱstate.ȱActivitiesȱsuchȱasȱMeasuringȱsoilȱsalinityȱandȱsoilȱpHȱ
willȱhelpȱyouȱdetermineȱifȱyourȱestuaryȱhasȱareasȱofȱacidȱsulphateȱsoils.ȱ
I nte rpr et ingȱ map sȱ andȱa e r ia l s:ȱ facing ȱthe ȱground ȱtruthȱ ȱ
Afterȱcompletingȱyourȱanalysisȱitȱisȱrecommendedȱthatȱyourȱdataȱbeȱgroundtruthed.ȱThisȱsimplyȱmeansȱ
goingȱintoȱtheȱfieldȱwithȱaȱGPSȱandȱcheckingȱthatȱwhatȱyouȱthoughtȱyouȱsawȱonȱtheȱphotosȱorȱmapsȱisȱ
actuallyȱthere.ȱȱ
Markȱanyȱareasȱthatȱareȱdifferentȱfromȱyourȱoriginalȱassessmentȱandȱredoȱanyȱcalculationsȱbasedȱonȱthisȱ
newȱdata.ȱȱ
FurtherȱinformationȱonȱmappingȱmangrovesȱandȱsaltmarshȱcanȱbeȱfoundȱinȱWiltonȱ&ȱSaintilanȱ(2000).ȱȱ
M or eȱd eta i le dȱa n a ly s is ȱ
Ifȱyourȱgroupȱbecomesȱveryȱinterestedȱinȱanalysingȱaerialȱphotography,ȱyouȱmayȱbeȱpreparedȱtoȱspendȱ
theȱtimeȱtoȱlearnȱtheȱuseȱofȱaȱcomputerisedȱgeographicȱinformationȱsystemȱ(GIS).ȱTheseȱpackagesȱ
simplifyȱtheȱgeorectificationȱandȱscalingȱofȱyourȱphotographs,ȱandȱmayȱprovideȱveryȱsophisticatedȱ
analyses.ȱFreeȱpublicȱdomainȱGISȱpackagesȱareȱavailableȱforȱthoseȱinterestedȱinȱexploringȱthisȱ
technology.ȱMoreȱinformationȱ(andȱtheȱsoftware)ȱcanȱbeȱfoundȱatȱtheȱfollowingȱwebȱaddresses:ȱ
— <www.microimages.com>ȱisȱtheȱsiteȱforȱfreeȱTNTliteȱsoftwareȱ(sizeȱlimitedȱversionȱofȱTNTmips)ȱ
— <grass.baylor.edu>isȱtheȱsiteȱforȱfree,ȱopenȱsourceȱGRASSȱsoftwareȱdevelopedȱbyȱtheȱUSȱmilitaryȱ
— <www.esri.com/software/arcexplorer>isȱaȱveryȱbasicȱfreeȱGISȱfromȱtheȱmakersȱofȱArcInfoȱ
— <www.tiem.utk.edu/~sada>ȱisȱtheȱfreeȱSpatialȱAnalysisȱandȱDecisionȱAssistanceȱsoftwareȱpageȱ
— <www.mapmaker.com>ȱisȱtheȱsiteȱtoȱdownloadȱMapmakerȱGratis.ȱ
P r es ent ing ȱy ou rȱdata ȱ
Dataȱfromȱthisȱactivityȱisȱpresentedȱasȱaȱlossȱorȱgainȱinȱhabitatȱareaȱorȱdevelopmentȱchangesȱoverȱaȱ
period.ȱWhenȱdiscussingȱthisȱdataȱitȱisȱimportantȱtoȱmentionȱtheȱyearsȱbeingȱcomparedȱandȱtheȱscaleȱofȱ
theȱoriginalȱphotographsȱorȱmaps.ȱȱ
Aerialȱphotographȱinterpretationȱisȱsomewhatȱsubjective,ȱwhichȱisȱwhyȱgroundtruthingȱisȱveryȱ
important.ȱ
Theȱsignificanceȱofȱchangesȱmustȱbeȱassessedȱwhenȱinterpretingȱdataȱfromȱthisȱactivity.ȱChangesȱinȱlandȱ
coverȱofȱlessȱthanȱ10%ȱoverȱ10ȱorȱ20ȱyearsȱmayȱnotȱbeȱsignificant.ȱTheȱerrorȱinȱtheȱprocessesȱusedȱmayȱ
accountȱforȱaȱconsiderableȱamountȱofȱtheȱerror.ȱIfȱthereȱwasȱaȱconsistentȱ10%ȱchangeȱinȱlandȱcoverȱeveryȱ
year,ȱforȱaȱperiodȱofȱ3–4ȱyears,ȱthisȱmayȱbeȱsignificant.ȱȱ
Availabilityȱofȱphotographs,ȱorȱpoorȱqualityȱhistoricalȱphotos,ȱmayȱbeȱaȱdifficultyȱforȱsomeȱgroupsȱorȱ
areas.ȱTheȱCoastȱandȱMarineȱBranchȱhasȱplacedȱaȱconsiderableȱquantityȱofȱcoastalȱhabitatȱmappingȱ
(includingȱsomeȱhistoricalȱdataȱforȱpartsȱofȱtheȱSAȱcoast)ȱonlineȱinȱtheȱSouthȱAustralianȱnodeȱofȱtheȱ
CoastalȱAtlas.ȱTheȱAtlasȱmayȱbeȱaccessedȱbyȱvisitingȱtheȱwebsiteȱatȱ<www.atlas.sa.gov.au/coastal/>.ȱȱ
102
ESTUARINE
MONITORING
GUIDANCE
MANUAL
Measuring beach litter
LitterȱonȱourȱbeachesȱandȱfloatingȱinȱAustralianȱmarineȱandȱestuarineȱ
watersȱisȱaȱbigȱproblem,ȱparticularlyȱnonȬbiodegradableȱlitter.ȱItȱ
harmsȱourȱmarineȱlife,ȱdiversȱandȱbeachȬusers.ȱSoftȱdrinkȱringsȱmayȱ
trapȱseabirds,ȱplasticȱbagsȱmayȱbeȱeatenȱbyȱseaȱmammalsȱorȱentangleȱ
fish,ȱsharpȱneedlesȱandȱbitsȱofȱglassȱgiveȱnastyȱcutsȱorȱdiseasesȱtoȱ
beachȬusers,ȱandȱbitsȱofȱnetȱentrapȱanythingȱfromȱhumansȱtoȱmarineȱ
mammalsȱorȱfish.ȱCansȱfullȱofȱpropellantȱandȱheavyȱoilȱcauseȱminiȱ
oilȬspillsȱthatȱmayȱkillȱsignificantȱcoloniesȱofȱbarnaclesȱorȱotherȱ
marineȱlife.ȱAustralianȱbeachesȱareȱsomeȱofȱtheȱbestȱinȱtheȱworld,ȱandȱ
litterȱmakesȱthemȱtoȱlookȱunsightly.ȱȱ
Thisȱactivityȱencouragesȱvolunteersȱtoȱcollectȱallȱtheȱlitterȱtheyȱfindȱ
alongȱaȱbeltȱofȱbeach,ȱrockȱembankmentȱorȱmudflat.ȱTheȱcollectedȱ
litterȱisȱthenȱsortedȱintoȱdifferentȱcategoriesȱandȱweighed.ȱȱ
TheȱinformationȱgainedȱfromȱthisȱactivityȱprovidesȱyourȱWaterwatchȱ
coordinatorȱandȱKESABȱ(KeepȱSouthȱAustraliaȱBeautiful)ȱwithȱusefulȱ
dataȱonȱtheȱamountȱofȱlitterȱbuildingȱupȱandȱalsoȱgivesȱyouȱaȱgoodȱ
opportunityȱtoȱcleanȱupȱyourȱshoreline.ȱThisȱactivityȱcouldȱbeȱ
undertakenȱasȱpartȱofȱCleanȬupȱAustraliaȱDayȱactivitiesȱeachȱyear.ȱIfȱ
youȱwishȱtoȱregisterȱforȱCleanȬupȱAustraliaȱDay,ȱcontactȱKESABȱviaȱ
theirȱwebsiteȱatȱ<www.kesab.asn.au>.ȱȱ
AnotherȱusefulȱsourceȱofȱinformationȱisȱtheȱbrochureȱKeepingȱTabsȱonȱ
MarineȱDebris.ȱTheȱbrochureȱandȱrecordȱformsȱareȱonȱtheȱinternetȱatȱ
<www.environment.sa.gov.au/coasts/pdfs/marine_debris_info.pdf>.ȱȱ
Toȱobtainȱtheȱmostȱvaluableȱdata,ȱyourȱstretchȱofȱbeachȱshouldȱbeȱ
cleanedȱeveryȱthreeȱtoȱsixȱmonths,ȱalthoughȱonceȱaȱyearȱwillȱsuffice.ȱ
Dataȱfromȱthisȱactivityȱcanȱhelpȱdetermineȱifȱeducationȱprogramsȱorȱ
legislationȱtoȱreduceȱlitteringȱareȱworking,ȱidentifiesȱtheȱmajorȱ
sourcesȱofȱlitterȱandȱhelpsȱraiseȱpublicȱawarenessȱofȱtheȱproblemȱofȱ
litterȱinȱaquaticȱenvironments.ȱȱ
What you may need:
–
beachȱlitterȱrecordȱformȱ
–
heavyȬdutyȱplastic,ȱhessianȱorȱCleanȬupȱAustraliaȱDayȱbagsȱȱ
–
bathroomȱscalesȱaccurateȱtoȱ0.2ȱkgȱ
–
50Ȭmȱmeasuringȱtapeȱȱ
–
clipboardȱandȱdatasheetȱȱ
–
topographicȱmapȱorȱGPSȱ
–
specialȱcontainerȱforȱsharpsȱȱ
–
glovesȱandȱprotectiveȱshoesȱforȱeveryone.ȱȱ
Activity:
3 Core
Age: All
Time: 2 or 3
Why? Many nonbiodegradable articles
cause harm to marine life
(entanglements and
ingestion), people (diver
entanglements, cuts to
beach-users) and to marine
vessels (propeller snags,
etc). The estuarine benthic
habitat may also become
smothered with nonbiodegradable wastes.
Safety: Ensure everyone is
wearing gloves and
protective shoes.
As with all field work,
ensure that a first aid kit is
available. A yellow sharps
container should be on
hand to place all broken
glass and needles into.
If an object is large or
heavy, ask for someone else
to help you pick it up.
Dead aquatic plants,
animals and birds often
wash up on the shore.
Leave them there—they are
part of the estuarine
ecosystem and are usually
meant to be there. Note
large numbers of dead flora
or fauna if the quantity
seems unnatural.
To ensure good results:
Beachȱlitterȱcollectionȱisȱfairlyȱsubjective.ȱItȱdependsȱonȱwhatȱtheȱvolunteersȱconsiderȱtoȱbeȱlitter,ȱhowȱ
thoroughȱtheȱsearchȱisȱandȱtheȱtimeȱofȱyearȱthatȱtheȱsurveyȱisȱdone.ȱAnotherȱlimitationȱisȱthatȱonlyȱ
visibleȱlitterȱcanȱbeȱcollected.ȱSomeȱlitterȱmayȱbeȱburiedȱbyȱsand.ȱ
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ESTUARINE
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MANUAL
What to do:
Selectȱaȱsuitableȱbeach,ȱmuddyȱshoreȱorȱrockyȱembankmentȱinȱyourȱestuary.ȱItȱshouldȱbeȱeasilyȱ
accessible,ȱbeȱknownȱtoȱhaveȱaȱbuildȬupȱofȱlitterȱandȱhaveȱnoȱotherȱroutineȱcleaning.ȱEstuarineȱsitesȱ
shouldȱbeȱfreeȱofȱmangrovesȱorȱotherȱstructures,ȱandȱbeȱclearȱofȱdirectlyȱdumpedȱrubbish.ȱDoȱnotȱ
monitorȱbeachȱdunesȱforȱrubbish,ȱasȱtheyȱareȱfragileȱandȱmonitoringȱmayȱsometimesȱbeȱmoreȱharmfulȱ
thanȱtheȱrubbish.ȱȱ
Selectȱaȱstartingȱpointȱandȱlayȱoutȱaȱ500Ȭmȱtransectȱ(orȱasȱcloseȱasȱyouȱcanȱget)ȱusingȱaȱmeasuringȱtape.ȱAȱ
50Ȭmȱtapeȱmayȱbeȱused,ȱbyȱgettingȱseveralȱpeopleȱtoȱmeasureȱoutȱ10ȱlengthsȱofȱtheȱtape.ȱRecordȱtheȱ
width,ȱstartingȱpoint,ȱlengthȱandȱdirectionȱofȱtheȱtransectȱonȱaȱmapȱorȱusingȱaȱGPS.ȱȱ
Startȱwalkingȱalongȱtheȱbeachȱatȱtheȱbeginningȱofȱtheȱtransectȱandȱwalkȱinȱaȱcloseȱzigzagȱpattern,ȱ
coveringȱtheȱentireȱareaȱofȱtheȱtransect.ȱCollectȱallȱrubbishȱandȱplaceȱintoȱaȱsuitableȱstrengthȱrubbishȱbag.ȱ
Onceȱfinishedȱtakeȱallȱbagsȱfromȱtheȱbeachȱtoȱaȱsortingȱarea.ȱȱ
Atȱtheȱsortingȱareaȱemptyȱallȱbagsȱandȱsortȱtheȱlitterȱintoȱtheȱrubbishȱtypesȱlistedȱonȱtheȱdatasheet.ȱCountȱ
theȱnumberȱofȱlitterȱitemsȱinȱeachȱcategoryȱandȱrecordȱthem.ȱȱ
Brushȱsandȱorȱmudȱfromȱeachȱitemȱofȱlitterȱusingȱaȱbrushȱ(orȱhoseȱoff)ȱandȱplaceȱintoȱplasticȱbagsȱ
labelledȱwithȱtheȱtypeȱofȱrubbishȱtheȱbagȱcontains.ȱWeighȱallȱtheȱbagsȱforȱeachȱcategoryȱusingȱyourȱ
scales.ȱRecordȱtheȱweightsȱforȱeachȱcategoryȱonȱyourȱsheet.ȱȱ
Foamȱorȱotherȱlightȱitemsȱcanȱbeȱputȱintoȱbagsȱofȱaȱknownȱsizeȱratherȱthanȱcleaningȱandȱweighingȱthem.ȱ
Recordȱtheȱnumberȱandȱsizeȱofȱtheseȱbagsȱonȱyourȱdatasheet.ȱFishingȱlineȱcanȱbeȱrecordedȱinȱitsȱ
approximateȱlengthȱratherȱthanȱbeingȱweighed.ȱȱ
Disposeȱofȱtheȱdebrisȱitemsȱintoȱaȱrubbishȱskipȱorȱatȱaȱrubbishȱtip.ȱWhereȱpossible,ȱrecycleȱrubbish.ȱȱ
Youȱmayȱalsoȱrecordȱtheȱpresenceȱofȱwashedȱupȱmarineȱorganicȱmatterȱ(egȱseagrassesȱorȱalgae)ȱonȱyourȱ
recordȱsheet.ȱȱ
Separatingȱlitterȱintoȱcategoriesȱmakesȱanalysingȱtheȱdataȱeasier.ȱItȱensuresȱthatȱtheȱsourceȱandȱ
transportationȱmethodsȱofȱeachȱofȱtheȱrubbishȱcategoriesȱcanȱbeȱassessed.ȱHaveȱaȱtryȱatȱguessingȱtheȱ
sourcesȱofȱyourȱrubbish.ȱWhereȱdoȱyouȱthinkȱitȱcameȱfrom?ȱWhatȱcluesȱareȱgivenȱaboutȱhowȱitȱgotȱtoȱ
yourȱtransectȱarea?ȱDoȱyouȱthinkȱthatȱthereȱwasȱanȱacceptableȱamountȱofȱlitterȱonȱtheȱbeach?ȱ
Dataȱisȱbetterȱinterpretedȱasȱweightȱofȱlitterȱperȱlengthȱofȱbeachȱ(ratherȱthanȱweightȱperȱunitȱarea)ȱdueȱtoȱ
theȱtendencyȱforȱmuchȱbeachȱlitterȱtoȱbeȱclumpedȱalongȱaȱnarrowȱbandȱatȱtheȱhighȱtideȱmark.ȱItȱisȱbetterȱ
toȱuseȱweightȱasȱanȱindicatorȱthanȱtotalȱnumberȱofȱitems,ȱasȱmanyȱitemsȱtendȱtoȱbreakȱupȱintoȱsmallerȱ
fragments.ȱȱ
Beachȱlitterȱmonitoringȱisȱbestȱconductedȱeveryȱoneȱtoȱthreeȱmonths.ȱPleaseȱnoteȱthatȱincreasedȱ
quantitiesȱofȱlitterȱareȱlikelyȱtoȱbeȱfoundȱafterȱstrongȱwinds,ȱcurrentsȱorȱstorms.ȱAlwaysȱcollectȱlitterȱatȱ
lowȱtideȱwhenȱtheȱbeachȱareaȱisȱexposed.ȱȱ
ȱ
ȱ
104

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