UseofecologicalindicatorstoassessthequalityofGreat

EcologicalIndicators11(2011)1609–1622ContentslistsavailableatScienceDirectEcologicalIndicatorsjournalhomepage:∗,PatriciaChow-FraserMcMasterUniversity,DepartmentofBiology,1280MainSt.West,Hamilton,OntarioL8S4K1,CanadaarticleinfoArticlehistory:Received21October2010Receivedinrevisedform5March2011Accepted10April2011Keywords:CoastalwetlandsDegradationFishMacrophytesPristineWaterqualityabstractOver2000coastalwetlandcomplexeshavebeenidentifiedintheLaurentianGreatLakeswatershed,eachprovidingcriticalhabitatfornumerousaquaticandterrestrialspecies.Researchhasshownthereisadirectlinkbetweenanthropogenicactivities(urbanizationandagriculturaldevelopment)anddeteriorationinwetlandhealthintermsofwaterqualityandbioticintegrity.Inthisstudy,weevaluatecoastalmarshesthroughouttheGreatLakesbasinusingasuiteofpublishedecologicalindicesdevelopedspecificallyforcoastalwetlandsoftheGreatLakes(WaterQualityIndex(WQI),WetlandMacrophyteIndex(WMI),andtheWetlandFishIndex(WFIBasin)).Wesurveyed181wetlands,including19inLakeSuperior(11%),11inLakeMichigan(6%),13inLakeHuron(7%),92inGeorgianBayandtheNorthChannel(51%),18inLakeErie(10%),and28inLakeOntario(15%),overa13yearperiod(1995–2008).Waterqualityparametersweremeasuredateverysite,whilepairedfykenetswereusedtoassessthefishcommunity(132sites)andmacrophytesweresurveyedandidentifiedtospecies(174sites);allofthisinformationwasusedtocalculatetheassociatedindexscores.One-wayANOVAresultsshowedthatthereweresignificantdifferencesinwetlandqualityamonglakes.AccordingtotheWQI,wefoundthatover50%ofmarshesinLakesMichigan,Erie,andOntariowereindegradedcondition,whileover70%ofmarshesinLakesSuperior,Huron,andGeorgianBaywereminimallyimpacted.GeorgianBayhadthehighestproportionofwetlandsinverygoodandexcellentconditionandleastnumberofwetlandsinadegradedstate.TheWMIandWFIshowedsimilarresults.Thisisthelargestbi-nationaldatabaseofcoastalwetlandsandthefirststudytoprovideasnapshotofthequalityofcoastalhabitatswithintheGreatLakesbasin.WerecommendthisinformationbeusedtoguideconservationandrestorationeffortswithintheLaurentianGreatLakes.©2011ElsevierLtd.Allrightsreserved.1.IntroductionWetlandsareoneofthemostbiodiversesystemsintheworldandprovideessentialecosystemservicesvaluedgloballyattrillionsofdollarsperyear(Costanzaetal.,1997).WithintheLauren-tianGreatLakes,whichincludeLakesSuperior,Huron,Michigan,ErieandOntario,therearemorethantwothousandcoastalwet-landscoveringover216,000haalongatotalshorelineof17,071km(GLCWC;Ingrametal.,2004).Majorityofthesewetlandsaremarshes,whicharehydrologicallyconnectedwiththeGreatLakesandextremelyimportantfortheGreatLakefishcommunity.Theyprovidecriticalspawningandnurseryhabitatfor80%oftheGreatLakesfishspeciesatsometimeintheirlifecycle(Chow-FraserandAlbert,1999)andprovideshelter,food,andrefugeforresi-dentfishes(JudeandPappas,1992;Randalletal.,1996).Talhelm(1988)estimatedthatanglersintheGreatLakesspent$1to$2bil-lion(U.S.dollars)in1985,andthatatotalimpactofthisspendingontheregionaleconomywouldhaverangedfrom$2to$4billion∗Correspondingauthor.Tel.:[phone]x27461,fax:[phone].E-mailaddress:[e-mail](M.Cvetkovic).(U.S.dollars).Whenadjustmentforinflationisfactoredin,the2010dollarscouldbetwicethisamount.Besidesfishspecies,coastalmarshesintheGreatLakesarealsoessentialhabitatforinvertebrates,birds,turtles,amphibians,andlargemammalssuchasbearandmoose.SinceEuropeansettlementinthemid1800s,thiscriticalhabitathasbeendestroyedbyurbanandagriculturaldevelopmentinsettledareasoftheGreatLakesshoreline(JudeandPappas,1992;Mayeretal.,2004).Ithasbeenestimatedthatlessthan30%ofthepre-EuropeanwetlandsthatonceexistedintheLaurentianbasinarecurrentlyavailableasGreatLakesfishhabitat(Snell,1987;Smithetal.,1991;JudeandPappas,1992)andmanyoftheseareinadegradedconditionbecauseofland-usealterationinwetlandcatchments(Chow-Fraser,2006).Agricultureisoneofthetwoprimaryfactorsresponsibleforhabitatlossanddeteriorationanddominatesinthesouthernpor-tionofthebasinduetofavourableclimateandsoilconditions;urbanizationisthesecondfactor,andisespeciallyprominentontheU.S.coastwheremajorcitieshavebeenestablished(e.g.LakesErieandMichigan),whilelargecitiesontheCanadianshorelineexistmainlyonthenortherncoastlineofLakeOntarioandtheSt.LawrenceRiver(Mayeretal.,2004).Theresultofthisland-usealterationisincreasedsedimentandnutrientloadsintothecoastal1470-160X/$–seefrontmatter©2011ElsevierLtd.Allrightsreserved.doi:10.1016/j.ecolind.2011.04.0051610M.Cvetkovic,P.Chow-Fraser/EcologicalIndicators11(2011)1609–1622watersheds(Chow-Fraser,2006;Danzetal.,2007;Trebitzetal.,2007;Morriceetal.,2008),includingrunofffromimpropersewagefacilities(e.g.Chow-Fraser,1998).Alargebodyofpublishedworkhasdocumentedtherela-tionshipbetweenwater-qualityconditionandwetlandhealthforGreatLakescoastalwetlands.CrosbieandChow-Fraser(1999),McNairandChow-Fraser(2003)andTrebitzetal.(2007,2009)haveshownthatbothpoint-sourceanddiffuse-sourcepollutioncanleadtoeutrophicationandincreasedalgalgrowt