Evaluationofmicrobiologicalwaterquality

BaselineEvaluationofmicrobiologicalwaterqualityinthePettaquamscuttRiver(RhodeIsland,USA)usingchemical,molecularandculture-dependentmethodsJanetA.Atoyana,ElizabethM.Herronb,JoséA.Amadora,⇑aLaboratoryofSoilEcologyandMicrobiology,UniversityofRhodeIsland,Kingston,RI02881,USAbWatershedWatchProgram,CoastalInstituteinKingston,UniversityofRhodeIsland,Kingston,RI02881,USAarticleinfoKeywords:PettaquamscuttRiverFecalindicatorbacteriaOpticalbrightenersBifidobacteriumadolescentisNarragansettBay,RhodeIslandabstractWeevaluatedmicrobiologicalwaterqualityinthePettaquamscuttRiver(RhodeIsland,USA),anestua-rineriver.Fecalcoliform(FC)andenterococci(FE)bacteria,presenceofBifidobacteriumadolescentisDNA(indicatinghumanfecalcontamination),andopticalbrightener(OB)fluorescence(associatedwithlaundrydetergents)weredeterminedfor14stationsfromMaytoSeptember2010.SixstationshadhighcountsofFEandFC,andthepresenceofB.adolescentisDNAandhighOBfluorescenceindicatedhumanfecalcontamination–fourhadsepticsystemsaslikelysourcesofcontamination;theotherswereinsew-eredareas.TheabilityofFCandFEtoindicatehumanfecalcontaminationwasassessedagainstapositiveB.adolescentistest.FCandFEhadfalsepositiveratesof25%and17%,respectively,andfalsenegativesof44%forFCand63%forFE.Inclusionofmolecularandchemicalindicatorsshouldimprovetrackingofhumanfecalcontaminationsourcesintheriver.2011ElsevierLtd.Allrightsreserved.WeevaluatedmicrobiologicalwaterqualityalongthePett-aquamscuttRiver(NarrowRiver),anestuarineriverfeedingintoNarragansettBay,RhodeIsland,USA(Fig.1).Theriverconsistsoftwobrackishkettlelakesseparatedfromeachotherbyashallowsill,andfromRhodeIslandSoundbyashallowriverthatisseveralkilometerslong(GainesandPilson,1972).Themainfreshwaterin-putisGilbertStuartstream,onthenorthernendoftheestuary,withseawaterenteringtherivernearthesouthernendfromRhodeIslandSound(GainesandPilson,1972).LandusewithinthePett-aquamscuttRiverwatershedincludesamixofurban,forestedandwetlandareas,andagriculturallandthatisrepresentativeofmanycoastalcommunitiesinthenortheasternUnitedStates.EstablishedsitesmonitoredbytheNarrowRiverPreservationAssociation,acommunityorganizationoftrained,experiencedvol-unteers,werethetargetofthiseffort.Anumberofareasalongtheriverhavewell-documentedfecalcoliform(FC)contaminationconcerns,withsignificantquestionsaboutsources.Previousassessmentsofsourcesoffecalindicatorbacteria(FIB)conductedbytheRhodeIslandDepartmentofEnvi-ronmentalManagement(RIDEM)inthePettaquamscuttRiverwa-tershedsuggestedanimalfecalsources,despitecontinuedlocalconcernsabouthumansources(RIDEM,2001,2002).ThepresenceofFIBinawaterbodycanresultfrommanysources,includingani-malfeces,faultyorleakingsepticsystems,leakingsewersystems,stormwaterrunoff,andboatsanitarywaste(USEPA,1986).Ofpar-ticularconcernisfecalcontaminationofhumanorigin,sinceitismorelikelytocarryhumanpathogensthancontaminationfromthefecesofotherspecies(USEPA,2007).Reducinghumansourcesoffecalcontaminationcanbeaccomplishedthroughvariousstrat-egies–includingadoptionofwastewatermanagementordinances,updatingsewagedisposalsystemsandrepairingsewerlines–whichdifferconsiderablyfromthoseusedtoreducefecalcontam-inationfromlivestockordomesticanimals(e.g.installingmanuremanagementstructures,fencing-offanimals,plantingvegetativefilterstrips).Implementationofappropriatemanagementstrate-giesrequiresidentifyingthesourcesoffecalcontamination.TheUSEnvironmentalProtectionAgency(USEPA)mandatestheuseoffecalenterococci(FE)asabetterbacterialindicatoroftheriskofcontractingagastrointestinalillnessfromswimmingincontaminatedwatersthanFC,onwhichpreviousstandardswerebased(USEPA,1986).However,neitheroftheseFIBarespecificforhumanfecalcontamination(Fieldetal.,2003),sincetheyarefoundinfecesfromawidevarietyofwarm-bloodedanimals.Anumberoftechniquestotracksourcesofhumanfecalcontaminationthatrelyonindicatorsmorespecificallyassociatedwithhumanshaveemergedinthepasttwodecades.Bifidobacteriumadolescentishasbeensuggestedasahuman-specificintestinalbacteriumthat,inconjunctionwithotheranalyses,mayaccuratelyidentifyhumanfecalcontaminationinestuarineandfreshwaters.B.adolescentisisaGram-negative,anaerobicrodreportedtogrowexclusivelyintheintestinesofhumans(Matsukietal.,2004).B.adolescentishasbeensuggestedasanalternativetoFEandFCasanindicator0025-326X/$-seefrontmatter2011ElsevierLtd.Allrightsreserved.doi:10.1016/j.marpolbul.2011.04.032⇑Correspondingauthor.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](J.A.Amador).MarinePollutionBulletin62(2011)1577–1583ContentslistsavailableatScienceDirectMarinePollutionBulletinjournalhomepage:(MaraandOragui,1983;Mushietal.,2010).Anestedpolymerasechainreaction(PCR)methodfortheexclusivedetec-tionofB.adolescentisfromhumanfeceshasbeenusedsuccessfullyinwaterandsedimentsamples(Kingetal.,2007;Sinigallianoetal.,2007;Morrisonetal.,2008).Fluorescencefromopticalbrighteners(OB)–laundrydetergentadditives–hasbeensugges