ML17229B109

1998 Annual Environ Operating Rept for St Lucie Unit 2.

ML17229B109
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Issue date:	12/31/1998
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FLORIDAPOWER4LIGHTCOMPAZ'WST.LUCIEUIGT2Al.'VKJALElVVIRONME<NTALOPERATINGREPORT1998~gNGagFLORIDAPOWER8rLIGHTCOMPANYJUNOBEACH,FLORIDAQUANTUMRESOURCES,INC.PALMBEACHGARDENS,FLORIDAi9905040ii9.990428>PDRADOCK050003898PDRJ ENVIRONMENTALOPERATINGREPORTTABLEOFCONTENTSPARTI1.0ExecutiveSummary1.1Introduction1.2TurtleNestingSurvey1.3IntakeCanalMonitoring2.0Introductionlv2.1Background2.2AreaDescription2.3PlantDescription3.0Turtle3.1Introduction3.2MaterialsandMethods3.2.1NestingSurvey3.2.2IntakeCanalMonitoring3.3ResultsandDiscussion3.3.1NestingSurvey3.3.1.11998LoggerheadNestingSummary3.3.1.2SpatialDistributionofLoggerheadTurtleNests63.3.1.3Long-TermTrendsinLoggerheadTurtleNesting73.3,1.4SeasonalPatternsofLoggerheadTurtleNesting7,3.3.1.5PredationonLoggerheadTurtleNests3.3.1.61998GreenandLeatherbackNestingSurvey83.3.1.7TrendsinGreenandLeatherbackTurtleNesting9 3.3.2IntakeCanalMonitoring3.3.2.11998CanalCaptureSummary10103.3.2.2RelativeAbundanceandTemporalDistribution103.3.2.3SizeClassDistributions3.3.2.4SexRatios3.3.2.5CaptureEfficiencies3.3.2.6BarrierNetMaintenance3.3.2.7RelativeCondition3.3.2.8Mortalities3.3.2.9RecaptureIncidents3.3.3Summary4.0LiteratureCited5.0Figures6.0Tables1212131414171932PARTII1.0Introduction2.0SeaTurtleMonitoringandAssociatedActivities3.0TaproggeCondenserTubeCleaningSystemOperation4.0OtherRoutineReports5.0TableandFigures3636363738

1.1INTRODUCTION

TheSt.LuciePlantisanelectricgeneratingstationonHutchinsonIslandinSt.LucieCounty,Florida.Theplantconsistsoftwonuclear-fueled850netMWeunits;Unit1wasplacedon-lineinMarch1976andUnit2inApril1983.ThisdocumenthasbeenpreparedtosatisfytherequirementscontainedinAppendixB,EnvironmentalProtectionPlan(EPP),toSt.LucieUnit2FacilityOperatingLicenseNo.NPF-16.ThisreportprimarilydiscussesenvironmentalprotectionactivitiesrelatedtoseaturtlesasrequiredbySubsection4.2oftheEPP.OtherroutineannualreportingrequirementsareaddressedinVolume2.1.2TURTLENESTINGSURVEYSincemonitoringbeganin1971,therehavebeenconsiderableyear-to-yearfluctuationsinseaturtlenestingactivityonHutchinsonIsland.However,datacollectedthrough1998haveshownnolong-termreductionsinnestingontheisland.Relativelyhighnestingduringrecentyearsmayactuallyreflectanincreaseinthenumberofnestingfemalesinthestudyarea.Onasmallerscale,powerplantoperationhashadnosignificanteffectonnestingneartheplant.Lownestingactivityin1975andagainin1981-1983inthevicinityoftheplantwasattributedtonighttimeconstructionactivitiesassociatedwithinstallationofplantintakeanddischargestructures.Nestingreturnedtonormalorabovenormallevelsfollowingbothperiodsofconstruction.During1991,daytimeconstructionactivitiesassociatedwithvelocitycaprepairshadnoapparenteffectonnesting.Formalrequirementstoconductnestingsurveysexpiredin1986,butthisprogramhasbeencontinuedthrough1998withagreementfromfederalandstateagencies.In1998,thecontinuationofthenestingsurveyprogramwasmandatedaspartofthebiologicalopinionandincidentaltakestatementissuedbytheNationalMarineFisheriesService.1.3INTAKECANALMONITORINGSinceplantoperationbeganin1976,6086seaturtles(includingrecaptures)representingfivedifferentspecieshavebeenremovedfromtheintakecanal.Themajorityoftheturtlescaptured(59percent)wereloggerheads.Differencesinthenumbersofturtlesfoundduringdifferentmonthsandyears,includingdramaticincreasesingreenturtlecapturesinrecentyears,havebeenattributedprimarilytonaturalvariationintheoccurrencesofturtlesinthevicinityoftheplant,ratherthantooperationalinfluencesoftheplantitself.Themajorityofturtlesremovedfromtheintakecanal(about97percent)werecapturedaliveandreleasedbackintotheocean.Ongoingevaluationsandimprovementstothecanalcaptureprogramhavesubstantiallyreducedmortalitiesofentrappedseaturtlesduringrecentyears.Turtlesconfinedbetweenthebarriernetandintakeheadwallstypicallyresideinthecanalforarelativelyshortperiodpriortocapture,andmostareingoodtoexcellentconditionwhencaught.AnimproveddesignbarriernetcompletedinJanuary1996isexpectedtofurtherreducetheresidencetimesandpotentialformortalitiestoseaturtlesintheintakecanalsystem.

2.0INTRODUCTION

2.1BACKGROUNDTliisdocumenthasbeenpreparedtosatisfytherequirementscontainedinAppendixB,EnvironmentalProtectionPlan,toSt.LucieUnit2FacilityOperatingLicenseNPF-16.St.LucieUnits1and2usetheAtlanticOceanasasourceofwaterforonce-throughcondensercooling.Since1971,thepotentialenvironmentaleffectsresultingfromtheintakeanddischargeofthiswaterhavebeenthesubjectofFPLsponsoredbioticstudiesatthesite.JurisdictionforseaturtlestudiesiswiththeNRC,whichisconsideredtobetheleadfederalagencyrelativetoconsultationundertheEndangeredSpeciesAct.Previousresultsdealingwithseaturtlestudiesarecontainedinfourteenannualenvironmentaloperatingreportscoveringtheperiodfrom1983through1997.Tliisreportdescribesthe1998environmentalprotectionactivitiesrelatedtoseaturtles,asrequiredbySubsection4.2oftheSt.LucieUnit2EnvironmentalProtectionPlan.2.2AREADESCRIPTIONTheSt.LuciePlantislocatedona457-hectaresiteonHutchinsonIslandonFlorida'sEastCoast(Figures1and2).TheplantisapproximatelymidwaybetweentheFt.PierceandSt.LucieInlets.ItisboundedontheEastSidebytheAtlanticOceanandontheWestSidebytheIndianRiverLagoon.HutchinsonIslandisabarrierislandthatextends36kmbetweeninletsandattainsitsmaximumwidthof2kmattheplantsite.Elevationsapproach5matopdunesborderingthebeachanddecreasetosealevelinthemangroveswampsthatarecommononmuchofthewesternside.TheAtlanticshorelineofHutchinsonIslandiscomposedofsandandshellhashwithintermittentrockypromontoriesprotrudingthroughthebeachfacealongthesouthernendoftheisland.Submergedcoquinoidrockformationsparallelmuchoftheislandofftheoceanbeaches.Theoceanbottomimmediatelyoffshorefromtheplantsiteconsistsprimarilyofsandandshellsediments,TheFloridaCurrent,whichflowsparalleltothecontinentalshelfmargin,beginstodivergefromthecoastlineatWestPalmBeach.AtHutchinsonIsland,thecurrentisapproximately33kmoffshore.Oceanicwaterassociatedwiththewesternboundaryofthecurrentperiodicallymeandersovertheinnershelf,especiallyduringsummermonths.2.3PLANTDESCRIPIIONTheSt.LuciePlantconsistsoftwo850netMWenuclear-fueledelectricgeneratingunitsthatusenearshoreoceanwatersfortheplant'sonce-throughcondensercoolingwatersystem.Waterfortheplantentersthroughthreesubmergedintakestructureslocatedabout365moffshore(Figure2).Eachoftheintakestructuresisequippedwithavelocitycaptominimizefishentrainment.Fromtheintakestructures,thewaterpassesthroughsubmergedpipes(two3.7mandone4.9mindiameter)underthebeachanddunesthatleadtoa1,500meterlongintakecanal,whichtransportswatertotheplant.Afterpassingthroughtheplant,theheatedwaterisdischargedintoa670meterlongcanalthatleadstotwoburieddischargepipelines.Thesepassunderneaththedunesandbeachandalongtheoceanfloortothesubmergeddischarges,thefirstofwhichisapproximately365moffshoreand730mnorthoftheintake.

3.1INTRODUCTION

HutchinsonIsland,Florida,isanimportantrookeryfortheloggerheadturtle,Carettacaretta,andalsosupportssomenestingofthegreenturtle,Chelonia~mdas,andtheleatherhackI,D~hl'.Sdfdlpllhpi.'Ihfd&governmenthasclassifiedtheloggerheadturtleasathreatenedspecies.ThefederalgovernmentendangeredspecieslistsincludetheleatherbackturtleandtheFloridanestingpopulationofthegreenturtle.IthasbeenanFPLgoalthattheSt.LuciePlantwouldnotadverselyaffecttheHutchinsonIslandrookery.Becauseofthisconcern,FPLhassponsoredmonitoringofmarineturtlenestingactivity,ontheislandsince1971.Daytimesurveystoquantifynesting,aswellasnighttimeturtletaggingprograms,wereconductedinoddnumberedyearsfrom1971through1979.Duringdaytimenestingsurveys,nine1.25km-longsurveyareasweremonitoredfivedaysperweek(Figure3).TheSt.LuciePlantbeganoperationin1976;therefore,thefirstthreesurveyyears(1971,1973,and1975)werepre-operational.Thoughthepowerplantwasnotoperatingduring1975,St.LuciePlantUnit1oceanintakeanddischargestructureswereinstalledduringthatyear.Installationofthesestructuresincludednighttimeconstructionactivitiesconductedoffshorefromandperpendiculartothebeach.Constructionhadbeencompletedandtheplantwasinfulloperationduringthe1977and1979surveys.Amodifieddaytimenestingsurveywasconductedin1980duringthepreliminaryconstructionoftheoceandischargestructureforSt.LucieUnit2.Duringthisstudy,fourofthepreviouslyestablished1.25km-longsurveyareasweremonitored.Additionally,eggsfromturtlenestspotentiallyendangeredbyconstructionactivitieswererelocated.Everyyearfrom1981through1998,36one-km-longsurveyareascomprisingtheentireislandweremonitoredsevendaysaweekduringthenestingseason(Figure3).Beginningin1994,thesouthernhalfoftheislandhasbeensurveyedbyEcologicalAssociatesofJensenBeach,Florida,andtheirdataisincludedinthisreport.TheSt.LucieUnit2dischargestructurewasinstalledduringthe1981nestingseason.OffshoreandbeachconstructionoftheUnit2intakestructureproceededthroughoutthe1982nestingseasonandwascompletedneartheendthe1983nestingseason.ConstructionactivitiesassociatedwithinstallationofbothstructuresweresimilartothoseconductedwhenUnit1intakeanddischargestructureswereinstalled.Eggsfromturtlenestspotentiallythreatenedbyconstructionactivitieswererelocated.During1991,anothermajoroffshoreconstructionprojectwasundertakentoreplacedamagedvelocitycapsonthethreeintakestructures.Alargeelevatedplatform,fromwhichrepairactivitieswereconducted,waserectedaroundthethreestructures.Constructionoccurredthroughoutthenestingseason.However,incontrasttopreviousoffshoreprojects,workwasrestrictedalmostentirelytodaylighthours,nighttimelightingoftheworkareawasminimal,andnoequipmentormaterialswereusedonthebeach.Aseaturtleprotectionplanimplementedinsupportoftheprojectincludedcagingofnestsalonga1,500metersectionofbeachwestoftheplatformandreleaseofhatchlingstounaffectedareastothenorthandsouth.Thisplanwas intendedtomitigateanynegativeeffectspotentiallyresultingfromrequiredsafetyandnavigationallightingonandneartheplatform.Requirement4.2.1oftheSt.LucieUnit2AppendixBEnvironmentalProtectionPlanwascompletewithsubmissionofthe1986nestingsurveydata(ABI,1987).Thenestingsurveywascontinuedvoluntarilythrough1998withagreementfromfederalandstateagencies.Resultsarepresentedinthisreportanddiscussedinrelationtopreviousfindings.Inadditiontomonitoringseaturtlenestingactivitiesandrelocatingnestsawayfromplantconstructionareas,removalofturtlesfromtheintakecanalhasbeenanintegralpartoftheSt.LuciePlantenvironmentalmonitoringprogram.Turtlesenteringtheoceanintakestructuresareentrainedwithcoolingwaterandrapidlytransportedthroughtheintakepipesintoanenclosedcanalsystemwheretheymustbemanuallycapturedandreturnedtotheocean.Sincetheplantbecameoperationalin1976,turtlesentrappedintheintakecanalhavebeensystematicallycaptured,measured,weighed,tagged,andreleased.Previouspublicationsandtechnicalreportshavepresentedfindingsofthenestingsurveys,nestrelocationactivitiesandcanalcaptureprogram(ABI,1994)(Quantum,1995,1996,1997,1998).Resultsofstudiestoassesstheeffectsofthermaldischargesonhatchlingswimmingspeedhavealsobeenreported(ABI,1978).InJuly1994,responsibilityforseaturtleresearchandconservationactivitieswastransferredfromEcologicalAssociates,Inc.(formerlyAppliedBiology,Inc.)toQuantumResources,Inc.Methodologiesemployedinboththenestingsurveysandcanalcaptureoperationsremainedessentiallyunchangedsothatdatacollectedin1994throughthepresentaredirectlycomparabletopreviousyear'sdata.Thepurposeofthisreportisto:1)present1998seaturtlenestingsurveydataandsummarizeobservedspatialandtemporalnestingpatternssince1971,2)documentandsummarizepredationonturtlenestssince1971,and3)present1998canalcapturedataandsummarizecomparabledatacollectedsince1976.3.2MATERIALSANDMETHODS3.2.l~tl'MethodologiesusedduringpreviousturtlenestingsurveysonHutchinsonIslandweredescribedinearlierreports(ABI1994).Methodsusedduringthe1998surveyweredesignedtoallowcomparisonswiththesepreviousstudies.In1998,onlyaicasA-SweresurveyedbyQuantumResourcesbiologists(Figure3).DatasuppliedbyEcologicalAssociates,Inc.areusedtoprovidewholeislandnestingtotalsinFigures6,8,and9.FromMarch24,1998throughApril14,1998,severalpreliminarynestsurveyswereconductedalongHutchinsonIslandinareasA-S.NonestingwasrecordedinareasA-SpriortothebeginningofformalnestingsurveysonApril15,1998.FromApril15,1998throughSeptember8,1998,nestsurveyswereconductedonadailybasis.ThelastnestrecordedinareaA-SwasonSeptember7,1998.Biologistsusedsmalloff-roadmotorcyclestosurveytheislandeachmorning.Newnests,non-nestingemergences(fa'Isecrawls),andnestsdestroyedby predatorswererecordedforeachofthe1-km-longsurveyareasA-S(Figure3).The1.25-km-longsurveyareasthatwereestablishedinearlierstudiesalsoweremonitoredsocomparisonscouldbemadewithpreviousstudies.DatacollectedfrombeachnestingsurveyswerereportedtotheFloridaDepartmentofEnvironmentalProtection(FDEP)aspartoftheFDEPIndexNestingBeachSurvey.Inacooperativeeffort,datafromstrandedturtlesfoundduringbeachsurveyswereroutinelyprovidedtotheFloridaDepartmentofEnvironmentalProtectionandtheNationalMarineFisheriesService(NMFS)throughtheSeaTurtleStrandingandSalvageNetwork.3.2.2IntakeCanalMonitorinMostturtlesentrappedintheSt.LuciePlantintakecanalwereremovedbymeansoflarge-meshtanglenetsfishedneartheintakecanalheadwallsattheextremeeasternendoftheintakecanal(Figure2).Netsusedduring1998werefrom30to40minlength,3to4mdeepandcomposedof40cmstretchmeshmultifilamentnylon.Largefloatswereattachedtothesurface,andunweightedlinesusedalongthebottom.Turtlesentangledinthenetsgenerallyremainedatthewater'ssurfaceuntilremoved.Sinceitsinceptionin1976,thecanalcaptureprogramhasbeenundercontinualreviewandrefinementinanattempttominimizebothentrapmenttimeandinjuries/mortalitiestoentrappedseaturtles.PriortoApril1990,turtlenetswereusuallydeployedonMondaymorningandretrievedonFridayafternoon.Duringperiodsofdeployment,thenetswereinspectedforcapturesatleasttwiceeachday(morningsandafternoons).Additionally,St.LuciePlantpersonnelcheckedthenetsperiodically,andbiologistswerenotifiedimmediatelywhenacapturewasobserved.Seaturtlespecialists,thatretrievecapturedturtlesfromtheplantintakecanalsystem,wereoncall24hoursaday.BeginningApril1990,afterconsultationwithNMFS,netdeploymentwasscaledbacktodaylighthoursonly.Concurrently,surveillanceoftheintakecanalwasincreasedandbiologistsremainedonsiteforthedurationofeachday'snettingactivities.Thismeasuredecreasedresponsetimeforremovalofentangledturtlesfromnetsandprovidedanopportunitytoimprovedailyassessmentsofturtlelevelswithinthecanal.Recordsofdailycanalobservationswerecomparedwithcapturedatatoassesscaptureefficiencies.In1978,abarriernetattheA1ABridgewasconstructedtoconfineturtlestotheeasternmostsectionoftheintakecanal,wherecapturetechniqueshavebeenmosteffective.Thisnetisconstructedoflargediameterpolypropyleneropeandhasameshsizeof20.3cmx20.3cm.Acableandseriesoflargefloatsareusedtokeepthetopofthenetabovethewater'ssurface,andthebottomisanchoredbyaseriesofconcreteblocks.Thenetisinclinedataslopeof1:1,withthebottompositionedupstreamofthesurfacecable.Thisreducesbowinginthecenterandminimizestheriskofaweakorinjuredturtlebeingpinnedunderwaterbystrongcurrents.Inthepast,theintegrityofthebarriernetwasoccasionallycompromised,andturtleswereabletomovewestofA1A.Theseturtleswerefurtherconstraineddownstreambyanunderwaterintrusiondetectionsystem(UIDS)consisting,inpart,ofalargebarrierpositionedperpendiculartothenorth-southarmofthecanal(Figure2).TheUIDSsecuritybarrierhasameshsizeof22.9cmx22.9cm.PriortocompletionoftheUIDSinDecember1986,turtlesunconfinedbythe A1AbarriernetwereusuallyremovedfromthecanalattheintakewellsofUnits1and2(Figure2).Theretheywereretrievedbymeansoflargemechanicalrakesorspeciallydesignednets.FollowingconstructionoftheUIDSbarrier,allbutthesmallestindividualswereunabletoreachtheintakewells.ImprovementsmadetotheA1Abarriernetduring1990haveeffectivelyconfinedallturtleslargerthan32.5-cmcarapacelength(28.7-cmcarapacewidth)totheeasternendofthecanal.Inresponsetothelargenumbersofsmallturtlesencounteredintheintakecanalinrecentyears,animproveddesign,smallmeshbarriernetwaserectedeastoftheA1Abarriernet,Constructionwas,completeinJanuary1996.Thisimprovedbarriernetisdesignedtoconfineallturtleswithacarapacewidthgreaterthan18cmtotheextremeeasternportionoftheintakecanal.Formaldailyinspectionsoftheintakecanalweremadetodeterminethenumbers,locations,andspeciesofturtlespresent.Surfaceobservationswereaugmentedwithperiodicunderwaterinspections,particularlyinandaroundthebarriernets.Inadditiontotheuseoftanglenets,dipnetsandhandcapturesusingsnorkelandSCUBAwerealsoemployed.Longhandleddipnets,employedfromsmallboats,thecanalbanksandheadwallstructuresweremoderatelyeffectiveincapturingturtleswithcarapacelengthsofabout30cmorless.Diverswereemployedtohandcaptureturtleswheneverunderwatervisibilitypermits,andthistechniquehasprovenhighlyeffectiveinthecaptureofturtlesofallsizes,particularlylessactiveindividualsoftenfoundpartiallyburiedinthesedimentinthevicinityofthebarriernets.Handcaptureeffortshavehadasignificantimpactinreducingentrapmenttimesforturtlesintheintakecanal.Regardlessofcapturemethod,allturtlesremovedfromthecanalwereidentifiedtospecies,measured,weighed,taggedandexaminedforoverallcondition(wounds,abnormalities,parasites,etc.).BeginninginJuly1994,allturtlescapturedhavebeenphotographeddorsallyandventrallypriortorelease,andthephotographsretainedforfuturereference.Healthyturtleswerereleasedintotheoceanthesamedayofcapture.Sickorinjuredturtlesweretreatedandoccasionallyheldforobservationpriortorelease.Whentreatmentwaswarranted,turtlesweretransportedtoanapprovedrehabilitationfacility.Resuscitationtechniqueswereusedifaturtlewasfoundthatappearedtohavediedrecently.Beginningin1982,necropsieswereconductedondeadturtlesfoundinfreshcondition.FloridaPower&LightCompanyandQuantumResources,Inc.continuedtoassistotherseaturtleresearchersin1998.Sincetheprogrambegan,data,specimensand/orassistancehavebeengiventotheFloridaDepartmentofEnvironmentalProtection,NationalMarineFisheriesService,USFishandWildlifeService,USArmyCorpsofEngineers,SmithsonianInstitution,SouthCarolinaWildlifeandMarineResourcesDivision,CenterforSeaTurtleResearch(UniversityofFlorida),FloridaAtlanticUniversity,UniversityofCentralFlorida,TexasAEcMUniversity,UniversityofRhodeIsland,UniversityofSouthCarolina,UniversityofIllinois,UniversityofGeorgia,VirginiaInstituteofMarineScience,WesternAtlanticTurtleSymposium,SouthAtlanticFisheryManagementCouncil,FloridaMarineFisheriesCommission,HarborandBranchOceanographicInstitutionandtheNationalResearchCouncil.

3.3RESULTSANDDISCUSSION3.3.1N~iS3.3.1.11998LoerheadNestinSummaIn1998,7962loggerheadturtlenestswererecordedinthe36one-kilometersegmentscomprisingHutchinsonIsland.ThisfigureisinaccordancewithageneralincreaseinloggerheadturtlenestingonHutchinsonIslandsincesurveysbeganin1971,althoughsignificantyeartoyearfluctuationsareevident.loggerheadnestsandemergencesforsurveyareasA-SispresentedinFigure4.3.3.1.2SatialDistributionofLoerheadTurtleNestsFrom1981through1998,36one-km-longsegmentscomprisingtheisland'scoastlinehavebeensurveyed.Thedistributionofnestsamongthese36surveyareashasshownanincreaseinnestingfromnorthtosouthalongthenorthernhalfoftheisland(ABI,1987,1994).Alongthesouthernhalfoftheislandtherehasbeeneithernogradientoragradientofdecreasingnestingfromnorthtosouth.Thoughbeachdynamicsmaysometimesaffecttheselectionofnestingsitesbyloggerheadturtles,relationshipsbetweenspatialnestingpatternsandspecificenvironmentalconditionsareoftendifficulttoestablishbecauseoftheinterrelationshipofthefactorsinvolved.Notallventuresontothebeachbyafemaleturtleculminateinsuccessfulnests.These"falsecrawls"(non-nestingemergences)mayoccurformanyreasonsandarecommonlyencounteredatotherrookeries.DavisandWhiting(1977)suggestedthatrelativelyhighpercentagesoffalsecrawlsmightreflectdisturbancesorunsatisfactorynestingbeachcharacteristics.Therefore,certainfactorsmayaffectaturtle'spreferencetoemergeonabeach,whileotherfactorsmayaffectaturtle'stendencytonestafterithasemerged.Anindex,whichrelatesthenumberofneststothenumberoffalsecrawlsinanarea,isusefulinestimatingthepost-emergencesuitabilityofabeachfornesting.Inthepresentstudythisindexistermed"nestingsuccess"andisdefinedasthepercentageoftotalemergencesthatresultinnests.loggerheadnestingsuccessforareasA-Sin1998ispresentedinFigure5.Historically,thepatternofloggerheademergencesontheislandhasgenerallyparalleledthedistributionofnests(ABI,1987,1994).Incontrast,nestingsuccessbyloggerheadsalongtheislandhastypicallylackedgradients(ABI,1987,1994).Thus,therelativelyhighnumbersofloggerheadnestsobservedincertainareasareusuallyaresultofmoreturtlescomingashoreinthoseareasratherthanofmorepreferablenestingconditionsbeingencounteredbytheturtlesaftertheyemerged.Avarietyofenvironmentalfactors(i.e.,offshorebottomcontours,distributionofreefs,typeandextentofdunevegetation,andhumanactivityonthebeachatnight)mayeffectloggerheadturtleemergencepatternsandseveralhavebeenreportedtoaffectemergencepatternsonHutchinsonIsland(ABI,1988,1989).Undoubtedly,acombinationoffactorsaccountsfortheoveralldistributionofemergencesandthereforetheoverallnestingpatternontheisland.NestingsurveysonHutchinsonIslandwereinitiatedinresponsetoconcernsthattheoperationoftheSt.LuciePlantmightnegativelyimpactthelocalseaturtlerookery.Previousr

analysis,usinglog-likelihoodtestsofindependence(G-test;SokalandRohlf,1981)demonstratedthattheconstructionoftheplant'soffshoreintakeanddischargestructuressignificantlyreducednestingattheplantsiteduringconstructionyears-1975,1981,1982,1983(ABI,1987).However,nestingattheplantconsistentlyreturnedtolevelssimilartoorgreaterthanthoseatacontrolsiteinyearsfollowingconstruction.During1991whenoffshoreconstructionwasrestrictedalmostentirelytodaylighthours,nestsweremoreabundantattheplantsitethanatthecontrolsite.Datacollectedthrough1998haveshownthatpowerplantoperationexclusiveofnighttimeintake/dischargeconstructionhashadnoapparenteffectonnesting.3.3.1.3Lon-TermTrendsinLoerheadTurtleNestinVariousmethodswereusedduringsurveyspriorto1981toestimatethetotalnumberofloggerheadnestsonHutchinsonIslandbasedonthenumberofnestsfoundinthenine1.25lan-longsurveyareas(ABI,1980a).Eachofthesemethodswassubsequentlyfoundtoconsistentlyoverestimateislandtotals(ABI,1987).Sincewhole-islandsurveysbeganin1981,ithasbeenpossibletodeterminetheactualproportionoftotalnestsdepositedinthenineareas.Thishasallowedextrapolationfromtheninesurveyareastotheentireislandforyearspriorto1981.From1981through1993thetotalnumberofnestsinthenineareasvariedfrom32.5to35.6percentofthetotalnumberofnestsontheisland.Thisisslightlyhigherthanthe31.3percent,whichwouldbeexpected,basedstrictlyontheproportionoflinearcoastlinecomprisedbythenineareas.Usingthethirteen-yearmeanof33.81percent,estimatesofthetotalnumberofnestsonHutchinsonIslandcanbecalculatedbymultiplyingthenumberofnestsinthenineareasby2.958.Thistechnique,whenappliedtotheninesurveyareasduringthethirteenyearsinwhichtheentireislandwassurveyed,producedwhole-islandestimateswithin5.3percentoftheactualnumberofnestscounted.Becausetheproportionofnestsrecordedintheninesurveyareasremainedrelativelyconstantoverthelastthirteenyears,thisextrapolationprocedureprovidesafairlyaccurateestimateoftotalloggerheadnestingforyearspriorto1981,andisusedtogeneratedatapointsfor1971through1979inFigure6.Itisclearthatloggerhead-nestingactivityonHutchinsonIslandfluctuatesconsiderablyfromyeartoyear(Figure6).Annualvariationsinnestdensitiesalsoarecommonatotherrookeries,andmayresultfromnon-annualreproductivebehavior.Despitehighvariability,datacollectedthrough1998suggestanoverallincreaseinnestingonHutchinsonIslandsincesurveysbeganin1971.Totalnestingactivitywasgreatestduring1995when8184loggerheadnestswererecorded.Norelationshipsbetweentotalnestingactivityandpowerplantoperationorintake/dischargeconstructionwereindicatedbyyear-to-yearvariationsintotalnestingonHutchinsonIsland.3.3.1.4SeasonalPatternsofLoerheadTurtleNestinTheloggerheadturtlenestingseasonusuallybeginsbetweenmid-AprilandearlyMay,attainsamaximumduringJuneorJuly,andendsbymid-September(ABI,1987).Nestingactivityduring1998followedthissamepattern.Co'olwaterintrusionsfrequentlyoccuroverthecontinentalshelfofsoutheastFlorida duringthesummer(Smith,1982).TheseintrusionsmayhavebeenresponsibleforthetemporarydeclinesinloggerheadturtlenestingactivitypreviouslyobservedonHutchinsonIsland(ABI,1994).ThoughnaturalfluctuationsintemperaturehavebeenshowntoaffecttemporalnestingpatternsonHutchinsonIsland,therehasbeennoindicationthatpowerplantoperationhasaffectedthesetemporalpatterns(ABI,1988).3.3.1.5PredationonLoerheadTurtleNestsSincenestsurveysbeganin1971,raccoonpredationhasbeenamajorcauseofturtlenestdestructiononHutchinsonIsland.Researchersatotherlocationshavereportedraccoonpredationlevelsashighas70tonearly100percent(Hopkinsetal.,1979).RaccoonpredationofloggerheadturtlenestsonHutchinsonIslandhasnotapproachedthislevelduringanystudyyear,thoughlevelsforindividual1.25km-longareashavebeenashighas80percent.Overallpredationratesforsurveyyears1971through1977werebetween21and44percent,withahighof44percentrecordedin1973.Apronounceddecreaseinraccoonpredationoccurredafter1977andoverallpredationratesforthenineareashavenotexceeded10percentsince1979,AdeclineinpredationratesonHutchinsonIslandmaybeattributabletotrappingprograms,constructionactivities,habitatloss,anddisease.During1998,raccoonpredationlevelswereextremelylow,withonlyoneloggerheadnestinareasA-Sdepredatedbyraccoons(Figure7).Inpreviousyears(ABI,1994),predationofturtlenestswasprimarilyrestrictedtothemoreundevelopedportionsoftheisland.Ghostcrabshavebeenreportedbynumerousresearchersasimportantpredatorsofseaturtlenests(Hopkinsetal,1979;Stancyk,1982).ThoughturtlenestsonHutchinsonIslandprobablyhavebeendepredatedbyghostcrabssincenestingsurveysbeganin1971,quantificationofghostcrabpredationdidnotbeginuntil1983.Overallpredationratesbyghostcrabshavevariedfrom0.1to2.1percentfrom1983-1998.During1998,threeloggerheadnestinareasA-Sweredepredatedbyghostcrabs(Figure7).Nestsdestroyedbyacombinationofraccoonandghostcrabpredationhavebeenincludedasraccoonpredationsinpreviousdiscussions.Whenthesecombinationpredationsareincludedascrabpredations,theoverallpredationratesbyghostcrabsrangefrom0.1to4.7percent.During1998,nosuchcombinationpredationswererecorded.3.3.1.61998GreenandLeatherbackNestinSummaIn1998,258greenturtleand77leatherbackturtlenestswererecordedinthe36one-kmsegmentscomprisingHutchinsonIsland.ThegreenturtletotalrepresentsanewrecordforHutchinsonIslandgreenturtlenestingandasubstantialincreasefromlastyear'stotals,1998wasalsoarecordyearforleatherbackturtlenestingonHutchinsonIsland(Figures8and9).Althoughstrongyeartoyearfluctuationsarecommon,thegeneraltrendsince1971mayreflectanincreaseinthenumbersofnestingfemalesintheHutchinsonIslandarea.

3.3.1.7TrendsinGreenandLeatherbackTurtleNestinGreenandleatherbackturtlesnestonHutchinsonIsland,butinfewernumbersthanloggerheadturtles.Priorto1981,bothsurvey(nine1.25km-longsections)andinter-surveyareasweremonitoredforthepresenceofgreenandleatherbacknests.Thirty-onekilometersofbeachfromArea1southtotheSt.LucieInletwereincludedinthateffort.Duringwhole-islandsurveysfrom1981through1993,only2.6percent(7)oftheleatherbacknests(n=266)andonly1.4percent(12)ofthegreenturtlenests(n=831)wererecordedonthefivekilometersofbeachnorthofArea1.Therefore,previouscountsofgreenandleatherbacknestswithinthe31kilometerssurveyedprobablywerenotappreciablydifferentfromtotaldensitiesfortheentireisland.Basedonthisassumption,greenandleatherbacknestdensitiesmaybecomparedamongallsurveyyears,except1980,whenlessthan15kilometersofbeachweresurveyed.Sincesurveysbeganin1971,thenumberofnestsobservedontheislandrangedfrom5to258forgreenturtlesandfrom1to77forleatherbacks(Figures8and9).Temporalnestingpatternsforthesespeciesdifferfromthepatternforloggerheadturtles.GreenturtlestypicallynestonHutchinsonIslandfrommid-JunethroughthefirstorsecondweekofSeptember.LeatherbackturtlesusuallybeginnestinginMarchorAprilandcontinuetonestthroughearlytomid-July.Considerablefluctuationsingreenturtlenestingontheislandhaveoccurredamongsurveyyears(Figure8).Thisisnotunusualsincetherearedrasticyear-to-yearfluctuationsinthenumbersofgreenturtlesnestingatotherbreedinggrounds(Carretal.,1982).Despitethesefluctuations,datacollectedthrough1998suggestanoverallincreaseinnestingsince1971andmayreflectanincreaseinthenumberofnestingfemalesintheHutchinsonIslandarea.During1998,greenturtlesnestedmostfrequentlyalongthesouthernhalfoftheisland.Thisisconsistentwithresultsofprevioussurveys.LeatherbackturtlenestdensitieshaveremainedlowonHutchinsonIsland,however,increasednestingduringrecentyears(Figure9)mayreflectanoverallincreaseinthenumberofnestingfemalesintheHutchinsonIslandarea.

3.3.2INTAKECANALMONITORINGEntrainmentofseaturtlesattheSt.LuciePlanthasbeenattributedtothepresumedphysicalattractivenessoftheoffshorestructureshousingtheintakepipesratherthantoplantoperatingcharacteristics(ABI,1980band1986).Thevelocitycaps,whicharesupportedabovetheopeningstoeachintakepipe,eliminateverticalwaterentrainmentandsubstantiallyreducecurrentvelocitiesnearthestructuresbyspreadinghorizontaldrawoverawiderarea.Evenwhenbothunitsareoperatingatfullcapacity,turtlesmustactivelyswimintothemouthofoneofthepipesbeforetheyencountercurrentvelocitiessufficientlystrongtoeffectentrainment.Consequently,aturtle'sentrapmentrelatesprimarilytotheprobabilitythatitwilldetectandsubsequentlyenteroneoftheintakestructures.3.3.2.11998CanalCatureSummaIn1998,666seaturtleswerecapturedintheintakecanaloftheSt.LuciePlant.Capturesincluded393loggerheads,268greenturtles,1leatherback,2hawksbill,and2Kemp'sridleyturtles(Table1).3.3.2.2RelativeAbundanceandTemoralDistributionSinceintakecanalmonitoringbeganinMay1976,3578loggerhead(including222recaptures),2432green(including478recaptures),21leatherback,33Kemp'sridleys,and21hawksbillcapturehavetakenplaceattheSt.LuciePlant.Annualcatchesforallspeciescombinedrangedfromalowof33in1976(partialyearofplantoperationandmonitoring)to933in1995.Exceptfor1993through1997,whenthegreenturtlewasthemostabundantspeciesinthecanal,loggerheadshave'dominatedannualcaptures.Since1977,thefirstfullyearofplantoperation,thenumberofloggerheadscapturedeachyearrangedfrom62in1981to393in1998(Figure10).Numbershaveexhibitedconsiderableyear-to-yearfluctuationswithnopersistenttrendsevident,althoughrecentyear'sdataaresuggestiveofapossibleincreasingtrend.Thenumberofgreenturtlescapturedeachyearsince1977haverangedfrom3in1979toarecordhighof673in1995(Figure10).Increasingnumbersofcapturesoverrecentyearsmayreflectanincreaseinthenumberofturtlesinhabitingthenearshorecoastalareaneartheplantormaysimplyrepresentstatisticalvariation.Greenturtlecapturesweredownsharplyin1997,butshowedamodestreboundin1998.Additionalyearsofcapturedatawillberequiredbeforeanylong-termtrendscanbeestablished.During1998,themonthlycatchofloggerheadsrangedfrom10(November)to60(March),withamonthlymeanof32.7(Table2).Overtheentiiehistoryofthecaptureprogram,monthlycatcheshaverangedfrom0to87,withthegreatestnumberofcapturesoccurringduringJuly1996.During1998,themonthlycatchofgreenturtlesrangedfrom7(July)to58(February),withamonthlymeanof23.3(Table3).TheMarch1996catchof147greenturtlesisthelargestnumberofcapturesforthisspeciesforanymonthonrecord.Seasonalabundancepatternsof10 greenturtleshavetypicallybeenmuchmorepronouncedthanforloggerheads,withover50percentofallcapturesoccurringbetweenJanuaryandMarch.In1995through1998,however,nosuchseasonalpatternwasevident,withcapturesdistributedmoreorlessevenlythroughouttheyear.Catchesofleatherbacks,hawksbills,andKemp'sridleyshavebeeninfrequentandscatteredthroughouttheyears.Eachspecieshasshownratherpronouncedseasonaloccurrences;over60percentofallleatherbackswerecapturedinMarchandApril,over60percentofthehawksbillswerecapturedbetweenJulyandSeptember,andalmost90percentoftheKemp'sridleyswerecaughtbetweenDecemberandApril.3.3.2.3Size-ClassDistributionsThesize-classdistributionforloggerheadsremovedfromtheintakecanalin1998ispresentedinFigure11.Thesizeclassdistributionforgreenturtlesremovedfromtheintakecanalin1998arepresentedinFigure12.ABI(1994)presentssize-classdataforturtlesremovedfromtheintakecanalfrom1976-1993.Theleatherbackcapturedin1998wasanadult,withastraight-linecarapacelength(SLCL)ofover121cm(Hirth,1980).Bothhawksbillscapturedin1998wereadults(SLCL>63cm)(Witzell,1983).BothKemp'sridleyscapturedin1998werejuvenilesSLCL(60cm)(Hirth,1980).3.3.2.4SexRatiosOfthe390loggerheadscapturedin1998forwhichstraightlinecarapacelengthsareavailable,276werejuvenileswithastraightlinecarapacelength(SLCL)lessthanorequalto70cm,81wereadults(SLCL>85cm)and33weretransitional(SLCL71-85cm)(Hirth,1980).Thelattergroupprobablyincludesbothmatureandimmatureindividuals.Ofthe81individualsclassifiedasadultsforwhomsexwasrecorded,76werefemalesandfiveweremales,withfemalespredominatingbyaratioof15:1.Ofthe267greenturtlescapturedin1998forwhichstraightlinecarapacelengthsareavailable,263werejuvenilesorsub-adults(SLCL(83cm)(WhitheringtonandEhrhart,1989).Ofthe4adultgreenturtlescapturedin1998,2weremalesand2werefemales.ABI(1994)discussessexratiodataforpreviousyears.3.3.2.5CatureEfficienciesNettingmethodologieshavebeenundercontinualreviewandrefinementasnetmaterials,configurations,andplacementbevariedinanefforttominimizeseaturtleentrapmenttimes.Additionally,alternativecapturetechniqueshavebeenevaluated,andpotentialdeterrentsystemstestedinthelaboratory.Currentcaptureprocedureshaveproventoprovideasafe,efficient,andcost-effectiveprogramforremovingentrappedturtlesfromtheintakecanal.Formaldailyinspectionsoftheintakecanalareconductedeverydaythatcapturenetsaredeployed,andthenumber,locationandrelativesizeofentrappedturtlesarerecordedonfieldobservationforms.Betterutilizationofcurrentsandeddies,adjustmentstotetheringlines,multi-11 netdeploymentsandincreasedeffortstohandcaptureturtleshavecontributedtoreducedentrapmenttimesduringrecentyears.EntrapmenttimesmaybeextendedforturtlesswimmingpasttheAlAbarriernet(ABI,1987).BecausecaptureeffortswestoftheA1Abridgeweregenerallylesseffectivethanthoseneartheintakeheadwalls,mostturtlesbreachingthebarriernetwerenotcaughtuntiltheyenteredtheintakewellsofUnits1and2.Becauseoftheirrelativelysmallsizes,virtuallyalltheturtlesreachingtheintakewellsaregreenturtles.During1998,5ofthe268greenturtlecaptures(1.8percent)occurredattheintakewells.Thesubstantialdecreaseinthepercentageofcapturesattheplantintakewellscomparedtothe1995figureof14.5percentisattributedtotheeffectivenessofthenewsmallmeshbarriernetinstalledeastofAIAinJanuary1996.During1998,99.1percentofallturtlesentrappedinthecanalwerecapturedeastoftheA1ABridge,547bytanglenetsand119byhandordipnetcapture.TheeffectiveconfinementofturtleseastofA1Ahasbeenamajorcontributortothehighcaptureefficiencyachievedduringrecentyears.TheinstallationofanimprovedbarriernetcompletedinJanuary1996hasfurtherincreasedcaptureefficiencybymoreeffectivelyconfiningturtlesofallsizestoasmallerareaeasttotheA1Abarriernet.3.3.2.6BarrierNetMaintenanceBarriernetmaintenanceiscriticalinreducingtheopportunityformortalitiesintheplantintakewellareaandinreducingresidencetimesforturtlesintheintakecanalsystem.Dailyinspectionsareperformedfromasmallboattoremovefloatingdebrisandtorepairholesnearoratthewatersurface.Whenunderwatervisibilityconditionspermit,aweeklyunderwaterinspectionisconducted.Aformalinspectionisconductedmonthly,includingholerepair,debrisremoval,andairliftdredgingofaccumulatedsiltifneeded.Maintenanceconductedin1998includedtherepairofanyholesinthemeshdiscoveredduringthedaily,weeklyandmonthlyinspectionsandextensivedebrisremovalandairliftdredgingofaccumulatedsedimentconductedinNovember.InSeptember,October,andNovember1998,largeinfluxesofjeHyfishintotheintakecanalrequiredtheprimarybarriernettobeloweredperiodically,sometimesfordaysatatime,topreventthenetfromfailingundertheweightofaccumulatedjellyfish.Theloweringmechanismfunctionedasdesignedandnodamagewassustained.3.3.2.7RelativeConditionTurtlescapturedaliveintheintakecanaloftheSt.LuciePlantwereassignedarelativeconditionbasedonweight,activity,parasiteinfestation,barnaclecoverage,wounds,injuriesandanyotherabnormalitieswhichmighthaveaffectedoverallvitality.During1998,95.2%percent(373)ofallloggerheadsfoundinthecanalwerealiveandingoodcondition.Only4.8percent(19)loggerheadcapturesinvolvedindividualsinfairorpoorcondition,andonewasdead.Ofthe268greenturtlesremovedfromtheintakecanalduring1998,254(94.8percent)wereingood'condition,14(5.2percent)wereinfairorpoorcondition,andnoneweredead.The2hawksbills,2Kemp'sridleys,andtheleatherbackcapturedin1998wereallingoodcondition.12 Relativeconditionratingscanbeinfluencedbyanumberoffactors,somerelatedandothersunrelatedtoentrainmentand/orentrapmentintheintakecanal.Aratingofgoodindicatesthatturtleshavenotbeennegativelyimpactedbytheirentrapmentinthecanal,atleastasevidencedbyphysicalappearance.Althoughratingsoffairorpoorimplyreducedvitality,theextenttowhichentrainmentandentrapmentisresponsibleisoftenindeterminable.Insomeinstances,conditionsresponsibleforlowerratings,suchasboatcollisionorfisheriesgearentanglementinjuriesobviouslyweresustainedpriortoentrainment.During1998,71ofthe666turtlescaptured(10.7percent)hadnotableinjuriessuchasmissingappendages,brokenormissingpiecesofcarapace,ordeeplacerations.Manyofthesewereold,well-healedwounds,anddidnotrequireveterinaryattention.Ofthe665liveremovalsduring1998,652werereleasedintotheoceanthedayofcapture.Nineturtles(allloggerheads)inobviousillhealthorsufferingseriousinjuriesweretransportedtoSeaWorldofFloridaortheMarinelifeCenterofJunoBeachfortreatmentandrehabilitation.Twohadseriouscarapacedamage,presumablyfromaboatcollision,onehadingestedmonofilamentfishingline,andsixwereweak,lethargic,andemaciatedwhencaptured.Fifteengreenturtleswithfibropapillomatumorswereremovedfromthecanalin1998.ThreeturtleswithextensivetumorsweretransferredtotheFloridaDEPfortransportationtoarehabilitationfacility.Twelveturtleswithminortumorsweretaggedandreleased.Onegreenturtlewasheldovernightforinstallationofasatellite-trackingtransmitterandwaslaterreleased.3.3.2.8MortalitiesSeaturtlemortalitieshavebeencloselymonitoredthroughoutthelifeofthecanalcaptureprograminanattempttoassignprobablecausesandtakeappropriateremedialactiontominimizefutureoccurrences.Previousanalysesofcapturedataidentifieddrowninginnets(A1Abarriernet,UIDSbarrier,and.tanglenets),drowningintheintakepipesduringperiodsofreducedintakeflow,injuriessustainedfromdredgingoperations,andinjuriessustainedfromthemechanicalrakesusedintheintakewellsasprobablemortalityfactors(ABI,1987)(FPL,1995).Althoughdifficulttoquantify,theentrapmentandsubsequentdemiseofinjuredorsickturtleshasprobablyaccountedforaportionofobservedmortalities.Overtheentiremonitoringprogramhistory,135(3.8percent)ofthe3578loggerheadsand52(2.1percent)ofthe2432greenturtlesentrappedinthecanalwerefounddead.Mortalitiesspannedtherangeofsizeclassesforloggerheads(SLCL=47.5-103cm),whileallgreenturtlemortalitiesinvolvedjuvenileslessthan42cminlength.ThefourKemp'sridleymortalitiesdocumentedattheplantduring1987and1988weretheonlydeathsforthisspeciestodate;nodeadleatherbackorhawksbillturtleshavebeenrecoveredattheSt.LuciePlant.Modificationstocaptureprocedures,improvementstobarriernets,andvirtualeliminationoflowflowconditionswithinthecanalhaveresultedinasubstantialreductioninseaturtlemortalitiesoverthelifeofthecanalcaptureprogram.Mortalityrate,expressedasthepercentageoftotalcapturesinvolvingdeadanimals,declinedfrom7.8percentduringtheperiod1976-1984to2.1percentsince1984,and1.0%since1990(Table1).13 In1998,oneturtle(aloggerhead)wasremoveddeadfromtheintakecanal,foranoverallmortalityrateof0.15percent.TheturtlewasfoundfloatingupagainsttheA1Abarriernetduringaperiodwhentheprimarybarriernetwasloweredduetoajellyfishinflux.Theturtlewasmoderatelydecomposed,andnocauseofdeathcouldbedetermined.Inresponsetothe1995mortalitiesandthedramaticincreaseinintakecanalcapturesin1995,consultationwasinitiatedwithFPL,NRC,andtheNMFSunderSection7oftheEndangeredSpeciesAct.Asaresultofthatconsultation,FPLhasdesignedandconstructedanimproved,smallermeshbarriernetlocatedbetweentheA1Abarriernetandtheintakecanalheadwalls(Figure2).ConstructionofthenetwascompletedinJanuary1996.ThisbarriernetpreventsturtlesfromreachingtheintakewellsorUIDSbarrierandincreasescaptureefficiencybyconfiningturtlestoasmallerareaoftheintakecanal.3.3.2.9RecatureIncidentsSincetheSt.LuciePlantcaptureprogrambegan,mostturtlesremovedfromtheintakecanalhavebeentaggedandreleasedintotheoceanatvariouslocationsalongHutchinsonIsland.Consequently,individualturtlescanbeidentifiedaslongastheyretaintheirtags.OverthehistoryoftheprogramattheSt.LuciePlant,700recaptures(222loggerheadsand478greenturtles)haveoccurred,andanumberofturtleshavebeenrecapturedmorethanonce,Therecapturerateforgreenturtlesin1998was37percentandtherecapturerateforloggerheadswasonly5.3percent.ThelargenumberofgreenturtlerecapturesprobablyreflectsthesaturationoflocalgreenturtlepopulationswithturtlestaggedattheSt.LuciePlantandpossiblyindicatesadifferenceinsitefidelitybetweengreenturtlesandloggerheads.Severalotherturtleswithtagscarshavealsobeenrecoveredindicatingthattheactualnumberofrecapturesmaybehigher.3.3.3SUMMARYAgradientofincreasingloggerheadturtlenestdensitiesfromnorthtosouthalongthenorthernhalfofHutchinsonIslandhasbeenshownduringmostsurveyyears.Thisgradientmayresultfromvariationsinbeachtopography,offshoredepthcontours,distributionofnearshorereefs,onshoreartificiallighting,andhumanactivityonthebeachatnight.Lownestingactivityinthevicinityofthepowerplantduring1975andfrom1981through1983wasattributedtonighttimeconstructionactivitiesassociatedwithinstallationofpowerplantintakeanddischargestructures.Nestingreturnedtonormalorabovenormallevelsfollowingbothperiodsofconstruction.During1991,daytimeconstructionactivitiesassociatedwithvelocitycaprepairshadnoapparenteffectonnesting.Statisticalanalysesindicatethatpowerplantoperation,exclusiveofnighttimeconstruction,hashadnosignificanteffectonnestdensitiesneartheplant.In1998,7962loggerheadturtlenestswererecordedonHutchinsonIsland.Therehavebeenconsiderableyear-to-yearfluctuationsinloggerheadnestingactivityonHutchinsonIslandfrom1971through1998.Fluctuationsarecommonatotherrookeriesandmayresultfromnon-annualreproductivebehavior.Despitethesefluctuations,loggerhead-nestingactivityhasremainedhighduringrecentyearsandmayreflectanoverallincreaseinthenumberofnestingfemalesintheHutchinsonIslandarea.Norelationshipbetweentotalnestingontheislandandpowerplantoperationorintake/dischargeconstructionwasindicated.14

~,

TemporalnestingpatternsoftheHutchinsonIslandpopulationmaybeinfluencedbynatural,largescalefluctuationsinwatertemperature,suchasthoseproducedbythecoolwaterintrusionsthatfrequentlyoccuroverthecontinentalshelfofsoutheastFloridaduringthenestingseason.However,localizedfluctuationsinwatertemperatureassociatedwithpowerplantoperationhavehadnoapparenteffectonnesting.Sincenestingsurveysbeganin1971,raccoonpredationhasbeenoneofthemajorcausesofturtlenestdestructiononHutchinsonIsland.From1971through1977,overallpredationratesintheninesurveyareaswerebetween21and44percent.However,apronounceddecreaseinraccoonpredationoccurredafter1977,andoverallpredationratesintheninesurveyareashavenotexceededtenpercentsince1979.Decreasedpredationbyraccoonsprobablyreflectsadeclineintheraccoonpopulation.Moreyearsofsurveydatawillberequiredtodetermineiftheextremelylowlevelofraccoonpredationin1996through1998isanisolatedoccurrenceorpartofacontinuingtrend.Ghostcrabpredationontheturtlenestsmaybemoresignificantthanpreviouslydocumentedbutremainsrelativelyminorcomparedtoraccoonpredation.During1998,258greenturtleand77leatherbackturtlenestswererecordedonHutchinsonIsland,arecordhighforbothspecies.Nestingactivitybythesetwospecieshasexhibitedconsiderableannualfluctuations,ashasbeenrecordedatotherrookeries,buthasremainedrelativelyhighduringrecentyears.ThismayreflectanoverallincreaseinthenumberofnestinggreenandleatherbackturtlesintheHutchinsonIslandarea.During1998,393loggerheads,268greenturtles,2hawksbills,2Kemp'sridleys,andoneleatherbackwereremovedfromtheSt.LuciePlantintakecanal.SincemonitoringbeganinMay1976,3578loggerhead,2432green,21leatherback,21hawksbilland33Kemp'sridleyturtleshavebeencapturedandtagged.Overthelifeofthemonitoringprogram,annualcatchesforloggerheadturtleshaverangedfrom33in1976(partialyearofplantoperationandmonitoring)toahighof393in1998.Yearlycatchesofgreenturtleshaverangedfrom0in1976to673in1995.Differencesinthenumberofturtlesentrappedduringdifferentyearsandmonthsareattributedprimarilytonaturalvariationintheoccurrenceofturtlesinthevicinityoftheoffshoreintakestructures,ratherthantoplantoperationcharacteristics.Size-classdistributionsofloggerheadturtlesremovedeachyearfromthecanalhaveconsistentlybeendominatedbyjuvenilesbetween50and70cminstraight-linecarapacelength.Over75percentofallgreenturtlesentrappedinthecanalwerejuveniles40cmorlessinlength.Forbothspecies,thelargestnumberofcapturesforallyearscombinedoccurredduringwinter,but,withtheexceptionof1995,andtolesserextent1996,theseseasonalpeaksweremuchmorepronouncedforgreenturtles.Thesexratioofloggerheadscaughtinthecanalcontinuedtobebiasedtowardsfemales.During1998,about95percentofallloggerheadsandgreenturtlesremovedfromthecanalwerecategorizedbyphysicalappearanceasbeingingoodcondition.About10percentoftheturtlesremovedfromtheintakecanalduring1998hadsubstantialinjuries,andthevastmajorityofthosewerewellhealedandapparentlysustainedpriortoentrapment.Onceinthecanal,turtlesconfinedeastofA1Ahadverybriefresidencytimes.Thus115 therelativeconditionofmostturtleswasnotaffectedbytheirentrapment.During1998,onlyonemortalitywasaxordedintheintakecanal.Programmodifications,includingcontinualsurveillanceoftanglenetsduringperiodsofdeployment,improvementstotheintegrityofthebarriernetsystem,andgreaterefforttohandcaptureturtleshavecontributedtoasubstantialdeclineinseaturtlemortalitiesduringrecentyears.ThedesignandconstructionofanimprovedbarriernetcompletedinJanuary1996wasexpectedtoreducemortalitiesandentrapmenttimesforturtlesintheintakecanal.Datasincethenindicatethatthenewbarriernetconfigurationhasbeenhighlyeffectiveinexcludingturtlesfromtheplantintakewells,buthasnotbeenaseffectiveinreducingtheoverallmortalityrateasanticipated,althoughthe1998mortalityrateof0.15%,thelowestmortalityrateintheprogram'shistory,wasanoutstandingachievementandahopefulsignforthefuture.16 4.0LITERATURECITED~~~~~ABI(AppliedBiology,Inc.),1978.EcologicalMonitoringAtTheFloridaPower&LightCompanySt.LuciePlant,AnnualReport1977.VolumesIandII.AB-101.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCompany,Miami.1980a.FloridaPower&LightCompany,St.LuciePlantAnnualNon-RadiologicalEnvironmentalMonitoringReport1979.VolumesIIandIII,Bioticmonitoring.AB-244.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCompany,Miami.1980b.TurtleEntrainmentDeterrentStudy.AB-290.PreparedbyAppliedBiology,Inc.ForFloridaPower&I.ightCompany,Miami.1986.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1985.AB-563~PreparedbyAppliedBiology,Inc.forFloridaPower&LightCompany,JunoBeach.1987.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1986.AB-579.PreparedbyAppliedBiologyInc.forFloridaPower&LightCompany,JunoBeach.1988.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1987.AB-595.PreparedbyAppliedBiologyInc.forFloridaPower&LightCompany,JunoBeach.1989.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1988.AB-596.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCompany,JunoBeach.1994.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalMonitoringReport.AB-631.PreparedbyAppliedBiology,Inc.,forFloridaPower&LightCompany,JunoBeach.Carr,A.,A.Meyan,J.Mortimer,K.BjorndalandT.Carr,1982.SurveysofSeaTurtlePopulationsandHabitatsintheWesternAtlantic.NOAATechnicalMemorandumNMFS-SEFC-91:1-82.Davis,G.E.,andM.C.Whiting,1977.LoggerheadSeaTurtleNestinginEvergladesNationalPark,Florida,U.S.A.Herpetologica33:18-28.AssessmentoftheImpactsoftheSt.LucieNuclearGeneratingPlantonSeaTurtleSpeciesFoundintheInshoreWatersofFlorida.FloridaPower&LightCompany,JunoBeach,FL.FPL,1995.Hirth,H.F.,1980.SomeAspectsoftheNestingBehaviorandReproductiveBiologyofSeaTurtles.AmericanZoologist20:507-523.17 Hopkins,S.R.,T.M.Murphy,Jr.,K.B.StansellandP.M.Wilkinson,1979.BioticandAbioticFactorsAffectingNestMortalityintheAtlanticLoggerheadTurtle.ProceedingAnnualConferenceofSoutheasternFishAndWildlifeAgencies32:213-223.QuantumResourcesInc.,1995.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1994.PreparedbyQuantumResourcesInc.forFloridaPower&LightCompany,JunoBeach,FL.1996.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1995.PreparedbyQuantumResourcesInc.forFloridaPower&LightCompany,JunoBeach,FL.1997.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1996.PreparedbyQuantumResourcesInc.forFloridaPower&LightCompany,JunoBeach,FL.1998.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1997.PreparedbyQuantumResourcesInc.forFloridaPower&LightCompany,JunoBeach,FL.Smith,N.P.,1982.UpwellinginAtlanticShelfWatersofSouthFlorida.FloridaScientist45(2):125-138.Sokal,R.R.andF.J.Rohlf,1981.Biometry.ThePrinciplesandPracticeofStatisticsinBiologicalResearch,S.H.FreemanandCompany,SanFrancisco.859pp.Stancyk,S.E.,1982.Non-HumanPredatorsofSeaTurtleandTheirControl.Pages139-152inBjorndal,K.A.,ed.BiologyandConservationofSeaTurtles.SmithsonianInstitutionPress.Washington,DCWitherington,B.E,andL.M,Ehrhart,1989.StatusandReproductiveCharacteristicsOfGreenTurtles(Chelonia~mdasNestinginFlorida.Pages351-352inOgren,L.,F.Berry,K.Bjorndal,H.Kumpf,R.Mast,G.Medina,H.ReichartandR.Witham,editors.ProceedingoftheSecondWesternAtlanticTurtleSymposium.Mayaguez,PuertoRico,12-16October1987.NOAATechnicalMemorandumNMFS-SEFC-226.WIIIWN.1983.839IIEIIHMDE*HEEET\~EIIimbricata(Linnaeus,1766).FAOFisheriesSynopsis,137:1-78.18 FLORIDAGULFOFMEXICO-N-OKEECHOSEESTLUCIEPLANT~o>r~Figure1.LocationofSt.LuciePlant20 HUTCHINSONISLANDINDIANRIVERvr~CGIQMUOCREEK,WTAIIS~~WELLSOISCHAACiEPIPESlAOSBAISIIEAo'llj5I~0~IIA(CHEAOWALLSATLANTICOCEANNAIA5'~SIIBABBIOIBAWCEBNH0MAKESIBVCTUIIESINDIANRIVERFigure2.St.I.uciePlantCoolingWaterIntakeandDischargeSystem21

~+oFT.PIERCEINLETA8DFQGHQSTATEHWYA1AK)OClNFPLST.LUCIEPLANTaQTUSTLucIEwQXYzgCCDDEgaGGHHpLIMITOFCURRENTSURVEYST.LUCIEINLETDRAWINGNOTTOSCALEf04llWSM2$F)~)Figure3.DesignationandLocationofNine1.25-KmSegmentsandThirty-Six1-KmSegmentsSurveyedforSeaTurtleNesting,HutchinsonIsland,1971-1998.22 1000%900%80.0%7PP%60.0%500%0540.0%300%200%100%0.0%ABCDEFGHIJKLMN0PQRSPowerPlantFigure4.NumberofLoggerheadTurtlesNestsandEmergencesforAreasAThroughS,HutchinsonIsland,AprilThroughSeptember1998.23 12000nestsClemergences1000V8000600R4002000ABCDEFGHIJKLAREAMN0PowerPlantQRSFigure5.LoggerheadTurtleNestingSuccess(PercentageofEmergencesResultinginNests)forAreasAThroughS,HutchinsonIsland,AprilThroughSeptember1998.24

• Il/~

9000800070006000z5000040003000z2000100071727374757677787980818283848586878889909192939495969798Figure6.NumberofLoggerheadTurtleNests,HutchinsonIsland1971Through1998.Valuesfor1971Through1979AreEstimates(SeeText);Valuesfor1981Through1998ArePromWholeIslandSurveys.25 8CRABSONLY8RACCOONSONLY4rn10NoPFABCDEFGHIJKLMN2PQRSAREAPowerPlantIFigure7.PercentageofLoggerheadTurtleNestsPredatedbyRaccoonsand/orGhostCrabsinAreasAThroughS,HutchinsonIsland,AprilThroughSeptember1998.26 300250~F200z150100z5071727374757677787980818283848586878889909192939495969798Figure8.Number.ofGreenSeaTurtleNests,HutchinsonIsland,1971Through1998.Valuesfor1971Through1979AreEstimates(SeeText).Valuesfor1981Through1998ArefromWholeIslandSurveys.27 908070l"60z500g4030z201071727374757677787980818283848586878889909192939495969798Figure9.NumberofLeatherbackTurtleNests,HutchinsonIsland,1971Through1998.Valuesfor1971Through1979AreEstimates(SeeText).Valuesfor1981Through1998ArefromWholeIslandSurveys.28 800700~LOGGERHEAD~GREEN600g5000>4003002001007677787980818283848586878889909192939495969798Figure10.Numberof-LoggerheadandGreenTurtlesRemovedEachYearfromtheIntakeCanal,St.LuciePlant,1976Through1998.29 908070605040302010(4141-4546-5051-5556-6061-6566-7071-7576-8081-8586-9091-9596-100101-105106-110)110SIRAIGHI'TANDARDCARAPACELENGTH(cm)Figure11.SizeDistribution(SSCL)ofLoggerheadTurtles(N=391)RemovedfromtheIntakeCanal,St.LuciePlant,1998.30 706050g40030201088~~~8888808888IIIIIIIIIIIIII8840R88g8STRAIGHTSTANDARDCARAPACELENGTH(cm)Figure12.SizeDistribution(SSCL)ofGreenTurtles(N=267)RemovedfromtheIntakeCanal,St.LuciePlant,1998.31 GreenSpeciesLeatherback'-HamksbillKemp'sRidleyTotal1976197719781979198019811982198319841985198619871988198919901991199219931994199519961997199833(4)80(5)138(19)172(13)116(5)62(5)101(16)119(4)148(3)157(4)195(27)175(11)134(6)111(4)112(1)107(1)123(2)147164254(1)349(3)188393(1)5(2)6(1)3(1)10(3)32(2)823(4)69(2)1422(1)3542(2)17(1)20(2)1261(2)179(1)193(4)673(15)549(4)191(5)26816(2)5(2)233(4)86(7)148(20)175(14)126(8)97(7)110(16)142(8)220(5)172(4)220(28)218(13)181(10)133(5)132(3)121(1)187(4)337(1)361(4)933(16)906(7)382(5)666(1)Total357S(135)AnnualMean*162.62432(52)110.51.0211.034(4)1.55420(191)275.1*Excludes1976artialearoflantoration.Table1.TotalNumberofCapturesand(NumberofDead)TurtlesRemovedfromtheIntakeCanal33

'".Number':,'of.':;."-,.-';.-'--.'---;-:-;-".:-'.'---:--';-:-";-';-:--."::Percent:of.-."",;-:,';,"",-.';-.~:-'=-:-'-"'.,:,.;"'.~'>'."..".>;-.::'-'-Sta'ndard'<',":.-':--'"'-.-."--'-"--':.'-;-Mont1i:-'.::Catuxes'-"'-',;.,".':.<','":,'"".All[Ca'iir'es'-',.-Minimuiii'=;;::Ahmimimi'=:.-.'."'-'Mea'n.Deviation'.-.--"..'=::--.-;="':'.':.';:".:.'-'1998';";JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember42133535436430436440532419419312516211.9%9.4%10.0%10.3%S.6%10.3%11.4%9.1%5.5%5.4%3.5%4.6%65100,302100139346047404287431927151319.115.216.116.513.816.518.414.78.88.85.77.410.28.414.712.710.411.120.112.25.2633.94.1362860472926574317271013TotalMeanStd.Deviation354508713.44.639332.816.3*Firstfullyearofplantoperation.Anadditional33loggerheadswerecapturedduring1976.Table2.TotalNumberofLoggerheadTurtlesRemovedEachMonthfromIntakeCanal,St.LuciePlant,1977-1998.34 Month.'umber=of-:.=,.Percent.of.'.:-,',-.-.-Standard;-'.Catures,-'-.'All-Catures-:Minimum"Maxim'um:MeanDeviation--1998JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember28428937021018013712515114819815019011.7%11.9%15.2%8.6%7.4%5.6%5.1%6.2%6.1%8.1%6.2%7.8%000000000000596414764915261647754426812.913.116.89.58.26.25.76.96.79.06.88.615.518.335.617.320.212.614.115.217.815.410.815.82558302035167231025109TotalMeanStd.Deviation24321479.23.426822.314.4~Firstfullearoflantoration.Table3.TotalNumberofGreenTurtlesRemovedEachMonthfromtheIntakeCanal,St.LuciePlant,1977-1998.

ANNUALENVIRONMENTALOPERATINGREPORTPARTII

1.0INTRODUCTION

TheSt.LucieUnit2EnvironmentalProtectionPlan(EPP)requiresthesubmittalofanannualreportforvariousactivitiesattheplantsiteincludingthereportingonseaturtlemonitoringprogramsandothermattersrelatedtoFederalandStateenvironmentalpermitsandcertifications.2.0SEATURTLEMONITORINGANDASSOCIATEDACTIVITIESSurveillanceandmaintenanceofthelightscreentomiiuinizeseaturtledisorientationaszcquiredbySection4.2.4oftheEPPisongoing.Thevegetationlightscreenlocatedonthebeachdunebetweenthepowerplantandtheoceanisroutinelysurveyedtodetermineitsoverallvitality.Thevegetationlineissurveyedforanygapsoccurringfrommortality,whichwouldresultinunacceptablelightlevelsonthebeach.Trees,vegetation,orshadeclothsarereplacedasnecessarytomaintaintheoverallintegrityofthelightscreen.Plantparkinglotlightingisalsodesignedandmaintainedtominimizelightlevelsonthebeach.3.0TAPROGGECONDENSERTUBECLEANINGSYSTEMOPERATIONATaproggecondensertubecleaningsystem(CTCS)becameoperationalonSt.LucieUnit2inJanuary1996andonUnit1inJuly1996.Thissystemutilizesspongeballs,approximately24mmindiameter,tocleanthecondensertubesthroughwhichseawaterflowstocoolsteamafteritspassthroughtheplant'sturbines.Thissystemimprovesplantperformancewhilereducingtheneedforchemicaltreatmentssuchandbiocidesorchlorinetocontrolbiofouling.Normally,theSt.LucieCTCSutilizesabout1800spongeballs,whicharecontinuallyrecirculatedthrougheachoffour"waterboxes"oneachunit.Thesespongeballsareretainedinthesystembyaballstrainerlocatedontheoutletofeachwaterbox.Theballstrainers(meshsize5mm)areopenedroutinelytodischargedebris,whichcandecreasefiowandobstructspongeballmovement.throughthesystem.Thespongeballsarecollectedpriortoopening,orbackflushing,theballstrainers.Atthattime,thespongeballsareexaminedandreplacediftheyareworntothepointthattheycannolongereffectivelycleanthecondensertubes.Spongeballinventoriesandestimatesofspongeballlosstotheenvironmenthavebeenperformedsincesystemstart-uponbothunits.Numberofballstrainerbackflusheshasalsobeentracked.Inaddition,dailybeachsurveyshavebeenperformedonplantproperty(approximately2.5miles)tonoteanyspongeballsthatmayhaveappearedasaresultoflossfromtheplant.Thissurveyareahasbeenextendedduringtheturtle-nestingseasontoalmost12miles.Theresultsoftheprogramfor1998arepresentedinTable1.LargerspongeballlossesoccurredonUnit2fortheyear.Theselossesareprobablyrelatedtothefactthat1998representstheendoffuelcycleforthatunit.Estimatedspongeballlossfrombothunitswas20.2ballsperdayfor1998.Fiftyspongeballswerefoundwholeintheenvironmentneartheplant.Thisisanincrease36 overpreviousyears,butthenumberindicatesthatfewballsactuallyreachtheenvironmentwhole.Figure1indicatesthatestimatedspongeballlossgenerallyincreasedthroughthemonthofAprilof1998,Averagedailyballlossin1998increasedfromthe1996and1997totals(Figure2).Itisbelievedthatmuchofthelossesarecausedbyincreasedgrowthinsidethewaterboxes.Newcoatingsonthesesurfacesarebeingusedtotrytoeleviatethisproblem.ThesecoatingwereappliedtoUnit2inDecember1998.IfthecoatingproveseffectiveitwillbeappliedtoUnit1inSeptember1999.4.0OTHERROUTINEREPORTSThefollowingitemsforwhichreportingisrequiredarelistedbysectionnumberfromtheplant'sEnvironmentalProtectionPlan:5.4.1(a)EPPNONCOMPLIANCESANDCORRECTIVEACTIONSTAKENNononcompliance'sunderEPPSection5.4.1(a)weredeterminedtohaveoccurredduring1998.5.4.1(b)CHANGESINSTATIONDESIGNOROPERATIONTESTSANDEXPERIMENTSINACCORDANCEWITHEPPSUBSECTION3.15.4.1(c)FPLletterL-98-180transmittedtherequestformodificationofWastewaterPermitApplicationtoFDEP.Themodificationincludestheuseofbiocideintheplantclosedcoolingwatersystemsandtheuseofdimethylamineandcarbohydrazideintheplantsteamgeneratorblowdown.ThisletterwastransmittedJune26,1998.NONROUHNBREPORTSSUBMITI'EDTOTHENRCFORTHEYEAR1998INACCORDANCEWITHEPPSUBSECTION5.4.22.ReportconcerningthemortalityLeastTernsattheplantNuclearTrainingCenterJuly6,1998andJuly17,1998.Deathsoccurredinthebuilding'sdrainagesystemduringheavyrainfall.EventswerereportedtoNRCbyFPLletterL-98-196onJuly23,1998.ReportconcerninganincreaseofjellyfishandsubsequenteffectofplantoperationonSeptember9,1998;reportedtotheNRCbyFPLletterL-98-250onOctober1,1998.37 TABLE11998ST.LUCIEPLANTCONDENSERTUBECLEANINGSYSTEMSUlVBZARY'MONTH'.;,-.STRAINER.BACKQLUSEES;,.';.;ESTIMATED'.;BALL'"XOSS~',A:..j.':'."UNIT;:2'-.;+',;,'BALLS'FOUND.',;.,ONTHE.BEACH;"-',:.":"';:,JanuaryFebruaryMarch10222226+26":'~2541698627613AprilMayJune0"252924241242+22QQQ852580JulyAugustSeptemberOctober2925312327202313066114129586483228November24623229December2576759Total1972341853551050Duetopoorspongeballrecovery,strainerswerenotback-flushed.Unitwasdown-powered,waterboxestakenoutofserviceformanualremovalofgrowthandballs.Unit1systemshutdownduringrefueling,1/1to1/19/98.Unit2systemshutdownduringrefueling,11/6to12/12/98.Netgainininventory.38 504540Q35~~3025g20gis10JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECMONTHFigure1.EstimatedAverageDailySpongeBanLossbyMonthfromSt.LuciePlant(BothUnits)for1998.39 2520015g10199619971998Figure2.AverageDailySpongeBallLossfromtheSt.LuciePlant(BothUnits)SinceSystemStart-Up(January1996)40 FLOKfBAPOWERdkLIGHTCOMPANYST.LUCIEUNIT2AINMJALElVVIR()bMIKNYALOPERATING.REPORT1998FLORlDAPOWER&LIGHT.COMPANYJUNOBEACH,FLORIDAQUANTIUMRESOURCES,INC.PALMBEACHGARDENS,FLORIDA

F<2AZRONMENTALOPERATINGREPORTTABLEOFCONTENTSPARTI1.0ExecutiveSummary1.1Introduction1.2TurtleNestingSurvey1.3IntakeCanalMonitoring2.0Introductioniv2.1Background2.2AreaDescription2.3PlantDescription3.0Turtle3.1Introduction3.2MaterialsandMethods3.2.1NestingSurvey3.2.2IntakeCanalMonitoring3.3ResultsandDiscussion3.3.1NestingSurvey3.3.1.11998LoggerheadNestingSummary3.3.1.2SpatialDistributionofLoggerheadTurtleNests63.3.1.3Long-TermTrendsinLoggerheadTurtleNesting73.3.1.4SeasonalPatternsofLoggerheadTurtleNesting73.3.1.5PredationonLoggerheadTurtleNests3.3.1.61998GreenandLeatherbackNestingSurvey3.3.1.7TrendsinGreenandLeatherbackTurtleNesting9 3.3.2IntakeCanalMonitoring3.3.2.11998CanalCaptureSummary10103.3.2.2RelativeAbundanceandTemporalDistribution103.3.2.3SizeClassDistributions3.3.2.4SexRatios3.3.2.5CaptureEfficiencies3.3.2.6BarrierNetMaintenance3.3.2.7RelativeCondition3.3.2.8Mortalities3.3.2.9RecaptureIncidents3.3.3Summary4.0LiteratureCited12121314175.0Figures6.0Tables1932PARTII1.0Introduction2.0SeaTurtleMonitoringandAssociatedActivities3.0TaproggeCondenserTubeCleaningSystemOperation4.0OtherRoutineReports5.0TableandFigures3636363738

1.1INTRODUCTION

TheSt.LuciePlantisanelectricgeneratingstationonHutchinsonIslandinSt.LucieCounty,Florida.Theplantconsistsoftwonuclear-fueled850netMWeunits;Unit1wasplacedon-lineinMarch1976andUnit2inApril1983.ThisdocumenthasbeenpreparedtosatisfytherequirementscontainedinAppendixB,EnvironmentalProtectionPlan(EPP),toSt.LucieUnit2FacilityOperatingLicenseNo.NPF-16.ThisreportprimarilydiscussesenvironmentalprotectionactivitiesrelatedtoseaturtlesasrequiredbySubsection4.2oftheEPP.OtherroutineannualreportingrequirementsareaddressedinVolume2.1.2TURTLENESTINGSURVEYSincemonitoringbeganin1971,therehavebeenconsiderableyear-to-yearfluctuationsinseaturtlenestingactivityonHutchinsonIsland.However,datacollectedthrough1998haveshownnolong-termreductionsinnestingontheisland.Relativelyhighnestingduringrecentyearsmayactuallyreflectanincreaseinthenumberofnestingfemalesinthestudyarea.Onasmallerscale,powerplantoperationhashadnosignificanteffectonnestingneartheplant.Lownestingactivityin1975andagainin1981-1983inthevicinityoftheplantwasattributedtonighttimeconstructionactivitiesassociatedwithinstallationofplantintakeanddischargestructures.Nestingreturnedtonormalorabovenormallevelsfollowingbothperiodsof~~~~~~~~~~~construction.During1991,daytimeconstructionactivitiesassociatedwithvelocitycaprepairshadnoapparenteffectonnesting.Formalrequirementstoconductnestingsurveysexpiredin1986,butthisprogramhasbeencontinuedthrough1998withagreementfromfederalandstateagencies.In1998,thecontinuationofthenestingsurveyprogramwasmandatedaspartofthebiologicalopinionandincidentaltakestatementissuedbytheNationalMarineFisheriesService.1.3INTAKECANALMONITORINGSinceplantoperationbeganin1976,6086seaturtles(includingrecaptures)representingfivedifferentspecieshavebeenremovedfromtheintakecanal.Themajorityoftheturtlescaptured(59percent)wereloggerheads.Differencesinthenumbersofturtlesfoundduringdifferentmonthsandyears,includingdramaticincreasesingreenturtlecapturesinrecentyears,havebeenattributedprimarilytonaturalvariationintheoccurrencesofturtlesinthevicinityoftheplant,ratherthantooperationalinfluencesoftheplantitself.Themajorityofturtlesremovedfromtheintakecanal(about97percent)werecapturedaliveandreleasedbackintotheocean.Ongoingevaluationsandimprovementstothecanalcaptureprogramhavesubstantiallyreducedmortalitiesofentrappedseaturtlesduringrecentyears.Turtlesconfinedbetweenthebarriernetandintakeheadwallstypicallyresideinthecanalforarelativelyshortperiodpriortocapture,andmostareingoodtoexcellentconditionwhencaught.AnimproveddesignbarriernetcompletedinJanuary1996isexpectedtofurtherreducetheresidencetimesandpotentialformortalitiestoseaturtlesintheintakecanalsystem.

2.0INTRODUCTION

2.1BACKGROUNDThisdocumenthasbeenpreparedtosatisfytherequirementscontainedinAppendixB,EnvironmentalProtectionPlan,toSt.LucieUnit2FacilityOperatingLicenseNPF-16.St.LucieUnits1and2usetheAtlanticOceanasasourceofwaterforonce-throughcondensercooling.Since1971,thepotentialenvironmentaleffectsresultingfromtheintakeanddischargeofthiswaterhavebeenthesubjectofFPLsponsoredbioticstudiesatthesite.JurisdictionforseaturtlestudiesiswiththeNRC,whichisconsideredtobetheleadfederalagencyrelativetoconsultationundertheEndangeredSpeciesAct.Previousresultsdealingwithseaturtlestudiesarecontainedinfourteenannualenvironmentaloperatingreportscoveringtheperiodfrom1983through1997.Thisreportdescribesthe1998environmentalprotectionactivitiesrelatedtoseaturtles,asrequiredbySubsection4.2oftheSt.LucieUnit2EnvironmentalProtectionPlan.2.2AI&ADESCRIPTIONTheSt,LuciePlantislocatedona457-hectaresiteonHutchinsonIslandonFlorida'sEastCoast(Figures1and2).TheplantisapproximatelymidwaybetweentheFt.PierceandSt.LucieInlets.ItisboundedontheEastSidebytheAtlanticOceanandontheWestSidebytheIndianRiverLagoon.HutchinsonIslandisabarrierislandthatextends36kmbetweeninletsandattainsitsmaximumwidthof2kmattheplantsite.Elevationsapproach5matopdunesborderingthebeachanddecreasetosealevelinthemangroveswampsthatarecommononmuchofthewesternside.TheAtlanticshorelineofHutchinsonIslandiscomposedofsandandshellhashwithintermittentrockypromontoriesprotrudingthroughthebeachfacealongthesouthernendoftheisland.Submergedcoquinoidrockformationsparallelmuchoftheislandofftheoceanbeaches.Theoceanbottomimmediatelyoffshorefromtheplantsiteconsistsprimarilyofsandandshellsediments.TheFloridaCurrent,whichflowsparalleltothecontinentalshelfmargin,beginstodivergefromthecoastlineatWestPalmBeach.AtHutchinsonIsland,thecurrentisapproximately33kmoffshore.OceanicwaterassociatedwiththewesternboundaryofthecurrentperiodicaHymeandersovertheinnershelf,especially.duringsummermonths.2.3PLANTDESCRIPIIONTheSt.LuciePlantconsistsoftwo850netMWenuclear-fueledelectricgeneratingunitsthatusenearshoreoceanwatersfortheplant'sonce-throughcondensercoolingwatersystem.Waterfortheplantentersthroughthicesubmergedintakestructureslocatedabout365moffshore(Figure2).Eachoftheintakestructuresisequippedwithavelocitycaptominimizefishentraiiiment.Fromtheintakestructures,thewaterpassesthroughsubmergedpipes(two3.7mandone4.9mindiameter)underthebeachanddunesthatleadtoa1,500meterlongintakecanal,whichtransportswatertotheplant.Afterpassingthroughtheplant,theheatedwaterisdischargedintoa670meterlongcanalthatleadstotwoburieddischargepipelines.Thesepassunderneaththedunesandbeachandalongtheoceanfloortothesubmergeddischarges,thefirstofwhichisapproximately365moffshoreand730mnorthoftheintake.

3.1INTRODUCTION

HutchinsonIsland,Florida,isanimportantrookeryfortheloggerheadturtle,Caxettacaretta,andalsosupportssomenestingofthegreenturtle,Chelonia~mdas,andtheleatherhackI,~D*h*l'.SdfH*MpHitwi.ThfdIgovernmenthasclassifiedtheloggerheadturtleasathreatenedspecies.ThefederalgovernmentendangeredspecieslistsincludetheleatherbackturtleandtheFloridanestingpopulationofthegreenturtle.IthasbeenanFPLgoalthattheSt.LuciePlantwouldnotadverselyaffecttheHutchinsonIslandrookery.Becauseofthisconcern,FPLhassponsoredmonitoringofmarineturtlenestingactivityontheislandsince1971.Daytimesurveystoquantifynesting,aswellasnighttimeturtletaggingprograms,wereconductedinoddnumberedyearsfrom1971through1979.Duringdaytimenestingsurveys,nine1.25km-longsurveyareasweremonitoredfivedaysperweek(Figure3).TheSt.LuciePlantbeganoperationin1976;therefore,thefirstttueesurveyyears(1971,1973,and1975)werepre-operational.Thoughthepowerplantwasnotoperatingduring1975,St.LuciePlantUnit1oceanintakeanddischargestructureswereinstalledduringthatyear.Installationofthesestructuresincludednighttimeconstructionactivitiesconductedoffshorefromandperpendiculartothebeach.Constructionhadbeencompletedandtheplantwasinfulloperationduringthe1977and1979surveys.Amodifieddaytimenestingsurveywasconductedin1980duringthepreliminaryconstructionoftheoceandischargestructureforSt.LucieUnit2.Duringthisstudy,fourofthepreviouslyestablished1.25km-longsurveyareasweremonitored.Additionally,eggsfromturtlenestspotentiallyendangeredbyconstructionactivitieswererelocated.Everyyearfrom1981through1998,36one-km-longsurveyareascomprisingtheentireislandweremonitoredsevendaysaweekduringthenestingseason(Figure3).Beginningin1994,thesouthernhalfoftheislandhasbeensurveyedbyEcologicalAssociatesofJensenBeach,Florida,andtheirdataisincludedinthisreport;TheSt.LucieUnit2dischargestructurewasinstalledduringthe1981nestingseason.OffshoreandbeachconstructionoftheUnit2intakestructureproceededthroughoutthe1982nestingseasonandwascompletedneartheendthe1983'estingseason.ConstructionactivitiesassociatedwithinstallationofbothstructuresweresimilartothoseconductedwhenUnit1intakeanddischargestructureswereinstalled.Eggsfxomturtlenestspotentiallythreatenedbyconstructionactivitieswererelocated.During1991,anothermajoroffshoreconstructionprojectwasundertakentoreplacedamagedvelocitycapsonthethreeintakestructures.Alargeelevatedplatform,fromwhichrepairactivitieswereconducted,waserectedaroundthethreestructures.Constructionoccurredthroughoutthenestingseason.However,incontrasttopreviousoffshoreprojects,workwasrestrictedalmostentirelytodaylighthours,nighttimelightingoftheworkareawasminimal,andnoequipmentormaterialswereusedonthebeach.Aseaturtleprotectionplanimplementedinsupportoftheprojectincludedcagingofnestsalonga1,500metersectionofbeachwestoftheplatformandreleaseofhatchlingstounaffectedareastothenorthandsouth.Thisplanwas intendedtomitigateanynegativeeffectspotentiallyresultingfromreIuiredsafetyandnavigational~~~~~~~~~~~~~~~~lightingonandneartheplatform.Requirement4.2.1oftheSt.LucieUnit2AppendixBEnvironmentalProtectionPlanwascompletewithsubmissionofthe1986nestingsurveydata(ABI,1987).Thenestingsurveywascontinuedvoluntarilythrough1998withagreementfromfederalandstateagencies.Resultsarepresentedinthisreportanddiscussedinrelationtopreviousfindings.Inadditiontomonitoringseaturtlenestingactivitiesandrelocatingnestsawayfromplantconstructionareas,removalofturtlesfromtheintakecanalhasbeenanintegralpartoftheSt.LuciePlantenvironmentalmonitoringprogram.Turtlesenteringtheoceanintakestructuresareentrainedwithcoolingwaterandrapidlytransportedthroughtheintakepipesintoanenclosedcanalsystemwheretheymustbemanuallycapturedandreturnedtotheocean.Sincetheplantbecameoperationalin1976,turtlesentrappedintheintakecanalhavebeensystematicallycaptured,measured,weighed,tagged,andreleased.Previouspublicationsandtechnicalreportshavepresentedfindingsofthenestingsurveys,nestrelocationactivitiesandcanalcaptureprogram(ABI,1994)(Quantum,1995,1996,1997,1998).Resultsofstudiestoassesstheeffectsofthermaldischargesonhatchlingswimniingspeedhavealsobeenreported(ABI,1978).InJuly1994,responsibilityforseaturtleresearchandconservationactivitieswastransferredfromEcologicalAssociates,Inc.(formerlyAppliedBiology,Inc.)toQuantumResources,Inc.Methodologiesemployedinboththenestingsurveys~~~~~~andcanalcaptureoperationsremainedessentiallyunchangedsothatdatacollectedin1994throughthepresentaredirectlycomparabletopreviousyear'sdata.Thepurposeofthisreportisto:1)present1998seaturtlenestingsurveydataandsummarizeobservedspatialandtemporalnestingpatternssince1971,2)documentandsummarizepredationonturtlenestssince1971,and3)present1998canalcapturedataandsummarizecomparabledatacollectedsince1976.3.2MATEIUALSANDMETHODS3.2.1~N'31MethodologiesusedduringpreviousturtlenestingsurveysonHutchinsonIslandweredescribedinearlierreports(ABI1994).Methodsusedduringthe1998surveyweredesignedtoallowcomparisonswiththesepreviousstudies.In1998,onlyareasA-SweresurveyedbyQuantumResourcesbiologists(Figure3).DatasuppliedbyEcologicalAssociates,Inc.areusedtoprovidewholeislandnestingtotalsinFigures6,8,and9.FromMarch24,1998throughApril14,1998,severalpreliminarynestsurveyswereconductedalongHutchinsonIslandinareasA-S.NonestingwasrecordedinareasA-SpriortothebeginningofformalnestingsurveysonApril15,1998.FromApril15,1998throughSeptember8,1998,nestsurveyswereconductedonadailybasis.Thelastnestrecordedinarea~~~~A-SwasonSeptember7,1998.Biologistsusedsmalloff-roadmotorcyclestosurveytheislandeachmorning.Newnests,non-nestingemergences(falsecrawls),andnestsdestroyedby predatorswererecordedforeachofthe1-km-longsurveyareasA-S(Figure3).The1.25-km-longsurveyareasthatwereestablishedinearlierstudiesalsoweremonitoredsocomparisonscouldbemadewithpreviousstudies.DatacollectedfrombeachnestingsurveyswerereportedtotheFloridaDepartmentofEnvironmentalProtection(FDEP)aspartoftheFDEPIndexNestingBeachSurvey.Inacooperativeeffort,datafromstrandedturtlesfoundduringbeachsurveyswereroutinelyprovidedtotheFloridaDepartmentofEnvironmentalProtectionandtheNationalMarineFisheriesServicePG&S)throughtheSeaTurtleStrandingandSalvageNetwork:3.2.2IntakeCanalMonitorinMostturtlesentrappedintheSt.LuciePlantintakecanalwereremovedbymeansoflarge-meshtanglenetsfishedneartheintakecanalheadwallsattheextremeeasternendoftheintakecanal(Figure2).Netsusedduring1998werefrom30to40minlength,3to4mdeepandcomposedof40cmsketchmeshmultifilamentnylon.Largefloatswereattachedtothesurface,andunweightedlinesusedalongthebottom.Turtlesentangledinthenetsgenerallyremainedatthewater'ssurfaceuntilremoved.Sinceitsinceptionin1976,thecanalcaptureprogramhasbeenundercontinualreviewandrefinementinanattempttominimizebothentrapmenttimeandinjuries/mortalitiestoentrappedseaturtles.PriortoApril1990,turtlenetswereusuallydeployedonMondaymorningandretrievedonFridayafternoon.Duringperiodsofdeployment,thenetswereinspectedforcapturesatleasttwiceeachday(morningsandafternoons).Additionally,St.LuciePlantpersonnelcheckedthenetsperiodically,andbiologistswerenotifiedimmediatelywhenacapturewasobserved.Seaturtle'specialists,thatretrievecapturedturtlesfromtheplantintakecanalsystem,wereoncall24hoursaday.BeginningApril1990,afterconsultationwithNMFS,netdeploymentwasscaledbacktodaylighthoursonly.Concurrently,surveillanceoftheintakecanalwasincreasedandbiologistsremainedonsiteforthedurationofeachday'snettingactivities.Thismeasuredecreasedresponsetimeforremovalofentangledturtlesfromnetsandprovidedanopportunitytoimprovedailyassessmentsofturtlelevelswithinthecanal.Recordsofdailycanalobservationswerecomparedwithcapturedatatoassesscaptureefficiencies.In1978,abarriernetattheA1ABridgewasconstructedtoconfineturtlestotheeasternmostsectionoftheintakecanal,wherecapturetechniqueshavebeenmosteffective.Thisnetisconstructedoflargediameterpolypropyleneropeandhasameshsizeof20.3cmx20.3cm.Acableandseriesoflargefloatsareusedtokeepthetopofthenetabovethewater'ssurface,andthebottomisanchoredbyaseriesofconcreteblocks.Thenetisinclinedataslopeof1:1,withthebottompositionedupstreamofthesurfacecable.Thisreducesbowinginthecenterandminimizestheriskofaweakorinjuredturtlebeingpinnedunderwaterbystrongcurrents.Inthepast,theintegrityofthebarriernetwasoccasionallycompromised,andturtleswereabletomovewestofA1A.Theseturtleswerefurtherconstraineddownstreambyanunderwaterintrusiondetectionsystem(UIDS)consisting,inpart,ofalargebarrierpositionedperpendiculartothenorth-southarmofthecanal(Figure2).TheUIDSsecuritybarrierhasameshsizeof22.9cmx22.9cm.PriortocompletionoftheUIDSinDecember1986,turtlesunconfinedbythe A1AbarriernetwereusuallyxemovedfromthecanalattheintakewellsofUnits1and2(Figure2).Theretheywereretrievedbymeansoflargemechanicalrakesorspeciallydesignednets.FollowingconstructionoftheUIDSbarrier,allbutthesmallestindividualswereunabletoreachtheintakewells.ImprovementsmadetotheA1Abarriernetduring1990haveeffectivelyconfinedallturtleslargerthan-32.5-cmcarapacelength(28.7-cmcarapacewidth)totheeasternendofthecanal.Inresponsetothelargenumbersofsmallturtlesencounteredintheintakecanalinrecentyears,animproveddesign,smallmeshbarriernetwaserectedeastoftheA1Abarriernet.ConstructionwascompleteinJanuary1996.Thisimprovedbarriernetisdesignedtoconfineallturtleswithacarapacewidthgreaterthan18cmtotheextremeeasternportionoftheintakecanal.Formaldailyinspectionsoftheintakecanalweremadetodeterminethenumbers,locations,andspeciesofturtlespresent.Surfaceobservationswereaugmentedwithperiodicunderwaterinspections,particularlyinandaroundthebarriernets.Inadditiontotheuseoftanglenets,dipnetsandhandcapturesusingsnorkelandSCUBAwerealsoemployed.Longhandleddipnets,employedfromsmallboats,thecanalbanksandheadwallstructuresweremoderatelyeffectiveincapturingturtleswithcarapacelengthsofabout30cmorless.Diverswereemployedtohandcaptureturtleswheneverunderwatervisibilitypermits,andthistechniquehasprovenhighlyeffectiveinthecaptureofturtlesofallsizes,particularlylessactiveindividualsoftenfoundpartiallyburiedinthesedimentinthevicinityofthebarriernets.Handcaptureeffortshavehadasignificantimpactinreducingentrapmenttimesforturtlesintheintakecanal.Regardlessofcapturemethod,allturtlesxemovedfromthecanalwereidentifiedtospecies,measured,weighed,taggedandexaminedforoverallcondition(wounds,abnormalities,parasites,etc.).BeginninginJuly1994,allturtlescapturedhavebeenphotographeddorsallyandventxallypriortoxelease,andthephotographsretainedforfuturereference.Healthyturtleswerereleasedintotheoceanthesamedayofcapture.Sickorinjuredturtlesweretreatedandoccasionallyheldforobservationpriortorelease.Whentreatmentwaswarranted,turtlesweretransportedtoanapprovedrehabilitationfacility.Resuscitationtechniqueswereusedifaturtlewasfoundthatappearedtohavediedrecently.Beginningin1982,necropsieswereconductedondeadturtlesfoundinfreshcondition.'loridaPower&LightCompanyandQuantumResources,Inc.continuedtoassistotherseaturtleresearchersin1998.Sincetheprogrambegan,data,specimensand/orassistancehavebeengiventotheFloridaDepartmentofEnvironmentalProtection,NationalMarineFisheriesService,USFishandWildlifeService,USArmyCorpsofEngineers,SmithsonianInstitution,SouthCarolinaWildlifeandMarineResourcesDivision,CenterforSeaTurtleResearch(UniversityofFlorida),FloridaAtlanticUniversity,UniversityofCentralFlorida,TexasA&MUniversity,UniversityofRhodeIsland,UniversityofSouthCarolina,UniversityofIllinois,UniversityofGeorgia,VirginiaInstituteofMarineScience,WesternAtlanticTurtleSymposium,SouthAtlanticFisheryManagementCouncil,FloridaMarineFisheriesCommission,HarborandBranchOceanographicInstitutionandtheNationalResearchCouncil.

3.3RESULTSANDDISCUSSION3.3.1N~33.3.1..11998LoerheadNestinSummIn1998,7962loggerheadturtlenestswererecordedinthe36one-kilometersegmentscomprisingHutchinsonIsland.ThisfigureisinaccordancewithageneralincreaseinloggerheadturtlenestingonHutchinsonIslandsincesurveysbeganin1971,althoughsignificantyeartoyearfluctuationsareevident.loggerheadnestsandemergencesforsurveyareasA-SispresentedinFigure4.3.3.1.2SatialDistributionofLoerheadTurtleNestsFrom1981through1998,36one-km-longsegmentscomprisingtheisland'scoastlinehavebeensurveyed.Thedistributionofnestsamongthese36surveyareashasshownanincreaseinnestingfromnorthtosouthalongthenorthernhalfoftheisland(ABI,1987,1994).Alongthesouthernhalfoftheislandtherehasbeeneithernogradientoragradientofdecreasingnestingfromnorthtosouth.Thoughbeachdynamicsmaysometimesaffecttheselectionofnestingsitesbyloggerheadturtles,relationshipsbetweenspatialnestingpatternsandspecificenvironmentalconditionsareoftendifficulttoestablishbecauseoftheinterxelationshipofthefactorsinvolved.Notallventuresontothebeachbyafemaleturtleculminateinsuccessfulnests.These"falsecrawls"(non-nestingemergences)mayoccurformanyreasonsandarecommonlyencounteredatotherrookeries.DavisandWhiting(1977)suggestedthatrelativelyhighpercentagesoffalsecrawlsmightreflectdisturbancesorunsatisfactorynestingbeachcharacteristics.Thexefore,certainfactorsmayaffectaturtle'spreferencetoemergeonabeach,whileotherfactorsmayaffectaturtle'stendencytonestafterithasemerged.Anindex,whichrelatesthenumberofneststothenumberoffalsecrawlsinanarea,isusefulinestimatingthepost-emergencesuitabilityof'abeachfornesting.Inthepresentstudythisindexistermed"nestingsuccess"andisdefinedasthepercentageoftotalemergencesthatresultinnests.loggerheadnestingsuccessforareasA-Sin1998ispresentedinFigure5.Historically,thepatternofloggerheademergencesontheislandhasgenerallyparalleledthedistributionofnests(ABI,1987,1994).Incontrast,nestingsuccessbyloggerheadsalongtheislandhastypicallylackedgradients(ABI,1987,1994).Thus,therelativelyhighnumbersofloggerheadnestsobservedincertainareasareusuallyaresultofmoreturtlescomingashoreinthoseareasratherthanofmorepreferablenestingconditionsbeingencounteredbythetuxtlesaftertheyemerged.Avarietyofenvironmentalfactors(i.e.,offshorebottomcontours,distributionofreefs,typeandextentofdunevegetation,andhumanactivityonthebeachatnight)mayeffectloggerheadturtleemergencepatternsandseveralhavebeenreportedtoaffectemergencepatternsonHutchinsonIsland(ABI,1988,1989).Undoubtedly,acombinationoffactorsaccountsfortheoveralldistributionofemergencesandthereforetheoverallnestingpatternontheisland.NestingsurveysonHutchinsonIslandwereinitiatedinresponsetoconcernsthattheoperationoftheSt.LuciePlantmightnegativelyimpactthelocalseaturtlexookery.Previous analysis,usinglog-likelihoodtestsofindependence(G-test;SokalandRohlf,1981)demonstratedthattheconstructionoftheplant'soffshoreintakeanddischargestructuressignificantlyreducednesting-attheplantsiteduringconstructionyears-1975,1981,1982,1983(ABI,1987).However,nestingattheplantconsistentlyreturnedtolevelssimilartoor,greaterthanthoseatacontrolsiteinyearsfollowingconstruction.During1991whenoffshoreconstructionwasrestrictedalmostentirelytodaylighthours,nests'weremoreabundantattheplantsitethanatthecontrolsite.Datacollectedthrough1998haveshownthatpowerplantoperationexclusiveofnighttimeintake/dischargeconstructionhashadnoapparenteffectonnesting.3.3.1.3Lon-TermTrendsinLoerheadTurtleNestinVariousmethodswereusedduringsurveyspriorto1981toestimatethetotalnumberofloggerheadnestsonHutchinsonIslandbasedonthenumberofnestsfoundinthenine1.25km-longsurveyareas(ABI,1980a).Eachofthesemethodswassubsequentlyfoundtoconsistentlyoverestimateislandtotals(ABI,1987).Sincewhole-islandsurveysbeganin1981,ithasbeenpossibletodeterminetheactualproportionoftotalnestsdepositedinthenineareas.ThishasaHowedextrapolationfromtheninesurveyareastotheentireislandforyearspriorto1981.From1981through1993thetotalnumberofnestsinthenineareasvariedfrom32.5to35.6percentofthetotalnumberofnestsontheisland.Thisisslightlyhigherthanthe31.3percent,whichwouldbeexpected,basedstrictlyontheproportionoflinearcoastlinecomprisedbythenineareas.Usingthethirteen-yearmeanof33.81percent,estimatesofthetotalnumberofnestsonHutchinsonIslandcanbecalculatedbymultiplyingthenumberofnestsinthenineareasby2.958.Thistechnique,whenappliedtotheninesurveyareasduringthethirteenyearsinwhichtheentireislandwassurveyed,producedwhole-islandestimateswithin5.3percentoftheactualnumberofnestscounted.Becausetheproportionofnestsrecordedintheninesurveyareasremainedrelativelyconstantoverthelastthirteenyears,thisextrapolationprocedureprovidesafairlyaccurateestimateoftotalloggerheadnestingforyearspriorto1981,andisusedtogeneratedatapointsfor1971through1979inFigure6.Itisclearthatloggerhead-nestingactivityonHutchinsonIslandfluctuatesconsiderablyfromyeartoyear(Figure6).Annualvariationsinnestdensitiesalsoarecommonatotherrookeries,andmayresultfromnon-annualreproductivebehavior.Despitehighvariability,datacollectedthxough1998suggestanoverallincreaseinnestingonHutchinsonIslandsincesurveysbeganin1971.Totalnestingactivitywasgreatestduring1995when8184loggerheadnestswererecorded.Norelationshipsbetweentotalnestingactivityandpowerplantoperationorintake/dischargeconstructionwereindicatedbyyear-to-yearvariationsintotalnestingonHutchinsonIsland.3.3.1.4SeasonalPatternsofLoerheadTurtleNestinTheloggerheadturtlenestingseasonusuallybeginsbetweenmid-AprilandearlyMay,attainsamaximumduringJuneorJuly,andendsbymid-September(ABI,1987).Nestingactivityduring1998followedthissamepattern.CoolwaterintrusionsfrequentlyoccuroverthecontinentalshelfofsoutheastFlorida duringthesummer(Smith,1982).TheseintrusionsmayhavebeenresponsibleforthetemporarydeclinesinloggerheadturtlenestingactivitypreviouslyobservedonHutchinsonIsland(ABI,1994).ThoughnaturalfluctuationsintemperaturehavebeenshowntoaffecttemporalnestingpatternsonHutchinsonIsland,therehasbeennoindicationthatpowerplantoperationhasaffectedthesetemporalpatterns(ABI,1988).3.3.1.5PredationonLoerheadTurtleNestsSincenestsurveysbeganin1971,raccoonpredationhasbeenamajorcauseofturtlenestdestructiononHutchinsonIsland.Researchersatotherlocationshavereportedraccoonpredationlevelsashighas70tonearly100percent(Hopkinsetal.,1979).RaccoonpredationofloggerheadturtlenestsonHutchinsonIslandhasnotapproachedthislevelduringanystudyyear,thoughlevelsforindividual1.25km-longareashavebeenashighas80percent.Overallpredationratesforsurveyyears1971through1977werebetween21and44percent,withahighof44percentrecordedin1973.Apronounceddecreaseinraccoonpredationoccurredafter1977andoverallpredationratesforthenineareashavenotexceeded10percentsince1979.AdeclineinpredationratesonHutchinsonIslandmaybeattributabletotrappingprograms,constructionactivities,habitatloss,anddisease.During1998,raccoonpredationlevelswereextremelylow,withonlyoneloggerheadnestinareasA-Sdepredatedbyraccoons(Figure7).Inpreviousyears(ABI,1994),predationofturtlenestswasprimarilyrestrictedtothemoreundevelopedportionsoftheisland.Ghostcrabshavebeenreportedbynumerousresearchersasimportantpredatorsofseaturtlenests(Hopkinsetal,1979;Stancyk,1982).ThoughturtlenestsonHutchinsonIslandprobablyhavebeendepredatedbyghostcrabssincenestingsurveysbeganin1971,quantificationofghostcrabpredationdidnotbeginuntil1983.Overallpredationratesbyghostcrabshavevariedfrom0.1to2.1percentfrom1983-1998.During1998,threeloggerheadnestinareasA-Sweredepxedatedbyghostcrabs(Figure7).Nestsdestroyedbyacombinationofraccoonandghostcrabpredationhavebeenincludedasraccoonpredationsinpreviousdiscussions.Whenthesecombinationpredationsareincludedascrabpredations,theoverallpredationratesbyghostcrabsrangefrom0.1to4.7percent.During1998,nosuchcombinationpredationswererecorded.3.3.1.61998GreenandLeatherbackNestinSummIn1998,258greenturtleand77leatherbackturtlenestswererecordedinthe36one-kmsegmentscomprisingHutchinsonIsland.ThegreenturtletotalrepresentsanewrecordforHutchinsonIslandgreenturtlenestingandasubstantialincreasefromlastyear'stotals.1998wasalsoarecordyearforleatherbackturtlenestingonHutchinsonIsland(Figures8and9).Althoughstrongyeartoyearfluctuationsarecommon,thegeneraltrendsince1971mayreflectanincreaseinthenumbersofnestingfemalesintheHutchinsonIslandarea.

3.3.1.7TrendsinGreenandLeatherbackTurtleNestin~~~~~~GreenandleatherbackturtlesnestonHutchinsonIsland,butinfewernumbersthanloggerheadturtles.Priorto1981,bothsurvey(nine1.25km-longsections)andinter-surveyareasweremonitoredforthepresenceofgreenandleatherbacknests.Thirty-onekilometersofbeachfromArea1southtotheSt.LucieInletwereincludedinthateffort.Duringwhole-islandsurveysfrom1981through1993,only2.6percent(7)oftheleatherbacknests(n=266)andonly1.4percent(12)ofthegreenturtlenests(n=831)wererecordedonthefivekilometersofbeachnorthofArea1.Therefore,previouscountsofgreenandleatherbacknestswithinthe31kilometerssurveyedprobablywerenotappreciablydifferentfromtotaldensitiesfortheentireisland.Basedonthisassumption,greenandleatherbacknestdensitiesmaybecomparedamongallsurveyyears,except1980,whenlessthan15kilometersofbeachweresurveyed.Sincesurveysbeganin1971,thenumberofnestsobservedontheislandrangedfrom5to258forgreenturtlesandfrom1to77forleatherbacks(Figures8and9).Temporalnestingpatternsforthesespeciesdifferfromthepatternforloggerheadturtles.GreenturtlestypicallynestonHutchinsonIslandfrommid-JunethroughthefirstorsecondweekofSeptember.LeatherbackturtlesusuallybeginnestinginMarchorAprilandcontinuetonestthroughearlytomid-July.Considerablefluctuationsingreenturtlenestingontheislandhaveoccurredamongsurveyyears(Figure8).Thisisnotunusualsincetherearedrasticyear-to-yearfluctuationsinthenumbersofgreenturtlesnestingatotherbreedinggrounds(Carretal.,1982).Despitethesefluctuations,datacollectedthrough1998suggestanoverallincreaseinnestingsince1971andmay~~~reflectanincreaseinthenumberofnestingfemalesintheHutchinsonIslandarea.During1998,greenturtlesnestedmostfrequentlyalongthesouthernhalfoftheisland.Thisisconsistentwithresultsofprevioussurveys.LeatherbackturtlenestdensitieshaveremainedlowonHutchinsonIsland,however,increasednestingduringrecentyears(Figure9)mayreflectanoverallincreaseinthenumberofnestingfemalesintheHutchinsonIslandarea.

3.3.2INTAKECANALMONITORING~~~~~~EntrainmentofseaturtlesattheSt.LuciePlanthasbeenattributedtothepresumedphysicalattractivenessoftheoffshorestructureshousingtheintakepipesratherthantoplantoperatingcharacteristics(ABI,1980band1986).Thevelocitycaps,whichaxesupportedabovetheopeningstoeachintakepipe,eliminateverticalwaterentraimnentandsubstantiallyreducecurrentvelocitiesnearthestructuresbyspreadinghorizontaldrawoverawiderarea.Evenwhenbothunitsareoperatingatfullcapacity,turtlesmustactivelyswimintothemouthofoneofthepipesbeforetheyencountercurrentvelocitiessufficientlystrongtoeffectentraimnent.Consequently,aturtle'sentrapmentrelatesprimarilytotheprobabilitythatitwilldetectandsubsequentlyenteroneoftheintakestructures.3.3.2.11998CanalCatureSummIn1998,666seaturtleswerecapturedintheintakecanaloftheSt.LuciePlant.Capturesincluded393loggerheads,268greenturtles,1leatherback,2hawksbill,and2Kemp'sridleyturtles(Table1).3.3.2.2RelativeAbundanceandTemoralDistributionSinceintakecanalmonitoringbeganinMay1976,3578loggerhead(including222recaptures),2432green(including478recaptuxes),21leatherback,33Kemp'sridleys,and21hawksbillcapturehavetakenplaceattheSt.LuciePlant.Annualcatchesforallspeciescombinedrangedfromalowof33in1976(paxtialyearofplantoperationandmonitoring)to933in1995.Exceptfor1993thxough1997,whenthegreenturtlewasthemostabundantspeciesinthecanal,loggerheadshavedominatedannualcaptures.Since1977,thefirstfullyearofplantoperation,thenumberofloggerheadscapturedeachyearrangedfrom62in1981to393in1998(Figure10).Numbershaveexhibitedconsiderableyear-to-yearfluctuationswithnopersistenttrendsevident,althoughrecentyear'sdataaresuggestiveofapossibleincreasingtrend.Thenumberofgreenturtlescapturedeachyearsince1977haverangedfrom3in1979toarecordhighof673in1995(Figure10).Increasingnumbersofcapturesoverrecentyearsmayreflectanincreaseinthenumberofturtlesinhabitingthenearshorecoastalareaneartheplantormaysimplyrepresentstatisticalvariation.Greenturtlecapturesweredownsharplyin1997,butshowedamodestreboundin1998.Additionalyearsofcapturedatawillberequiredbeforeanylong-termtrendscanbeestablished.During1998,themonthlycatchofloggerheadsrangedfrom10(November)to60(March),withamonthlymeanof32.7(Table2).Overtheentirehistoryofthecaptureprogram,monthlycatcheshaverangedfrom0to87,withthegreatestnumberofcapturesoccurringduringJuly1996.During1998,themonthlycatchofgreenturtlesrangedfrom7(July)to58(February),withamonthlymeanof23.3(Table3).TheMarch1996catchof147greenturtlesisthelargestnumberofcapturesforthisspeciesforanymonthonrecord.Seasonalabundancepatternsof10 greenturtleshavetypicallybeenmuchmorepronouncedthanforloggerheads,withover50percentofallcapturesoccurringbetweenJanuaryandMarch.In1995through1998,however,nosuchseasonalpatternwasevident,withcapturesdistributedmoreorlessevenlythroughouttheyear.Catchesofleatherbacks,hawksbills,andKemp'sridleyshavebeeninfrequentandscatteredthroughouttheyears.Eachspecieshasshownratherpronouncedseasonaloccurrences;over60percentofaHleatherbackswerecapturedinMarchandApril,over60percentofthehawksbillswerecapturedbetweenJulyandSeptember,andalmost90percentoftheKemp'sridleyswerecaughtbetweenDecemberandApril.3.3.2.3Size-ClassDistributionsThesize-classdistributionforloggerheadsremovedfromtheintakecanalin1998ispresentedinFigure11.Thesizeclassdistributionforgreenturtlesremovedfromtheintakecanalin1998aiepresentedinFigure12.ABI(1994)presentssize-classdataforturtlesremovedfromtheintakecanalfrom1976-1993.Theleatherbackcapturedin1998wasanadult,withastraight-linecarapacelength(SLCL)ofover121cm(Hirth,1980).Bothhawksbillscapturedin1998wereadults(SLCL)63cm)(Witzell,1983).BothKemp'sridleyscapturedin1998werejuvenilesSLCL(60cm)(Hirth,1980).3.3.2.4SexRatiosOfthe390loggerheadscapturedin1998forwhichstraightlinecarapacelengthsareavailable,276werejuvenileswithastraightlinecarapacelength(SLCL)lessthanorequalto70cm,81wereadults(SLCL)85cm)and33weretransitional(SLCL71-85cm)(Hirth,1980).'helattergroupprobablyincludesbothmatureandimmatureindividuals.Ofthe81individualsclassifiedasadultsforwhomsexwasrecorded,76werefemalesandfiveweremales,withfemalespredominatingbyaratioof15:1.Ofthe267greenturtlescapturedin1998forwhichstraightlinecarapacelengthsareavailable,263werejuvenilesorsub-adults(SLCL(83cm)(WhitheringtonandEhrhart,1989).Ofthe4adultgreenturtlescapturedin1998,2weremalesand2werefemales.ABI(1994)discussessexratiodataforpreviousyears.3.3.2.5CatureEfficienciesNettingmethodologieshavebeenundercontinualreviewandrefinementasnetmaterials,configurations,andplacementbevariedinanefforttomiiiiinizeseaturtleentrapmenttimes.Additionally,alternativecapturetechniqueshavebeenevaluated,andpotentialdeterrentsystemstestedinthelaboratory.Currentcaptureprocedureshaveproventoprovideasafe,efficient,andcost-effectiveprogramforremovingentrappedturtlesfromtheintakecanal.Formaldailyinspectionsoftheintakecanalareconductedeverydaythatcapturenetsaredeployed,andthenumber,locationandrelativesizeofentrappedturtlesarerecordedonfieldobservationforms.Betterutilizationofcurrentsandeddies,adjustmentstotetheringlines,multi-11 netdeploymentsandincreasedeffortstohandcaptureturtleshavecontributedtoreducedentrapmenttimesduringrecentyears.EntrapmenttimesmaybeextendedforturtlesswimmingpasttheA1Abarriernet(ABI;1987).BecausecaptureeffortswestoftheAIAbridgeweregenerallylesseffectivethanthoseneartheintakeheadwalls,mostturtlesbreachingthebarriernetwerenotcaughtuntiltheyenteredtheintakewells.ofUnits1and2..Becauseoftheirrelativelysmallsizes,virtuallyalltheturtlesreachingtheintakewellsaregreenturtles.During1998,5ofthe268greenturtlecaptures(1.8percent)occurredattheintakewells.Thesubstantialdecreaseinthepercentageofcapturesattheplantintakewellscomparedtothe1995figureof14.5percentisattributedtotheeffectivenessofthenewsmallmeshbarriernetinstalledeastofAIAinJanuary1996.During1998,99.1percentofallturtlesentrappedinthecanalwerecapturedeastoftheA1ABridge,547bytanglenetsand119byhandordipnetcapture.TheeffectiveconfinementofturtleseastofA1Ahasbeenamajorcontributortothehighcaptureefficiencyachievedduringrecentyears.TheinstallationofanimprovedbarriernetcompletedinJanuary1996hasfurtherincreasedcaptureefficiencybymoreeffectivelyconfiningturtlesofallsizestoasmallerareaeasttotheA1Abarriernet.3.3.2.6BarrierNetMaintenanceBarriernetmaintenanceiscriticalinreducingtheopportunityformortalitiesintheplantintakewellareaandinreducingresidencetimesforturtlesintheintakecanalsystem.Dailyinspectionsareperformedfromasmallboattoremovefloatingdebrisandtorepairholesnearoratthewatersurface.Whenunderwatervisibilityconditionspermit,aweeklyunderwaterinspectionisconducted.Aformalinspectionisconductedmonthly,includingholerepair,debrisremoval,andairlift'dredgingofaccumulatedsiltifneeded.Maintenanceconductedin1998includedtherepairofanyholesinthemeshdiscoveredduringthedaily,weeklyandmonthlyinspectionsandextensivedebrisremovalandairliftdredgingofaccumulatedsedimentconductedinNovember.InSeptember,October,andNovember1998,largeinfluxesofjellyfishintotheintakecanalrequiredtheprimarybarriernettobeloweredperiodically,sometimesfordaysatatime,topreventthenetfromfailingundertheweightofaccumulatedjellyfish.Theloweringmechanismfunctionedasdesignedandnodamagewassustained.3.3.2.7RelativeConditionTurtlescapturedaliveintheintakecanaloftheSt.LuciePlantwereassignedarelativeconditionbasedonweight,activity,parasiteinfestation,barnaclecoverage,wounds,injuriesandanyotherabnormalitieswhichmighthaveaffectedoverallvitality.During1998,95.2%percent(373)ofallloggerheadsfoundinthecanalwerealiveandingoodcondition.Only4.8percent(19)loggerheadcapturesinvolvedindividualsinfairorpoorcondition,andonewasdead.Ofthe268greenturtlesremovedfromtheintakecanalduring1998,254(94.8percent)wereingoodcondition,14(5.2percent)wereinfairorpoorcondition,andnoneweredead.The2hawksbills,2Kemp'sridleys,andtheleatherbackcapturedin1998wereallingoodcondition.12 Relativeconditionratingscanbeinfluencedbyanumberoffactors,somerelatedandothersunrelatedtoentrainmentand/orentrapmentintheintakecanal.Aratingofgoodindicatesthatturtleshavenotbeennegativelyimpactedbytheirentrapmentinthecanal,atleastasevidencedbyphysicalappearance.Althoughratingsoffairorpoorimplyreducedvitality,theextenttowhichentrainmentandentrapmentisresponsibleisoftenindeterminable.Insomeinstances,conditionsresponsibleforlowerratings,suchasboatcollisionorfisheriesgearentanglementinjuriesobviouslyweresustainedpriortoentrainment.During1998,71ofthe666turtlescaptured(10.7percent)hadnotableinjuriessuchasmissingappendages,brokenormissingpiecesofcarapace,ordeeplacerations.Manyofthesewereold,.well-healedwounds,anddidnotrequireveterinaryattention.Ofthe665liveremovalsduring1998,652werereleasedintotheoceanthedayofcapture.Nineturtles(allloggerheads)inobviousillhealthorsufferingseriousinjuriesweretransportedtoSeaWorldofFloridaortheMarinelifeCenterofJunoBeachfortreatmentandrehabilitation.Twohadseriouscarapacedamage,presumablyfromaboatcollision,onehadingestedmonofilamentfishingline,andsixwereweak,lethargic,andemaciatedwhencaptured.Fifteengreenturtleswithfibropapillomatumorswereremovedfromthecanalin1998.ThreeturtleswithextensivetumorsweretransferredtotheFloridaDEPfortransportationtoarehabilitationfacility.Twelveturtleswithminortumorsweretaggedandreleased.Onegreenturtlewasheldovernightforinstallationofasatellite-trackingtransmitterandwaslaterreleased.3.3.2.8MortalitiesSeaturtlemortalitieshavebeencloselymonitoredthroughoutthelifeofthecanalcaptureprogmminanattempttoassignprobablecausesandtakeappropriateremedialactiontominimizefutureoccurrences.PreviousanalysesofcapturedataidentiTieddrowninginnets(A1Abarriernet,UIDSbarrier,andtanglenets),drowningintheintakepipesduringperiodsofreducedintakeflow,injuriessustainedfromdredgingoperations,andinjuriessustainedfromthemechanicalrakesusedintheintakewellsasprobablemortalityfactors(ABI,1987)(FPL,1995).Althoughdifficulttoquantify,theentrapmentandsubsequentdemiseofinjuredorsickturtleshasprobablyaccountedforaportionofobservedmortalities.Overtheentiremonitoringprogramhistory,135(3.8percent)ofthe3578loggerheadsand52(2.1percent)ofthe2432greenturtlesentrappedinthecanalwerefounddead.Mortalitiesspannedtherangeofsizeclassesfor.loggerheads(SLCL=47.5-103cm),whileallgreenturtlemortalitiesinvolvedjuvenileslessthan42cminlength.ThefourKemp'sridleymortalitiesdocumentedattheplantduring1987and1988weretheonlydeathsforthisspeciestodate;nodeadleatherbackorhawksbillturtleshavebeenrecoveredattheSt.LuciePlant.Modificationstocaptureprocedures,improvementstobarriernets,andvirtualeliminationoflowflowconditionswithinthecanalhaveresultedinasubstantialreductioninseaturtlemortalitiesoverthelifeofthecanalcaptureprogram.Mortalityrate,expressedasthepercentageoftotalcapturesinvolvingdeadanimals,declinedfrom7.8percentduringtheperiod1976-1984to2.1percentsince1984,and1.0%since1990(Table1).13 In1998,oneturtle(aloggerhead)wasremoveddeadfromtheintakecanal,foranoverallmortalityrateof0.15percent.Theturtlewasfoundfloatingupagainstthe'A1Abarriernetduringaperiodwhentheprimarybarriernetwasloweredduetoajellyfishinflux.Theturtlewasmoderatelydecomposed,andnocauseofdeathcouldbedetermined.Inresponsetothe1995mortalitiesandthedramaticincreaseinintakecanalcapturesin1995,consultationwasinitiatedwithFPL,NRC,andtheNMFSunderSection7oftheEndangeredSpeciesAct.Asaresultofthatconsultation,FPLhasdesignedandconstructedanimproved,smallermeshbarriernetlocatedbetweentheA1Abarriernetandtheintakecanalheadwalls(Figure2).ConstructionofthenetwascompletedinJanuary1996.ThisbarriernetpreventsturtlesfromreachingtheintakewellsorUIDSbarrierandincreasescaptureefficiencybyconfiningturtlestoasmallerareaoftheintakecanal.3.3.2.9RecatuxeIncidentsSincetheSt.LuciePlantcaptureprogrambegan,mostturtlesremovedfromtheintakecanalhavebeentaggedandreleasedintotheoceanatvariouslocationsalongHutchinsonIsland.Consequently,individualturtlescanbeidentifiedaslongastheyretaintheirtags.OverthehistoryoftheprogramattheSt.LuciePlant,700recaptures(222loggerheadsand478greentuxtles)haveoccurred,andanumberofturtleshavebeenrecapturedmorethanonce.Therecapturerateforgreenturtlesin1998was37percentandtherecapturerateforloggerheadswasonly5.3pexcent.ThelargenumberofgreenturtlerecapturesprobablyreflectsthesaturationoflocalgreenturtlepopulationswithturtlestaggedattheSt.LuciePlantandpossiblyindicatesadifferenceinsitefidelitybetweengreenturtlesandloggerheads.Severalotherturtleswithtagscarshavealsobeenrecoveredindicatingthattheactualnumberofxecaptuxesmaybehigher.3.3.3SUMMARYAgradientofincreasingloggerheadturtlenestdensitiesfromnorthtosouthalongthenorthernhalfofHutchinsonIslandhasbeenshownduringmostsurveyyears.Thisgradientmayxesultfxomvariationsinbeachtopography,offshoredepthcontours,distributionofnearshorereefs,onshoreaxtiflciallighting,andhumanactivityonthebeachatnight.Lownestingactivityinthevicinityofthepowerplantduring1975andfrom1981through1983wasattributedtonighttimeconstructionactivitiesassociatedwithinstallationofpowerplantintakeanddischargestructures.Nestingreturnedtonormalorabovenormallevelsfollowingbothperiodsofconstruction.During1991,daytimeconstructionactivitiesassociatedwithvelocitycaprepairshadnoapparenteffectonnesting.Statisticalanalysesindicatethatpowerplantoperation,exclusiveofnighttimeconstruction,hashadnosignificanteffectonnestdensitiesneartheplant.In1998,7962loggerheadturtlenestswererecordedonHutchinsonIsland.Therehavebeenconsiderableyear-to-yearfluctuationsinloggerheadnestingactivityonHutchinsonIslandfrom1971through1998.Fluctuationsarecommonatotherxookeriesandmayresultfromnon-annualreproductivebehavior.Despitethesefluctuations,loggerhead-nestingactivityhasremainedhighduringrecentyearsandmayreflectanoverallincreaseinthenumberofnestingfemalesintheHutchinsonIslandarea.Norelationshipbetweentotalnestingontheislandandpowerplantoperationorintake/dischargeconstructionwasindicated.14 TemporalnestingpatternsoftheHutchinsonIslandpopulationmaybeinfluencedbynatural,largescalefluctuationsinwatertemperature,suchasthoseproducedbythecoolwaterintrusionsthatfrequentlyoccuroverthecontinentalshelfofsoutheastFloridaduringthenestingseason.However,localizedfluctuationsinwatertemperatureassociatedwithpowerplantoperationhavehadnoapparenteffectonnesting.Sincenestingsurveysbeganin1971,raccoonpredationhasbeenoneofthemajorcausesofturtlenestdestructiononHutchinsonIsland.From1971through1977,overallpredationratesintheninesurveyareaswerebetween21and44percent.However,apronounceddecreaseinraccoonpredationoccurredafter1977,andoverallpredationratesintheninesurveyareashavenotexceededtenpercentsince1979.Decreasedpredationbyraccoonsprobablyreflectsadeclineintheraccoonpopulation.Moreyearsofsurveydatawillberequiredtodetermineiftheextremelylowlevelofraccoonpredationin1996through1998isanisolatedoccurrenceorpartofacontinuingtrend.Ghostcrabpredationontheturtlenestsmaybemoresignificantthanpreviouslydocumentedbutremainsrelativelyminorcomparedtoraccoonpredation.During1998,258greenturtleand77leatherbackturtlenestswererecordedonHutchinsonIsland,arecordhighforbothspecies.Nestingactivitybythesetwospecieshasexhibitedconsiderableannualfluctuations,ashasbeenrecordedatotherrookeries,buthasremainedrelativelyhighduringrecentyears.ThismayreflectanoverallincreaseinthenumberofnestinggreenandleatherbackturtlesintheHutchinsonIslandarea.During1998,393loggerheads,268greenturtles,2hawksbills,2Kemp'sridleys,andoneleatherbackwereremovedfromtheSt.LuciePlantintakecanal.SincemonitoringbeganinMay1976,3578loggerhead,2432green,21leatherback,21hawksbilland33Kemp'sridleyturtleshavebeencapturedandtagged.Overthelifeofthemonitoringprogram,annualcatchesforloggerheadturtleshaverangedfrom33in1976(partialyearofplantoperationandmonitoring)toahighof393in1998.Yearlycatchesofgreenturtleshaverangedfrom0in1976to673in1995.Differencesinthenumberofturtlesentrappedduringdifferentyearsandmonthsareattributedprimarilytonaturalvariationintheoccunenceofturtlesinthevicinityoftheoffshoreintakestructures,ratherthantoplantoperationcharacteristics.Size-classdistributionsofloggerheadturtlesremovedeachyearfromthecanalhaveconsistentlybeendominatedbyjuvenilesbetween50and70cminstraight-linecarapacelength.Over75percentofallgreenturtlesentrappedinthecanalwerejuveniles40cmorlessinlength.Forbothspecies,thelargestnumberofcapturesforallyearscombinedoccurredduringwinter,but,withtheexceptionof1995,andtolesserextent1996,theseseasonalpeaksweremuchmore'ronouncedforgreenturtles.Thesexratioofloggerheadscaughtinthecanalcontinuedtobebiasedtowardsfemales.During1998,about95percentofallloggerheadsandgreenturtlesremovedfromthecanalwerecategorizedbyphysicalappearanceasbeingingoodcondition.About10percentoftheturtlesremovedfromtheintakecanalduring1998hadsubstantialinjuries,andthevastmajorityofthosewereweHhealedandapparentlysustainedpriortoentrapment.Onceinthecanal,turtlesconfinedeastofA1Ahadverybriefresidencytimes.Thus15 therelativeconditionofmostturtleswasnotaffectedbytheirentrapment.~~~~~~~~~~~~~~During1998,onlyonemortalitywasxecordedintheintakecanal.Programmodifications,includingcontinualsurveillanceoftanglenetsduringperiodsofdeployment,improvementstotheintegrityofthebarriernetsystem,andgreaterefforttohandcaptureturtleshavecontributedtoasubstantialdeclineinseaturtlemortalitiesduringrecentyears.ThedesignandconstructionofanimprovedbarriernetcompletedinJanuary1996wasexpectedtoreducemortalitiesandentrapmenttimesforturtlesintheintakecanal.Datasincethenindicatethatthenewbarriernetconfigurationhasbeenhighlyeffectiveinexcludingturtlesfromtheplantintakewells,buthasnotbeenaseffectiveinreducingtheoverallmortalityrateasanticipated,althoughthe1998mortalityrateof0.15%,thelowestmortalityrateintheprogramshistory,wasanoutstandingachievementandahopefulsignforthefuture.16 4.0LITERATURECITEDABI(AppliedBiology,Inc.),1978.EcologicalMonitoringAtTheFloridaPower&LightCompanySt.LuciePlant,AnnualReport1977;VolumesIandII.AB-101.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCompany,Miami.1980a.FloridaPower&LightCompany,St.LuciePlantAnnualNon-RadiologicalEnvironmentalMonitoringReport1979.VolumesIIandIII,Bioticmonitoring.AB-244.Preparedby.AppliedBiology,Inc.forFloridaPower&LightCompany,Miami.1980b.TurtleEntrainmentDeterrentStudy.AB-290.PreparedbyAppliedBiology,Inc.ForFloridaPower&LightCompany,Miami.1986.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1985.AB-563.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCompany,JunoBeach.1987.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1986.AB-579.PreparedbyAppliedBiologyInc.forFloridaPower&LightCompany,JunoBeach.1988.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1987.AB-595.PreparedbyAppliedBiologyInc.-forFloridaPower&LightCompany,JunoBeach.1989.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1988.AB-596.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCompany,JunoBeach.1994.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalMonitoringReport.AB-631.PreparedbyAppliedBiology,Inc.,forFloridaPower&LightCompany,JunoBeach.Carr,A.,A.Meyan,J.Mortimer,K.BjorndalandT.Carr,1982.'urveysofSeaTurtlePopulationsandHabitatsintheWesternAtlantic.NOAATechnicalMemorandumNMFS-SEFC-91:1-82.Davis,G.E.,andM.C.Whiting,1977.LoggerheadSeaTurtleNestinginEvergladesNationalPark,Florida,U.S.A.Herpetologica33:18-28.FPL,1995.AssessmentoftheImpactsoftheSt.LucieNuclearGeneratingPlantonSeaTurtleSpeciesFoundintheInshoreWatersofFlorida.FloridaPower&LightCompany,JunoBeach,FL.Hirth,H.F.,1980.SomeAspectsoftheNestingBehaviorandReproductiveBiologyofSea~~~Turtles.AmericanZoologist20:507-523.17 Hopkins,S.R.,T.M.Murphy,Jr.,K.B.StansellandP.M.Wilkinson,1979.BioticandAbioticFactorsAffectingNestMortalityintheAtlanticLoggerheadTurtle.ProceedingAnnualConferenceofSoutheasternFishAndWildlifeAgencies32:213-223.QuantumResourcesInc.,1995.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1994.PreparedbyQuantumResourcesInc.forFloridaPower&LightCompany,JunoBeach,FL.1996.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1995.PreparedbyQuantumResourcesInc.forFloridaPower&LightCompany,JunoBeach,FL.1997.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1996.PreparedbyQuantumResourcesInc.forFloridaPower&LightCompany,JunoBeach,FL.1998.FloridaPower&LightCompany,St.LucieUnit2AnnualEnvironmentalOperatingReport1997.PreparedbyQuantumResourcesInc.forFloridaPower&LightCompany,JunoBeach,FL.Smith,N.P.,1982.UpwellinginAtlanticShelfWatersofSouthFlorida.FloridaScientist~~~~~~~~~~~~45(2):125-138.Sokal,R.R.andF.J.Rohlf,1981.Biometry.ThePrinciplesandPracticeofStatisticsinBiologicalResearch.S.H.FreemanandCompany,SanFrancisco.859pp.Stancyk,S.E.,1982.Non-HumanPredatorsofSeaTurtleandTheirControl.Pages139-152inBjorndal,K.A.,ed.BiologyandConservationofSeaTurtles.SmithsonianInstitutionPress.Washington,DCWitherington,B.E.andL.M.Ehrhart,1989.StatusandReproductiveCharacteristicsOfGreenTurtles(Chelonia~mdasNestinginFlorida.Pages351-352inOgren,L.,F.Berry,K.Bjorndal,H.Kumpf,R.Mast,G.Medina,H.ReichartandR.Witham,editors.ProceedingoftheSecondWesternAtlanticTurtleSymposium.Mayaguez,PuertoRico,12-16October1987.NOAATechnicalMemorandumNMFS-SEFC-226.Wlll,.N.1993.SpPl9lIDLED9NISNNS~Simbricata(Linnaeus,1766).FAOFisheriesSynopsis,137:1-78.18 FLORIDAGULFOFMEXICOic~iZy0-N-OKEECHOBEEOSTLUCIEPLANTFigure1.LocationofSt.LuciePlant20 HUTCHINSONISLANDINDIANRIVERIMCCOiLBIGMUOCREEK(/()Qi0ONII1<<.WTAKE~WEI.LSgPguOgnElk5cQ=AW~%frIIi0~IfAAAC~~IIAKEHEAOWNLSAIA$'E'SIIBARBERSAHKIEANETSCKAHARIGEPIPESATLANTICOCEANt41AKESTRVCIIKIESINDIANRIVERFigure2.St.LuciePlantCoolingW'aterIntakeandDischargeSystem21 ooFT.PIERCEINLET'6AI0FQHQISTATEHWYA1AOPaQRSTUFPLST.LUCIEPLANTUNITOFCURRENTSURVEYDIERIVERwQXYODHQHGGHHST.LUCIEINLETDRAWINGNOTTOSCALEfg4VO50l25ffSAOIFigure3.DesignationandLocationofNine1.25-KmSegmentsandThirty-Six1-KmSegmentsSurveyedforSeaTurtleNesting,HutchinsonIsland.1971-1998.22 1000%90.0%~GPP%7PP%U6ppV5pp0400Pal300%20P300%ppABCDEFGHIJKLMN0PQRSPowerPlantFigure4.NumberofLoggerheadTurtlesNestsandEmergencesforAreasAThroughS,HutchinsonIsland,AprilThroughSeptember1998.23 12008nestsIIemergences100048000600400200ABCDEFGHIJKLMN0PQRSAREAPowerPlantFigure5.LoggerheadTurtleNestingSuccess(PercentageofEmergencesResultinginNests)forAreasAThroughS,HutchinsonIsland,AprilThroughSeptember1998.24 90008000-70006000z5000040003000K20001000-71727374757677787980818283848586878889909192939495969798Figure6.NumberofLoggerheadTurtleNests,HutchinsonIsland1971Through1998.Valuesfor1971Through1979AreEstimates(SeeText);Valuesfor1981Through1998AreFromWholeIslandSurveys.25 8CRABSONLY~RACCOONSONLYarn10ABCDEFGHIJKLMNgPQRSAREAPowerPlantTFigure7.PercentageofLoggerheadTurtleNestsPredatedbyRaccoonsand/orGhostCrabsinAreasAThroughS,HutchinsonIsland,AprilThroughSeptember1998.26 300250F200z150gl005071727374757677787980818283848586878889909192939495969798Figure8.NumberofGreenSeaTurtleNests,HutchinsonIsland,1971Through1998.Valuesfor1971Through1979AreEstimates(SeeText).Valuesfor1981Through1998ArefromWholeIslandSurveys.27 9080-70C6K040-30K201071727374757677787980818283848586878889909192939495969798Figure9.NumberofLeatherbackTurtleNests,HutchinsonIsland,1971Through1998.Valuesfor1971Through1979AreEstimates(SeeText).Valuesfor1981Through1998ArefromWholeIslandSurveys.28

800700~LOGGERHEAD~GREEN600g50000300-200.100-7677787980818283848586878889909192939495969798Pigure10.NumberofLoggerheadandGreenTurtlesRemovedEachYearfromtheIntakeCanal,St.LuciePlant,1976Through1998.29 1009080-7060g50302010(4141-4546-5051-5556-6061-6566-7071-7576-8081-8586-9091-9596-100101-105106-110)110SIRAIGHTSTANDARDCARAPACELENGTH(cm)Figure11.SizeDistribution(SSCL)ofLoggerheadTurtles(N=391)RemovedfromtheIntakeCanal,St.LuciePlant,1998.30

7060-50"4020108A8488888'P8S88IIIIIfIIIII1II8R888g8STRAIGHTSTANDARDCARAPACELENGTH(cm)Figure12.SizeDistribution(SSCL)ofGreenTurtles(N=267)RemovedfromtheIntakeCanal,St.LuciePlant,1998.31 6.0TABLES32

'-YEAR.Loggerhead-SpeciesLeatherbaekHawksbill---=--'..Kemp'sRidley.--'.=.-Total-1976197719781979198019811982198319841985198619871988198919901991199219931994199519961997199833(4)80(5)138(19)172(13)116(5)62(5)101(16)119(4)148(3)157(4)195(27)175(11)134(6)111(4)112(1)107(1)123(2)147164254(1)349(3)188393(1)5(2)6(1)3(1)10(3)32(2)823(4)69(2)14.22(1)3542(2)17(1)20(2)1261(2)179(1)193(4)673(15)549(4)191(5)26816(2)5(2)233(4)86(7)148(20)175(14)126(8)97(7)110(16)142(8)220(5)172(4)220(28)218(13)181(10)133(5)132(3)121(1)187(4)337(1)361(4)933(16)906(7)382(5)666(1)Total3578(135)AnnualMean*162.6*Excludes1976artial2432(52)110.5earoflantoeration.211.0211.034(4)1.55420(191)275.1Table1.TotalNumberofCapturesand(NumberofDead)TurtlesRemovedfromtheIntakeCanal33

MonO>NumberofCapturesPercentofStandardAttCstnurmMnimumMaximum"Mean:Deviation1998JanuaryFebruaryMard>AprilMayJuneJulyAugustSeptemberOctoberNovemberDecember42133535436430436440532419419312516211.9%9.4%10.0%10.3%8.6%10.3%11.4%9.1%5.5%5.4%3.5%4.6%39346047404287431927151319.115.216.116.513.816.518.414.78.88.85.77.410.28.414.712.710.411.120.112.25.26.33.94.1362860472926574317271013TotalMeanStd.Deviation35458713.44.639332.816.3*Firstfullyearofplantoperation.Anadditional33loggerheadswerecapturedduring1976.Table2.TotalNumberofLoggerheadTurtlesRemovedBachMonthfromIntakeCanal,St.LuciePlant,1977-1998.34 Number'of.=..::,':==:-'.Percentof-.--':='-,".;-'-::--,.,;,-.'.'-."..',Standard:-.Montk'i'::,-,,::::'.Captures'...:."Alt'Cauptuees.:"..Minimum:Ma'xlmutni',Meiin:-':Beylation:1998:,JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember28428937021018013712515114819815019011.7%11.9%15.2%8.6%7.4%5.6%5.1%6.2%6.1%8.1%-6.2%7.8%000000000000596414764915261647754426812.915.513.118.316.835.69.517.38.220.26.212.65.714.16.915.26.717.89.015.46.810.88.615.82558302035167231025109TotalMeanStd.Deviation243201479.23.426822.314.4"Firstfullearoflantoeration.Table3.TotalNumberofGreenTurtlesRemovedEachMonthfromtheIntakeCanal,St.LuciePlant,1977-1998.35 V0 ANNUAL%2AZRONM~22ITALOPERATINGREPORTPARTII

1.0INTRODUCTION

TheSt.LucieUnit'2EnvironmentalProtectionPlan(EPP)requiresthesubmittalofanannualreportforvariousactivitiesattheplantsiteincludingthereportingonseaturtlemonitoringprogramsandothermattersrelatedtoFederalandStateenvironmentalpermitsandcertifications.2.0SEATURTLEMONITORINGANDASSOCIATEDACTIVITIESSurveillanceandmaintenanceofthelightscreentomininuzeseaturtledisorientationasrequiredbySection4.2.4oftheEPPisongoing.Thevegetationlightscreenlocatedonthebeachdunebetweenthepowerplantandtheoceanisroutinelysurveyedtodetermineitsoverallvitality.Thevegetationlineissurveyedforanygapsoccurringfrommortality,whichwouldresultinunacceptablelightlevelsonthebeach.Trees,vegetation,orshadeclothsarereplacedasnecessarytomaintaintheoverallintegrityofthelightscreen.Plantparkinglotlightingisalsodesignedandmaintainedtomirumizelightlevelsonthebeach.3.0TAPROGGECONDENSERTUBECLEANINGSYSTEMOPERATIONATaproggecondensertubecleaningsystem(CTCS)becameoperationalonSt.LucieUnit2inJanuary1996andonUnit1inJuly1996.Thissystemutilizesspongeballs,approximately24mmindiameter,tocleanthecondensertubesthroughwhichseawaterflowstocoolsteamafteritspassthroughtheplant'sturbines.Thissystemimprovesplantperformancewhilereducingtheneedforchemicaltreatmentssuchandbiocidesorchlorinetocontrolbiofouling.Normally,theSt.LucieCTCSutTiizesabout1800spongeballs,whichamcontinuallyrecirculatedthrougheachoffour"waterboxes"oneachunit.Thesespongeballsareretainedinthesystembyaballstrainerlocatedontheoutletofeachwaterbox.Theballstrainers(meshsize5mm)areopenedroutinelytodischargedebris,whichcandecreaseflowandobstructspongeballmovementthroughth'esystem.Thespongeballsarecollectedpriortoopening,orbackflushing,theballstrainers.Atthattime,thespongeballsareexaminedandreplacediftheyareworntothepointthattheycannolongereffectivelycleanthecondensertubes.Spongeballinventoriesandestimatesofspongeballlosstotheenvironmenthavebeenperformedsincesystemstart-uponbothunits.Numberofballstrainerbackflusheshasalsobeentracked.Inaddition,dailybeachsurveyshavebeenperformedonplantproperty(approximately2.5miles)tonoteanyspongeballsthatmayhaveappearedasaresultoflossfromtheplant.Thissurveyareahasbeenextendedduringtheturtle-nestingseasontoalmost12miles.Theresultsoftheprogramfor1998arepresentedinTable1.LargerspongeballlossesoccurredonUnit2fortheyear.Theselossesareprobablyrelatedtothefactthat1998representstheendoffuelcycleforthatunit.Estimatedspongeballlossfrombothunitswas20.2ballsperdayfor1998.Fiftyspongeballswerefoundwholeintheenvironmentneartheplant.Thisisanincrease36 overpreviousyears,butthenumberindicatesthatfewballsactuallyreachtheenvironmentwhole.~~~~~~~~~~~~~~~Figure1indicatesthatestimatedspongeballlossgenerallyincreasedthroughthemonthofAprilof1998.Averagedailyballlossin1998increasedfromthe1996and1997totals(Figure2).Itisbelievedthatmuchofthelossesarecausedbyincreasedgrowthinsidethewaterboxes.Newcoatingsonthesesurfacesarebeingusedtotrytoeleviatethisproblem.ThesecoatingwereappliedtoUnit2inDecember1998.IfthecoatingproveseffectiveitwillbeappliedtoUnit1inSeptember1999.4.0OTHERROVIINEREPORTSThefollowingitemsforwhichreportingisrequiredarelistedbysectionnumberfromtheplant'sEnvironmentalProtectionPlan:5.4.1(a)EPPNONCOMPLIANCESANDCORRECTIVEACTIONSTAKENNononcompliance'sunderEPPSection5.4.1(a)weredeterminedtohaveoccurredduring1998.5.4.1(b)CHANGESINSTATIONDESIGNOROPERATIONTESTSANDEXPERIMENTSINACCORDANCEWITHEPPSUBSECTION3.1FPLletterI98-180transmittedtherequestformodificationofWastewaterPermitApplicationtoFDEP.Themodificationincludestheuseofbiocideintheplantclosedcoolingwatersystemsandtheuseofdimethylamineandcarbohydrazideintheplantsteamgeneratorblowdown.ThisletterwastransmittedJune26,1998.5.4.1(c)NONROUTINEREPORTSSUBMHTEDTOTHENRCFORTHEM~1998INACCORDANCEWITHEPPSUBSECTION5.4.22.ReportconcerningthemortalityLeastTernsattheplantNuclearTrainingCenterJuly6,1998andJuly17,1998.Deathsoccurredinthebuilding'sdrainagesystemduringheavyrainfall.EventswerereportedtoNRCbyFPLletterI98-196onJuly23,1998.ReportconcerninganincreaseofjellyfishandsubsequenteffectofplantoperationonSeptember9,1998;reportedtotheNRCbyFPLletterL-98-250onOctober1,1998.37

TABLE11998ST.LUCIEPLANTCONDENSERTUBECLEANINGSYSTEMSUMIVCARY:-.-',.MONS'"-'i.'.:;STRAD';BACKPLUSHES;:::--,::",.:,.:"',:.UNIT1~'--'.:"-""".UMI;:-:.',.-.;',:;:.:~PALMATEDBA'LL:XQSS;.:'-;;:.',BAPS;FOUND';::,";.ON-'THESEACH:;:.:i-':JanuaryFebruaryMarch102222262541698627613AprilMay0"2529241242852580June24+22+++July3323130586AugustSeptemberOctober29253127202366114129483228NovemberDecember242562376229759Total1972341853551050Duetopoorspongeballrecovery,strainerswerenotback-flushed.Unitwasdown-powered,waterboxestakenoutofserviceformanualremovalofgrowthandballs.Unit1systemshutdownduringrefueling,1/1to1/19/98.Unit2systemshutdownduringrefueling,11/6to12/12/98.Netgainininventory.

504540C3530)2s20gis10JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECMONTHFigureI.EstimatedAverageDailySpongeBallLossbyMonthfromSt.LuciePlant(BothUnits)for1998.39 25200151019961997YEAR1998Figure2.AverageDailySpongeBallLossfromtheSt.LuciePlant(BothUnits)SinceSystemStart-Up(January1996)40