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| document type = ENVIRONMENTAL MONITORING REPORTS(&RADIOLOGICAL)-PERIODIC, TEXT-ENVIRONMENTAL REPORTS | | document type = ENVIRONMENTAL MONITORING REPORTS(&RADIOLOGICAL)-PERIODIC, TEXT-ENVIRONMENTAL REPORTS | ||
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{{#Wiki_filter:FLORIDAPOWER8LIGHTCOMPANYST.LUCIEUNITNO.2ANNUALENVIRONMENTALREPORT(FPL-87)APRIL1988gp-887>i~><>~g~gczoig5Coo.NI@t;,jii~A24W6fOocumea4g",6JV<jOR7OXRH7%4P~O+NfeSa+88050301858889k&'DRADGCK05000389'RDCD 1 | |||
FLORIDAPOWER8LIGHTCOMPANYST.LUCIEUNITNO.2ANNUALENVIRONMENTALREPORT(FPL-87)APRIL1988 | |||
~e~ClIll Page1of4ANNUALENVIRONMENTALREPORTIntroductionTheSt.LuciePlantUnit2EnvironmentalProtectionPlan(EPP)requiresthesubmittalofanannualreportforvariousactivitiesattheplantsiteincludingthereportingonseaturtlemonitoringprograms,andothermattersrelatedtoFederalandStateenvironmentalpermitsandcertifications.Thisreportfulfillsthesereportingrequirements.II.SeaTurtleMonitoringandAssociatedActivitiesAquaticandterrestrialseaturtlemonitoringprogramstosatisfySections4.2.1(BeachNestingSurveys),4.2.3(StudiestoEvaluateand/orMitigateIntakeCanalMortality)and4.2.5(CaptureandReleaseProgram)isconcurrentlysubmittedinaseparatereport(AB-595)preparedbyAppliedBiology,Inc.Studiestoevaluateand/ormitigateintakeentrapmentrequiredbySection4.2.2oftheEPPhavebeenpreviouslyperformed.AfinalreportwassubmittedtotheOfficeofNuclearReactorRegulationonApril18,1985.Withsubmittalofthatreport,theEPPrequirementwasfulfilledandwillnotbereaddressedinthisorfuturereports. | |||
III Page2of4FPLwillrequestmodificationofcertainsectionsoftheEnvironmentalProtectionPlanrelatedtoseaturtleprograms,toreflectimplementationandsatisfactionofthoserequirementswhichhavebeencompletedasdescribedabove.RequirementsforreportingonthestatusofalightscreentominimizeturtledisorientationasrequiredbySection4.2.4oftheEPPisongoing.TheAustralianPinelightscreen,locatedonthebeachdunebetweenthepowerplantandtheocean,isroutinelysurveyedtodetermineitsoverallvitality.Thetreelineissurveyedforanygapsoccurringfromtreemortalitywhichwouldresultinunacceptablelightlevelsonthebeach.Treesarereplacedasnecessarytomaintaintheintegrityoftheoveralllightscreen.III.OtherRoutineReportsThefollowingitemsforwhichreportingisrequiredarelistedbysectionnumberfromtheEnvironmentalProtectionPlan(EPP):5.4,.1(a)EPPNONCOMPLIANCESANDCORRECTIVEACTIONSTAKENNononcompliancesunderEPPSection5.4.1(a)weredeterminedtohaveoccurredduring1987. | |||
Page3of4541(b)STATIONDESIGNANDOPERATIONCHANGESgTESTSgANDEXPERIMENTSAFFECTINGTHEENVIRONMENTNoplantsiteactivitiesweredeterminedtobereportableunderSection5.4.1(b)during1987.5.4.1(c)NONROUTINEREPORTSSUBMITTEDTOTHENRCFORTHEYEAR1987INACCORDANCEWITHEPPSUBSECTION5.4.2:1.ReportconcerninganoverflowfromtheSt.LucieUnit1SewageTreatmentPlantreportedtoEPAonFebruary24,1987andtheNRConMarch18,1987.2.ReportconcerningreceiptofthefinalNPDESPermitfortheSt.LuciePlant.(TheStateofFlorida401CertificationandtheStateofFloridaSiteCertificationforSt.LucieUnit2areattachmentstotheNPDESPermit.)PermiteffectivedateSeptember30,1987.ThefollowingreportsweresubmittedtotheNRCforinformationalpurposesalthoughnotrequiredunderprovisionsof5.4.2:1.Reportconcerninganexceedanceofthemaximumtemperaturedifference(dT)fortheSt.LucieUnits Cl Page4of41and2oncethroughcoolingwatersystemwhichwasreportedtotheEPAonFebruary25,1987andtotheNRConMarch18,1987.2.SeaturtleactivitiesquarterlyreportdatedApril2,1987forthefirstquarter1987.3.SeaturtleactivitiesquarterlyreportdatedJuly8,1987forthesecondquarter1987.4.SeaturtleactivitiesquarterlyreportdatedOctober6,1987forthethirdquarter1987.5.SeaturtleactivitiesreportdatedJanuary5,1988forthefourthquarter1987. | |||
APPLIEDBIOLOGY,INC.AB-595FLORIDAPOWER8LIGHTCOMPANYST.LUCIEUNIT2ANNUALENVIRONMENTALOPERATINGREPORT198702968ANORTHDECATURROAD~ATLANTA,GEORGIA30033~404-296-3900) 0 AB-595FLORIDAPOWER5LIGHTCOMPANYST.LUCIEUNIT2ANNUALENVIRONMENTALOPERATINGREPORT1987APRIL1988FLORIDAPOWER5LIGHTCOMPANYJUNOBEACH,FLORIDAAPPLIEDBIOLOGY,INC.ATLANTA,GEORGIA | |||
~i'f/Itlt ENVIRONMENTALOPERATINGREPORTTABLEOFCONTENTSTABLEOFCONVERSIONFACTORSFORMETRICUNITSEXECUTIVESUMMARYIntroductionTurtleNestingSurveyIntakeCanalMonitoring-OtherRelatedActivitiesINTRODUCTION-BackgroundAreaDescription--PlantDescription~Pae1v1v1VvvTURTLESIntroductionIMaterialsandMethods-NestingSurveyIntakeCanalMonitoringStudiestoEvaluateand/orMitigateIntakeEntrapment----LightScreentoMinimizeTurtleDisorientation-----------ResultsandDiscussionNestingSurveyDistributionofLoggerheadNestsAlongHutchinsonIslandNumberofNestsandLoggerheadPopulationEstimates---TemporalLoggerheadNestingPatternsPredationonLoggerheadTurtleNestsGreenandLeatherbackTurtleNestingIntakeCanalMonitoringSpeciesNumberandTemporalDistribution-Size-ClassDistributions-SexRatios-CaptureEfficienciesRelativeConditionMortalitiesRecaptureIncidentsSummary-LITERATURECITEDFIGURESTABLES-11ll1316161616162325262729303234363842464752598111 TABLEOFCONVERSIONFACTORSFORMETRICUNITSToconvertcentigrade(degrees)centigrade(degrees)centimeters(cm)centimeters(cm)centimeters/second(cm/sec)cubiccentimeters(cm3)grams(g)grams(g)hectares(ha)kilograms(kg)kilograms(kg)kilograms(kg)kilometers(km)kilometers(km)liters(1)liters(1)meters(m)meters(m)meters(m)microns(9)milligrams(mg)milligrams/liter(mg/1)milliliters(ml)millimeters(mm)millimeters(mm)squarecentimeters(cm2)squaremeters(m2)squaremillimeters(mm2)Multiplyby)(Cx1.8)+32C+273.18,3.937x103.281x10"3.281x101.0x102.205x103.527x10"2.4711.0x1032.20463.5274x1016.214x10-11.0x1061.0x102.642x103.2813.937x10l.0941.0x1061.0x10"31.01.0x103.937x10"23.281x101.550x101.076x101.55x10Toobtainfahrenheit(degrees)kelvin(degrees)inchesfeetfeetpersecondliterspoundsounces(avoirdupois)acresgramspoundsounces(avoirdupois)miles(statute)mi11imeterscubiccentimeters(cm3)gallons(U.S.liquid)feetinchesyardsmetersgramspartspermi11ionliters(U.S.liquid)inchesfeetsquareinchessquarefeetsquareinches | |||
EXECUTIVESUMMARYINTRODUCTIONTheSt.LuciePlantisanelectricgeneratingstationonHutchinsonIslandinSt.LucieCounty,Florida.Theplantconsistsoftwonuclear-fueled850-MWunits;Unit1wasplacedon-lineinMarch1976andUnit2inMay1983.ThisdocumenthasbeenpreparedtosatisfytherequirementscontainedintheUnitedStatesNuclearRegulatoryCommission'sAppendix8EnvironmentalProtectionPlan(EPP)toSt.LucieUnit2FacilityOperatingLicenseNo.NPF-16.Thisreportdiscussesenvironmentalpro-tectionactivitiesrelatedtoseaturtlesasrequiredbySubsection4.2oftheEPP.TURTLENESTINGSURVEYTherehavebeenconsiderableyear-to-yearfluctuationsinseaturtlenestingactivityonHutchinsonIslandsincemonitoringbeganin1971.Lownestingactivityin1975and1981-1983inthevicinityofthepowerplantwasattributedtoconstructionofplantintakeanddischargestruc-tures.Nestingreturnedtonormalorabovenormallevelsfollowingbothperiodsofconstruction.Powerplantoperationexclusiveofconstructionhashadnosignificanteffectonnestingneartheplant.Datacollectedthrough1987haveshownnolong-termreductionsintotalnesting,totalemergencesornestingsuccessontheisland.Formalrequirementstocon-ductthisprogramexpiredin1986butwerevoluntarilycontinuedin1987withagreementfromfederalandstateagencies. | |||
0 INTAKECANALMONITORINGSinceplantoperationbeganin1976,1,748seaturtles(including79recaptures)representingfivedifferentspecieshavebeenremovedfromtheintakecanal.Eighty-sixpercentofthesewereloggerheads.Differencesinthenumbersofturt'lesfoundduringdifferentmonthsandyearswereattribute'dtonaturalvariationintheoccurrencesofturtlesinthevicinityoftheplant,ratherthantoanyinfluenceoftheplantitself.Themajority(about92percent)oftheturtlesremovedfromtheintakecanalwerecapturedaliveandreleasedbackintotheocean.TurtlesconfinedbetweentheA1Abarriernetandintakeheadwallsusuallyresidedinthecanalforarelativelyshortperiodoftime,andmostwereingoodtoexcellentconditionwhencaught.Drowningwasthoughttoberesponsibleformostrecentcanalmortalitiesandappropriatemeasures,includingtheinstallationofanewbarriernet,weretakentominimizefuturemortalities.OTHERRELATEDACTIVITIESTheintegrityofavegetativelightscreenalongthedunelineattheSt.LuciePlantisassessedonacontinuingbasis.During1987,routineinspectionsofthescreenweremadeandreplantingsconductedasneeded.Studiestoevaluatevariousintakedeterrentsystems,asrequiredbytheNRC'sUnit2EnvironmentalProtectionPlan,wereconductedduring1982,and1983.Resultsandevaluationsofthosestudieswerepresentedtoregulatoryagenciesduring1984,andtherequirementisnowconsideredcompleted. | |||
INTRODUCTIONBACKGROUNDThisdocumenthasbeenpreparedtosatisfytherequirementscon-tainedintheUnitedStatesNuclearRegulatoryCommission's(NRC)AppendixBEnvironmentalProtectionPlantoSt.LucieUnit2FacilityOperatingLicenseNo.NPF-16.In1970,FloridaPower5LightCompany(FPL)wasissuedPermitNo.CPPR-74bytheUnitedStatesAtomicEnergyCommission,nowtheNuclearRegulatoryCommission,thatallowedconstructionofUnit1oftheSt.LuciePlant,an850-HWnuclear-poweredelectricgeneratingstationonHutchinsonIslandinSt.LucieCounty,Florida.St.LuciePlantUnit1wasplacedon-lineinHarch1976.InHay1977,FPLwasissuedPermitNo.CPPR-144bytheNRCfortheconstructionofasecond850-HWnuclear-poweredunit.Unit2wasplacedon-lineinHay1983andbegancommercialoperationinAugustofthatyear.St.LuciePlantUnits1and2usetheAtlanticOceanasasourceofwaterforonce-throughcondensercooling.Since1971,thepotentialenvironmentaleffectsresultingfromtheintakeanddischargeofthiswaterhavebeenthesubjectofFPL-sponsoredbioticstudiesatthesite. | |||
BaselineenvironmentalstudiesofthemarineenvironmentadjacenttotheSt.LuciePlantweredescribedinaseriesofreportspublishedbytheFloridaDepartmentofNaturalResources(Campetal.,1977;FutchandDwinell,1977;Gallagher,1977;GallagherandHollinger,1977;WorthandHollinger,1977;MofflerandVanBreedveld,1979;TesterandSteidinger,1979;Walker1979;Walkeretal.,1979;WalkerandSteidinger,1979).TheresultsofUnit1operationalandUnit2preoperationalbioticmoni-toringattheSt.~LuciePlantwerepresentedinsixannualreports(ABI,1977,1978,1979,1980a,1981b,1982).InJanuary1982,aNationalPollutantDischargeEliminationSystem(NPDES)permitwasissuedtoFPLbytheU.S.EnvironmentalProtectionAgency(EPA).TheEPAguidelinesfortheSt.Luciesitebiologicalstudieswerebasedonthedocumententitled"ProposedSt.LuciePlantPreoperationalandOperationalBiologicalMonitoringProgram-August1981"(ABI,198lc).Findingsfromthesestudieswerereportedinthreeannualreports(ABI,1983,1984a,1985a).TheEPAbioticmonitoringrequirementsweredeletedfromtheNPDESpermitin1985.JurisdictionforseaturtlestudiesiswiththeNRC,whichiscon-sideredtobetheleadfederalagencyrelativetoconsultationundertheEndangeredSpeciesAct.Previousresultsdealingexclusivelywithseaturtlestudiesarecontainedinfourenvironmentaloperatingreports(ABI,1984b,1985b,1986,1987).Thisreportdescribesthe1987environ-mentalprotectionactivitiesrelatedtoseaturtles,asrequiredbySubsection4.2oftheSt.LuciePlantUnit2EnvironmentalProtectionPlan. | |||
AREADESCRIPTIONTheSt.LuciePlantislocatedona457-hasiteonHutchinsonIslandonFlorida'seastcoast(FiguresIand2).TheplantisapproximatelymidwaybetweentheFt.PierceandSt.LucieInlets.ItisboundedonitseastsidebytheAtlanticOceanandonitswestsidebytheIndianRiverLagoon.HutchinsonIslandisabarrierislandthatextends36kmbetweeninletsandobtainsitsmaximumwidthof2kmattheplantsite.Eleva-tionsapproach5matopdunesborderingthebeachanddecreasetosealevelinthemangroveswampsthatarecommononmuchofthewesternside.IslandvegetationistypicalofsoutheasternFloridacoastalareas;densestandsofAustralianpine,palmetto,seagrapeandSpanishbayonetarepresentatthehigherelevations,andmangrovesaboundatthelowerele-vations.Largestandsofblackmangroves,includingsomeontheplantsite,havebeenki11edbyfloodingformosquitocontroloverpastdecades.TheAtlanticshorelineofHutchinsonIslandiscomposedofsandandshellhashwithintermittentrockypromontoriesprotrudingthroughthebeachfacealongthesouthernendoftheisland.Submergedcoquinoidrockformationsparallelmuchoftheislandofftheoceanbeaches.Theoceanbottomimmediatelyoffshorefromtheplantsiteconsistsprimarilyofsandandshel1sediments.Theunstablesubstratelimitstheestablishmentofrootedmacrophytes. | |||
TheFloridaCurrent,whichflowsparalleltothecontinentalshelfmargin,beginstodivergefromthecoastlineatWestPalmBeach.AtHutchinsonIsland,thecurrentisapproximately33kmoffshore.Oceanicwaterassociatedwiththewesternboundaryofthecurrentperiodicallymeanders.overtheinnershelf,especiallyduringsummermonths.PLANTDESCRIPTIONTheSt.LuciePlantconsistsoftwo850-HWnuclear-fueledelectricgeneratingunitsthatusenearshoreoceanwatersfortheplant'soncethroughcondensercoolingwatersystem.Waterfortheplantentersthroughthreesubmergedintakestructureslocatedabout365moffshore(Figure2).Eachoftheintakestructuresisequippedwithavelocitycaptominimizefishentrainment.Horizontalintakevelocitiesarelessthan30cm/sec.Fromtheintakestructures,tliewaterpassesthroughsubmergedpipes(two3.7mandone4.9mindiameter)underthebeachanddunesthatleadtoa1500-mlongintakecanal.Thiscanaltransportsthewatertotheplant.Afterpassingthroughtheplant,theheatedwaterisdischargedintoa670-mlongcanalthatleadstotwoburieddischargepipelines.Thesepassunderneaththedunesandbeachandalongtheoceanfloortothesubmergeddischarges,thefirstofwhichisapproximately365moffshoreand730mnorthoftheintake.HeatedwaterleavesthefirstdischargelinefromaY-shapednozzle(diffuser)atadesignvelocityof396cm/sec.Thishigh-momentumjetentrainsambientwaterresultinginrapidheatdissipation.Theoceandepthintheareaofthefirstdischargeisabout6m.Heatedwater leavestheseconddischargelinethroughaseriesof48equallyspacedhighvelocityjetsalonga323-mmanifold(multiportdiffuser).Thisdiffuserstarts168mbeyondthefirstdischargeandterminates856mfromshore.Theoceandepthatdischargealongthisdiffuserisfromabout10to12m.Aswiththefirstdiffuser,thepurposeoftheseconddiffuseristoentrainambientwaterandrapidlydissipateheat.Fromthepointsofdischargeatbothdiffusers,thewarmerwaterrisestothesurfaceandformsasurfaceplumeofheatedwater.Theplumethenspreadsoutonthesurfaceoftheoceanundertheinfluenceofwindandcurrentsandtheheatdissipatestotheatmosphere. | |||
TURTLESTheNRC'sSt.LucieUnit2AppendixBEnvironmentalProtectionPlanissuedApril1983containsthefollowingtechnicalspecifications:4.2Terrestrial/AuaticIssuesIssuesonendangeredorthreatenedseaturtlesraisedintheUnit2FES-OL[NRC,1982jandintheEndangeredSpeciesBiologicalAssessment(March1982)[Bellmundetal.,1982]willbeaddressedbyprogramsasfollows:4.2.1BeachNestinSurvesBeachnestingsurveysforallspeciesofseaturtleswillbeconductedonayearlybasisfortheperiodof1982through1986.Thesesurveyswillbecon-ductedduringthenestingseasonfromapproximatelymid-AprilthroughAugust.TheHutchinsonIslandbeachwillbedividedinto36one-km-longsurveyareas.Inaddition,thenine1.25-km-longsurveyareasusedinpreviousstudies(1971-1979)willbemaintainedforcomparisonpur-poses.Surveyareaswillbemarkedwithnumberedwoodenplaquesand/orexistinglandmarks.Theentirebeachwillbesurveyedsevendaysaweek.Allnewnestsandfalsecrawlswillbecountedandrecordedineacharea.Aftercounting,allcrawltrackswillbeobliteratedtoavoidrecounting.Predationonnestsbyraccoonsorotherpredatorswillberecordedasitoccurs.Recordswillbekeptofanyseasonalchangesinbeachtopographythatmayaffectthesuitabilityofthebeachfornesting.4.2.2StudiestoEvaluateand/orMitiateIntakeAprogramthatemployslightand/orsoundtodeterturtlesfromtheintakestructurewillbeconducted.Thestudywilldeterminewithlaboratoryandfieldexperimentsifsoundand/orlightwillresultina'reductionoftotalturtleentrapmentrate.Thestudyshallbeimplementednolaterthanafterthefinalremovalfromtheoceanofequipmentand structuresassociatedwithconstructionofthethirdintakestructureandtheexperimentsshallterminate18monthslater.Fourmonthsaftertheconclusionoftheexperimentalperiod,areportontheresultsofthestudywillbesubmittedtoNRC,EPA,NationalMarineFisheriesService(NMFS),andtheU.S.FishandWildlifeService(USFWS)fortheirevaluation.Ifastatisticallysignificantreductioninannualtotalturtleentrapmentrateof80percentorgreatercanbedemonstrated,usingthedevelopedtechnologyanduponFPLreceivingwrittencon-currencebyNRC,EPA,NMFS,andUSFWSthenpermanentinstallationofthedeterrentsystemshallbecompletedandfunctioningnolaterthanI(monthsaftertheagencies'oncurrence.Thedesignofthisstudyneedstotakeintoaccountthesignificantannualvariationinturtleentrapmentobservedinthepast.Ifan80percentreductionofturtleentrapmentcan-notbeprojectedtoallthreeintakestructures,thenaninteragencytaskforcecomposedofHRC,EPA,NMFS,USFWS,andFPLshallconvene18monthsaftercompletionofthethirdintakeanddetermineifothercoursesofactiontomitigateand/orreduceturtleentrapmentarewarranted(suchasphysicalbarrier,emergenceofnewtechnologyormethodstodeterturtles).4.2.3StudiestoEvaluateand/orMitiateIntakeAlternativemethodsorproceduresforthecaptureofseaturtlesentrappedintheintakecanalwillbeevaluated.Ifamethodorprocedureisconsideredfeasibleandcosteffectiveandmayreducecapturemortalityrates,itwillbefieldtestedintheintakecanal.4.2.4LihtScreentoMinimizeTurtleDisorienta-tion[N:1s1sasoSection4.2otheNRCSt.LucieUnit1AppendixBTechnicalSpecificationsissuedMay1982]Australianpine"orothersuitableplants(i.e.,nativevegetationsuchasliveoak,nativefigs,wildtamarindandothers)shallbeplantedandmain-tainedasalightscreen,alongthebeachdunelineborderingtheplantproperty,tominimizeturtledisorientation. | |||
4.2.5CatureandReleaseProramSeaturtleremovalfromtheintakecanalwillbeconductedonacontinuingbasis.Theturtleswi11becapturedwithlargemeshnets,orothersuitablenondestructivedevice(s),ifdeemedappropriate.Aformalizeddailyinspection,fromtheshoreline,ofthecapturedevice(s)willbemadebyaqualifiedindividualwhenthedevice(s)aredeployed.Theturtleswillbeidentifiedtospecies,measured,weighed(ifappropriate),taggedandreleasedbackintotheocean.Recordsofwounds,freshorold,andasubjectivejudgementontheconditionoftheturtle(e.g.,barnaclecoverage,underweight)wi11bemaintained.Methodsofobtainingadditionalbiological/physiologicaldata,suchasbloodanaly-sesandparasiteloads,fromcapturedseaturtleswillbepursued.Deadseaturtleswillbesubjectedtoagrossnecropsy,iffoundinfreshcondition.INTRODUCTIONHutchinsonIsland,Florida,isanimportantrookeryfortheloggerheadturtle,Carettacaretta,andalsosupportssomenestingoftheCh1l~,dh1hkcoriacea(Caldwelletal.,1959;Routa,1968;Gallagheretal.,1972;WorthandSmith,1976;Williams-Wallsetal.,1983).Allthreespeciesareprotectedbystateandfederalstatutes.Thefederalgovernmentclassifiestheloggerheadturtleasathreatenedspecies.Theleather-backturtleandtheFloridanestingpopulationofthegreenturtlearelistedbythefederalgovernmentasendangeredspecies.Becauseofreductionsinworldpopulationsofmarineturtlesresultingfromcoastaldevelopmentandfishingpressure(NMFS,1978),maintainingthevitalityoftheHutchinsonIslandrookeryisimportant. | |||
0jf IthasbeenaprimeconcernofFPLthattheconstructionandsub-sequentoperationoftheSt.LuciePlantwouldnotadverselyaffecttheHutchinsonIslandrookery.Becauseofthisconcern,FPLhassponsoredmonitoringofmarineturtlenestingactivityontheislandsince1971.Daytimesurveystoquantifynesting,aswellasnighttimeturtletaggingprograms,wereconductedinoddnumberedyearsfrom1971through1979.Duringdaytimenestingsurveys,nine1.25-km-longsurveyareasweremonitoredfivedaysperweek(Figure3).TheSt.LuciePlantbeganoperationin1976;therefore,thefirstthreesurveyyears(1971,1973and1975)werepreoperational.Thoughthepowerplantwasnotoperatingduring1975,St.LuciePlantUnitNo.1oceanintakeanddischargestruc-tureswereinstalledduringthatyear.Installationofthesestructuresincludedconstructionactivitiesconductedoffshorefromandperpen-diculartothebeach.Constructionhadbeencompletedandtheplantwasinfulloperationduringthe1977and1979surveys.Amodifieddaytimenestingsurveywasconductedin1980duringthepreliminaryconstructionoftheoceandischargestructureforSt.LuciePlantUnit2.Duringthisstudy,fourofthepreviouslyestablished1.25-km-longsurveyareasweremonitored.Additionally,eggsfromturtlenestspotentiallyendangeredbyconstructionactivitieswererelocated.Everyyearfrom1981through1987,thirty-six1-km-longsurveyareascomprisingtheentireislandweremonitoredsevendaysaweekduringthenestingseason(Figure3).TheSt.LuciePlantUnit2dischargestruc-turewasinstalledduringthe1981nestingseason.OffshoreandbeachconstructionoftheUnit2intakestructureproceededthroughoutthe1982nestingseasonandwascompletedneartheendofthe1983season.ConstructionactivitiesassociatedwithinstallationofbothstructuresweresimilartothoseconductedwhenUnit1intakeanddischargestruc-tureswereinstalled.Eggsfromturtlenestspotentiallyendangeredbyconstructionactivitieswererelocatedduringallthreeyears.Requirement.4.2.1oftheNRC'sSt.LucieUnit2AppendixBEnvironmentalProtectionPlanwascompletedwithsubmissionofthe1986nestingsurveydata(ABI,1987).Thenestingsurveywascontinuedvolun-tarilyin1987withagreementfromfederalandstateagencies.Resultsarepresentedinthisreportanddiscussedinrelationtopreviousfin-dings.Inadditiontomonitoringseaturtlenestingactivitiesandrelo-catingnestsawayfromplantconstructionareas,monitoringofturtlesintheintakecanalhasbeenanintegralpartoftheSt.LuciePlantenvironmentalmonitoringprogram.Turtlesenteringtheoceanintakestructuresarerapidlytransportedwithcoolingwaterthroughtheintakepipesandintotheenclosedcanalsystemwheretheyareentrapped.Sincetheplantbecameoperationalin1976,turtlesentrappedintheintakecanalhavebeencaptured,measured,taggedandreturnedalivetotheocean.10 | |||
Previouspublicationsandtechnicalreportshavepresentedfindingsofthenestingsurveys,nestrelocationactivitiesandcanalcaptureprogram(Gallagheretal.,1972;WorthandSmith,1976;ABI,1978,1980a,1981a,1982,1983,1984b,1985b,1986,1987;Williams-Wallsetal.,1983;Proffittetal.,1986;Ernestetal.,inpress;Martinetal.,inpress).Resultsofstudiestoassesstheeffectsofthermaldischargesonhatchlingswimmingspeedhavealsobeenreported(ABI,1978;O'ara,1980).Thepurposeofthisreportisto1)present1987seaturtlenestingsurveydataandsummarizeobservedspatialandtemporalnestingpatternssince1971,2)documentandsummarizepredationonturtlenestssince1971,and3)present1987canalcapturedataandsummarizerelateddatacollectedsince1976.MATERIALSANDMETHODSNestinSurveMethodologiesusedduringpreviousturtlenestingsurveysonHutchinsonIslandweredescribedbyGallagheretal.(1972),WorthandSmith(1976)andABI(1978,198la,1982,1987).Methods.usedduringthe1987surveyweredesignedtoallowcomparisonswiththesepreviousstu-dies.From16Aprilthrough29April1987,eightpreliminarynestsurveyswereconductedalongHutchinsonIslandfromtheFt.PierceInletsouthtotheSt.LucieInlet.After29April,surveyswereconducteddailythrough11September.Severaladditionalsurveyswereconductedafter11Septembertoconfirmthatnestinghadceased,thelastsurveybeingcon-ductedon18September.Biologistsusedsmalloff-roadmotorcyclestosurveytheislandeachmorning.Newnests,non-nestingemergences(falsecrawls),andnestsdestroyedbypredatorswererecordedforeachofthethirty-six1-km-longsurveyareascomprisingtheentireisland(Figure3).Thenine1.25-km-longsurveyareasestablishedbyGallagheretal.(1972)alsoweremonitoredsocomparisonscouldbemadewithpreviousstudies.Duringthedailynestmonitoring,anymajorchangesintopographythatmayhaveaffectedthebeach'ssuitabilityfornestingwererecorded.Inaddition,eachofthethirty-six1-km-longsurveyareashasbeensystematicallyanalyzedandcategorizedbasedonbeachslope(steep,moderate,etc.),widthfromhightidelinetothedune,presenceofbenches(areasofabruptverticalrelief)andmiscellaneouscharac-teristics(packedsand,scatteredrock,vegetationonthebeach,exposedrootsontheprimarydune,etc.).Inacooperativeeffort,theFloridaDepartmentofNaturalResources(DNR)wasnotifiedofallgreenturtlenests.EggsfromsomeofthesenestswerecollectedaspartoftheFloridaDNRHeadstartProgram.Additionally,datafromstrandedturtlesfoundduringbeachsurveyswereroutinelyprovidedtotheNationalMarineFisheriesServicethroughtheSeaTurtleStrandingandSalvageNetwork.12 | |||
IntakeCanalMonitorinRoutinecaptureofseaturtlesfromtheSt.LuciePlantintakecanalcontinuedduring1987.Turtleswereremovedfromthecanalwithlarge-meshtanglenetsfishedbetweentheintakeheadwallsandabarriernetlocatedattheHighwayA1Abridge(Figure2).ThesenetswereusuallydeployedonMondaymorningandretrievedonFridayafternoon.Todetectcaptures,formaldailyinspectionsofthenets(morningsandafternoons)weremadeeachdayofdeployment.Varioussizes,numbersandlocationsoftanglenetshavebeenusedtodateascapturetechniqueshavebeenrefined.Netsinrecentusewerefrom32to61minlength,2.7to3.7mindepthand30to40cminstretchmesh.Largefloatskeptthenetsatthesurface,andbecausenetswerenotweightedwithleadlines,turtleswhichbecameentangledremainedatthewater'ssurfaceuntilremoved.ThebarriernetattheA1Abridgeisintendedtoconfineturtlestotheeasternmostsectionoftheintakecanal,wherecapturetechniqueshavebeenmosteffective.However,theintegrityofthebarriernetoccasionallyhasbeencompromised,andturtleshavebeenabletoswimoverorunderit.PriortoDecember1986,mostturtlescircumventingthebarrierneteventuallyemergedintheintakewellsofUnits1and2(Figure2),wheretheywereretrievedbymeansoflargemechanicalrakesorspeciallydesignednets.However,during1986,asecurityintrusionbarrierwasconstructedacrossthenorth-southarmoftheintakecanal.Afteritsemplacement,turtleslargerthan30.5cmincarapacewidthwere13 impededfromreachingtheintakewellsbyalarge-meshchainnet.TanglenetsweresetwestoftheA1Abarriernettocapturetheseturtles.Turtlessmallerthan30.5cmcanpassthroughthemeshofboththebarriernetandtheintrusionbarrier.PersonnelofAppliedBiology,Inc.wereoncall24hoursadaytoretrievecapturedturtlesfromboththeintakewellsandturtlenets.Theutmostcarewastakeninhandlingcapturedturtlestopreventinjuryortrauma.Afterremovalfromthecanal,turtleswereidentifiedtospecies,measured,weighed,tagged,examinedforoverallcondition(wounds,abnor-malities,parasites,etc.)andreleasedbackintotheocean.Althoughbothstraight-lineandcurvedcarapacelengthsweremeasured,onlystraight-linemeasurementswereusedinanalysespresentedinthisreport.Straight-linecarapacelength(SLCL)wasmeasuredfromthepre-centralscutetothenotchbetweenthepostcentralscutes(minimumcara-pacelengthofPritchardetal.,1983).Since1982,bloodsampleshavebeencollectedandanalyzedtoinvestigatethepotentialoccurrenceandsignificanceofanemiaincap-turedanimalsandtodeterminethesexofimmatureturtles.BloodwasremovedfromthepaireddorsalcervicalsinusesofsubjectturtlesusingthetechniquedescribedbyOwensandRuiz(1980).Asmallsubsampleofwholebloodwashemolyzedandhemoglobinmeasuredingramsper100mlbycolorimetryusinganA.O.10100hemoglobinometer.Theremainderofthe~~ | |||
lli bloodsamplewascentrifugedfor15minutestoseparatecellsandserum.SexdeterminationsweresubsequentlymadebyresearchersatTexasA5MUniversityusingradioimmunoassayforserumtestosterone(Owensetal.,1978).During1984and1985,bloodcellsampleswerealsoprovidedtotheNationalMarineFisheriesServiceforthepurposeofdevelopingandrefiningmethodsforuseinconductingturtlestockanalysis.Sickorinjuredturtlesweretreatedandoccasionallyheldforobservationpriortorelease.Whentreatmentwaswarranted,injectionsofantibioticsandvitaminswereadministeredbyalocalveterinarian.Resuscitationtechniqueswereusedifaturtlewasfoundthatappearedtohavediedrecently.Beginningin1982,necropsieswereconductedondeadturtlesfoundinfreshcondition;twoindividuals,oneKemp'sridleyandoneloggerhead,werefoundsuitablefornecropsyin1987.FloridaPower5LightCompanyandAppliedBiology,Inc.continuedtoassistotherseaturtleresearchersin1987.InadditiontotheFloridaDNR'sHeadstartProgram,data,specimensand/orassistancehavebeengiventotheNationalMarineFisheriesServices,U.S.ArmyCorpsofEngineers,SmithsonianInstitution,SouthCarolinaWildlifeandMarineResourcesDivision,CenterforSeaTurtleResearch(UniversityofFlorida),TexasA&MUniversity,UniversityofRhodeIsland,UniversityofSouthCarolina,UniversityofIllinois,UniversityofGeorgiaandtheWesternAtlanticTurtieSymposium.15 StudiestoEvaluateand/orMitiateIntakeEntramentAprogramthatassessedthefeasibilityofusinglightand/orsoundtodeterturtlesfromenteringtheSt.LuciePlantintakestructureswasconductedin1982and1983andcompletedinJanuary1984.Asrequired,testresultsandevaluationswerewrittenupandapresentationwasmadetotheNRC,NationalMarineFisheriesServiceandtheFloridaDepartmentofNaturalResourcesonllApril1984.Requirement4.2.2oftheNRC'sSt.LucieUnit2AppendixBEnvironmentalProtectionPlanisconsideredcompletedwithsubmissionofdeterrentstudyfindings.LihtScreentoMinimizeTurtleDisorientationAvegetativebeachdunelightscreencreatedtominimizeturtledisorientationattheSt.LuciePlantwasroutinelyinspectedbyFPLper-~~sonnelduring1987.Replantingswereconductedasrequiredtomaintainitsintegrity.RESULTSANDDISCUSSIONNestinSurveDistributionofLoerheadNestsAlonHutchinsonIslandWhenseaturtlenestingsurveysbeganonHutchinsonIsland,nine1.25-km-longsurveyareaswereusedtoestimateloggerheadnestingacti-vityfortheentireisland.Since1981,all361-km-longsegmentscomprisingtheisland'scoastlinehavebeensurveyed.-Regardlessoftechnique,loggerheadnestdensitieshaveshownconsiderableannualvariationwithinindividualsurveyareas(Figures4and5).Yet,theannualspatialdistributionofthosenestsamongsurveyareashaspro-16 ducedaratheruniformgradient,nestdensitiesconsistentlyincreasingfromnorthtosouth(ABI,1987).Thegradientappearstobelinearwhenonlythenine1.25-km-longsurveyareasareused(Figure4),butbecomescurvilinearwhenall361-km-longsurveyareasareincludedintheanaly-sis(Figure5).During1987thedistributionofloggerheadnestsalongtheislandfollowedthesamegeneralpatternaspreviouslyreported,nestdensitiesincreasingabruptlyfromnorthtosouthalongthenorthernpor-tionoftheisland,reachingmaximumdensitiesincentralsurveyareasandthendecreasingslightlytowardthesouthernportionoftheisland(Figure5).Inthepast,thepronouncedgradientobservedonthenorthernendoftheislandwasoccasionallyinfluencedbyphysicalprocessesoccurringthere;periodsofheavyaccretionreducedthegradient,whileperiodsoferosionaccentuatedit(WorthandSmith,1976;Williams-Wallsetal.,1983).However,duringrecentyearsnoconsistentrelationshipwasapparentwhenfieldobservationsofbeachwidthswerecomparedtothe-spatialdistributionofnestsalongtheisland(ABI,1987).Thus,eventhoughbeachdynamicsmaysometimesaffecttheselectionofnestingsites1byloggerheadturtles,otherfactorsmustalsocontributetotheselec-tionprocess.Offshorebottomcontours,spatialdistributionofnearshorereefs,typeandextentofdunevegetation,anddegreeofhumanactivityonthebeachatnighthavebeenidentifiedassomeofthefac-torsaffectingnesting(Caldwell,1962;HendricksonandBalasingam,1966;Bustard,1968;BustardandGreenham,1968;Hughes,1974;DavisandWhiting,1977;Mortimer,1982).Relationshipsbetweenspatialnesting17 patternsandspecificenvironmentalconditionsareoftendifficulttoestablishbecauseoftheinterrelationshipofthefactorsinvolvedandmaybeobscuredbynestsitetenacity.Schulz(1975)suggestedthatnestsitetenacitymayforceadultfemalestomaintaintheirnestingsiteaslongaspossible,eventhoughthosesitesmaybeundergoingenvironmentalchanges.Notallventuresontothebeachbyafemaleturtleculminateinsuc-cessfulnests.These"falsecrawls"(non-nestingemergences)mayoccurformanyreasonsandarecommonlyencounteredatotherrookeries(BaldwinandLofton,1959;Schulz,1975;DavisandWhiting,1977;Talbertetal.,1980;Raymond,1984).DavisandWhiting(1977)suggestedthatrelativelyhighpercentagesoffalsecrawlsmayreflectdisturbancesorunsatisfac-torynestingbeachcharacteristics.Therefore,certainfactorsmayaffectaturtle'spreferencetoemergeonabeach,whileotherfactorsmayaffectaturtle'stendencytonestafterithasemerged.Anindexwhichrelatesthenumberofneststothenumberoffalsecrawlsinanareaisusefulinestimatingthepost-emergencesuitabilityofabeachfornesting.Inthepresentstudythisindexistermed"nestingsuccess"andisdefinedasthepercentageoftotalemergencesthatresultinnests.Historically,thepatternofloggerheademergencesontheislandhasparalleledthedistributionofnests(ABI,1987),andthissametrendwasapparentin1987(Figure6).Incontrast,nestingsuccessbyloggerheadsalongtheislandhastypicallylackedgradients(Figure7).Thus,the18 0 | |||
relativelyhighnumbersofloggerheadnestsusuallyobservedalongthesouthernhalfoftheislandhaveresultedprimarilyfrommoreturtlescomingashoreinthatarearatherthanfrommorepreferablenestingcon-ditionsbeingencounteredbytheturtlesaftertheyemerged.Hughes(1974)andBustard(1968)foundthatloggerheadspreferredbeachesadjacenttooutcropsofrocksorsubtidalreefs.Williams-Wallsetal.(1983)suggestedthatthenestinggradientonHutchinsonIslandmaybeinfluencedbytheoffshorereefsiffemaleturtlesconcentrateonthereefsclosesttothebeachtorestorfeed.Theproximityofoffshorereefswouldputthegreatestconcentrationofturtlesnearthesouthernhalfoftheislandwherecoincidentallynestingishighest.Loggerheadnestingdensitiesduring1987weregenerallywithintherangeofvaluespreviouslyrecorded(Figures4and5).TwonotableexceptionsincluderecordlownestinginAreaFandrecordhighnestinginAreaJJ.LownestinginAreaFwasapparentlyduetopre-emergentaswellaspost-emergentfactorssinceboththenumberofemergencesandnestingsuccesswerelowduring1987(Figures6and7).TheremovalofconsiderablebeachfrontvegetationinAreaFbetweenthe1986and1987nestingseasonsoffersoneexplanation.BaldwinandLofton(1959)indi-catedthatnestingturtlesshowapreferenceforbeachesbackedbyhighdunesorvegetationandahesitancytoemergeonbarrenbeaches.Anotherexplanationinvolvestheuseofthebeachatnightbyoffroadvehicles.Althoughillegal,vehiculartrafficonthebeachinArea19 Fwasconsiderableduring1987.Turtlesareverysensitivetoalarmingstimulibothpriortoemergingontoabeach(Schulz,1975)andduringtheirascentofthebeach(Hirth,1971).Amongthesealarmingstimuli,movinglightswillfrightennestingseaturtlesofallspecies(Mortimer,1982).Lightsassociatedwithvehiclesonthebeachmayhavecontributedtodecreasesinboththenumberofemergencesandnestingsuccess.RecordhighloggerheadnestinginAreaJJduring1987(Figure5)maybeattributabletounfavorablenestingconditionsontheadjacentnorthernsectionofbeach.SandbagsinstalledinAreaIIbetweenthe1986and1987nestingseasonswereapparentlyresponsibleforahighnumberoffalsecrawlswhichaccountedfortherecordlownestingsuccessobservedinthatareaduring1987(Figure7).ThehighnumberofemergencesinAreaII(Figure6)probablyreflectsrepeatedunsuccessfulnestingattemptsbyindividualturtles.ManyoftheseturtlesprobablyreemergedinAreaJJwhere,becauseofmorefavorablebeachconditions,theynested.In1987asinpreviousyears,loggerheademergenceswereleastnumerousinAreaAand.increasedsteadilyinasoutherlydirectiontoaboutAreaK(Figure6).Thepresenceofdeepwaterclosetoshorehasbeensuggestedasafactorwhichmightinfluenceseaturtlestoemergeonparticularbeaches(HendricksonandBalasingam,1966;Mortimer,1982).Thedistancefromshoretothethirty-footwaterdepthcontourdecreasescontinuouslyfromAreaAthroughAreaF,andthismaypartiallyaccountfortheobservedpatternofincreasedemergencesfromnorthtosouth20 alongthenorthendoftheisland.Furthermore,1argepublicbeachaccessesinAreasAthroughC,combinedwithconsiderableartificiallightinginthoseareas,providethepotentialforextensiveandhighlyvisiblehumanactivityonthebeachatnight.Aspreviouslystated,turtlesareverysensitivetoalarmingstimulijustpriortoandduringemergencesontobeaches.Nighttimehumanactivityintheseareasmaydeterturtlesfromemergingorfromnestingaftertheyemergeontothebeach,andmayhavecontributedtothesomewhatlowernestingsuccessobservedthere(Figure7).Historically,lownestingsuccessinthenorthernmostareashasbeenattributedtobeachcharacteristicssuchaspersistentandextensiveareasofverticalrelief(benches),accumula-tionsofrocksandshells,andcompactsand.Apparently,acombinationoffactorsaffectingbothemergenceandnestingsuccesshasbeenrespon-siblefortheextremelylownestdensitiesusuallyobservedalongthatpartoftheisland.NumbersofloggerheademergencesandconsequentlynestdensitieshaveremainedrelativelylowinAreaZfrom1981through1987(Figures5and6).Sincethisareaincludesalargepublicbeachaccess,amotelandconsiderableartificiallighting,nighttimehumanactivitymaydeterturtlesfromcomingashore.NestingsurveysonHutchinsonIslandwereinitiatedinresponsetoconcernsthattheoperationoftheSt.LuciePlantmightnegativelyimpactthelocalseaturtlerookery.Previousanalyses,usinglog-likelihoodtestsofindependence(G-test;SokalandRohlf,1981)21 demonstratedthattheconstructionoftheplant'soffshoreintakeanddischargestructuressignificantlyreducednestingattheplantsiteduringconstructionyears(1975,1981,1982and1983;Proffittetal.,1986;ABI,1987).However,nestingattheplantconsistentlyreturnedto1evelssimi1artoorgreaterthanthoseatacontrolsiteinyearsfol1owingconstruction(Figure8).TheG-testwasalsousedtoassesstheimpactsofpowerplantopera-tion,exclusiveofconstruction(ABI,1987).Thistestindicatedasignificantdifferenceintherelativeproportionofnestsbetweentheplantsite(Area4)andacomparablecontrolsite(Area5)whenbaselineyears(1971and1973)andoperationalyearswithoutconstructionwerecompared.However,thisdifferenceresultedfromadisproportionatelyhighnumberofnestsinArea4duringasingleyear(1986)ratherthanfromanylong-termdeclineinnestingresultingfrompowerplantopera-tion.Whendatafrom1986wereexcluded,nosignificantdifferencebe-tweenbaselineandoperationalperiods'eredetected.Thesameresultswereobtainedwhen1987datawereincludedintheanalyses.Datacollectedthrough1987haveshownnolong-termreductioninloggerheadnestdensities,totalemergencesornestingsuccessineitherthenine1.25-km-longsurveyareasorthe361-km-longsurveyareas'Table1;Figure9).-22 NumberofNestsandLoerheadPoulationEstimatesVariousmethodswereusedduringsurveyspriorto1981toestimatethetotalnumberofloggerheadnestsonHutchinsonIslandbasedonthenumberofnestsfoundinthenine1.25-km-longsurveyareas(Gallagheretal.,1972;WorthandSmith,1976;ABI,1980a).Eachofthesemethodsweresubsequentlyfoundtoconsistentlyoverestimateislandtotals(ABI,1987).Sincewhole-islandsurveysbeganin1981,ithasbeenpossibletodeterminetheactualproportionof'otalnestsdepositedinthenineareas.Thishasthenallowedextrapolationfromtheninesurveyareastotheentireislandforyearspriorto1981.From1981through1987thetotalnumberofnestsinthenineareasvariedfrom33.1to35.6percentofthetotalnumberofnestsontheisland(Table1).Thisisslightlyhigherthanthe31.3percentwhichwouldbeexpectedbasedstrictlyontheproportionoflinearcoastlinecomprisedbythenineareas.Usingtheseven-yearmeanof33.9percent,estimatesofthetotalnumberofnestsonHutchinsonIslandcanbecalcu-latedbymultiplyingthenumberofnestsinthenineareasby2.95.Thistechnique,whenappliedtotheninesurveyareasduringthesevenyearsinwhichtheentire'islandwassurveyed,producedwhole-islandestimateswithinfivepercentoftheactualnumberofnestscounted.Becausetheproportionofnestsrecordedintheninesurveyareasremainedrelativelyconstantoverthelastsevenyears,thisextrapolationprocedureshouldprovideafairlyaccurateestimateoftotalloggerheadnestingforyearspriorto1981.23 ItisclearthatloggerheadnestingactivityonHutchinsonIslandfluctuatesconsiderablyfromyeartoyear(Table1);Annualvariationsinnestdensitiesalsoarecommonatotherrookeries(Hughes,1976;DavisandWhiting,1977;Ehrhart,1980)andmayresultfromtheoverlappingofnon-annualbreedingpopulations.Duringthelastsixye'ars,however,annualnestproductionhasremainedrelativelyhigh.Totalnestingacti-vitywasgreatestduring1986when5,483loggerheadnestswererecordedontheisland.During1987,4,623nestswerecounted.Norelationshipsbetweentotalnestingactivityandpowerplantoperationorintake/dis-chargeconstructionwereindicatedbyyear-to-yearvariationsintotalnestingonHutchinsonIsland.InordertodeterminethetotalnumberoffemaleloggerheadturtlesnestingonHutchinsonIslandduringagivenseason,anestimateofthenumberofnestsproducedbyeachfemalemustbedetermined.Acomparisonofthenumberofnestsproducedbytaggedturtlesduringthe1975,1977and1979surveysindicatedthatanaverageoftwonestsperfemalewastproducedduringanestingseason(ABI,1980a)..Thus,estimatesofthetotalnumbersoffemalesnestingduringprevioussurveyyearsmaybeobtainedbydividingthecalculatedtotalnumberofnestsbytwo.Basedonextrapolationestimatesoftotalnesting,thenumberoffemaleloggerheadturtlesnestingonHutchinsonIslandvariedfromapproximately1,400to2,200individualsduringsurveyyears1971through1979.Usingwhole-islandnestcounts,theestimatedtotalnumberofnestingfemalesvariedfrom1,558to2,742individualsbetween1981and1987.24 | |||
TemoralLoerheadNestinPatternsTheloggerheadturtlenestingseasonusuallybeginsinearlyMay,whenoceantemperaturesreach23'o24'C,attainsamaximumduringJuneorJuly,andendsbylateAugustorearlySeptember(ABI,1987).Nestingactivityduring1987followedthissamepattern(Figure10).ShiftsinthetemporalnestingpatternonHutchinsonIsland.maybeinfluencedbyfluctuationsinwa'tertemperature.Thiswasobservedduring1975and1982whenearlynestinginAprilcoincidedwithaverageoceantem-peraturesabove24"C(ABI,1983;Williams-Wallsetal.,1983).CoolwaterintrusionsfrequentlyoccuroverthecontinentalshelfofsoutheastFloridaduringthesummer(TaylorandStewart,1958;Smith,1982).WorthandSmith(1976),Wil1iams-Wallsetal.(1983)andABI(1982,1983,1984b,1985b,1986,1987)suggestedthattheseintrusionsmayhavebeenresponsibleforthetemporarydeclinesinloggerheadturtlenestingactivitypreviouslyobservedonHutchinsonIsland.ConsiderabledecreasesinoceantemperatureswererecordedattheSt.LuciePlantduringJuneandearlyAugust1987(Figure10).Asubstantialdecreaseinnestingontheislandcorrespondedwiththelatterofthesecoolwaterintrusions.Todetermineifplantoperationhasaffectedthetimingofnestingactivity,seasonalnestingpatterns(nestdensityonamonth-to-monthbasis)forArea4(plantsite)andArea5(controlsite)werecomparedstatisticallyduringeachstudyyear(Kolmogorov-Smirnovtest;SokalandRohlf,1981).Nosignificant(P<0.05)differencesweredetectedbetween~~25 | |||
areasduringanystudyyear,eitherbeforeorafterthepowerplantbeganoperating.Theresultsoftheseanalysesindicatethatplantoperationhasnotsignificantlyaffectedtemporalnestingpatternsadjacenttotheplant.PredationonLoerheadTurtleNestsSincenestsurveysbeganin1971,raccoonpredationprobablyhasbeenthemajorcauseofturtlenestdestructiononHutchinsonIsland.Researchersatotherlocationshavereportedraccoonpredationlevelsashighas70tonearly100percent(DavisandWhiting,1977;Ehrhart,1979;Hopkinsetal.,1979;Talbertetal.,1980).RaccoonpredationofloggerheadturtlenestsonHutchinsonIslandhasnotapproachedthislevelduringanystudyyear,thoughlevelsforindividual1.25-km-longareashavebeenashighas80percent(Figure11).Overallpredationratesfor-surveyyears1971through1977werebetween21and44percent,withthehighof44percentrecordedin1973.Apronounceddecreaseinraccoonpredationoccurredafter1977,andoverallpredationratesforthenineareashavenotexceeded10percentsince1979.AdeclineinpredationratesonHutchinsonIslandhasbeenvariouslyattributedtotrappingprograms,constructionactivities,habitatlossanddisease(Williams-Wallsetal.,1983;ABI,1987).During1987,sevenpercent(304)oftheloggerheadnests(n=4,623)ontheislandweredepredatedbyraccoons.Asinpreviousyears(ABI,1987),predationofturtienestswasprimarilyrestrictedtothemostundevelopedportionoftheisland(i.e.,AreasfthroughU)andthesouthernmostareas(AreasIIandJJ;Figure12).26 Ghostcrabshavebeenreportedbynumerousresearchersasimportantpredatorsofseaturtlenests(BaldwinandLofton,1959;Schulz,1975;Diamond,1976;Fowler,1979;Hopkinsetal.,1979;Stancyk,1982).ThoughturtlenestsonHutchinsonIslandprobablyhavebeendepredatedbyghostcrabssincenestingsurveysbeganin1971,thissourceofnestdestructiondidnotbecomeapparentuntil1983.guantificationofghostcrabpredationwasinitiatedthesameyear.Overallpredationratesbyghostcrabshavevariedfrom0.3to2.1percentduringthelastfiveyears(ABI,1987).During1987,0.3percent(15)oftheloggerheadnests(n=4,623)ontheislandweredestroyedbyghostcrabs(Figure12).Nestsdestroyedbyacombinationofraccoonandghostcrabpredationhavebeenincludedasraccoonpredationsinpreviousdiscussions.Whenthesecombinationpredationsareincludedascrabpre-dations,theoverallpredationratesbyghostcrabsrangefrom1.5to3.2percent.During1987,1.5percent(71nests)weredestroyedbyeitherghostcrabsoracombination'ofghostcrabsandraccoons.GreenandLeatherbackTurtleNestinGreenand,leatherbackturtlesalsonestonHutchinsonIsland,butinfewernumbersthanloggerheadturtles.Priorto1981,bothsurvey(nine1.25-km-longsections)andinter-surveyareasweremonitoredforthepre-senceofgreenandleatherbacknests.Thirty-onekilometersofbeachfromArea1southtotheSt.Lucieinletwereincludedinthateffort.Duringwholeislandsurveysfrom1981through1987,onlytwoof101leatherbacknestsandonlyfourof350greennestswererecordedonthe27 | |||
fivekilometersofbeachnorthofArea1.Therefore,previouscountsofgreenandleatherbacknestswithinthe31kilometerssurveyedwerepro-bablynotappreciablydifferentfromtotaldensitiesfortheentireisland.Basedonthisassumption,greenandleatherbacknestdensitiesmaybecomparedamongallsurveyyears,except1980,whenlessthan15kilometersofbeachweresurveyed.Priorto1987,thenumberofnestsobservedontheislandrangedfrom5to68forgreenturtlesandfrom1to20forleatherbacks(Figure13).Duringthe1987survey,72greenturtleand18leatherbackturtlenestswererecordedonHutchinsonIsland.Temporalnestingpatternsforthesespeciesdifferfromthepatternforloggerheadturtles.GreenturtlestypicallynestonHutchinsonIslandfrommid-JunethroughthefirstorsecondweekofSeptember.During1987,greenturtles.nestedfrom15Junethrough9September.Leatherbackturtlesusuallynestontheislandfrommid-Aprilthroughearlytomid-July.During1987thisspeciesnestedfrom3Maythrough20July.Considerablefluctuationsingreenturtlenestingontheislandhaveoccurredamongsurveyyears(Figure13).Thisisnotunusualsincetherearedrasticyear-to-yearfluctuationsinthenumbersofgreenturtlesnestingatotherbreedinggrounds(Carretal.,1982).Despitethesefluctuations,greenturtlenestinghasremainedrelativelyhighduringthelastsixyears(1982through1987)andmayreflectanincreaseinthe28 numberofnestingfemalesintheHutchinsonIslandarea.During1987,greenturtlesnestedmostfrequentlyalongthesouthernhalfoftheisland.Thisisconsistentwithresultsofprevioussurveys.LeatherbackturtlenestdensitieshaveremainedlowonHutchinsonIsland;however,densitiesduringthelasteightsurveyyearshavebeenhigherthanduringthefirstfoursurveyyears(Figure13).ThismayreflectanoverallincreaseinthenumberofnestingfemalesintheHutchinsonIslandarea.During1987,leatherbackturtlesprimarilynestedonthesouthernhalfoftheislandbetweenAreasBBandGG(Figure3).IntakeCanalMonitorinEntrainmentofseaturtlesattheSt.LuciePlanthasbeenattri-butedtothepresumedphysicalattractivenessoftheoffshorestructureshousingtheintakepipesratherthantoplantoperatingcharacteristics(ABI,1980band1986).Evenwhenbothunitsareoperatingatfullcapa-city,turtlesmustactivelyswimintooneoftheintakepipesbeforetheyencountercurrentvelocitiessufficientlystrongtoeffectentrainment.Consequently,aturtle'sentrapmentrelatesprimarilytotheprobabilitythatitwilldetectandsubsequentlyenteroneoftheintakestructures.Assumingthatdetectiondistancesdonotvaryappreciablyovertimeandthatallturtles(oraconstantproportion)areequallyattractedtothestructures,capturerateswillvaryproportionatelytothenumberofturtlesoccurringinthevicinityofthestructures.Ifthisassumptionistrue,datafromthecanalcaptureprogramshouldreflectnaturalvariabilityinthestructureofthepopulationbeingsampled.29 SeciesNumberandTemoralDistributionDuring1987,218seaturtlecapturestookplaceintheintakecanaloftheSt.LuciePlant(Table2).FourofthefivespeciesofseaturtlesoccurringincoastalwatersofthesoutheasternUnitedStateswererepresentedinthecatches,including175loggerheads,35greens,2hawksbillsand6Kemp'sridleys.SinceintakecanalmonitoringbeganinHay1976,1,497loggerhead(including79recaptures),227green(including1recapture),8leatherback,6hawksbilland10Kemp'sridleycaptureshavebeenreportedfromtheSt.LuciePlant.Annualcatchesofloggerheadsincreasedsteadilyfromalowof33in1976(partialyearofplantoperationandmonitoring)to173in1979~~(Figure14).Afterdecliningbetween1979and1981,yearlycatchesof1oggerheadsagainrosesteadily,reachingahighof195during1986.Capturesin1987weredownslightlyfrom1986.TwooffshoreintakestructureswereinplacepriortoUnit1start-upin1976;thethirdandlargeststructurewasinstalledduring1982-1983.Eventhoughallthreestructuresareinrelativelycloseproximity,theadditionofanotherpipemayhaveincreasedtheprobabi1-ityofaturtlebeingentrained.Becausethischangecannotbequan-tified,datacollectedpriorto1982maynotbecomparablewiththatcollectedafter1983.Nevertheless,thegeneralriseincanalcapturessince1981,evenafterthethirdstructurewascompleted,suggestsagenuine,long-termincreaseinthenumberofturtlesoccurringneartheplant.30 i | |||
During1987,themonthlycatchof1oggerheadsrangedfrom3(October)to26(JanuaryandJune),withamonthlymeanof14.6(+8.9;Table3).CapturesduringApril,MayandJuneweremuchhigherthanhistoricalaveragesforthosemonths,whilecapturesduringSeptemberandOctoberweremuchlowerthanaverage(Figure15).Overtheentiremoni-toringperiod,monthlycatcheshaverangedfrom0to39;thegreatestnumberofcapturesoccurredduringJanuary1983.Whendatafromallfullyearsofmonitoring(1977-1987)werecom-bined,themajorityof1oggerheadswerecapturedinJanuary(13.2percent);fewestcapturesoccurredduringNovemberandDecember(Table3).However,monthlycatcheshaveshownconsiderableannualvariability.~~Monthshavingrelativelylowcatchesoneyearoftenhavehadrelativelyhighcatchesinanother..Catchesofgreenturtlesalsohavevariedwidelyamongyears,rangingfrom0in1976(partialyearofsampling)to69in1984(Table4).During1987,35individualswerecaptured.Theaverageannualcatchofgreenturtles,excluding1976,was20.6(+19.4).Noconsistenttrendsinannualcatchesareevidentfromthedata(Figure14).Green,turtleshavebeencaughtduringeverymonthoftheyear,withaveragemonthlycatchesforallyearscombinedrangingfrom0.3inMayto7.1inJanuary(Table4).However,seasonalabundancepatternsofgreensaremuchmorepronouncedthanforloggerheads,nearly75percentofallcapturesoccurringbetweenNovemberandMarch.During1987,thelargest.31 0 | |||
numberofgreens(11)werecapturedinDecember.caughtinonemonthwas37inJanuary1984.ThemostgreenseverCatchesofleatherbacks,hawksbillsandKemp'sridleyshavebeeninfrequentandscatteredthroughouttheelevenyearstudyperiod(Table2).Eachspecieshasshownratherpronouncedseasonaloccurrences;allbutoneoftheeightleatherbackswerecollectedbetweenFebruaryandMay,fiveofthesixhawksbillswerecollectedbetweenJuneandSeptember,andallbutoneofthe10Kemp'sridleyswerecaughtbetween~DecemberandApril.Size-ClassDistributionsTodate,liveloggerheadsremovedfromtheintakecanalhaverangedinlength(SLCL)from40.4to112.0cm(x=65.2+12.3cm)andinweightfrom10.9kgto154.7kg(Figures16and17).About75percentofallliveloggerheadscapturedwere70cmorlessinlengthandweighedlessthan100pounds.Acarapacelengthof70cmapproximatesthesmallestsizeofnestingloggerheadfemalesobservedalongtheAtlanticeastcoast(Hirth,1980).However,adultscanonlybereliablysexedonexternalmorphologicalcharacteristics(e.g.,relativetaillength)afterobtainingalengthofabout80cm.Basedonthesedivisions,dataweresegregatedintothreegroups:juvenile/sub-adults(<70cm;thedemarcationbetweenthesetwocomponentsisnotwellestablishedintheliterature),adults(>80cm)andtransitional(70-80cm).Thelattergroupprobablyincludessome32 JIL matureandsomeimmatureindividuals.Ofthe1,348capturesforwhich1engthdatawerecollected,75percentwerejuveni1es/sub-adults,themajorityofthesemeasuringbetween50and70cmSLCL(Table5).Theremaining25percentwasdividednearlyequallybetweenadultsandindi-vidualsinthetransitionalsizeclass.Similarsize-frequencydistribu-tions,indicatingapreponderanceofjuveniles,havebeenreportedfortheMosquito/IndianRiverLagoon(MendoncaandEhrhart,1982),theCanaveralshipchannel(OgrenandMcVea,1982),GeorgiaandSouthCarolina(Hi1lestadetal.,1982)andsuggestthatcoastalwatersofthesoutheasternUnitedStatesconstituteanimportantdevelopmentalhabitatforCarettacaretta.Seasonalpatternsofabundanceforvarioussizeclassesindicatedthatjuvenilesandsub-adultloggerheadswereslightlymoreabundantduringthewinterthanatothertimesoftheyear(Table5).About37percentofjuvenile/sub-adultloggerheadswerecapturedbetweenJanuaryandMarch,theremainderbeingratherevenlydistributedamongothermonths.Theseasonaldistributionofadult.loggerheadswasmuchmorepronounced,60percentofallcapturesoccurringbetweenJuneandAugust.ThisrepresentstheperiodofpeaknestingonHutchinsonIsland.Ifothernestingmonthsareincluded(MayandSeptember),75percentofalladultswerecapturedduringthenestingseason.Greenturtlesremovedalivefromtheintakecanalovertheentirestudyperiodrangedinsizefrom20to108cmSLCL(x=36.9+15.1cm)and0.9kgto177.8kg(Figures18and19).Nearlyall(96percent)were33 juvenilesorsub-adults.Over75percentwere40cmorlessinlength,and60percentweighedlessthan10pounds.Theseimmatureturtlesexhi-biteddistinctwinterpulsessuggestingmigratorybehavior(Table4).However,someimmaturegreenturtleswerepresentthroughouttheyear.Todate,onlysixadultgreenturtles(SLCL>83cm;WitheringtonandEhrhart,inpress)havebeenremovedfromthecanal;allwerecapturedduringorshortlyafterthenestingseason.FiveofthesixhawksbillsandalltenKemp'sridleysremovedfromthecanalwereimmature,ranginginsizefrom34to46cmSLCL(6.4-12.7kg)and27to47cmSLCL(3.2-15.4kg),respectively;theadulthawksbill(SLCL>53cm;Hirth,1980)hadaSLCLof70cmandweighed52.2kg.Theeightleatherbacksremovedfromthecanalrangedinlengthfrom112.5to150cm,andatleastsixwereadults(SLCL>121cm;Hirth,1980).Thelargestleatherbackforwhichanaccurateweightwasobtained,amalewithaSLCLof134.5cm,weighed233.6kg.SexRatiosSinceintakecanalmonitoringbeganin1976,198adultloggerheadshavebeensexed.Thesmallestwas75.5cminlengthandwasobservednestingonHutchinsonIslandsubsequenttoher.captureinthecanal.Femalespredominatedmalesbyaratioof4.9:1.0,whichsignificantlydepartsfroma1:1ratio(X2,P<0.05).Consequently,temporalpatternsinthenumberofadultloggerheadcapturesareheavilyinfluencedbythenumbersoffemalespresent.Whensexeswereseparated,itisevidentthatmaleswererelativelyevenlydistributedamongdifferentmonths, | |||
[1I whereasnearly80percentofthefemalesweretakenduringthenestingseason(MaythroughSeptember;Figure20).ThenumberofadultloggerheadscapturedattheSt.LuciePlantincreasedappreciablyafter1982.Between1976and1982,anaverageof7.4adultloggerheads(+4.4;range=2-15)wereentrappedeachyear,whereasoverthelastfive.years,anaverageof30.0adultsperyear(+8.9;range=19-40)werecaptured.Thisincreasecorrespondstoageneralriseinloggerheadnestingneartheplant(Figure21).Theyear1986representedthehighestnumberofnestseverrecorded,bothfortheentireislandandattheplantsite(Area4),andmoreadultfemales(35)wereentrappedinthecanalthaneverbefore.Thisassociationisnotunexpected,becauseincreasednearshoremovementassociatedwithnestingbehaviorincreasestheprobabilityofaturtledetectingoneoftheintakestructuresandhencetheprobabilityofentrainment.-Theadditionofthethirdoffshoreintakestructure,thelargestofthethreestruc-tures,in1982alsomayhavecontributedtoincreasedentrainmentofadults.SinceSeptember1982,258juvenileandsub-adultloggerheadturtlescapturedinthecanalhavebeensexedbyTexasA8NUniversityresearchersusingabioimmunoassaytechniqueforbloodserumtestosterone.Forthepurposeoftheseanalyses,Dr.Owensandhisasso-ciatesused76cmasthecutofflengthbetweenimmatureandadultturtles.BioimmunoassayresultsindicatethatforimmatureloggerheadsremovedfromtheSt.LuciePlantintakecanal,femalesoutnumberedma'les35 I | |||
byaratioof2.7:1.0.ThesexratiosofimmatureloggerheadscapturedintheCapeCanaveralshipchannel(1.7:1.0)andtheIndianRiverLagoon(1.4:1.0)arealsoreportedtobesignificantlyskewedinfavoroffema-les(X2,P<0.05;Wibbelsetal.,1984).Ofthesixadultgreenturtlescapturedsincemonitoringbegan,fourweremalesandtwowerefemales.Siximmaturegreenturtleshavebeensexedthroughbloodwork;allhavebeenfemales.Ofthefiveadultleatherbackturtlesforwhichsexwasrecorded,twowerefemalesandthreeweremales.Theonlyhawksbillthusfarsexedwasafemale.NosexinformationexistsforKemp'sridleys.CatureEfficienciesCapturemethodologiesevolvedoverthefirstseveralyearsofintakecanalmonitoringasnetmaterials,configurationsandplacementwerevariedinanefforttominimizeseaturtleentrapmenttimes.Concurrently,alternativecapturetechniqueswereevaluatedandpotentialdeterrentsystemstestedinthelaboratory.Duringthisperiod,captureefficienciesvariedinrelationtonettingeffortandtheeffectivenessofthesystemsdeployed.Acapture/recapturestudyconductedintheintakecanalbetweenOctober1980andJanuary1981indicatedthatmostturtlesconfinedbe-tweentheAIAbridgeandtheintakeheadwallswerecapturedwithintwoweeksoftheirentrainment(ABI,1983).Basedonmorerecentformaldailyinspections,itappearsthatcaptureefficiencieshavefurther36 improved.Mostturtlesenteringthecanalarenowcaughtwithinafewdaysoffirstsighting,andinmanyinstances,turtleshavebeencaughtinthetanglenetswithoutanypriorsighting,suggestingresidencytimesoflessthan24hours.Betterutilizationofcurrentsandeddies,adjustmentstotetheringlinesandmulti-netdeploymentshavecontributedtoreducedentrapmenttimes.EntrapmenttimesmaybeextendedforturtlesswimmingpasttheA1Abarriernet(ABI,1987).Occasionally,thetopofthenethasbeensub-mergedortheanchorcablepull,edfreefromthebottom,allowinglargerturtlestopass;turtleswithcarapacewidthslessthanabout30.5cmcanswimthroughthelargemesh.BecausecaptureeffortswestoftheA1Abridgehavegenerallybeenlesseffectivethanthoseneartheintakeheadwalls,mostturtlesbreachingthebarriernetwerenotcaughtuntiltheyenteredtheintakewellsofUnits1and2.Sincethecanalcaptureprogrambegan,about15percentofallturtlesentrappedinthecanalhavebeenremovedfromtheintakewells.Becauseoftheirrelativelysmallsizes,agreaterproportionofgreens(47.6percent)reachedtheplantthanloggerheads(9.4percent).AftercompletionofthesecurityintrusionbarrierinDecember1986,mostturtleslargerthan30.5cmincarapacewidthwerepreventedfromreachingtheintakewells.During1987,onlysevenloggerheadswereremovedfromtheplant,allduringJanuaryandFebruary.Theseturtleswerepresumablytrappednorthoftheintrusionbarrier(Figure2)beforeitwascompleted.Anadditional15loggerheadswereremovedfromthe37 canalwestoftheA1Abarriernetduring1987;12werehand-capturedatorneartheintrusionbarrier,twowerecaughtintanglenetssetwestoftheA1Abridge,andonewashedupalongthebank.Atotalof11greenturtlesmadeitpasttheA1Abarriernetduring1987.Ninewereremovedfromtheintakewells,onewashand-capturedneartheintrusionbarrierandonewascaughtinatanglenetsetwestoftheA1Abridge.FourKemp'sridleyswerealsocapturedwestoftheA1Abarriernetduring1987,allattheUnit1and2intakewells.Tomaximizeconfinementoflargerturtlestotheeasternmostsectionoftheintakecanal,andtherebyincreaseoverallcaptureefficiency,theA1Abarriernethasbeenperiodicallysurveyedand,asrequired,appropriatemeasurestakentoensureitsintegrity.SuchanadjustmentwasmadeduringAugust/September1985(ABI,1987).During1987,thebarriernethadtobedismantledbetweenAprilandJunebecauseofconstructionactivitiesinthecanal.ItwasultimatelyreplacedwithanewnetinNovember1987.RelativeConditionTurtles"capturedaliveintheintakecanaloftheSt.LuciePlantwereassignedarelativeconditionbasedonweight,activity,parasiteinfestation,barnaclecoverage,wounds,injuriesandanyotherabnor-malitiesswhichmighthaveaffectedoverallwell-being(Table6).During1987,86.3percent(151)ofallloggerheadsfoundinthecanalwerealiveandingoodtoexcellentcondition.Only7.5percent(13)ofloggerheadcapturesinvolvedindividualsinfairorpoorcondition;6.3percent(11)oftheloggerheadsremovedfromthecanalweredea'd.38 Ofthe35greenturtlesremovedfromtheintakecanalduring1987,85.7percent(30)wereingoodtoexcellentcondition,whileonly14.3percent(5)wereinfairorpoorcondition.ThreeofthesixKemp'sridleyscaughtduring1987wereingoodtoexcellentcondition,onewasinfairconditionandtwoweredead.Bothhawksbillscapturedduring1987wereinexcellentcondition.Overtheentiremonitoringperiod,about70and80percent,respec-tively,ofal1loggerheadandgreencaptureshaveinvolvedturtlesingoodtoexcellentcondition(Table6).Capturesofindividualsinfairtopoorconditionhaveoccurredabout22percentofthetimeforlogger-headsand13percentofthetimeforgreens.Allofthehawksbil1sandallbutone1eatherbackhavebeenremovedfromthecanalingoodtoexcellentcondition.,Although60percentoftheKemp'sridleyshavebeeningoodtoexcellentcondition,allcategorieshavebeenrepresentedinthecatches.Relativeconditionratingscanbeinfluencedbyanumberoffactors,somerelatedandothersunrelatedtoentrainmentand/orentrapmentintheintakecanal.Ratingsofgoodtoexcellentindicatethatturtleshavenotbeennegativelyimpactedbytheirentrapmentinthecanal,atleastasevidencedbyphysicalappearance.Althoughratingsoffairorpoorimplyreducedvitality,theextenttowhichentrainment/entrapmentisresponsibleisoftenindeterminable.Insomeinstances,conditionsresponsibleforlowerratings,suchasinjuries,obviouslyweresustainedpriortoentrainment.39 | |||
During1987,about13percentofallcapturesinvolvedindividualswithsevereinjuries,includingmissingappendages,brokenormissingpiecesofcarapaceordeeplacerations.However,nearlyallofthesewereold,wel1-healedwounds.Sharkattacksappearedtohavebeenresponsibleforalargepercentageoftheinjuries,asevidencedbycrescent-shapedbitemarks.Oneturtlehadobviouspropellerscarsonthecarapace.Althoughmanyturtlesremovedfromthecanalduring1987hadoneormorerecentsuperficialabrasionstothecarapaceorskin,onlytwoindividualsappearedtohavesustainedseriousinjuriesasaresultoftheirentrainment/entrapment.Bothweretreated,heldforobservationandsubsequentlyreleased.Onceinthecanal,anindividual'srelativeconditionappearstoberelatedtothelengthoftimeitremainsentrapped(ABI,1987).Asindi-catedearlier,entrapmentperiodsarerelativelyshortforturtlesremainingbetweentheA1Abarriernetandintakeheadwalls,whileresi-dencytimesincreaseforthoseindividualsbreachingthebarriernet.Previouscomparisonshavedemonstratedthattheproportionofloggerheadsingoodtoexcellentconditionisgreaterforindividualscaughtinthetanglenetsthanforindividualsremovedfromtheintakewells(ABI,1987).Loggerheadshaveatendencytoorientagainstcurrentsinthecanal,oftenrestingnearsubmergedstructures.ForindividualswestoftheA1Abridge,thisbehaviorprolongstheirtransporttotheintakewellsandtherebyextendstheirresidencytimes.40 Becausegreenturtlesentrappedinthecanalarerelativelysmall,theirmovementsaremoreeasilyinfluencedbycurrents.Individualspassingthroughthebarriernetprobablyarriveattheintakewellsinarelativelyshortamountoftime.Consequently,themeanrelativecon-ditionofgreenturtlescaughtbytanglenetsdoesnotdifferappreciablyfromthemeanconditionofindividualsremovedfromtheintakewells(ABI,1987).Therelativeconditionassignedtoaturtleisasubjectiveassess-mentpronetosomevariationamongobserversandisbasedsolelyonphy-sicalappearance.Aturtle'sphysicalappearancemayormaynotrelatetoitsphysiologicalhealth.Thus,measuresofphysiologicalconditionaredesirable.BloodhemoglobinlevelshavebeenmeasuredinturtlesremovedfromtheintakecanalsinceSeptember1982.During1987,valuesrangedfromlessthan4.0to14.9g/100ml(n=80).Themeanforturtlesinexcellentconditionwas10.1g/100ml(+1.52;n=38),whilethemeanvalueforindi-vidualsinfairconditionwasonly8.2g/100ml(+2.36;n=3).Althoughpreviousanalyseshavealsoindicatedageneralassociationbetweenrela-tiveconditionandhemoglobinvalue,theoverlapinrangesbetweengroupshasbeenconsiderable(ABI,1987).Todate,therehavebeennosignificantdifferencesinthemeanHbvaluesbetweenrelativeconditioncategories. | |||
Frair(1977)reportedthatmanyfactors,suchastemperature,sex,sizeandactivity,canaffectanindividualturtle'sbloodchemistryirrespectiveofgeneralhealth.Thus,hemoglobindatatakencollectivelyfromtheentirepopulationoverdifferentseasonsandenvironmentalcon-ditionsprobablymasksdifferenceswhichmightotherwisebeattributabletodifferencesinhealthamongindividualswithindistinctsegmentsofthepopulation.Asthedatabasecontinuestogrow,hemoglobinvaluescanbepartitionedbysizeclasses,sexandseasontoreducevariabilityandthusproduceabettergaugeofrelativehealthwithineachsub-group.MortalitiesDuring1987,11loggerheadmortalities(6.3percentofallloggerheadcaptures)wererecordedintheintakecanal.Eightoftheseturtleswereremovedfromthesecurityintrusionbarrier,twowerefoundfloatingagainsttheA1AbarriernetandonewasheduponthecanalbankwestofA1A.TwoKemp'sridleymortalitiesalsooccurredintheintakecanalduring1987;onewasremovedfromtheintakewellsandthe,otherfromaturtlenet.Nomortalitiestootherspecieswererecordedduring1987.Overtheentire12yearmonitoringperiod,116(7.7percent)ofthe1,322loggerheadsand16(7.0percent)ofthe227greenturtlesentrappedinthecanalwerefounddead(Table2).Mortalitiesspannedtherangeofsizeclassesforloggerheads(SLCL=47.5-125cm),whileallgreenturtlemortalitiesinvolvedjuvenileslessthan41cminlength.Thetwojuve-nileKemp'sridleymortalitiesdocumentedattheplantduring1987were42 theonlydeathsforthisspeciessincemonitoringbegan;noleatherbackorhawksbillmortalitieshaveoccurredattheSt.LuciePlant.Mortalitieshavebeencloselymonitoredthroughoutthelifeofthecanalcaptureprograminanattempttoassignprobablecausesandtake'ppropriatecorrectivemeasurestoreducefutureoccurrences.Previousanalysesofdatacollectedfromturtlescapturedbetween1976and1986identifieddrowninginnets,drowningintheintakepipesduringperiodsofreducedintakeflow,injuriessustainedfromdredgingoperationsandinjuriessustainedfromthemechanicalrakesusedintheintakewellsasprobablemortalityfactors(ABI,1987).Althoughdifficulttoquantify,theentrapmentandsubsequentdemiseofinjuredorsickturtlesalsopro-bablyaccountsforaportionofobservedmortalities.Overtheyears,materialsandprocedureshavebeenmodifiedtoreducethepotentialforaturtledrowningduringcapture.Leadlineshavebeenremovedfromthenetsanddeploymenttechniquesalteredtoallowturtleseasiermovementafterentanglement.Surveillanceofthenetshasalsoincreased.However,evenwiththeseprecautions,aturtlehasoccasionallydrowned.Inrecentyears,thishasoccurredprimarilywhenasmallturtlehasbecomeentangledwithoneormorelargerindivi-duals,apparentlyrestrictingitsmovementandabilitytosurface.Suchanincidentoccurredon10June1987,asajuvenileKemp'sridleybecameentangledinanetatnightwithtwolargerloggerheads.Overthe12yearhistoryofthecanalcaptureprogram,onlyeightofthemorethan1,700turtlesentrappedinthecanalhavedrownedasaresultofnettingactivities. | |||
MostrecentmortalitiesintheintakecanalapparentlyresultedfromdrowningsattheA1Abarriernetandthenewlyconstructedsecurityintrusionbarrier.Adramaticincreaseinloggerheadmortalitiesbetween1985and1986(Table2)wasthoughttohavebeenrelatedtoadjustmentsmadetotheA1Abarriernetduringthelatterpartof1985(ABI,1987).Presumably,theseadjustmentsincreasedtheprobabilityofaturtledrowning.Asapreventivemeasure,largeholeswerecutinthebarriernettoprovideescapehatchesforturtlestrappedagainstitbystrongcurrents.Concurrently,plansweremadetoinstallanewbarriernet,usingadifferentmethodofdeployment.Asaresultofthebarriernet'sgeneralineffectivenessduringmuchof1987,largerturtleswhichotherwisewouldhavebeenconfinedeastoftheAlAbridgewerepermittedfreeaccesstothatportionofthecanalwherecaptureeffortsarelesseffective.Twelveoftheseturtleswereeventuallyremovedfromthecanalatthesecurityintrusionbarrier;eightweredead.Theliveindividualsremovedfromtheintrusionbarrierweretangledinitsmeshorotherwisepinnedagainstitbystrongcurrents,andgenerallyshowedsignsofinjuriesorweakenedcondition.Sickorinjuredturtlescontactingthenetbelowthewater'ssurfacemaybeunabletosurfaceandthusareprobablymoresusceptibletodrowningthanhealthyindividuals.ConcurrentwiththeremovaloftheA1Abarriernet,surveillanceandcaptureeffortsinthecanalwereintensified,includingmulti-netdeploymentswestofA1Aanddeploymentofnetsovertheweekends.NologgerheadcapturesoccurredwestoftheA1AbridgeafterAugust1987andanewbarriernetwasinstalledduringNovemberofthatyear. | |||
Inadditiontothe11loggerheadmortalitiesrecordedduring1987,twoturtlesremovedfromthecanalinpoorconditionlaterdied.Bothwereveryemaciatedandweresolethargictheycouldbehand-captured.Onehadnumerousoldwounds.Anecropsyperformedontheindividualwithoutwoundsprovidednocluesastothecauseofdeath.However,both'fturtleshadbeeninthecanalforarelativelyshortperiod(basedondailyobservations),indicatingtheyweresickbeforetheirentrapment.Bothwereheavilyencrustedwithbarnaclesandhadnumerousparasites.Thisisaconditionoftenseeninstrandedindividualswherenoapparentwoundsorinjuriesarepresentandmaybeindicativeofpoorhealth.Thecaptureofterminallyillturtlesinthecanallendssupporttotheideathatatleastaportionofthemortalitiesoccurringinthecanalmaybearesultofpre-entrainmentconditions.Undoubtedly,pre-existinginjuriesandillnessescontributetosomeofthecanalmortalities.TwoKemp'sridleymortalitiesoccurredintheintakecanalduring1987.Thedrowninginthetanglenetwasdiscussedearlier.Theothermortalitywasrecordedattheplantintakewells.Similartothecon-ditionofmanyoftheloggerheadsremovedfromtheintrusionbarrier,thisindividualwasemaciatedandapparentlyinillhealth.Strongcurrentsinthevicinityoftheintakewellsmayhaveresultedinitsdrowning.Althoughanecropsywasperformed,causeofdeathcouldnotbepositivelydetermined.45 0 | |||
RecatureIncidentsSincetheSt.LuciePlantcaptureprogrambegan,mostturtlesremovedalivefromtheintakecanalhavebeentaggedandreleasedintotheoceanatvariouslocationsalongHutchinsonIsland.Consequently,individualturtlescanbeidentifiedaslongastheyretaintheirtags.Overthe12yearhistoryofturtleentrapmentattheSt.LuciePlant,48individuals(47loggerheadsand1green)'havebeenremovedfromthecanalmorethanonce.Severalotherturtleswithtagscarshavealsobeenremoved,indicatingthattheactualnumberofrecapturesmaybehigher.Ofthe47individualloggerheadsknowntohavebeencaughtmorethanonce,33werecaughttwice,sixwerecaughtthreetimes,fourwerecaughtfourtimes,twowerecapturedsixtimesandtwowerecaughtonsevenseparateoccasions,yieldingatotalof79recaptureincidents.Releasesitedidnotappeartohaveanyeffectonaturtle'sprobabilityofbeingrecaptured.Turtlesreleasedbothnorthandsouthoftheplantreturned.Recapturesalsodidnotappeartoberelatedtosize,asbothjuvenilesandadultswerecapturedmorethan.once(rangeofSLCL=47-89cm).However,themajorityofrecaptureincidentsinvolvedjuvenilesandsub-adults(SLCL<70cm).Recaptureintervalsforloggerheadsrangedfromfourto858days,withameanof143days(+161.5days).Theonlygreenturtlecaughtmorethanoncewascapturedontwooccasions,returningtothecanal59daysafterfirstbeingreleasedintotheocean.About57percentofallloggerheadrecaptureincidentsoccurredwithin90daysofpreviouscap-46 tureand91percentwithinoneyear(Figure22).Theaverageintervalbetweenfirstandlastcapturewas245days(+267.4days).ThesedatasuggestthatresidencytimesofloggerheadswithinthenearshorehabitatadjacenttotheSt.LuciePlantarerelativelyshort.SimilarfindingshavebeenreportedforloggerheadsinhabitingtheMosquito/IndianRiverLagoonsofeast-centralFlorida(MendoncaandEhrhart,1982).SUMMARYAgradientofincreasingloggerheadturtlenestdensitiesfromnorthtosouthalongthenorthernhalfofHutchinsonIslandhasbeenshownduringallsurveyyears.Thisgradientmayresultfromvariationsinbeachtopography,offshoredepthcontours,distributionofnearshorereefs,onshoreartificiallightingandhumanactivityonthebeachatnight.Lownestingactivityinthevicinityofthepowerplantduring1975andfrom1981through1983wasattributedtoconstructionofpowerplantintakeanddischargesystems.Nestingreturnedtonormalorabovenormallevelsfollowingbothperiodsofconstruction.Powerplantopera-tion,exclusiveofintake/dischargeconstruction,hashadnosignificanteffectonnestdensities.Therehavebeenconsiderableyear-to-yearfluctuationsinloggerheadnestingactivityonHutchinsonIslandfrom1971through1987.Fluctuationsarecommonatotherrookeriesandmayresultfromoverlappingofnon-annualbreedingpopulations.Despitethesefluc-tuations,loggerheadnestingactivityhasremainedrelativelyhighduringthelastsixyears.Norelationshipbetweentotalnestingandpowerplantoperationorintake/dischargeconstructionwasindicated.47 | |||
ResultsofthreeyearsoftaggingstudiesonHutchinsonIslandindi-catedthatanaverageoftwonestsperyearwereproducedbyeachnestingloggerheadturtle.Basedonthisaverage,thenestingpopulationofloggerheadturtlesontheislandhasvariedfromapproximately1,400individualsin1977toover2,700in1986.Thoughtemporalnestingpat-ternsoftheHutchinsonIslandpopulationmaybeinfluencedbyfluc-tuationsinwatertemperature,nosignificanteffectsduetopowerplantoperationhavebeenindicated.Sincenestsurveysbeganin1971,raccoonpredationwasconsideredthemajorcauseofturtlenestdestructiononHutchinsonIsland.From1971through1977,overallpredationratesintheninesurveyareaswerebetween21and44percent.However,apronounceddecreaseinraccoonpredationoccurredafter1977,andoverallpredationratesintheninesurveyareashavenotexceededtenpercentsince1979.Decreasedpreda-tionbyraccoonsprobablyreflectsadeclineintheraccoonpopulation.During1987,.72greenturtleand18leatherbackturtlenestswererecordedonHutchinsonIsland.Greenturtlenestingactivityexhibitedconsiderableannualfluctuations,ashasbeenrecordedatotherrookeries,buthasremainedrelativelyhighduringthelastsixyears.Annualleatherbacknestdensitiesduringthelasteightsurveyyearswerehigherthanthepreviousfoursurveyyears.During1987,175loggerheads,35greenturtles,2hawksbillsand6Kemp'sridleyswereremovedfromtheSt.LuciePlantintakecanal.Since48 monitoringbeganinMay1976,1,497loggerhead,227green,8leatherback,6hawksbilland10Kemp'sridleyturtleshavebeencaptured.Overthelifeofthemonitoringprogram,annualcatchesforloggerheadturtleshaverangedfrom33in1976(partialyearofplantoperationandmonitoring)to-ahighof195in1986.Yearlycatchesofgreenturtleshaverangedfrom0in1976to69in1984.Differencesinthenumberofturtlesentrappedduringdifferentyearsandmonthswereattributedtonaturalvariationintheoccurrenceofturtlesinthevicinityoftheoffshoreintakestructures,ratherthantoanyinfluenceoftheplantitself.Size-classdistributionsofloggerheadturtlesremovedeachyearfromthecanalhaveconsistentlybeenpredominatedbyjuvenilesandsub-adultsbetween50and70cminstraightlinecarapacelength.Mostgreenturtlesentrappedinthecanal(over75percent)werejuveniles40cmorlessinlength.Forbothspecies,thelargestnumberofcapturesforallyearscombinedoccurredduringthewinter,buttheseseasonalpeaksweremuchmorepronouncedforgreenturtles.Sexratiosofbothadultandimmatureloggerheadscaughtinthecanalcontinuedtobebiasedtowardsfemales.During1987,about86percentofallloggerheadsandgreenturtlesremovedfromthecanalwerecategorizedbyphysicalappearanceasbeingingoodtoexcellentcondition.Overtheentire12yearmonitoringperiod,about70and80percent,respectively,ofallloggerheadandgreenturtlecaptureshaveinvolvedindividualsinthesecategories;22 percentoftheloggerheadsand13percentofthegreenturtlesremovedfromthecanalhavebeeninfairorpoorcondition.About13percentoftheturtlesremovedfromtheintakecanalduring1987hadsevereinjuries.However,itappearedthatallbuttwooftheseinjuriesweresustainedpriortoentrapment.Onceinthecanal,turtlesconfinedeastofA1Ausuallyhadverybriefresidencytimesandthustherelativeconditionofmostturtleswasnotaffectedbytheirentrapment.During1987,22loggerheads,11greenturtlesan'd4Kemp'sridleysswamwestoftheA1Abridge.Themajorityoftheloggerheadswereretrievedatarecentlyinstalledsecurityintrusionbarrier,whileallbuttwoofthegreenturtlesandalloftheKemp'sridleyswereremovedfromthecanalattheintakewells.Sincemonitoringbegan,about9percentofallloggerheadand48percentofallgreenturtlecaptureshaveoccurredattheintakewells.During1987,twoKemp'sridleyandelevenloggerheadmortalitieswererecordedfortheintakecanal.Thisrepresentedasubstantialdecreaseinloggerheadmortalitiesfrom1986.Themajorityofdeathsduring1987appearedtohaveresultedfromdrowning,althoughtheexactcausesofdeathcouldnotbedetermined.Theintrusionbarrierwaspro-bablyresponsibleforeightoftheelevenloggerheadmortalities,butthesedeathsappearedtobeconfinedprimarilytoindividualswithinjuriesorinaweakenedcondition.50 Sinceintakecanalmonitoringbeganin1976,7.7percentoftheloggerheadsand7.0percentofthegreenturtlesremovedfromthecanalweredead.ThetwoKemp'sridleymortalitiesin1987werethefirstrecordedforthisspeciessincemonitoringbegan.Alloftheleather-backsandhawksbi11scapturedattheSt.LuciePlanthavebeenreleasedaliveintotheocean.51 LITERATURECITEDABI(AppliedBiology,Inc.)1977.EcologicalmonitoringattheFloridaPower&LightCo.St.LuciePlant,annualreport1976.VolumesIandII.AB-44.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1978.EcologicalmonitoringattheFloridaPower&LightCo.St.LuciePlant,annualreport1977.VolumesIandII.AB-101.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1979.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1978.VolumesIIandIII,Bioticmonitoring.AB-177.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,fliami.1980a.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1979.VolumesIIandIII,Bioticmonitoring.AB-244.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1980b.Turtleentrainmentdeterrentstudy.AB-290.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1981a.SuccessfulrelocationofseaturtlenestsneartheSt.LuciePlant,KutchinsonIsland,Florida.AB-317..PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1981b.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1980.VolumesIIandIII,Bioticmonitoring.AB-324.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1981c.ProposedSt.LuciePlantpreopera-tionalandoperationalbiologicalmonitoringprogram-August1981.AB-358.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1982.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1981.VolumesIIandIII,Bioticmonitoring.AB-379.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1983.FloridaPower&LightCompany,St.LuciePantannualnon-radiologicalaquaticmonitoringreport1982.VolumesIandII.AB-442.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.52 LITERATURECITED(continued)ABI(AppliedBiology,Inc.).1984a.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1983.VolumesIandII.AB-530.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami.1984b.FloridaPower8LightCompany,St.LuciePlantannualenvironmentaloperatingreport1983.AB-533.PreparedbyAppliedBiology,Inc.forFloridaPower5LightCo.,Miami.1985a.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1984.AB-553.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,JunoBeach.1985b.FloridaPower8LightCompany,St.LuciePlantannualenvironmentaloperatingreport1984.AB-555.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,JunoBeach.1986.FloridaPower8LightCompany,St.LuciePlantannualenvironmentaloperatingreport1985.AB-563.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,JunoBeach.1987.FloridaPower8LightCompany,St.LuciePlantannualenvironmentaloperatingreport1986.AB-579.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,JunoBeach.Baldwin,W.P.,Jr.andJ.P.Lofton,Jr.1959.TheloggerheadturtlesofCapeRomain,SouthCarolina.PreviouslyunpublishedmanuscriptabridgedandannotatedbyD.K.Caldwell,withouttheauthors.InD.K.CaldwellandA.Carr,coordinators,TheAtlanticloggerheadseaturtle,Carettacarettacaretta(L.),inAmerica.BulletinoftheFloridaStateMuseum,BiologicalSciences,4(10):319-348.Bellmund,S.,M.T.MasnikandG.LaRoche.1982.AssessmentoftheimpactsoftheSt.Lucie2NuclearStationonthreatenedorendangeredspecies.U.S.NuclearRegulatoryCommission,OfficeofNuclearReactorRegulation.Bustard,H.R.1968.Protectionforarookery:Bundabergseaturtles.WildlifeinAustralia5:43-44.Bustard,H.R.andP.Greenham.1968.Physicalandchemicalfactorsaffectinghatchinginthegreenseaturtle,Chelnnia~mdas(L.).Ecology49(2):269-276.53 LITERATURECITED(continued)Caldwell,D.K.1962.CommentsonthenestingbehaviorofAtlanticloggerheadseaturtles,basedprimarilyontaggingreturns.quarterlyJournaloftheFloridaAcademyofSciences25(4):287-302.Caldwell,D.K.,A.CarrandL.H.Ogren.1959.NestingandmigrationoftheAtlanticloggerheadturtle.InD.K.CaldwellandA.Carr,coor-dinators,TheAtlanticloggerheadseaturtleCarettacarettacaretta(L.),inAmerica.BulletinoftheFloridaStateMuseum,BiologicalSciences,4(10):295-308.Camp,D.K.,N.W.WhitingandR.E.Martin.1977.Nearshoremarineeco-logyatHutchinsonIsland,Florida:1971-1974.V.Arthropods.FloridaMarineResearchPublications25:1-63.Carr,A.,A.Meylan,J.Mortimer,K.BjorndalandT.Carr.1982.SurveysofseaturtlepopulationsandhabitatsintheWesternAtlantic.NOAATechnicalMemorandumNMFS-SEFC-91:1-82.Carr,A.,L.OgrenandC.McVea.1981.ApparenthibernationbytheAtlanticloggerheadturtleCarettacarettaoffCapeCanaveral,~~~~~~~Florida.BiologicalConservat>on19:7-14.Davis,G.E.,andM.C.Whiting.1977.LoggerheadseaturtlenestinginEvergladesNationalPark,Florida,U.S.A.Herpetologica33:18-28.Diamond,A.W.1976.BreedingbiologyandconservationofHawksbil1L.,CiI1,Syh11BiologicalConservation9:199-215.Ehrhart,L.M.1979.Reproductivecharacteristicsandmanagementpoten-tialoftheseaturtlerookeryatCanaveralNationalSeashore,Florida.Pages397-399inLinn,R.M.,ed.ProceedingsoftheFirstConferenceonScientificResearchintheNationalParks,9-12November,1976,NewOrleans,La.NPSTrans.andProc.SereNo.5.Ernest,R.G.,R.E.Martin,B.D.Peery,D.G.Strom,J.R.WilcoxandN.W.Walls.InPress.Seaturtleentrapmentatacoastalpowerplant.ProceedingsofSoutheasternWorkshoponAquaticEcologicalEffectsofPowerGeneration,3-5December,1986,Sarasota,Florida.Fowler,L.E.1979.Hatchingsuccessandnestpredationinthegreenseaturtle,Chelonia~mdasatTortuguero,CostaRica.Ecology60(5):945-955.Frair,W.1977.Turtleredbloodcel1packedvolumes,sizes,andnumbers.Herpetologica33:167-190.54 | |||
LITERATURECITED(continued)Futch,C.R.andS.E.Dwinel1.1977.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.IV.LanceletsandFishes.FloridaMarineResearchPublications24:1-23.Gallagher,R.M.1977.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.II.Sediments.FloridaMarineResearchPublications23:6-24.Gallagher,R.M.andM.L.Hollinger.1977.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.I.Introductionandrationale.FloridaMarineResearchPublications23:1-5.Gallagher,R.M.,M.L.Hollinger,R.M.IngleandC.R.Futch.1972.MarineturtlenestingonHutchinsonIsland,Floridain1971.FloridaDepartmentofNaturalResources,SpecialScientificReport37:1-11.Hendrickson,J.R.andE.Balasingam.1966.Nestingbeachpreferencesof.Malayanseaturtles.BulletinoftheNationalMuseumSingapore33(10):69-76.~~~~~~~~~Hi11estad,H.O.,J.I.Richardson,C.McYea,Jr.andJ.M.Watson,Jr.1982.Worldwideincidentalcaptureofseaturtles.Pages489-496inBjorndal,K.A.,ed.Biologyandconservationofseaturtles.SmithsonianInstitutionPress,Washington,D.C.Hirth,H.F.1980.Someaspectsofthenestingbehaviorandreproductivebiologyofseaturtles.AmericanZoologist20:507-523.Hopkins,S.R.,T.M.Murphy,Jr.,K.B.StansellandP.M.Wilkinson.1979.BioticandabioticfactorsaffectingnestmortalityintheAtlanticloggerheadturtle.ProceedingsAnnualConferenceofSoutheasternFishandWildlifeAgencies32:213-223.Hughes,G.R.1974.TheseaturtlesofsoutheastAfrica,1.Status,morphologyanddistribution's.SouthAfricanAssociationforMarineBiologicalResearch,OceanographicResearchInstitute,InvestigationalReportNo.35:1-144.1976.IrregularreproductivecyclesintheTongalandloggerheadseaturtle,Carettacaretta(L.)(Cryptodira:Chelonidae).ZoologicaAfricana11I2~285-291.Martin,R.E.,R.G.Ernest,N.W.WallsandJ.R.Wilcox.InPress.SizedistributionandseasonalabundanceofloggerheadandgreenturtlesinnearshorewatersoffHutchinsonIsland,Florida;Posterabstract.InProceedingsofSecondWesternAtlanticTurtleSymposium.Hayaguez,PuertoRico,12-16October1987.55 | |||
LITERATURECITED(continued)Mendonca,M.T.andL.M.Ehrhart.1982.Activity,populationsizeandstructureoftheimmatureChelonia~mdasandCarettacarettainMosquitoLagoon,Florida.Copeia1982:161-167.Moffler,M.D.andJ.F.VanBreedveld.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.X.Benthicalgaespecieslist.FloridaMarineResearchPublications34:118-122.Mortimer,J.A.1982.Factorsinfluencingbeachselectionbynestingseaturtles.Pages45-51inBjorndal,K.A.,ed.Biologyandconserva-tionofseaturtles.SmithsonianInstitutionPress.Washington,D.C.NMFS(NationalMarineFisheriesService).1978.FinalEISlistingandprotectingthegreenseaturtle(Chelonia~mdas),loggerheadseaturtle(Carettacaretta)andtilepac>f>cR>dleyseaturtle(Leidochelsoliv~aceaundertheEndangeredSpeciesActof1973.Rat>onemarinefssheriesService,Dept.ofCommerce,iiashington,D.C.NRC(U.S.NuclearRegulatoryCommission).1982.FinalenvironmentalstatementrelatedtotheoperationofSt.LuciePlantUnit2.DocketNo.50-389.O'ara,J.1980.Thermalinfluencesontheswimmingspeedofloggerheadturtlehatchlings.Copeia1980(4):773-780.Ogren,L.andC.McVea,Jr.1982.ApparenthibernationbyseaturtlesinNorthAmericanwaters.Pages127-132inBjorndal,K.A.,ed.Biologyandconservationofseaturtles.SmithsonianInstitutionPress,Washington,D.C.Owens,D.W.,J.R.Hendrickson,V.LanceandI.P.Cal1ard.1978.AtechniquefordeterminingsexofimmatureChelonia~mdasusingaradioimmunoassay.Herpetologica34:270-273.Owens,D.W.andG.J.Ruiz.1980.Newmethodsofobtainingbloodandcerebrospinalfluidfrommarineturtles.Herpetologica36:17-20.Pritchard,P.C.,P.R.Bacon,F.H.Berry,A.F.Carr,J.Fletemeyer,R.M.Gallagher,S.R.Hopkins,R.R.Lankford,R.MarquesM.,L.H.Ogren,W.G.Pringle,Jr.,H.A.ReichartandR.Witham.1983.Manualofseaturtleresearchandconservationtechniques.PreparedfortheWesternAtlanticTurtleSymposium,SanJose,CostaRica,July1983.126pp.Proffitt,C.E.,R.E.Martin,R.G.Ernest,B.J.Graunke,S.E.LeCroy,K.A.Muldoon,B.D.Peery,J.R.WilcoxandN.Williams-Walls.1986.Effectsofpowerplantconstructionandoperationonthenestingofthe1oggerheadseaturtle(Carettacaretta):1971-1984.Copeia1986(3):813-816. | |||
LITERATURECITED(continued)Raymond,P.W.1984.TheeffectsofbeachrestorationonmarineturtlesnestinginsouthBrevardCounty,Florida.M.S.thesis,UniversityofCentralFlorida.Routa,R.A.1968.SeaturtlenestsurveyofHutchinsonIsland,Florida.quarterlyJournalFloridaAcademyofSciences30(4):287-294.Schulz,J.'P.1975.SeaturtlesnestinginSurinam.ZoologischeVerhandelingen,uitgegevendoorhetRijksmuseumvanNatuurlijkeHistoricteLeiden,No.143:1-144.Smith,N.P.1982.UpwellinginAtlanticshelfwatersofsouthFlorida.FloridaScientist45(2):125-138.Sokal,R.R.andF.J.Rohlf.1981.Biometry.Theprinciplesandprac-ticeofstatisticsinbiologicalresearch.W.H.FreemanandCompany,SanFrancisco.859pp.Stancyk,S.E.1982.Non-humanpredatorsofseaturtlesandtheircon-trol.Pages139-152inBjorndal,K.A.,ed.Biologyandconserva-tionofseaturtles.SmithsonianInstitutionPress.Washington,D.C.Talbert,O.R.,S.E.Stancyk,J.M.DeanandJ.M.Will.1980.Nestingactivityoftheloggerheadturtle(Carettacaretta)inSouthCarolina.I:Arookeryintransition.Copeia1980:709-718.Taylor,C.B.,andH.B.Stewart.1958.SummerupwellingalongtheeastcoastofFlorida.JournalofGeophysicalResearch64(1):33-40.Tester,L.A.andK.A.Ste'idinger.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.VII.Phytoplankton,1971-1973.FloridaMarineResearchPublications34:16-61.Walker,'.M.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.IX.Dielplankton,1973-1974.FloridaMarineResearchPublications34:99-117.Walker,L.M.,B.M.GlassandB.S.Roberts.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.VIII.Zooplankton,1971-1973.FloridaMarineResearchPublications34:62-98.Walker,L.M.'andK.A.Steidi,nger.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.VI.Planktondynamics,1971-1973.FloridaMarineResearchPublications34:1-15. | |||
LITERATURECITED(continued)Wibbels,T.,D.Owens,Y.MorrisandM.Amoss.1984.SexratiosofimmatureloggerheadseaturtlescapturedalongtheAtlanticcoastoftheUnitedStates.FinalReporttotheNationalMarineFisheriesService.,ContractNo.NA81-GA-C-0039.47pp.Williams-Walls,N.,J.O'ara,R.M.Gallagher,D.F.Worth,B.D.PeeryandJ.R.Wi1cox.1983.SpatialandtemporaltrendsofseaturtlenestingonHutchinsonIsland,Florida,1971-1979.BulletinofMarineScience33(1):55-66.Witherington,B.E.andL.M.Ehrhart.InPress.Statusandreproductivecharacteristicsofgreenturtles(Chelonia~mdas)nestinginFlorida.Posterabstract.InProceedingsofSecondWesternAtlanticTurtleSymposium.Mayaguez,PuertoRico,12-16October1987.Worth,D.F.andM.L.Hollinger.1977.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.III.Physicalandchemicalenvironment.FloridaMarineResearchPublications23:25-85.Worth,D.F.,andJ.B.Smith.1976.MarineturtlenestingonHutchinsonIsland,Florida,in1973.FloridaMarineResearch.Publications18:1-17.58 | |||
GULFOFMEXICO0dOOVASSSKILOMDERSSCALE~~-N-St.LuciePlantFigure1.LocationoftheSt.LuciePlant. | |||
l gegI~~P,::HUTCHINSONV\h~'La7~~V~OdVgH~ISLANDC~'I~tqP~'DISCHARGE@G'.:PIPES~qS'i.0v'9INTAKE'<:.INTAKE0+HEADWALL',WELLSINTAKESTRUCTURESINTRUSIONBARRIER:BARRIER,.NET;7";;':.':S',,Cl'vINTAKECANAL0250500METERS~~rFigure2.St.LuciePlantcoolingwaterintakeanddischargesystem. | |||
L1 "i0'e~~'tPierceInletAAlgQQbb,eC7EaStateHwyA'0eH23LMN40FPLpSTLUCIEPLANTU.S.HwyI~n1eg4I0SkmR(VE,Rw/6YzQBBCCDDEE8FFHHGG~\ped1>.':e9~~St.LucleInletFigure3.Designationandlocationofnine1.25-kmsegmentsand~~~~~~thirty-six1-kmsegmentssurveyedforseaturtlenesting,HutchinsonIsland,1971-1987. | |||
3000329250z0200z15010050123456789NORTHPOWERPLANTSOUTHFigure4.Heanannualnumberofloggerheadturtlenestsineachofthenine1.25-km-longsurveyareas,HutchinsonIsland,1971-1986,comparedwithnumberofnestsduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values(1980datawereexcludedbecausenotallareasweresurveyed). | |||
0300250200R150Dz10050ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJABCDEFGHIJNORTH0POWERPLANTSOUTHFigure5.Heanannualnumberofloggerheadturtlenestsineachofthethirty-six1-km--longsurveyareas,HutchinsonIsland,1981-1986,comparedwithnumberofnestsduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values. | |||
500g)400Oz300200100NORTHABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJABCDEFGHIJPOWERPLANTSOUTHFigure6.Heanannualnumberofloggerheadturtleemergencesineachofthethirty-six1-km-longsurveyareas,HutchinsonIsland,1981-1986,comparedwithnumberofemergencesduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values. | |||
10080g(0COUJOOg60C9Z(0I-IIJz4020ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJABCDEFGHIJNORTHf'OWERPLANTSOUTHFigure7.Neanannualloggerheadturtlenestingsuccess(percentageofemergencesthatresultedinnests)foreachofthethirty-six1-km-longsurveyareas,HutchinsonIsland,1981-1986,comparedw'ithnestingsuccessduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values' | |||
250o~Area4(PowerPlantSite)X--XArea5(ControlSite)200z150z100~XXX////XXx~N<x/K///X5071737577798081828384858687Figure8.NumberofloggerheadturtlenestsinAreas4and5,HutchinsonIsland,1971-1987.Arrowsdenoteyearsduringwhichintake/dischargeconstructionoccurredinArea4. | |||
COI-COzDz50004000300020001000o10000z8000600040002000gCOCOLljOODCO(9zI-COUj8060402019811982198319841985198619879.Annualnumberofnests,numberofemergencesandnestingsuccessalongtheentire36.0-km-longAtlanticcoastlineofHutchinsonIsland,1981-1987. | |||
~OujKDI-IZIllQ.ILjI-2826242220906030015305APR1530515305153051530515MAYJUNJULAUGSEPFigure10.Dailyloggerheadturtlenestingactivityandwatertemperature,HutchinsonIsland,1987. | |||
50ALLAREASAREA150AREA250AREA3500-0W'o)50I-COLLIZAREA4AREA550I-Z50AREA650AREA750AREA8AREA9501971197319751977197919801981198219831984198519861987Figure11.Percentageofloggerheadturtlenestsdestroyedbyraccoonsinthenine1.25-km-longsurveyareas,HutchinsonIsland,1971-1987. | |||
QDestroyedbyghostcrabsgDestroyedbyraccoonsandghostcrabsDestroyedbyraccoons50CIg40CO30z20z2?%1001%1%1%1A-BCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJABCDEFGHIJNORTH0POWERPLANTSOUTHFigure12.Numberofloggerheadturtlenestsdes'troyedbyraccoonsandghostcrabsandpercentageofnestsdestroyedineach1-km-longsurveyarea,HutchinsonIsland,1987. | |||
60co45Zm30Z15p---pGreen(Cheloniamydas)8-+9Leatherback(Dermochelyscoriacea)rrpW-/Fs/Ii/I/I//I/Ix/~/IIIIIIIIIII19711973197519771979198119821983.1984198519861987Figure13.Numberofgreenturtleandleatherbackturtlenests,HutchinsonIsland,1971-1987. | |||
~, | |||
200~LOGGERHEAD(Carettacaretta)0---E3GREEN(Chelcniamidas)80175I-0150O125(901007550Z25I///0/I/I0////0x/0--000I)I5/\00070M6055040030.gD2010197619771978197919801981198219831984198519861987Figure14.Numberofloggerheadandgreenturtlesremovedeachyearfromtheintakecanal,St.LuciePlant,1976-1987. | |||
5050Pv40030mZZ204030201010JANFEBMARAPRMAYJUNJULAUG.SEPOCTNOVDECMONTHOFCAPTUREFigure16.Heannumberofloggerheadscapturedeachmonth,St.LuciePlantintakecanal,1977-1986,comparedwithnumberofmonthlycapturesduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values. | |||
300200DO00z0KILJKlz100200.100c4041-4546-5051-5556-6061-6566-7071-7576-8081-8586-9091-9596-101-106-111-116-100105110115120STRAIGHTLINECARAPACELENGTH(cm)Figure16.Lengthdistribution(SLCL)ofliveloggerheadseaturtles(N=1,278)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1987. | |||
18018016016014O0120Oz100Km8OD60140120100806040402020~2021-3031-4041-5051-6061-7071-8081-9091-100WEIGHT(Ibs)101-151-201-251-301-5350150200250300350figure17.Weightdistributionofliveloggerheadseaturtles(N=1,140)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1987. | |||
8080COD060CIz0KlU40z60402020-1516-21-26-31-36-41-46-51-56-61-66-71-76-81-86-91-96-101-106-11120253035404550556065707580'859095100105110115STRAIGHTLINECARAPACELENGTH(cm)Figure18.Lengthdistribution(SLCL)oflivegreenturtles(N=209)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1987. | |||
125125~100D00750K03D50.10075502525s1011-2021-3031-4041-5051-6061-7071-8081-9091-100WEIGHT(Ibs)101-151-201-251-i300150200250300Figure19.Weightdistributionoflivegreenturtles(N=205)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1987. | |||
'-'-.MALESFEMALES4040MDO30Clz0KujK20Dz30201010JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECMONTHOFCAPTUREFigure20.Numbersofadultloggerheads(N=202),includingrecaptures,removedeachmonthfromtheintakecanal,St.LuciePlant,1976-1987. | |||
400-0CANALCAPTURES300OKDOCOI-DO0KIDzDZZ3020100--~NESTS0Z'25PZ15075197619771978197919801981198219831984198519861987Figure21.Comparisonofcapturesofadultfemaleloggerheadsintheintakecanal,St.LuciePlant,1976-1987,andnumbersofloggerheadnestsinArea4adjacenttotheplant.Nonestingdatawerecollectedin1976and1978. | |||
80z0.60)I-DDo4020/0//r00//0III0I0II0III0III0III0/J~0-----oIntervalbetweensuccessivecapturesIntervalbetweenfirstandlastcapture.806040201002003004005006007008009001000110012001300RECAPTUREINTERVAL(days)Figure22.Cumulativepercentageofallloggerheadrecapturesoccurringwithinvarioustimeintervalsbetweensuccessivecaptures(N=77)andfirstandlastcapture(N=45),St.LuciePlantintakecanal,1976-1987. | |||
ESTIMATESOFTHENUMBERSOFLOGGERHEADTURTLENESTSONHUTCHINSONISLANDBASEDONSURVEYSOFNINE1.25-KM-LONGSURVEYAREAS,1971-1987,COMPAREDTOTHEACTUALNUMBEROFNESTSONTHEISLAND,1981-1987Year197119731975197719791981198219831984198519861987Numberofnestsinthenine1.25-km-longsurveyareas14201260149393214491031163415921439162318391645Extrapolationfromthenine418937174404274942753041482046964245478854254853surveyareastotheentireisland(seetext)Actualnumberofnestsontheentireisland3115469047434277487754834623 T2TOTALNUMBEROFSEATURTLEURESAND(NUMBEROFDEAD)TURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT1976-1987Year1976197719781979198019811982198319841985loerhead33(4)8o(s)138(19)173(13)116(5)62(s)101(16)119(4)148(3)157(4)Seciesreenleatherbacks(2)6(1)3(1)1O(3)32(2)23(4)69(2)14hawksbillKem'sridleTotal33(4)86(7)148(20)176(14)126(8)97(7)110(16)142(8)22O(S)172(4)19861987195(27)175(11)22(1)35Total1497(116)227(16)8(o)6(o)6(2)10(2)220(28)218(13)1748(134)AnnualMeana133.120.60.70.50.9158.9aExcludes1976(partialyearofplantoperation). | |||
TABLETOTALNUMBERAND(NUMBEROFD0)LOGGERHEADTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT1976-1987Month19761977197819791980198119821983JanuaryFebruary131924(3)1611(1)6(2)398(1)11(2)29(1)21(2)11(3)1113(1)MarchAprilMay727(2)11145(2)19(5)17213(1)0761411014617(4)June05103(1)8(3)677(1)July7(1)4027(2)017August231217(2)12September115(l)18(1)19OctoberNovemberDecember9541079(1)17(2)15(3)75(3)515(7)12462(1)62(1)9(1)8(2)09(5)1704(2)531(1)12Total33(4)80(5)138(19)173(13)116(5)62(5)101(16)119(4) | |||
TABL(continued)TOTALNUMBERAND(NUMBEROFDEAD)LOGGERHEADTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT1976-1987Month1984198519861987TotalMonthlyPercentofMeanTotalCatchaJanuaryFebruaryMarchApril111516(4)11157(14)14.362014(4)8(1)128(7)11.62(1)1320(2)24(3)124(13)11.3131115(2)26(3)193(11)17.513.210.78.78.5May7161223(1)98(6)8.26.6JuneJulyAugustSeptemberOctoberNovemberDecemberTotal16149(4)10711(2)938210106(10)8.8112(13)9.375(12)6.381(1)6.7148(3)157(4)195(27)175(11)1497(116)28(1)1720(1)26(1)137(8)11.412(1)20(3)26(2)19(1)130(10)10.82619(1)34(6)17(1)156(11)13.09.48.410.57.27.24.84.9aExcludes1976(partialyearofplantoperation). | |||
TOTALNUMBERAND(NUMBEROFDEAD)GREENTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT1976-1987MonthJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember197619771978197919801981210020(1)2(1)215(1)70204(1)1(1)01(1)001(1)02(1)198219838(1)3(2)4(1)Total5(2)6(1)3(1)10(3)32(2)23(4) | |||
TA4(continued)TOTALNUMBERAND(NUMBEROFDEAD)GREENTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT1976-1987MonthJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember1011116(1)34(1)198419851986198737(l)414Total78(3)34(2)20(4)13(2)4(1)10(1)9(1)1018(2)19MonthlyMean7.13.11.81.20.30.80.60.70.40.81.51.6PercentofTotalCatch34.415.08.85.71.84.43.14.02.2447.98.4Total69(2)1422(1)35227(16) | |||
NUMBEROFMONTHLYCAPTURESBYSIZECLASSFORLIVELOGGERHEADTURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT1976-1987aMonthSizeclassesSLCLincmJuveniles/Sub-AdultsTransitionAdults41-5051-6061-70TotalPercentae71-80Percentae81-9091-100>100TotalPercentaeJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember3419363172214323631474591478615112075143101103637839342366443338023431676434190239317214.612.010.18.36.68.06.79.07.27.24.36.3221416161010181513.78.710.010.05.06.36.311.35.69.48.75.0232210200030105010115213162113020101435403614125.41.61.63.37.619.021.719.67.66.53.32.7Total76504424100474.516011.911661718413.6aNodatawerecollectedfor33individuals. | |||
T6RELATIVECONDITIONSEATURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT1976-1987RelativeconditionLoerheadsNumberGreensNumberkNumberXNumberHawksbillsNumberAllseciesNumberTOTAL26017.434022.743829.325817.2765.11167.790.614976830.03917.27231.72310.162.6167.031.3227675.0112.522033011011022010112.5110466.633419.1116.638221.9116.652029.728316.2834.71347.7120.717481Excellent-normalorabovenormalweight,active,veryfewornobarnaclesorleeches,nowounds.2Verygood-intermediategoodtoexcellent.3Good-normalweight,active,lighttomediumcoverageofbarnaclesand/orleeches,woundsabsent,healedordonotappeartodebilitatetheanimal.4Fair5Poor-intermediatepoortogood.-emaciated,sloworinactive,heavybarnaclecoverageand/orleechinfestation,debilitatingwoundsormissingappendages.6Dead7Alivebutconditionotherwiseunknown. | |||
}} | }} | ||
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FLORIDAPOWER8LIGHTCOMPANYST.LUCIEUNITNO.2ANNUALENVIRONMENTALREPORT(FPL-87)APRIL1988gp-887>i~><>~g~gczoig5Coo.NI@t;,jii~A24W6fOocumea4g",6JV<jOR7OXRH7%4P~O+NfeSa+88050301858889k&'DRADGCK05000389'RDCD 1
FLORIDAPOWER8LIGHTCOMPANYST.LUCIEUNITNO.2ANNUALENVIRONMENTALREPORT(FPL-87)APRIL1988
~e~ClIll Page1of4ANNUALENVIRONMENTALREPORTIntroductionTheSt.LuciePlantUnit2EnvironmentalProtectionPlan(EPP)requiresthesubmittalofanannualreportforvariousactivitiesattheplantsiteincludingthereportingonseaturtlemonitoringprograms,andothermattersrelatedtoFederalandStateenvironmentalpermitsandcertifications.Thisreportfulfillsthesereportingrequirements.II.SeaTurtleMonitoringandAssociatedActivitiesAquaticandterrestrialseaturtlemonitoringprogramstosatisfySections4.2.1(BeachNestingSurveys),4.2.3(StudiestoEvaluateand/orMitigateIntakeCanalMortality)and4.2.5(CaptureandReleaseProgram)isconcurrentlysubmittedinaseparatereport(AB-595)preparedbyAppliedBiology,Inc.Studiestoevaluateand/ormitigateintakeentrapmentrequiredbySection4.2.2oftheEPPhavebeenpreviouslyperformed.AfinalreportwassubmittedtotheOfficeofNuclearReactorRegulationonApril18,1985.Withsubmittalofthatreport,theEPPrequirementwasfulfilledandwillnotbereaddressedinthisorfuturereports.
III Page2of4FPLwillrequestmodificationofcertainsectionsoftheEnvironmentalProtectionPlanrelatedtoseaturtleprograms,toreflectimplementationandsatisfactionofthoserequirementswhichhavebeencompletedasdescribedabove.RequirementsforreportingonthestatusofalightscreentominimizeturtledisorientationasrequiredbySection4.2.4oftheEPPisongoing.TheAustralianPinelightscreen,locatedonthebeachdunebetweenthepowerplantandtheocean,isroutinelysurveyedtodetermineitsoverallvitality.Thetreelineissurveyedforanygapsoccurringfromtreemortalitywhichwouldresultinunacceptablelightlevelsonthebeach.Treesarereplacedasnecessarytomaintaintheintegrityoftheoveralllightscreen.III.OtherRoutineReportsThefollowingitemsforwhichreportingisrequiredarelistedbysectionnumberfromtheEnvironmentalProtectionPlan(EPP):5.4,.1(a)EPPNONCOMPLIANCESANDCORRECTIVEACTIONSTAKENNononcompliancesunderEPPSection5.4.1(a)weredeterminedtohaveoccurredduring1987.
Page3of4541(b)STATIONDESIGNANDOPERATIONCHANGESgTESTSgANDEXPERIMENTSAFFECTINGTHEENVIRONMENTNoplantsiteactivitiesweredeterminedtobereportableunderSection5.4.1(b)during1987.5.4.1(c)NONROUTINEREPORTSSUBMITTEDTOTHENRCFORTHEYEAR1987INACCORDANCEWITHEPPSUBSECTION5.4.2:1.ReportconcerninganoverflowfromtheSt.LucieUnit1SewageTreatmentPlantreportedtoEPAonFebruary24,1987andtheNRConMarch18,1987.2.ReportconcerningreceiptofthefinalNPDESPermitfortheSt.LuciePlant.(TheStateofFlorida401CertificationandtheStateofFloridaSiteCertificationforSt.LucieUnit2areattachmentstotheNPDESPermit.)PermiteffectivedateSeptember30,1987.ThefollowingreportsweresubmittedtotheNRCforinformationalpurposesalthoughnotrequiredunderprovisionsof5.4.2:1.Reportconcerninganexceedanceofthemaximumtemperaturedifference(dT)fortheSt.LucieUnits Cl Page4of41and2oncethroughcoolingwatersystemwhichwasreportedtotheEPAonFebruary25,1987andtotheNRConMarch18,1987.2.SeaturtleactivitiesquarterlyreportdatedApril2,1987forthefirstquarter1987.3.SeaturtleactivitiesquarterlyreportdatedJuly8,1987forthesecondquarter1987.4.SeaturtleactivitiesquarterlyreportdatedOctober6,1987forthethirdquarter1987.5.SeaturtleactivitiesreportdatedJanuary5,1988forthefourthquarter1987.
APPLIEDBIOLOGY,INC.AB-595FLORIDAPOWER8LIGHTCOMPANYST.LUCIEUNIT2ANNUALENVIRONMENTALOPERATINGREPORT198702968ANORTHDECATURROAD~ATLANTA,GEORGIA30033~404-296-3900) 0 AB-595FLORIDAPOWER5LIGHTCOMPANYST.LUCIEUNIT2ANNUALENVIRONMENTALOPERATINGREPORT1987APRIL1988FLORIDAPOWER5LIGHTCOMPANYJUNOBEACH,FLORIDAAPPLIEDBIOLOGY,INC.ATLANTA,GEORGIA
~i'f/Itlt ENVIRONMENTALOPERATINGREPORTTABLEOFCONTENTSTABLEOFCONVERSIONFACTORSFORMETRICUNITSEXECUTIVESUMMARYIntroductionTurtleNestingSurveyIntakeCanalMonitoring-OtherRelatedActivitiesINTRODUCTION-BackgroundAreaDescription--PlantDescription~Pae1v1v1VvvTURTLESIntroductionIMaterialsandMethods-NestingSurveyIntakeCanalMonitoringStudiestoEvaluateand/orMitigateIntakeEntrapment----LightScreentoMinimizeTurtleDisorientation-----------ResultsandDiscussionNestingSurveyDistributionofLoggerheadNestsAlongHutchinsonIslandNumberofNestsandLoggerheadPopulationEstimates---TemporalLoggerheadNestingPatternsPredationonLoggerheadTurtleNestsGreenandLeatherbackTurtleNestingIntakeCanalMonitoringSpeciesNumberandTemporalDistribution-Size-ClassDistributions-SexRatios-CaptureEfficienciesRelativeConditionMortalitiesRecaptureIncidentsSummary-LITERATURECITEDFIGURESTABLES-11ll1316161616162325262729303234363842464752598111 TABLEOFCONVERSIONFACTORSFORMETRICUNITSToconvertcentigrade(degrees)centigrade(degrees)centimeters(cm)centimeters(cm)centimeters/second(cm/sec)cubiccentimeters(cm3)grams(g)grams(g)hectares(ha)kilograms(kg)kilograms(kg)kilograms(kg)kilometers(km)kilometers(km)liters(1)liters(1)meters(m)meters(m)meters(m)microns(9)milligrams(mg)milligrams/liter(mg/1)milliliters(ml)millimeters(mm)millimeters(mm)squarecentimeters(cm2)squaremeters(m2)squaremillimeters(mm2)Multiplyby)(Cx1.8)+32C+273.18,3.937x103.281x10"3.281x101.0x102.205x103.527x10"2.4711.0x1032.20463.5274x1016.214x10-11.0x1061.0x102.642x103.2813.937x10l.0941.0x1061.0x10"31.01.0x103.937x10"23.281x101.550x101.076x101.55x10Toobtainfahrenheit(degrees)kelvin(degrees)inchesfeetfeetpersecondliterspoundsounces(avoirdupois)acresgramspoundsounces(avoirdupois)miles(statute)mi11imeterscubiccentimeters(cm3)gallons(U.S.liquid)feetinchesyardsmetersgramspartspermi11ionliters(U.S.liquid)inchesfeetsquareinchessquarefeetsquareinches
EXECUTIVESUMMARYINTRODUCTIONTheSt.LuciePlantisanelectricgeneratingstationonHutchinsonIslandinSt.LucieCounty,Florida.Theplantconsistsoftwonuclear-fueled850-MWunits;Unit1wasplacedon-lineinMarch1976andUnit2inMay1983.ThisdocumenthasbeenpreparedtosatisfytherequirementscontainedintheUnitedStatesNuclearRegulatoryCommission'sAppendix8EnvironmentalProtectionPlan(EPP)toSt.LucieUnit2FacilityOperatingLicenseNo.NPF-16.Thisreportdiscussesenvironmentalpro-tectionactivitiesrelatedtoseaturtlesasrequiredbySubsection4.2oftheEPP.TURTLENESTINGSURVEYTherehavebeenconsiderableyear-to-yearfluctuationsinseaturtlenestingactivityonHutchinsonIslandsincemonitoringbeganin1971.Lownestingactivityin1975and1981-1983inthevicinityofthepowerplantwasattributedtoconstructionofplantintakeanddischargestruc-tures.Nestingreturnedtonormalorabovenormallevelsfollowingbothperiodsofconstruction.Powerplantoperationexclusiveofconstructionhashadnosignificanteffectonnestingneartheplant.Datacollectedthrough1987haveshownnolong-termreductionsintotalnesting,totalemergencesornestingsuccessontheisland.Formalrequirementstocon-ductthisprogramexpiredin1986butwerevoluntarilycontinuedin1987withagreementfromfederalandstateagencies.
0 INTAKECANALMONITORINGSinceplantoperationbeganin1976,1,748seaturtles(including79recaptures)representingfivedifferentspecieshavebeenremovedfromtheintakecanal.Eighty-sixpercentofthesewereloggerheads.Differencesinthenumbersofturt'lesfoundduringdifferentmonthsandyearswereattribute'dtonaturalvariationintheoccurrencesofturtlesinthevicinityoftheplant,ratherthantoanyinfluenceoftheplantitself.Themajority(about92percent)oftheturtlesremovedfromtheintakecanalwerecapturedaliveandreleasedbackintotheocean.TurtlesconfinedbetweentheA1Abarriernetandintakeheadwallsusuallyresidedinthecanalforarelativelyshortperiodoftime,andmostwereingoodtoexcellentconditionwhencaught.Drowningwasthoughttoberesponsibleformostrecentcanalmortalitiesandappropriatemeasures,includingtheinstallationofanewbarriernet,weretakentominimizefuturemortalities.OTHERRELATEDACTIVITIESTheintegrityofavegetativelightscreenalongthedunelineattheSt.LuciePlantisassessedonacontinuingbasis.During1987,routineinspectionsofthescreenweremadeandreplantingsconductedasneeded.Studiestoevaluatevariousintakedeterrentsystems,asrequiredbytheNRC'sUnit2EnvironmentalProtectionPlan,wereconductedduring1982,and1983.Resultsandevaluationsofthosestudieswerepresentedtoregulatoryagenciesduring1984,andtherequirementisnowconsideredcompleted.
INTRODUCTIONBACKGROUNDThisdocumenthasbeenpreparedtosatisfytherequirementscon-tainedintheUnitedStatesNuclearRegulatoryCommission's(NRC)AppendixBEnvironmentalProtectionPlantoSt.LucieUnit2FacilityOperatingLicenseNo.NPF-16.In1970,FloridaPower5LightCompany(FPL)wasissuedPermitNo.CPPR-74bytheUnitedStatesAtomicEnergyCommission,nowtheNuclearRegulatoryCommission,thatallowedconstructionofUnit1oftheSt.LuciePlant,an850-HWnuclear-poweredelectricgeneratingstationonHutchinsonIslandinSt.LucieCounty,Florida.St.LuciePlantUnit1wasplacedon-lineinHarch1976.InHay1977,FPLwasissuedPermitNo.CPPR-144bytheNRCfortheconstructionofasecond850-HWnuclear-poweredunit.Unit2wasplacedon-lineinHay1983andbegancommercialoperationinAugustofthatyear.St.LuciePlantUnits1and2usetheAtlanticOceanasasourceofwaterforonce-throughcondensercooling.Since1971,thepotentialenvironmentaleffectsresultingfromtheintakeanddischargeofthiswaterhavebeenthesubjectofFPL-sponsoredbioticstudiesatthesite.
BaselineenvironmentalstudiesofthemarineenvironmentadjacenttotheSt.LuciePlantweredescribedinaseriesofreportspublishedbytheFloridaDepartmentofNaturalResources(Campetal.,1977;FutchandDwinell,1977;Gallagher,1977;GallagherandHollinger,1977;WorthandHollinger,1977;MofflerandVanBreedveld,1979;TesterandSteidinger,1979;Walker1979;Walkeretal.,1979;WalkerandSteidinger,1979).TheresultsofUnit1operationalandUnit2preoperationalbioticmoni-toringattheSt.~LuciePlantwerepresentedinsixannualreports(ABI,1977,1978,1979,1980a,1981b,1982).InJanuary1982,aNationalPollutantDischargeEliminationSystem(NPDES)permitwasissuedtoFPLbytheU.S.EnvironmentalProtectionAgency(EPA).TheEPAguidelinesfortheSt.Luciesitebiologicalstudieswerebasedonthedocumententitled"ProposedSt.LuciePlantPreoperationalandOperationalBiologicalMonitoringProgram-August1981"(ABI,198lc).Findingsfromthesestudieswerereportedinthreeannualreports(ABI,1983,1984a,1985a).TheEPAbioticmonitoringrequirementsweredeletedfromtheNPDESpermitin1985.JurisdictionforseaturtlestudiesiswiththeNRC,whichiscon-sideredtobetheleadfederalagencyrelativetoconsultationundertheEndangeredSpeciesAct.Previousresultsdealingexclusivelywithseaturtlestudiesarecontainedinfourenvironmentaloperatingreports(ABI,1984b,1985b,1986,1987).Thisreportdescribesthe1987environ-mentalprotectionactivitiesrelatedtoseaturtles,asrequiredbySubsection4.2oftheSt.LuciePlantUnit2EnvironmentalProtectionPlan.
AREADESCRIPTIONTheSt.LuciePlantislocatedona457-hasiteonHutchinsonIslandonFlorida'seastcoast(FiguresIand2).TheplantisapproximatelymidwaybetweentheFt.PierceandSt.LucieInlets.ItisboundedonitseastsidebytheAtlanticOceanandonitswestsidebytheIndianRiverLagoon.HutchinsonIslandisabarrierislandthatextends36kmbetweeninletsandobtainsitsmaximumwidthof2kmattheplantsite.Eleva-tionsapproach5matopdunesborderingthebeachanddecreasetosealevelinthemangroveswampsthatarecommononmuchofthewesternside.IslandvegetationistypicalofsoutheasternFloridacoastalareas;densestandsofAustralianpine,palmetto,seagrapeandSpanishbayonetarepresentatthehigherelevations,andmangrovesaboundatthelowerele-vations.Largestandsofblackmangroves,includingsomeontheplantsite,havebeenki11edbyfloodingformosquitocontroloverpastdecades.TheAtlanticshorelineofHutchinsonIslandiscomposedofsandandshellhashwithintermittentrockypromontoriesprotrudingthroughthebeachfacealongthesouthernendoftheisland.Submergedcoquinoidrockformationsparallelmuchoftheislandofftheoceanbeaches.Theoceanbottomimmediatelyoffshorefromtheplantsiteconsistsprimarilyofsandandshel1sediments.Theunstablesubstratelimitstheestablishmentofrootedmacrophytes.
TheFloridaCurrent,whichflowsparalleltothecontinentalshelfmargin,beginstodivergefromthecoastlineatWestPalmBeach.AtHutchinsonIsland,thecurrentisapproximately33kmoffshore.Oceanicwaterassociatedwiththewesternboundaryofthecurrentperiodicallymeanders.overtheinnershelf,especiallyduringsummermonths.PLANTDESCRIPTIONTheSt.LuciePlantconsistsoftwo850-HWnuclear-fueledelectricgeneratingunitsthatusenearshoreoceanwatersfortheplant'soncethroughcondensercoolingwatersystem.Waterfortheplantentersthroughthreesubmergedintakestructureslocatedabout365moffshore(Figure2).Eachoftheintakestructuresisequippedwithavelocitycaptominimizefishentrainment.Horizontalintakevelocitiesarelessthan30cm/sec.Fromtheintakestructures,tliewaterpassesthroughsubmergedpipes(two3.7mandone4.9mindiameter)underthebeachanddunesthatleadtoa1500-mlongintakecanal.Thiscanaltransportsthewatertotheplant.Afterpassingthroughtheplant,theheatedwaterisdischargedintoa670-mlongcanalthatleadstotwoburieddischargepipelines.Thesepassunderneaththedunesandbeachandalongtheoceanfloortothesubmergeddischarges,thefirstofwhichisapproximately365moffshoreand730mnorthoftheintake.HeatedwaterleavesthefirstdischargelinefromaY-shapednozzle(diffuser)atadesignvelocityof396cm/sec.Thishigh-momentumjetentrainsambientwaterresultinginrapidheatdissipation.Theoceandepthintheareaofthefirstdischargeisabout6m.Heatedwater leavestheseconddischargelinethroughaseriesof48equallyspacedhighvelocityjetsalonga323-mmanifold(multiportdiffuser).Thisdiffuserstarts168mbeyondthefirstdischargeandterminates856mfromshore.Theoceandepthatdischargealongthisdiffuserisfromabout10to12m.Aswiththefirstdiffuser,thepurposeoftheseconddiffuseristoentrainambientwaterandrapidlydissipateheat.Fromthepointsofdischargeatbothdiffusers,thewarmerwaterrisestothesurfaceandformsasurfaceplumeofheatedwater.Theplumethenspreadsoutonthesurfaceoftheoceanundertheinfluenceofwindandcurrentsandtheheatdissipatestotheatmosphere.
TURTLESTheNRC'sSt.LucieUnit2AppendixBEnvironmentalProtectionPlanissuedApril1983containsthefollowingtechnicalspecifications:4.2Terrestrial/AuaticIssuesIssuesonendangeredorthreatenedseaturtlesraisedintheUnit2FES-OL[NRC,1982jandintheEndangeredSpeciesBiologicalAssessment(March1982)[Bellmundetal.,1982]willbeaddressedbyprogramsasfollows:4.2.1BeachNestinSurvesBeachnestingsurveysforallspeciesofseaturtleswillbeconductedonayearlybasisfortheperiodof1982through1986.Thesesurveyswillbecon-ductedduringthenestingseasonfromapproximatelymid-AprilthroughAugust.TheHutchinsonIslandbeachwillbedividedinto36one-km-longsurveyareas.Inaddition,thenine1.25-km-longsurveyareasusedinpreviousstudies(1971-1979)willbemaintainedforcomparisonpur-poses.Surveyareaswillbemarkedwithnumberedwoodenplaquesand/orexistinglandmarks.Theentirebeachwillbesurveyedsevendaysaweek.Allnewnestsandfalsecrawlswillbecountedandrecordedineacharea.Aftercounting,allcrawltrackswillbeobliteratedtoavoidrecounting.Predationonnestsbyraccoonsorotherpredatorswillberecordedasitoccurs.Recordswillbekeptofanyseasonalchangesinbeachtopographythatmayaffectthesuitabilityofthebeachfornesting.4.2.2StudiestoEvaluateand/orMitiateIntakeAprogramthatemployslightand/orsoundtodeterturtlesfromtheintakestructurewillbeconducted.Thestudywilldeterminewithlaboratoryandfieldexperimentsifsoundand/orlightwillresultina'reductionoftotalturtleentrapmentrate.Thestudyshallbeimplementednolaterthanafterthefinalremovalfromtheoceanofequipmentand structuresassociatedwithconstructionofthethirdintakestructureandtheexperimentsshallterminate18monthslater.Fourmonthsaftertheconclusionoftheexperimentalperiod,areportontheresultsofthestudywillbesubmittedtoNRC,EPA,NationalMarineFisheriesService(NMFS),andtheU.S.FishandWildlifeService(USFWS)fortheirevaluation.Ifastatisticallysignificantreductioninannualtotalturtleentrapmentrateof80percentorgreatercanbedemonstrated,usingthedevelopedtechnologyanduponFPLreceivingwrittencon-currencebyNRC,EPA,NMFS,andUSFWSthenpermanentinstallationofthedeterrentsystemshallbecompletedandfunctioningnolaterthanI(monthsaftertheagencies'oncurrence.Thedesignofthisstudyneedstotakeintoaccountthesignificantannualvariationinturtleentrapmentobservedinthepast.Ifan80percentreductionofturtleentrapmentcan-notbeprojectedtoallthreeintakestructures,thenaninteragencytaskforcecomposedofHRC,EPA,NMFS,USFWS,andFPLshallconvene18monthsaftercompletionofthethirdintakeanddetermineifothercoursesofactiontomitigateand/orreduceturtleentrapmentarewarranted(suchasphysicalbarrier,emergenceofnewtechnologyormethodstodeterturtles).4.2.3StudiestoEvaluateand/orMitiateIntakeAlternativemethodsorproceduresforthecaptureofseaturtlesentrappedintheintakecanalwillbeevaluated.Ifamethodorprocedureisconsideredfeasibleandcosteffectiveandmayreducecapturemortalityrates,itwillbefieldtestedintheintakecanal.4.2.4LihtScreentoMinimizeTurtleDisorienta-tion[N:1s1sasoSection4.2otheNRCSt.LucieUnit1AppendixBTechnicalSpecificationsissuedMay1982]Australianpine"orothersuitableplants(i.e.,nativevegetationsuchasliveoak,nativefigs,wildtamarindandothers)shallbeplantedandmain-tainedasalightscreen,alongthebeachdunelineborderingtheplantproperty,tominimizeturtledisorientation.
4.2.5CatureandReleaseProramSeaturtleremovalfromtheintakecanalwillbeconductedonacontinuingbasis.Theturtleswi11becapturedwithlargemeshnets,orothersuitablenondestructivedevice(s),ifdeemedappropriate.Aformalizeddailyinspection,fromtheshoreline,ofthecapturedevice(s)willbemadebyaqualifiedindividualwhenthedevice(s)aredeployed.Theturtleswillbeidentifiedtospecies,measured,weighed(ifappropriate),taggedandreleasedbackintotheocean.Recordsofwounds,freshorold,andasubjectivejudgementontheconditionoftheturtle(e.g.,barnaclecoverage,underweight)wi11bemaintained.Methodsofobtainingadditionalbiological/physiologicaldata,suchasbloodanaly-sesandparasiteloads,fromcapturedseaturtleswillbepursued.Deadseaturtleswillbesubjectedtoagrossnecropsy,iffoundinfreshcondition.INTRODUCTIONHutchinsonIsland,Florida,isanimportantrookeryfortheloggerheadturtle,Carettacaretta,andalsosupportssomenestingoftheCh1l~,dh1hkcoriacea(Caldwelletal.,1959;Routa,1968;Gallagheretal.,1972;WorthandSmith,1976;Williams-Wallsetal.,1983).Allthreespeciesareprotectedbystateandfederalstatutes.Thefederalgovernmentclassifiestheloggerheadturtleasathreatenedspecies.Theleather-backturtleandtheFloridanestingpopulationofthegreenturtlearelistedbythefederalgovernmentasendangeredspecies.Becauseofreductionsinworldpopulationsofmarineturtlesresultingfromcoastaldevelopmentandfishingpressure(NMFS,1978),maintainingthevitalityoftheHutchinsonIslandrookeryisimportant.
0jf IthasbeenaprimeconcernofFPLthattheconstructionandsub-sequentoperationoftheSt.LuciePlantwouldnotadverselyaffecttheHutchinsonIslandrookery.Becauseofthisconcern,FPLhassponsoredmonitoringofmarineturtlenestingactivityontheislandsince1971.Daytimesurveystoquantifynesting,aswellasnighttimeturtletaggingprograms,wereconductedinoddnumberedyearsfrom1971through1979.Duringdaytimenestingsurveys,nine1.25-km-longsurveyareasweremonitoredfivedaysperweek(Figure3).TheSt.LuciePlantbeganoperationin1976;therefore,thefirstthreesurveyyears(1971,1973and1975)werepreoperational.Thoughthepowerplantwasnotoperatingduring1975,St.LuciePlantUnitNo.1oceanintakeanddischargestruc-tureswereinstalledduringthatyear.Installationofthesestructuresincludedconstructionactivitiesconductedoffshorefromandperpen-diculartothebeach.Constructionhadbeencompletedandtheplantwasinfulloperationduringthe1977and1979surveys.Amodifieddaytimenestingsurveywasconductedin1980duringthepreliminaryconstructionoftheoceandischargestructureforSt.LuciePlantUnit2.Duringthisstudy,fourofthepreviouslyestablished1.25-km-longsurveyareasweremonitored.Additionally,eggsfromturtlenestspotentiallyendangeredbyconstructionactivitieswererelocated.Everyyearfrom1981through1987,thirty-six1-km-longsurveyareascomprisingtheentireislandweremonitoredsevendaysaweekduringthenestingseason(Figure3).TheSt.LuciePlantUnit2dischargestruc-turewasinstalledduringthe1981nestingseason.OffshoreandbeachconstructionoftheUnit2intakestructureproceededthroughoutthe1982nestingseasonandwascompletedneartheendofthe1983season.ConstructionactivitiesassociatedwithinstallationofbothstructuresweresimilartothoseconductedwhenUnit1intakeanddischargestruc-tureswereinstalled.Eggsfromturtlenestspotentiallyendangeredbyconstructionactivitieswererelocatedduringallthreeyears.Requirement.4.2.1oftheNRC'sSt.LucieUnit2AppendixBEnvironmentalProtectionPlanwascompletedwithsubmissionofthe1986nestingsurveydata(ABI,1987).Thenestingsurveywascontinuedvolun-tarilyin1987withagreementfromfederalandstateagencies.Resultsarepresentedinthisreportanddiscussedinrelationtopreviousfin-dings.Inadditiontomonitoringseaturtlenestingactivitiesandrelo-catingnestsawayfromplantconstructionareas,monitoringofturtlesintheintakecanalhasbeenanintegralpartoftheSt.LuciePlantenvironmentalmonitoringprogram.Turtlesenteringtheoceanintakestructuresarerapidlytransportedwithcoolingwaterthroughtheintakepipesandintotheenclosedcanalsystemwheretheyareentrapped.Sincetheplantbecameoperationalin1976,turtlesentrappedintheintakecanalhavebeencaptured,measured,taggedandreturnedalivetotheocean.10
Previouspublicationsandtechnicalreportshavepresentedfindingsofthenestingsurveys,nestrelocationactivitiesandcanalcaptureprogram(Gallagheretal.,1972;WorthandSmith,1976;ABI,1978,1980a,1981a,1982,1983,1984b,1985b,1986,1987;Williams-Wallsetal.,1983;Proffittetal.,1986;Ernestetal.,inpress;Martinetal.,inpress).Resultsofstudiestoassesstheeffectsofthermaldischargesonhatchlingswimmingspeedhavealsobeenreported(ABI,1978;O'ara,1980).Thepurposeofthisreportisto1)present1987seaturtlenestingsurveydataandsummarizeobservedspatialandtemporalnestingpatternssince1971,2)documentandsummarizepredationonturtlenestssince1971,and3)present1987canalcapturedataandsummarizerelateddatacollectedsince1976.MATERIALSANDMETHODSNestinSurveMethodologiesusedduringpreviousturtlenestingsurveysonHutchinsonIslandweredescribedbyGallagheretal.(1972),WorthandSmith(1976)andABI(1978,198la,1982,1987).Methods.usedduringthe1987surveyweredesignedtoallowcomparisonswiththesepreviousstu-dies.From16Aprilthrough29April1987,eightpreliminarynestsurveyswereconductedalongHutchinsonIslandfromtheFt.PierceInletsouthtotheSt.LucieInlet.After29April,surveyswereconducteddailythrough11September.Severaladditionalsurveyswereconductedafter11Septembertoconfirmthatnestinghadceased,thelastsurveybeingcon-ductedon18September.Biologistsusedsmalloff-roadmotorcyclestosurveytheislandeachmorning.Newnests,non-nestingemergences(falsecrawls),andnestsdestroyedbypredatorswererecordedforeachofthethirty-six1-km-longsurveyareascomprisingtheentireisland(Figure3).Thenine1.25-km-longsurveyareasestablishedbyGallagheretal.(1972)alsoweremonitoredsocomparisonscouldbemadewithpreviousstudies.Duringthedailynestmonitoring,anymajorchangesintopographythatmayhaveaffectedthebeach'ssuitabilityfornestingwererecorded.Inaddition,eachofthethirty-six1-km-longsurveyareashasbeensystematicallyanalyzedandcategorizedbasedonbeachslope(steep,moderate,etc.),widthfromhightidelinetothedune,presenceofbenches(areasofabruptverticalrelief)andmiscellaneouscharac-teristics(packedsand,scatteredrock,vegetationonthebeach,exposedrootsontheprimarydune,etc.).Inacooperativeeffort,theFloridaDepartmentofNaturalResources(DNR)wasnotifiedofallgreenturtlenests.EggsfromsomeofthesenestswerecollectedaspartoftheFloridaDNRHeadstartProgram.Additionally,datafromstrandedturtlesfoundduringbeachsurveyswereroutinelyprovidedtotheNationalMarineFisheriesServicethroughtheSeaTurtleStrandingandSalvageNetwork.12
IntakeCanalMonitorinRoutinecaptureofseaturtlesfromtheSt.LuciePlantintakecanalcontinuedduring1987.Turtleswereremovedfromthecanalwithlarge-meshtanglenetsfishedbetweentheintakeheadwallsandabarriernetlocatedattheHighwayA1Abridge(Figure2).ThesenetswereusuallydeployedonMondaymorningandretrievedonFridayafternoon.Todetectcaptures,formaldailyinspectionsofthenets(morningsandafternoons)weremadeeachdayofdeployment.Varioussizes,numbersandlocationsoftanglenetshavebeenusedtodateascapturetechniqueshavebeenrefined.Netsinrecentusewerefrom32to61minlength,2.7to3.7mindepthand30to40cminstretchmesh.Largefloatskeptthenetsatthesurface,andbecausenetswerenotweightedwithleadlines,turtleswhichbecameentangledremainedatthewater'ssurfaceuntilremoved.ThebarriernetattheA1Abridgeisintendedtoconfineturtlestotheeasternmostsectionoftheintakecanal,wherecapturetechniqueshavebeenmosteffective.However,theintegrityofthebarriernetoccasionallyhasbeencompromised,andturtleshavebeenabletoswimoverorunderit.PriortoDecember1986,mostturtlescircumventingthebarrierneteventuallyemergedintheintakewellsofUnits1and2(Figure2),wheretheywereretrievedbymeansoflargemechanicalrakesorspeciallydesignednets.However,during1986,asecurityintrusionbarrierwasconstructedacrossthenorth-southarmoftheintakecanal.Afteritsemplacement,turtleslargerthan30.5cmincarapacewidthwere13 impededfromreachingtheintakewellsbyalarge-meshchainnet.TanglenetsweresetwestoftheA1Abarriernettocapturetheseturtles.Turtlessmallerthan30.5cmcanpassthroughthemeshofboththebarriernetandtheintrusionbarrier.PersonnelofAppliedBiology,Inc.wereoncall24hoursadaytoretrievecapturedturtlesfromboththeintakewellsandturtlenets.Theutmostcarewastakeninhandlingcapturedturtlestopreventinjuryortrauma.Afterremovalfromthecanal,turtleswereidentifiedtospecies,measured,weighed,tagged,examinedforoverallcondition(wounds,abnor-malities,parasites,etc.)andreleasedbackintotheocean.Althoughbothstraight-lineandcurvedcarapacelengthsweremeasured,onlystraight-linemeasurementswereusedinanalysespresentedinthisreport.Straight-linecarapacelength(SLCL)wasmeasuredfromthepre-centralscutetothenotchbetweenthepostcentralscutes(minimumcara-pacelengthofPritchardetal.,1983).Since1982,bloodsampleshavebeencollectedandanalyzedtoinvestigatethepotentialoccurrenceandsignificanceofanemiaincap-turedanimalsandtodeterminethesexofimmatureturtles.BloodwasremovedfromthepaireddorsalcervicalsinusesofsubjectturtlesusingthetechniquedescribedbyOwensandRuiz(1980).Asmallsubsampleofwholebloodwashemolyzedandhemoglobinmeasuredingramsper100mlbycolorimetryusinganA.O.10100hemoglobinometer.Theremainderofthe~~
lli bloodsamplewascentrifugedfor15minutestoseparatecellsandserum.SexdeterminationsweresubsequentlymadebyresearchersatTexasA5MUniversityusingradioimmunoassayforserumtestosterone(Owensetal.,1978).During1984and1985,bloodcellsampleswerealsoprovidedtotheNationalMarineFisheriesServiceforthepurposeofdevelopingandrefiningmethodsforuseinconductingturtlestockanalysis.Sickorinjuredturtlesweretreatedandoccasionallyheldforobservationpriortorelease.Whentreatmentwaswarranted,injectionsofantibioticsandvitaminswereadministeredbyalocalveterinarian.Resuscitationtechniqueswereusedifaturtlewasfoundthatappearedtohavediedrecently.Beginningin1982,necropsieswereconductedondeadturtlesfoundinfreshcondition;twoindividuals,oneKemp'sridleyandoneloggerhead,werefoundsuitablefornecropsyin1987.FloridaPower5LightCompanyandAppliedBiology,Inc.continuedtoassistotherseaturtleresearchersin1987.InadditiontotheFloridaDNR'sHeadstartProgram,data,specimensand/orassistancehavebeengiventotheNationalMarineFisheriesServices,U.S.ArmyCorpsofEngineers,SmithsonianInstitution,SouthCarolinaWildlifeandMarineResourcesDivision,CenterforSeaTurtleResearch(UniversityofFlorida),TexasA&MUniversity,UniversityofRhodeIsland,UniversityofSouthCarolina,UniversityofIllinois,UniversityofGeorgiaandtheWesternAtlanticTurtieSymposium.15 StudiestoEvaluateand/orMitiateIntakeEntramentAprogramthatassessedthefeasibilityofusinglightand/orsoundtodeterturtlesfromenteringtheSt.LuciePlantintakestructureswasconductedin1982and1983andcompletedinJanuary1984.Asrequired,testresultsandevaluationswerewrittenupandapresentationwasmadetotheNRC,NationalMarineFisheriesServiceandtheFloridaDepartmentofNaturalResourcesonllApril1984.Requirement4.2.2oftheNRC'sSt.LucieUnit2AppendixBEnvironmentalProtectionPlanisconsideredcompletedwithsubmissionofdeterrentstudyfindings.LihtScreentoMinimizeTurtleDisorientationAvegetativebeachdunelightscreencreatedtominimizeturtledisorientationattheSt.LuciePlantwasroutinelyinspectedbyFPLper-~~sonnelduring1987.Replantingswereconductedasrequiredtomaintainitsintegrity.RESULTSANDDISCUSSIONNestinSurveDistributionofLoerheadNestsAlonHutchinsonIslandWhenseaturtlenestingsurveysbeganonHutchinsonIsland,nine1.25-km-longsurveyareaswereusedtoestimateloggerheadnestingacti-vityfortheentireisland.Since1981,all361-km-longsegmentscomprisingtheisland'scoastlinehavebeensurveyed.-Regardlessoftechnique,loggerheadnestdensitieshaveshownconsiderableannualvariationwithinindividualsurveyareas(Figures4and5).Yet,theannualspatialdistributionofthosenestsamongsurveyareashaspro-16 ducedaratheruniformgradient,nestdensitiesconsistentlyincreasingfromnorthtosouth(ABI,1987).Thegradientappearstobelinearwhenonlythenine1.25-km-longsurveyareasareused(Figure4),butbecomescurvilinearwhenall361-km-longsurveyareasareincludedintheanaly-sis(Figure5).During1987thedistributionofloggerheadnestsalongtheislandfollowedthesamegeneralpatternaspreviouslyreported,nestdensitiesincreasingabruptlyfromnorthtosouthalongthenorthernpor-tionoftheisland,reachingmaximumdensitiesincentralsurveyareasandthendecreasingslightlytowardthesouthernportionoftheisland(Figure5).Inthepast,thepronouncedgradientobservedonthenorthernendoftheislandwasoccasionallyinfluencedbyphysicalprocessesoccurringthere;periodsofheavyaccretionreducedthegradient,whileperiodsoferosionaccentuatedit(WorthandSmith,1976;Williams-Wallsetal.,1983).However,duringrecentyearsnoconsistentrelationshipwasapparentwhenfieldobservationsofbeachwidthswerecomparedtothe-spatialdistributionofnestsalongtheisland(ABI,1987).Thus,eventhoughbeachdynamicsmaysometimesaffecttheselectionofnestingsites1byloggerheadturtles,otherfactorsmustalsocontributetotheselec-tionprocess.Offshorebottomcontours,spatialdistributionofnearshorereefs,typeandextentofdunevegetation,anddegreeofhumanactivityonthebeachatnighthavebeenidentifiedassomeofthefac-torsaffectingnesting(Caldwell,1962;HendricksonandBalasingam,1966;Bustard,1968;BustardandGreenham,1968;Hughes,1974;DavisandWhiting,1977;Mortimer,1982).Relationshipsbetweenspatialnesting17 patternsandspecificenvironmentalconditionsareoftendifficulttoestablishbecauseoftheinterrelationshipofthefactorsinvolvedandmaybeobscuredbynestsitetenacity.Schulz(1975)suggestedthatnestsitetenacitymayforceadultfemalestomaintaintheirnestingsiteaslongaspossible,eventhoughthosesitesmaybeundergoingenvironmentalchanges.Notallventuresontothebeachbyafemaleturtleculminateinsuc-cessfulnests.These"falsecrawls"(non-nestingemergences)mayoccurformanyreasonsandarecommonlyencounteredatotherrookeries(BaldwinandLofton,1959;Schulz,1975;DavisandWhiting,1977;Talbertetal.,1980;Raymond,1984).DavisandWhiting(1977)suggestedthatrelativelyhighpercentagesoffalsecrawlsmayreflectdisturbancesorunsatisfac-torynestingbeachcharacteristics.Therefore,certainfactorsmayaffectaturtle'spreferencetoemergeonabeach,whileotherfactorsmayaffectaturtle'stendencytonestafterithasemerged.Anindexwhichrelatesthenumberofneststothenumberoffalsecrawlsinanareaisusefulinestimatingthepost-emergencesuitabilityofabeachfornesting.Inthepresentstudythisindexistermed"nestingsuccess"andisdefinedasthepercentageoftotalemergencesthatresultinnests.Historically,thepatternofloggerheademergencesontheislandhasparalleledthedistributionofnests(ABI,1987),andthissametrendwasapparentin1987(Figure6).Incontrast,nestingsuccessbyloggerheadsalongtheislandhastypicallylackedgradients(Figure7).Thus,the18 0
relativelyhighnumbersofloggerheadnestsusuallyobservedalongthesouthernhalfoftheislandhaveresultedprimarilyfrommoreturtlescomingashoreinthatarearatherthanfrommorepreferablenestingcon-ditionsbeingencounteredbytheturtlesaftertheyemerged.Hughes(1974)andBustard(1968)foundthatloggerheadspreferredbeachesadjacenttooutcropsofrocksorsubtidalreefs.Williams-Wallsetal.(1983)suggestedthatthenestinggradientonHutchinsonIslandmaybeinfluencedbytheoffshorereefsiffemaleturtlesconcentrateonthereefsclosesttothebeachtorestorfeed.Theproximityofoffshorereefswouldputthegreatestconcentrationofturtlesnearthesouthernhalfoftheislandwherecoincidentallynestingishighest.Loggerheadnestingdensitiesduring1987weregenerallywithintherangeofvaluespreviouslyrecorded(Figures4and5).TwonotableexceptionsincluderecordlownestinginAreaFandrecordhighnestinginAreaJJ.LownestinginAreaFwasapparentlyduetopre-emergentaswellaspost-emergentfactorssinceboththenumberofemergencesandnestingsuccesswerelowduring1987(Figures6and7).TheremovalofconsiderablebeachfrontvegetationinAreaFbetweenthe1986and1987nestingseasonsoffersoneexplanation.BaldwinandLofton(1959)indi-catedthatnestingturtlesshowapreferenceforbeachesbackedbyhighdunesorvegetationandahesitancytoemergeonbarrenbeaches.Anotherexplanationinvolvestheuseofthebeachatnightbyoffroadvehicles.Althoughillegal,vehiculartrafficonthebeachinArea19 Fwasconsiderableduring1987.Turtlesareverysensitivetoalarmingstimulibothpriortoemergingontoabeach(Schulz,1975)andduringtheirascentofthebeach(Hirth,1971).Amongthesealarmingstimuli,movinglightswillfrightennestingseaturtlesofallspecies(Mortimer,1982).Lightsassociatedwithvehiclesonthebeachmayhavecontributedtodecreasesinboththenumberofemergencesandnestingsuccess.RecordhighloggerheadnestinginAreaJJduring1987(Figure5)maybeattributabletounfavorablenestingconditionsontheadjacentnorthernsectionofbeach.SandbagsinstalledinAreaIIbetweenthe1986and1987nestingseasonswereapparentlyresponsibleforahighnumberoffalsecrawlswhichaccountedfortherecordlownestingsuccessobservedinthatareaduring1987(Figure7).ThehighnumberofemergencesinAreaII(Figure6)probablyreflectsrepeatedunsuccessfulnestingattemptsbyindividualturtles.ManyoftheseturtlesprobablyreemergedinAreaJJwhere,becauseofmorefavorablebeachconditions,theynested.In1987asinpreviousyears,loggerheademergenceswereleastnumerousinAreaAand.increasedsteadilyinasoutherlydirectiontoaboutAreaK(Figure6).Thepresenceofdeepwaterclosetoshorehasbeensuggestedasafactorwhichmightinfluenceseaturtlestoemergeonparticularbeaches(HendricksonandBalasingam,1966;Mortimer,1982).Thedistancefromshoretothethirty-footwaterdepthcontourdecreasescontinuouslyfromAreaAthroughAreaF,andthismaypartiallyaccountfortheobservedpatternofincreasedemergencesfromnorthtosouth20 alongthenorthendoftheisland.Furthermore,1argepublicbeachaccessesinAreasAthroughC,combinedwithconsiderableartificiallightinginthoseareas,providethepotentialforextensiveandhighlyvisiblehumanactivityonthebeachatnight.Aspreviouslystated,turtlesareverysensitivetoalarmingstimulijustpriortoandduringemergencesontobeaches.Nighttimehumanactivityintheseareasmaydeterturtlesfromemergingorfromnestingaftertheyemergeontothebeach,andmayhavecontributedtothesomewhatlowernestingsuccessobservedthere(Figure7).Historically,lownestingsuccessinthenorthernmostareashasbeenattributedtobeachcharacteristicssuchaspersistentandextensiveareasofverticalrelief(benches),accumula-tionsofrocksandshells,andcompactsand.Apparently,acombinationoffactorsaffectingbothemergenceandnestingsuccesshasbeenrespon-siblefortheextremelylownestdensitiesusuallyobservedalongthatpartoftheisland.NumbersofloggerheademergencesandconsequentlynestdensitieshaveremainedrelativelylowinAreaZfrom1981through1987(Figures5and6).Sincethisareaincludesalargepublicbeachaccess,amotelandconsiderableartificiallighting,nighttimehumanactivitymaydeterturtlesfromcomingashore.NestingsurveysonHutchinsonIslandwereinitiatedinresponsetoconcernsthattheoperationoftheSt.LuciePlantmightnegativelyimpactthelocalseaturtlerookery.Previousanalyses,usinglog-likelihoodtestsofindependence(G-test;SokalandRohlf,1981)21 demonstratedthattheconstructionoftheplant'soffshoreintakeanddischargestructuressignificantlyreducednestingattheplantsiteduringconstructionyears(1975,1981,1982and1983;Proffittetal.,1986;ABI,1987).However,nestingattheplantconsistentlyreturnedto1evelssimi1artoorgreaterthanthoseatacontrolsiteinyearsfol1owingconstruction(Figure8).TheG-testwasalsousedtoassesstheimpactsofpowerplantopera-tion,exclusiveofconstruction(ABI,1987).Thistestindicatedasignificantdifferenceintherelativeproportionofnestsbetweentheplantsite(Area4)andacomparablecontrolsite(Area5)whenbaselineyears(1971and1973)andoperationalyearswithoutconstructionwerecompared.However,thisdifferenceresultedfromadisproportionatelyhighnumberofnestsinArea4duringasingleyear(1986)ratherthanfromanylong-termdeclineinnestingresultingfrompowerplantopera-tion.Whendatafrom1986wereexcluded,nosignificantdifferencebe-tweenbaselineandoperationalperiods'eredetected.Thesameresultswereobtainedwhen1987datawereincludedintheanalyses.Datacollectedthrough1987haveshownnolong-termreductioninloggerheadnestdensities,totalemergencesornestingsuccessineitherthenine1.25-km-longsurveyareasorthe361-km-longsurveyareas'Table1;Figure9).-22 NumberofNestsandLoerheadPoulationEstimatesVariousmethodswereusedduringsurveyspriorto1981toestimatethetotalnumberofloggerheadnestsonHutchinsonIslandbasedonthenumberofnestsfoundinthenine1.25-km-longsurveyareas(Gallagheretal.,1972;WorthandSmith,1976;ABI,1980a).Eachofthesemethodsweresubsequentlyfoundtoconsistentlyoverestimateislandtotals(ABI,1987).Sincewhole-islandsurveysbeganin1981,ithasbeenpossibletodeterminetheactualproportionof'otalnestsdepositedinthenineareas.Thishasthenallowedextrapolationfromtheninesurveyareastotheentireislandforyearspriorto1981.From1981through1987thetotalnumberofnestsinthenineareasvariedfrom33.1to35.6percentofthetotalnumberofnestsontheisland(Table1).Thisisslightlyhigherthanthe31.3percentwhichwouldbeexpectedbasedstrictlyontheproportionoflinearcoastlinecomprisedbythenineareas.Usingtheseven-yearmeanof33.9percent,estimatesofthetotalnumberofnestsonHutchinsonIslandcanbecalcu-latedbymultiplyingthenumberofnestsinthenineareasby2.95.Thistechnique,whenappliedtotheninesurveyareasduringthesevenyearsinwhichtheentire'islandwassurveyed,producedwhole-islandestimateswithinfivepercentoftheactualnumberofnestscounted.Becausetheproportionofnestsrecordedintheninesurveyareasremainedrelativelyconstantoverthelastsevenyears,thisextrapolationprocedureshouldprovideafairlyaccurateestimateoftotalloggerheadnestingforyearspriorto1981.23 ItisclearthatloggerheadnestingactivityonHutchinsonIslandfluctuatesconsiderablyfromyeartoyear(Table1);Annualvariationsinnestdensitiesalsoarecommonatotherrookeries(Hughes,1976;DavisandWhiting,1977;Ehrhart,1980)andmayresultfromtheoverlappingofnon-annualbreedingpopulations.Duringthelastsixye'ars,however,annualnestproductionhasremainedrelativelyhigh.Totalnestingacti-vitywasgreatestduring1986when5,483loggerheadnestswererecordedontheisland.During1987,4,623nestswerecounted.Norelationshipsbetweentotalnestingactivityandpowerplantoperationorintake/dis-chargeconstructionwereindicatedbyyear-to-yearvariationsintotalnestingonHutchinsonIsland.InordertodeterminethetotalnumberoffemaleloggerheadturtlesnestingonHutchinsonIslandduringagivenseason,anestimateofthenumberofnestsproducedbyeachfemalemustbedetermined.Acomparisonofthenumberofnestsproducedbytaggedturtlesduringthe1975,1977and1979surveysindicatedthatanaverageoftwonestsperfemalewastproducedduringanestingseason(ABI,1980a)..Thus,estimatesofthetotalnumbersoffemalesnestingduringprevioussurveyyearsmaybeobtainedbydividingthecalculatedtotalnumberofnestsbytwo.Basedonextrapolationestimatesoftotalnesting,thenumberoffemaleloggerheadturtlesnestingonHutchinsonIslandvariedfromapproximately1,400to2,200individualsduringsurveyyears1971through1979.Usingwhole-islandnestcounts,theestimatedtotalnumberofnestingfemalesvariedfrom1,558to2,742individualsbetween1981and1987.24
TemoralLoerheadNestinPatternsTheloggerheadturtlenestingseasonusuallybeginsinearlyMay,whenoceantemperaturesreach23'o24'C,attainsamaximumduringJuneorJuly,andendsbylateAugustorearlySeptember(ABI,1987).Nestingactivityduring1987followedthissamepattern(Figure10).ShiftsinthetemporalnestingpatternonHutchinsonIsland.maybeinfluencedbyfluctuationsinwa'tertemperature.Thiswasobservedduring1975and1982whenearlynestinginAprilcoincidedwithaverageoceantem-peraturesabove24"C(ABI,1983;Williams-Wallsetal.,1983).CoolwaterintrusionsfrequentlyoccuroverthecontinentalshelfofsoutheastFloridaduringthesummer(TaylorandStewart,1958;Smith,1982).WorthandSmith(1976),Wil1iams-Wallsetal.(1983)andABI(1982,1983,1984b,1985b,1986,1987)suggestedthattheseintrusionsmayhavebeenresponsibleforthetemporarydeclinesinloggerheadturtlenestingactivitypreviouslyobservedonHutchinsonIsland.ConsiderabledecreasesinoceantemperatureswererecordedattheSt.LuciePlantduringJuneandearlyAugust1987(Figure10).Asubstantialdecreaseinnestingontheislandcorrespondedwiththelatterofthesecoolwaterintrusions.Todetermineifplantoperationhasaffectedthetimingofnestingactivity,seasonalnestingpatterns(nestdensityonamonth-to-monthbasis)forArea4(plantsite)andArea5(controlsite)werecomparedstatisticallyduringeachstudyyear(Kolmogorov-Smirnovtest;SokalandRohlf,1981).Nosignificant(P<0.05)differencesweredetectedbetween~~25
areasduringanystudyyear,eitherbeforeorafterthepowerplantbeganoperating.Theresultsoftheseanalysesindicatethatplantoperationhasnotsignificantlyaffectedtemporalnestingpatternsadjacenttotheplant.PredationonLoerheadTurtleNestsSincenestsurveysbeganin1971,raccoonpredationprobablyhasbeenthemajorcauseofturtlenestdestructiononHutchinsonIsland.Researchersatotherlocationshavereportedraccoonpredationlevelsashighas70tonearly100percent(DavisandWhiting,1977;Ehrhart,1979;Hopkinsetal.,1979;Talbertetal.,1980).RaccoonpredationofloggerheadturtlenestsonHutchinsonIslandhasnotapproachedthislevelduringanystudyyear,thoughlevelsforindividual1.25-km-longareashavebeenashighas80percent(Figure11).Overallpredationratesfor-surveyyears1971through1977werebetween21and44percent,withthehighof44percentrecordedin1973.Apronounceddecreaseinraccoonpredationoccurredafter1977,andoverallpredationratesforthenineareashavenotexceeded10percentsince1979.AdeclineinpredationratesonHutchinsonIslandhasbeenvariouslyattributedtotrappingprograms,constructionactivities,habitatlossanddisease(Williams-Wallsetal.,1983;ABI,1987).During1987,sevenpercent(304)oftheloggerheadnests(n=4,623)ontheislandweredepredatedbyraccoons.Asinpreviousyears(ABI,1987),predationofturtienestswasprimarilyrestrictedtothemostundevelopedportionoftheisland(i.e.,AreasfthroughU)andthesouthernmostareas(AreasIIandJJ;Figure12).26 Ghostcrabshavebeenreportedbynumerousresearchersasimportantpredatorsofseaturtlenests(BaldwinandLofton,1959;Schulz,1975;Diamond,1976;Fowler,1979;Hopkinsetal.,1979;Stancyk,1982).ThoughturtlenestsonHutchinsonIslandprobablyhavebeendepredatedbyghostcrabssincenestingsurveysbeganin1971,thissourceofnestdestructiondidnotbecomeapparentuntil1983.guantificationofghostcrabpredationwasinitiatedthesameyear.Overallpredationratesbyghostcrabshavevariedfrom0.3to2.1percentduringthelastfiveyears(ABI,1987).During1987,0.3percent(15)oftheloggerheadnests(n=4,623)ontheislandweredestroyedbyghostcrabs(Figure12).Nestsdestroyedbyacombinationofraccoonandghostcrabpredationhavebeenincludedasraccoonpredationsinpreviousdiscussions.Whenthesecombinationpredationsareincludedascrabpre-dations,theoverallpredationratesbyghostcrabsrangefrom1.5to3.2percent.During1987,1.5percent(71nests)weredestroyedbyeitherghostcrabsoracombination'ofghostcrabsandraccoons.GreenandLeatherbackTurtleNestinGreenand,leatherbackturtlesalsonestonHutchinsonIsland,butinfewernumbersthanloggerheadturtles.Priorto1981,bothsurvey(nine1.25-km-longsections)andinter-surveyareasweremonitoredforthepre-senceofgreenandleatherbacknests.Thirty-onekilometersofbeachfromArea1southtotheSt.Lucieinletwereincludedinthateffort.Duringwholeislandsurveysfrom1981through1987,onlytwoof101leatherbacknestsandonlyfourof350greennestswererecordedonthe27
fivekilometersofbeachnorthofArea1.Therefore,previouscountsofgreenandleatherbacknestswithinthe31kilometerssurveyedwerepro-bablynotappreciablydifferentfromtotaldensitiesfortheentireisland.Basedonthisassumption,greenandleatherbacknestdensitiesmaybecomparedamongallsurveyyears,except1980,whenlessthan15kilometersofbeachweresurveyed.Priorto1987,thenumberofnestsobservedontheislandrangedfrom5to68forgreenturtlesandfrom1to20forleatherbacks(Figure13).Duringthe1987survey,72greenturtleand18leatherbackturtlenestswererecordedonHutchinsonIsland.Temporalnestingpatternsforthesespeciesdifferfromthepatternforloggerheadturtles.GreenturtlestypicallynestonHutchinsonIslandfrommid-JunethroughthefirstorsecondweekofSeptember.During1987,greenturtles.nestedfrom15Junethrough9September.Leatherbackturtlesusuallynestontheislandfrommid-Aprilthroughearlytomid-July.During1987thisspeciesnestedfrom3Maythrough20July.Considerablefluctuationsingreenturtlenestingontheislandhaveoccurredamongsurveyyears(Figure13).Thisisnotunusualsincetherearedrasticyear-to-yearfluctuationsinthenumbersofgreenturtlesnestingatotherbreedinggrounds(Carretal.,1982).Despitethesefluctuations,greenturtlenestinghasremainedrelativelyhighduringthelastsixyears(1982through1987)andmayreflectanincreaseinthe28 numberofnestingfemalesintheHutchinsonIslandarea.During1987,greenturtlesnestedmostfrequentlyalongthesouthernhalfoftheisland.Thisisconsistentwithresultsofprevioussurveys.LeatherbackturtlenestdensitieshaveremainedlowonHutchinsonIsland;however,densitiesduringthelasteightsurveyyearshavebeenhigherthanduringthefirstfoursurveyyears(Figure13).ThismayreflectanoverallincreaseinthenumberofnestingfemalesintheHutchinsonIslandarea.During1987,leatherbackturtlesprimarilynestedonthesouthernhalfoftheislandbetweenAreasBBandGG(Figure3).IntakeCanalMonitorinEntrainmentofseaturtlesattheSt.LuciePlanthasbeenattri-butedtothepresumedphysicalattractivenessoftheoffshorestructureshousingtheintakepipesratherthantoplantoperatingcharacteristics(ABI,1980band1986).Evenwhenbothunitsareoperatingatfullcapa-city,turtlesmustactivelyswimintooneoftheintakepipesbeforetheyencountercurrentvelocitiessufficientlystrongtoeffectentrainment.Consequently,aturtle'sentrapmentrelatesprimarilytotheprobabilitythatitwilldetectandsubsequentlyenteroneoftheintakestructures.Assumingthatdetectiondistancesdonotvaryappreciablyovertimeandthatallturtles(oraconstantproportion)areequallyattractedtothestructures,capturerateswillvaryproportionatelytothenumberofturtlesoccurringinthevicinityofthestructures.Ifthisassumptionistrue,datafromthecanalcaptureprogramshouldreflectnaturalvariabilityinthestructureofthepopulationbeingsampled.29 SeciesNumberandTemoralDistributionDuring1987,218seaturtlecapturestookplaceintheintakecanaloftheSt.LuciePlant(Table2).FourofthefivespeciesofseaturtlesoccurringincoastalwatersofthesoutheasternUnitedStateswererepresentedinthecatches,including175loggerheads,35greens,2hawksbillsand6Kemp'sridleys.SinceintakecanalmonitoringbeganinHay1976,1,497loggerhead(including79recaptures),227green(including1recapture),8leatherback,6hawksbilland10Kemp'sridleycaptureshavebeenreportedfromtheSt.LuciePlant.Annualcatchesofloggerheadsincreasedsteadilyfromalowof33in1976(partialyearofplantoperationandmonitoring)to173in1979~~(Figure14).Afterdecliningbetween1979and1981,yearlycatchesof1oggerheadsagainrosesteadily,reachingahighof195during1986.Capturesin1987weredownslightlyfrom1986.TwooffshoreintakestructureswereinplacepriortoUnit1start-upin1976;thethirdandlargeststructurewasinstalledduring1982-1983.Eventhoughallthreestructuresareinrelativelycloseproximity,theadditionofanotherpipemayhaveincreasedtheprobabi1-ityofaturtlebeingentrained.Becausethischangecannotbequan-tified,datacollectedpriorto1982maynotbecomparablewiththatcollectedafter1983.Nevertheless,thegeneralriseincanalcapturessince1981,evenafterthethirdstructurewascompleted,suggestsagenuine,long-termincreaseinthenumberofturtlesoccurringneartheplant.30 i
During1987,themonthlycatchof1oggerheadsrangedfrom3(October)to26(JanuaryandJune),withamonthlymeanof14.6(+8.9;Table3).CapturesduringApril,MayandJuneweremuchhigherthanhistoricalaveragesforthosemonths,whilecapturesduringSeptemberandOctoberweremuchlowerthanaverage(Figure15).Overtheentiremoni-toringperiod,monthlycatcheshaverangedfrom0to39;thegreatestnumberofcapturesoccurredduringJanuary1983.Whendatafromallfullyearsofmonitoring(1977-1987)werecom-bined,themajorityof1oggerheadswerecapturedinJanuary(13.2percent);fewestcapturesoccurredduringNovemberandDecember(Table3).However,monthlycatcheshaveshownconsiderableannualvariability.~~Monthshavingrelativelylowcatchesoneyearoftenhavehadrelativelyhighcatchesinanother..Catchesofgreenturtlesalsohavevariedwidelyamongyears,rangingfrom0in1976(partialyearofsampling)to69in1984(Table4).During1987,35individualswerecaptured.Theaverageannualcatchofgreenturtles,excluding1976,was20.6(+19.4).Noconsistenttrendsinannualcatchesareevidentfromthedata(Figure14).Green,turtleshavebeencaughtduringeverymonthoftheyear,withaveragemonthlycatchesforallyearscombinedrangingfrom0.3inMayto7.1inJanuary(Table4).However,seasonalabundancepatternsofgreensaremuchmorepronouncedthanforloggerheads,nearly75percentofallcapturesoccurringbetweenNovemberandMarch.During1987,thelargest.31 0
numberofgreens(11)werecapturedinDecember.caughtinonemonthwas37inJanuary1984.ThemostgreenseverCatchesofleatherbacks,hawksbillsandKemp'sridleyshavebeeninfrequentandscatteredthroughouttheelevenyearstudyperiod(Table2).Eachspecieshasshownratherpronouncedseasonaloccurrences;allbutoneoftheeightleatherbackswerecollectedbetweenFebruaryandMay,fiveofthesixhawksbillswerecollectedbetweenJuneandSeptember,andallbutoneofthe10Kemp'sridleyswerecaughtbetween~DecemberandApril.Size-ClassDistributionsTodate,liveloggerheadsremovedfromtheintakecanalhaverangedinlength(SLCL)from40.4to112.0cm(x=65.2+12.3cm)andinweightfrom10.9kgto154.7kg(Figures16and17).About75percentofallliveloggerheadscapturedwere70cmorlessinlengthandweighedlessthan100pounds.Acarapacelengthof70cmapproximatesthesmallestsizeofnestingloggerheadfemalesobservedalongtheAtlanticeastcoast(Hirth,1980).However,adultscanonlybereliablysexedonexternalmorphologicalcharacteristics(e.g.,relativetaillength)afterobtainingalengthofabout80cm.Basedonthesedivisions,dataweresegregatedintothreegroups:juvenile/sub-adults(<70cm;thedemarcationbetweenthesetwocomponentsisnotwellestablishedintheliterature),adults(>80cm)andtransitional(70-80cm).Thelattergroupprobablyincludessome32 JIL matureandsomeimmatureindividuals.Ofthe1,348capturesforwhich1engthdatawerecollected,75percentwerejuveni1es/sub-adults,themajorityofthesemeasuringbetween50and70cmSLCL(Table5).Theremaining25percentwasdividednearlyequallybetweenadultsandindi-vidualsinthetransitionalsizeclass.Similarsize-frequencydistribu-tions,indicatingapreponderanceofjuveniles,havebeenreportedfortheMosquito/IndianRiverLagoon(MendoncaandEhrhart,1982),theCanaveralshipchannel(OgrenandMcVea,1982),GeorgiaandSouthCarolina(Hi1lestadetal.,1982)andsuggestthatcoastalwatersofthesoutheasternUnitedStatesconstituteanimportantdevelopmentalhabitatforCarettacaretta.Seasonalpatternsofabundanceforvarioussizeclassesindicatedthatjuvenilesandsub-adultloggerheadswereslightlymoreabundantduringthewinterthanatothertimesoftheyear(Table5).About37percentofjuvenile/sub-adultloggerheadswerecapturedbetweenJanuaryandMarch,theremainderbeingratherevenlydistributedamongothermonths.Theseasonaldistributionofadult.loggerheadswasmuchmorepronounced,60percentofallcapturesoccurringbetweenJuneandAugust.ThisrepresentstheperiodofpeaknestingonHutchinsonIsland.Ifothernestingmonthsareincluded(MayandSeptember),75percentofalladultswerecapturedduringthenestingseason.Greenturtlesremovedalivefromtheintakecanalovertheentirestudyperiodrangedinsizefrom20to108cmSLCL(x=36.9+15.1cm)and0.9kgto177.8kg(Figures18and19).Nearlyall(96percent)were33 juvenilesorsub-adults.Over75percentwere40cmorlessinlength,and60percentweighedlessthan10pounds.Theseimmatureturtlesexhi-biteddistinctwinterpulsessuggestingmigratorybehavior(Table4).However,someimmaturegreenturtleswerepresentthroughouttheyear.Todate,onlysixadultgreenturtles(SLCL>83cm;WitheringtonandEhrhart,inpress)havebeenremovedfromthecanal;allwerecapturedduringorshortlyafterthenestingseason.FiveofthesixhawksbillsandalltenKemp'sridleysremovedfromthecanalwereimmature,ranginginsizefrom34to46cmSLCL(6.4-12.7kg)and27to47cmSLCL(3.2-15.4kg),respectively;theadulthawksbill(SLCL>53cm;Hirth,1980)hadaSLCLof70cmandweighed52.2kg.Theeightleatherbacksremovedfromthecanalrangedinlengthfrom112.5to150cm,andatleastsixwereadults(SLCL>121cm;Hirth,1980).Thelargestleatherbackforwhichanaccurateweightwasobtained,amalewithaSLCLof134.5cm,weighed233.6kg.SexRatiosSinceintakecanalmonitoringbeganin1976,198adultloggerheadshavebeensexed.Thesmallestwas75.5cminlengthandwasobservednestingonHutchinsonIslandsubsequenttoher.captureinthecanal.Femalespredominatedmalesbyaratioof4.9:1.0,whichsignificantlydepartsfroma1:1ratio(X2,P<0.05).Consequently,temporalpatternsinthenumberofadultloggerheadcapturesareheavilyinfluencedbythenumbersoffemalespresent.Whensexeswereseparated,itisevidentthatmaleswererelativelyevenlydistributedamongdifferentmonths,
[1I whereasnearly80percentofthefemalesweretakenduringthenestingseason(MaythroughSeptember;Figure20).ThenumberofadultloggerheadscapturedattheSt.LuciePlantincreasedappreciablyafter1982.Between1976and1982,anaverageof7.4adultloggerheads(+4.4;range=2-15)wereentrappedeachyear,whereasoverthelastfive.years,anaverageof30.0adultsperyear(+8.9;range=19-40)werecaptured.Thisincreasecorrespondstoageneralriseinloggerheadnestingneartheplant(Figure21).Theyear1986representedthehighestnumberofnestseverrecorded,bothfortheentireislandandattheplantsite(Area4),andmoreadultfemales(35)wereentrappedinthecanalthaneverbefore.Thisassociationisnotunexpected,becauseincreasednearshoremovementassociatedwithnestingbehaviorincreasestheprobabilityofaturtledetectingoneoftheintakestructuresandhencetheprobabilityofentrainment.-Theadditionofthethirdoffshoreintakestructure,thelargestofthethreestruc-tures,in1982alsomayhavecontributedtoincreasedentrainmentofadults.SinceSeptember1982,258juvenileandsub-adultloggerheadturtlescapturedinthecanalhavebeensexedbyTexasA8NUniversityresearchersusingabioimmunoassaytechniqueforbloodserumtestosterone.Forthepurposeoftheseanalyses,Dr.Owensandhisasso-ciatesused76cmasthecutofflengthbetweenimmatureandadultturtles.BioimmunoassayresultsindicatethatforimmatureloggerheadsremovedfromtheSt.LuciePlantintakecanal,femalesoutnumberedma'les35 I
byaratioof2.7:1.0.ThesexratiosofimmatureloggerheadscapturedintheCapeCanaveralshipchannel(1.7:1.0)andtheIndianRiverLagoon(1.4:1.0)arealsoreportedtobesignificantlyskewedinfavoroffema-les(X2,P<0.05;Wibbelsetal.,1984).Ofthesixadultgreenturtlescapturedsincemonitoringbegan,fourweremalesandtwowerefemales.Siximmaturegreenturtleshavebeensexedthroughbloodwork;allhavebeenfemales.Ofthefiveadultleatherbackturtlesforwhichsexwasrecorded,twowerefemalesandthreeweremales.Theonlyhawksbillthusfarsexedwasafemale.NosexinformationexistsforKemp'sridleys.CatureEfficienciesCapturemethodologiesevolvedoverthefirstseveralyearsofintakecanalmonitoringasnetmaterials,configurationsandplacementwerevariedinanefforttominimizeseaturtleentrapmenttimes.Concurrently,alternativecapturetechniqueswereevaluatedandpotentialdeterrentsystemstestedinthelaboratory.Duringthisperiod,captureefficienciesvariedinrelationtonettingeffortandtheeffectivenessofthesystemsdeployed.Acapture/recapturestudyconductedintheintakecanalbetweenOctober1980andJanuary1981indicatedthatmostturtlesconfinedbe-tweentheAIAbridgeandtheintakeheadwallswerecapturedwithintwoweeksoftheirentrainment(ABI,1983).Basedonmorerecentformaldailyinspections,itappearsthatcaptureefficiencieshavefurther36 improved.Mostturtlesenteringthecanalarenowcaughtwithinafewdaysoffirstsighting,andinmanyinstances,turtleshavebeencaughtinthetanglenetswithoutanypriorsighting,suggestingresidencytimesoflessthan24hours.Betterutilizationofcurrentsandeddies,adjustmentstotetheringlinesandmulti-netdeploymentshavecontributedtoreducedentrapmenttimes.EntrapmenttimesmaybeextendedforturtlesswimmingpasttheA1Abarriernet(ABI,1987).Occasionally,thetopofthenethasbeensub-mergedortheanchorcablepull,edfreefromthebottom,allowinglargerturtlestopass;turtleswithcarapacewidthslessthanabout30.5cmcanswimthroughthelargemesh.BecausecaptureeffortswestoftheA1Abridgehavegenerallybeenlesseffectivethanthoseneartheintakeheadwalls,mostturtlesbreachingthebarriernetwerenotcaughtuntiltheyenteredtheintakewellsofUnits1and2.Sincethecanalcaptureprogrambegan,about15percentofallturtlesentrappedinthecanalhavebeenremovedfromtheintakewells.Becauseoftheirrelativelysmallsizes,agreaterproportionofgreens(47.6percent)reachedtheplantthanloggerheads(9.4percent).AftercompletionofthesecurityintrusionbarrierinDecember1986,mostturtleslargerthan30.5cmincarapacewidthwerepreventedfromreachingtheintakewells.During1987,onlysevenloggerheadswereremovedfromtheplant,allduringJanuaryandFebruary.Theseturtleswerepresumablytrappednorthoftheintrusionbarrier(Figure2)beforeitwascompleted.Anadditional15loggerheadswereremovedfromthe37 canalwestoftheA1Abarriernetduring1987;12werehand-capturedatorneartheintrusionbarrier,twowerecaughtintanglenetssetwestoftheA1Abridge,andonewashedupalongthebank.Atotalof11greenturtlesmadeitpasttheA1Abarriernetduring1987.Ninewereremovedfromtheintakewells,onewashand-capturedneartheintrusionbarrierandonewascaughtinatanglenetsetwestoftheA1Abridge.FourKemp'sridleyswerealsocapturedwestoftheA1Abarriernetduring1987,allattheUnit1and2intakewells.Tomaximizeconfinementoflargerturtlestotheeasternmostsectionoftheintakecanal,andtherebyincreaseoverallcaptureefficiency,theA1Abarriernethasbeenperiodicallysurveyedand,asrequired,appropriatemeasurestakentoensureitsintegrity.SuchanadjustmentwasmadeduringAugust/September1985(ABI,1987).During1987,thebarriernethadtobedismantledbetweenAprilandJunebecauseofconstructionactivitiesinthecanal.ItwasultimatelyreplacedwithanewnetinNovember1987.RelativeConditionTurtles"capturedaliveintheintakecanaloftheSt.LuciePlantwereassignedarelativeconditionbasedonweight,activity,parasiteinfestation,barnaclecoverage,wounds,injuriesandanyotherabnor-malitiesswhichmighthaveaffectedoverallwell-being(Table6).During1987,86.3percent(151)ofallloggerheadsfoundinthecanalwerealiveandingoodtoexcellentcondition.Only7.5percent(13)ofloggerheadcapturesinvolvedindividualsinfairorpoorcondition;6.3percent(11)oftheloggerheadsremovedfromthecanalweredea'd.38 Ofthe35greenturtlesremovedfromtheintakecanalduring1987,85.7percent(30)wereingoodtoexcellentcondition,whileonly14.3percent(5)wereinfairorpoorcondition.ThreeofthesixKemp'sridleyscaughtduring1987wereingoodtoexcellentcondition,onewasinfairconditionandtwoweredead.Bothhawksbillscapturedduring1987wereinexcellentcondition.Overtheentiremonitoringperiod,about70and80percent,respec-tively,ofal1loggerheadandgreencaptureshaveinvolvedturtlesingoodtoexcellentcondition(Table6).Capturesofindividualsinfairtopoorconditionhaveoccurredabout22percentofthetimeforlogger-headsand13percentofthetimeforgreens.Allofthehawksbil1sandallbutone1eatherbackhavebeenremovedfromthecanalingoodtoexcellentcondition.,Although60percentoftheKemp'sridleyshavebeeningoodtoexcellentcondition,allcategorieshavebeenrepresentedinthecatches.Relativeconditionratingscanbeinfluencedbyanumberoffactors,somerelatedandothersunrelatedtoentrainmentand/orentrapmentintheintakecanal.Ratingsofgoodtoexcellentindicatethatturtleshavenotbeennegativelyimpactedbytheirentrapmentinthecanal,atleastasevidencedbyphysicalappearance.Althoughratingsoffairorpoorimplyreducedvitality,theextenttowhichentrainment/entrapmentisresponsibleisoftenindeterminable.Insomeinstances,conditionsresponsibleforlowerratings,suchasinjuries,obviouslyweresustainedpriortoentrainment.39
During1987,about13percentofallcapturesinvolvedindividualswithsevereinjuries,includingmissingappendages,brokenormissingpiecesofcarapaceordeeplacerations.However,nearlyallofthesewereold,wel1-healedwounds.Sharkattacksappearedtohavebeenresponsibleforalargepercentageoftheinjuries,asevidencedbycrescent-shapedbitemarks.Oneturtlehadobviouspropellerscarsonthecarapace.Althoughmanyturtlesremovedfromthecanalduring1987hadoneormorerecentsuperficialabrasionstothecarapaceorskin,onlytwoindividualsappearedtohavesustainedseriousinjuriesasaresultoftheirentrainment/entrapment.Bothweretreated,heldforobservationandsubsequentlyreleased.Onceinthecanal,anindividual'srelativeconditionappearstoberelatedtothelengthoftimeitremainsentrapped(ABI,1987).Asindi-catedearlier,entrapmentperiodsarerelativelyshortforturtlesremainingbetweentheA1Abarriernetandintakeheadwalls,whileresi-dencytimesincreaseforthoseindividualsbreachingthebarriernet.Previouscomparisonshavedemonstratedthattheproportionofloggerheadsingoodtoexcellentconditionisgreaterforindividualscaughtinthetanglenetsthanforindividualsremovedfromtheintakewells(ABI,1987).Loggerheadshaveatendencytoorientagainstcurrentsinthecanal,oftenrestingnearsubmergedstructures.ForindividualswestoftheA1Abridge,thisbehaviorprolongstheirtransporttotheintakewellsandtherebyextendstheirresidencytimes.40 Becausegreenturtlesentrappedinthecanalarerelativelysmall,theirmovementsaremoreeasilyinfluencedbycurrents.Individualspassingthroughthebarriernetprobablyarriveattheintakewellsinarelativelyshortamountoftime.Consequently,themeanrelativecon-ditionofgreenturtlescaughtbytanglenetsdoesnotdifferappreciablyfromthemeanconditionofindividualsremovedfromtheintakewells(ABI,1987).Therelativeconditionassignedtoaturtleisasubjectiveassess-mentpronetosomevariationamongobserversandisbasedsolelyonphy-sicalappearance.Aturtle'sphysicalappearancemayormaynotrelatetoitsphysiologicalhealth.Thus,measuresofphysiologicalconditionaredesirable.BloodhemoglobinlevelshavebeenmeasuredinturtlesremovedfromtheintakecanalsinceSeptember1982.During1987,valuesrangedfromlessthan4.0to14.9g/100ml(n=80).Themeanforturtlesinexcellentconditionwas10.1g/100ml(+1.52;n=38),whilethemeanvalueforindi-vidualsinfairconditionwasonly8.2g/100ml(+2.36;n=3).Althoughpreviousanalyseshavealsoindicatedageneralassociationbetweenrela-tiveconditionandhemoglobinvalue,theoverlapinrangesbetweengroupshasbeenconsiderable(ABI,1987).Todate,therehavebeennosignificantdifferencesinthemeanHbvaluesbetweenrelativeconditioncategories.
Frair(1977)reportedthatmanyfactors,suchastemperature,sex,sizeandactivity,canaffectanindividualturtle'sbloodchemistryirrespectiveofgeneralhealth.Thus,hemoglobindatatakencollectivelyfromtheentirepopulationoverdifferentseasonsandenvironmentalcon-ditionsprobablymasksdifferenceswhichmightotherwisebeattributabletodifferencesinhealthamongindividualswithindistinctsegmentsofthepopulation.Asthedatabasecontinuestogrow,hemoglobinvaluescanbepartitionedbysizeclasses,sexandseasontoreducevariabilityandthusproduceabettergaugeofrelativehealthwithineachsub-group.MortalitiesDuring1987,11loggerheadmortalities(6.3percentofallloggerheadcaptures)wererecordedintheintakecanal.Eightoftheseturtleswereremovedfromthesecurityintrusionbarrier,twowerefoundfloatingagainsttheA1AbarriernetandonewasheduponthecanalbankwestofA1A.TwoKemp'sridleymortalitiesalsooccurredintheintakecanalduring1987;onewasremovedfromtheintakewellsandthe,otherfromaturtlenet.Nomortalitiestootherspecieswererecordedduring1987.Overtheentire12yearmonitoringperiod,116(7.7percent)ofthe1,322loggerheadsand16(7.0percent)ofthe227greenturtlesentrappedinthecanalwerefounddead(Table2).Mortalitiesspannedtherangeofsizeclassesforloggerheads(SLCL=47.5-125cm),whileallgreenturtlemortalitiesinvolvedjuvenileslessthan41cminlength.Thetwojuve-nileKemp'sridleymortalitiesdocumentedattheplantduring1987were42 theonlydeathsforthisspeciessincemonitoringbegan;noleatherbackorhawksbillmortalitieshaveoccurredattheSt.LuciePlant.Mortalitieshavebeencloselymonitoredthroughoutthelifeofthecanalcaptureprograminanattempttoassignprobablecausesandtake'ppropriatecorrectivemeasurestoreducefutureoccurrences.Previousanalysesofdatacollectedfromturtlescapturedbetween1976and1986identifieddrowninginnets,drowningintheintakepipesduringperiodsofreducedintakeflow,injuriessustainedfromdredgingoperationsandinjuriessustainedfromthemechanicalrakesusedintheintakewellsasprobablemortalityfactors(ABI,1987).Althoughdifficulttoquantify,theentrapmentandsubsequentdemiseofinjuredorsickturtlesalsopro-bablyaccountsforaportionofobservedmortalities.Overtheyears,materialsandprocedureshavebeenmodifiedtoreducethepotentialforaturtledrowningduringcapture.Leadlineshavebeenremovedfromthenetsanddeploymenttechniquesalteredtoallowturtleseasiermovementafterentanglement.Surveillanceofthenetshasalsoincreased.However,evenwiththeseprecautions,aturtlehasoccasionallydrowned.Inrecentyears,thishasoccurredprimarilywhenasmallturtlehasbecomeentangledwithoneormorelargerindivi-duals,apparentlyrestrictingitsmovementandabilitytosurface.Suchanincidentoccurredon10June1987,asajuvenileKemp'sridleybecameentangledinanetatnightwithtwolargerloggerheads.Overthe12yearhistoryofthecanalcaptureprogram,onlyeightofthemorethan1,700turtlesentrappedinthecanalhavedrownedasaresultofnettingactivities.
MostrecentmortalitiesintheintakecanalapparentlyresultedfromdrowningsattheA1Abarriernetandthenewlyconstructedsecurityintrusionbarrier.Adramaticincreaseinloggerheadmortalitiesbetween1985and1986(Table2)wasthoughttohavebeenrelatedtoadjustmentsmadetotheA1Abarriernetduringthelatterpartof1985(ABI,1987).Presumably,theseadjustmentsincreasedtheprobabilityofaturtledrowning.Asapreventivemeasure,largeholeswerecutinthebarriernettoprovideescapehatchesforturtlestrappedagainstitbystrongcurrents.Concurrently,plansweremadetoinstallanewbarriernet,usingadifferentmethodofdeployment.Asaresultofthebarriernet'sgeneralineffectivenessduringmuchof1987,largerturtleswhichotherwisewouldhavebeenconfinedeastoftheAlAbridgewerepermittedfreeaccesstothatportionofthecanalwherecaptureeffortsarelesseffective.Twelveoftheseturtleswereeventuallyremovedfromthecanalatthesecurityintrusionbarrier;eightweredead.Theliveindividualsremovedfromtheintrusionbarrierweretangledinitsmeshorotherwisepinnedagainstitbystrongcurrents,andgenerallyshowedsignsofinjuriesorweakenedcondition.Sickorinjuredturtlescontactingthenetbelowthewater'ssurfacemaybeunabletosurfaceandthusareprobablymoresusceptibletodrowningthanhealthyindividuals.ConcurrentwiththeremovaloftheA1Abarriernet,surveillanceandcaptureeffortsinthecanalwereintensified,includingmulti-netdeploymentswestofA1Aanddeploymentofnetsovertheweekends.NologgerheadcapturesoccurredwestoftheA1AbridgeafterAugust1987andanewbarriernetwasinstalledduringNovemberofthatyear.
Inadditiontothe11loggerheadmortalitiesrecordedduring1987,twoturtlesremovedfromthecanalinpoorconditionlaterdied.Bothwereveryemaciatedandweresolethargictheycouldbehand-captured.Onehadnumerousoldwounds.Anecropsyperformedontheindividualwithoutwoundsprovidednocluesastothecauseofdeath.However,both'fturtleshadbeeninthecanalforarelativelyshortperiod(basedondailyobservations),indicatingtheyweresickbeforetheirentrapment.Bothwereheavilyencrustedwithbarnaclesandhadnumerousparasites.Thisisaconditionoftenseeninstrandedindividualswherenoapparentwoundsorinjuriesarepresentandmaybeindicativeofpoorhealth.Thecaptureofterminallyillturtlesinthecanallendssupporttotheideathatatleastaportionofthemortalitiesoccurringinthecanalmaybearesultofpre-entrainmentconditions.Undoubtedly,pre-existinginjuriesandillnessescontributetosomeofthecanalmortalities.TwoKemp'sridleymortalitiesoccurredintheintakecanalduring1987.Thedrowninginthetanglenetwasdiscussedearlier.Theothermortalitywasrecordedattheplantintakewells.Similartothecon-ditionofmanyoftheloggerheadsremovedfromtheintrusionbarrier,thisindividualwasemaciatedandapparentlyinillhealth.Strongcurrentsinthevicinityoftheintakewellsmayhaveresultedinitsdrowning.Althoughanecropsywasperformed,causeofdeathcouldnotbepositivelydetermined.45 0
RecatureIncidentsSincetheSt.LuciePlantcaptureprogrambegan,mostturtlesremovedalivefromtheintakecanalhavebeentaggedandreleasedintotheoceanatvariouslocationsalongHutchinsonIsland.Consequently,individualturtlescanbeidentifiedaslongastheyretaintheirtags.Overthe12yearhistoryofturtleentrapmentattheSt.LuciePlant,48individuals(47loggerheadsand1green)'havebeenremovedfromthecanalmorethanonce.Severalotherturtleswithtagscarshavealsobeenremoved,indicatingthattheactualnumberofrecapturesmaybehigher.Ofthe47individualloggerheadsknowntohavebeencaughtmorethanonce,33werecaughttwice,sixwerecaughtthreetimes,fourwerecaughtfourtimes,twowerecapturedsixtimesandtwowerecaughtonsevenseparateoccasions,yieldingatotalof79recaptureincidents.Releasesitedidnotappeartohaveanyeffectonaturtle'sprobabilityofbeingrecaptured.Turtlesreleasedbothnorthandsouthoftheplantreturned.Recapturesalsodidnotappeartoberelatedtosize,asbothjuvenilesandadultswerecapturedmorethan.once(rangeofSLCL=47-89cm).However,themajorityofrecaptureincidentsinvolvedjuvenilesandsub-adults(SLCL<70cm).Recaptureintervalsforloggerheadsrangedfromfourto858days,withameanof143days(+161.5days).Theonlygreenturtlecaughtmorethanoncewascapturedontwooccasions,returningtothecanal59daysafterfirstbeingreleasedintotheocean.About57percentofallloggerheadrecaptureincidentsoccurredwithin90daysofpreviouscap-46 tureand91percentwithinoneyear(Figure22).Theaverageintervalbetweenfirstandlastcapturewas245days(+267.4days).ThesedatasuggestthatresidencytimesofloggerheadswithinthenearshorehabitatadjacenttotheSt.LuciePlantarerelativelyshort.SimilarfindingshavebeenreportedforloggerheadsinhabitingtheMosquito/IndianRiverLagoonsofeast-centralFlorida(MendoncaandEhrhart,1982).SUMMARYAgradientofincreasingloggerheadturtlenestdensitiesfromnorthtosouthalongthenorthernhalfofHutchinsonIslandhasbeenshownduringallsurveyyears.Thisgradientmayresultfromvariationsinbeachtopography,offshoredepthcontours,distributionofnearshorereefs,onshoreartificiallightingandhumanactivityonthebeachatnight.Lownestingactivityinthevicinityofthepowerplantduring1975andfrom1981through1983wasattributedtoconstructionofpowerplantintakeanddischargesystems.Nestingreturnedtonormalorabovenormallevelsfollowingbothperiodsofconstruction.Powerplantopera-tion,exclusiveofintake/dischargeconstruction,hashadnosignificanteffectonnestdensities.Therehavebeenconsiderableyear-to-yearfluctuationsinloggerheadnestingactivityonHutchinsonIslandfrom1971through1987.Fluctuationsarecommonatotherrookeriesandmayresultfromoverlappingofnon-annualbreedingpopulations.Despitethesefluc-tuations,loggerheadnestingactivityhasremainedrelativelyhighduringthelastsixyears.Norelationshipbetweentotalnestingandpowerplantoperationorintake/dischargeconstructionwasindicated.47
ResultsofthreeyearsoftaggingstudiesonHutchinsonIslandindi-catedthatanaverageoftwonestsperyearwereproducedbyeachnestingloggerheadturtle.Basedonthisaverage,thenestingpopulationofloggerheadturtlesontheislandhasvariedfromapproximately1,400individualsin1977toover2,700in1986.Thoughtemporalnestingpat-ternsoftheHutchinsonIslandpopulationmaybeinfluencedbyfluc-tuationsinwatertemperature,nosignificanteffectsduetopowerplantoperationhavebeenindicated.Sincenestsurveysbeganin1971,raccoonpredationwasconsideredthemajorcauseofturtlenestdestructiononHutchinsonIsland.From1971through1977,overallpredationratesintheninesurveyareaswerebetween21and44percent.However,apronounceddecreaseinraccoonpredationoccurredafter1977,andoverallpredationratesintheninesurveyareashavenotexceededtenpercentsince1979.Decreasedpreda-tionbyraccoonsprobablyreflectsadeclineintheraccoonpopulation.During1987,.72greenturtleand18leatherbackturtlenestswererecordedonHutchinsonIsland.Greenturtlenestingactivityexhibitedconsiderableannualfluctuations,ashasbeenrecordedatotherrookeries,buthasremainedrelativelyhighduringthelastsixyears.Annualleatherbacknestdensitiesduringthelasteightsurveyyearswerehigherthanthepreviousfoursurveyyears.During1987,175loggerheads,35greenturtles,2hawksbillsand6Kemp'sridleyswereremovedfromtheSt.LuciePlantintakecanal.Since48 monitoringbeganinMay1976,1,497loggerhead,227green,8leatherback,6hawksbilland10Kemp'sridleyturtleshavebeencaptured.Overthelifeofthemonitoringprogram,annualcatchesforloggerheadturtleshaverangedfrom33in1976(partialyearofplantoperationandmonitoring)to-ahighof195in1986.Yearlycatchesofgreenturtleshaverangedfrom0in1976to69in1984.Differencesinthenumberofturtlesentrappedduringdifferentyearsandmonthswereattributedtonaturalvariationintheoccurrenceofturtlesinthevicinityoftheoffshoreintakestructures,ratherthantoanyinfluenceoftheplantitself.Size-classdistributionsofloggerheadturtlesremovedeachyearfromthecanalhaveconsistentlybeenpredominatedbyjuvenilesandsub-adultsbetween50and70cminstraightlinecarapacelength.Mostgreenturtlesentrappedinthecanal(over75percent)werejuveniles40cmorlessinlength.Forbothspecies,thelargestnumberofcapturesforallyearscombinedoccurredduringthewinter,buttheseseasonalpeaksweremuchmorepronouncedforgreenturtles.Sexratiosofbothadultandimmatureloggerheadscaughtinthecanalcontinuedtobebiasedtowardsfemales.During1987,about86percentofallloggerheadsandgreenturtlesremovedfromthecanalwerecategorizedbyphysicalappearanceasbeingingoodtoexcellentcondition.Overtheentire12yearmonitoringperiod,about70and80percent,respectively,ofallloggerheadandgreenturtlecaptureshaveinvolvedindividualsinthesecategories;22 percentoftheloggerheadsand13percentofthegreenturtlesremovedfromthecanalhavebeeninfairorpoorcondition.About13percentoftheturtlesremovedfromtheintakecanalduring1987hadsevereinjuries.However,itappearedthatallbuttwooftheseinjuriesweresustainedpriortoentrapment.Onceinthecanal,turtlesconfinedeastofA1Ausuallyhadverybriefresidencytimesandthustherelativeconditionofmostturtleswasnotaffectedbytheirentrapment.During1987,22loggerheads,11greenturtlesan'd4Kemp'sridleysswamwestoftheA1Abridge.Themajorityoftheloggerheadswereretrievedatarecentlyinstalledsecurityintrusionbarrier,whileallbuttwoofthegreenturtlesandalloftheKemp'sridleyswereremovedfromthecanalattheintakewells.Sincemonitoringbegan,about9percentofallloggerheadand48percentofallgreenturtlecaptureshaveoccurredattheintakewells.During1987,twoKemp'sridleyandelevenloggerheadmortalitieswererecordedfortheintakecanal.Thisrepresentedasubstantialdecreaseinloggerheadmortalitiesfrom1986.Themajorityofdeathsduring1987appearedtohaveresultedfromdrowning,althoughtheexactcausesofdeathcouldnotbedetermined.Theintrusionbarrierwaspro-bablyresponsibleforeightoftheelevenloggerheadmortalities,butthesedeathsappearedtobeconfinedprimarilytoindividualswithinjuriesorinaweakenedcondition.50 Sinceintakecanalmonitoringbeganin1976,7.7percentoftheloggerheadsand7.0percentofthegreenturtlesremovedfromthecanalweredead.ThetwoKemp'sridleymortalitiesin1987werethefirstrecordedforthisspeciessincemonitoringbegan.Alloftheleather-backsandhawksbi11scapturedattheSt.LuciePlanthavebeenreleasedaliveintotheocean.51 LITERATURECITEDABI(AppliedBiology,Inc.)1977.EcologicalmonitoringattheFloridaPower&LightCo.St.LuciePlant,annualreport1976.VolumesIandII.AB-44.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1978.EcologicalmonitoringattheFloridaPower&LightCo.St.LuciePlant,annualreport1977.VolumesIandII.AB-101.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1979.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1978.VolumesIIandIII,Bioticmonitoring.AB-177.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,fliami.1980a.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1979.VolumesIIandIII,Bioticmonitoring.AB-244.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1980b.Turtleentrainmentdeterrentstudy.AB-290.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1981a.SuccessfulrelocationofseaturtlenestsneartheSt.LuciePlant,KutchinsonIsland,Florida.AB-317..PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1981b.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1980.VolumesIIandIII,Bioticmonitoring.AB-324.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1981c.ProposedSt.LuciePlantpreopera-tionalandoperationalbiologicalmonitoringprogram-August1981.AB-358.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1982.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologicalenvironmentalmonitoringreport1981.VolumesIIandIII,Bioticmonitoring.AB-379.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.1983.FloridaPower&LightCompany,St.LuciePantannualnon-radiologicalaquaticmonitoringreport1982.VolumesIandII.AB-442.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami.52 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LITERATURECITED(continued)Caldwell,D.K.1962.CommentsonthenestingbehaviorofAtlanticloggerheadseaturtles,basedprimarilyontaggingreturns.quarterlyJournaloftheFloridaAcademyofSciences25(4):287-302.Caldwell,D.K.,A.CarrandL.H.Ogren.1959.NestingandmigrationoftheAtlanticloggerheadturtle.InD.K.CaldwellandA.Carr,coor-dinators,TheAtlanticloggerheadseaturtleCarettacarettacaretta(L.),inAmerica.BulletinoftheFloridaStateMuseum,BiologicalSciences,4(10):295-308.Camp,D.K.,N.W.WhitingandR.E.Martin.1977.Nearshoremarineeco-logyatHutchinsonIsland,Florida:1971-1974.V.Arthropods.FloridaMarineResearchPublications25:1-63.Carr,A.,A.Meylan,J.Mortimer,K.BjorndalandT.Carr.1982.SurveysofseaturtlepopulationsandhabitatsintheWesternAtlantic.NOAATechnicalMemorandumNMFS-SEFC-91:1-82.Carr,A.,L.OgrenandC.McVea.1981.ApparenthibernationbytheAtlanticloggerheadturtleCarettacarettaoffCapeCanaveral,~~~~~~~Florida.BiologicalConservat>on19:7-14.Davis,G.E.,andM.C.Whiting.1977.LoggerheadseaturtlenestinginEvergladesNationalPark,Florida,U.S.A.Herpetologica33:18-28.Diamond,A.W.1976.BreedingbiologyandconservationofHawksbil1L.,CiI1,Syh11BiologicalConservation9:199-215.Ehrhart,L.M.1979.Reproductivecharacteristicsandmanagementpoten-tialoftheseaturtlerookeryatCanaveralNationalSeashore,Florida.Pages397-399inLinn,R.M.,ed.ProceedingsoftheFirstConferenceonScientificResearchintheNationalParks,9-12November,1976,NewOrleans,La.NPSTrans.andProc.SereNo.5.Ernest,R.G.,R.E.Martin,B.D.Peery,D.G.Strom,J.R.WilcoxandN.W.Walls.InPress.Seaturtleentrapmentatacoastalpowerplant.ProceedingsofSoutheasternWorkshoponAquaticEcologicalEffectsofPowerGeneration,3-5December,1986,Sarasota,Florida.Fowler,L.E.1979.Hatchingsuccessandnestpredationinthegreenseaturtle,Chelonia~mdasatTortuguero,CostaRica.Ecology60(5):945-955.Frair,W.1977.Turtleredbloodcel1packedvolumes,sizes,andnumbers.Herpetologica33:167-190.54
LITERATURECITED(continued)Futch,C.R.andS.E.Dwinel1.1977.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.IV.LanceletsandFishes.FloridaMarineResearchPublications24:1-23.Gallagher,R.M.1977.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.II.Sediments.FloridaMarineResearchPublications23:6-24.Gallagher,R.M.andM.L.Hollinger.1977.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.I.Introductionandrationale.FloridaMarineResearchPublications23:1-5.Gallagher,R.M.,M.L.Hollinger,R.M.IngleandC.R.Futch.1972.MarineturtlenestingonHutchinsonIsland,Floridain1971.FloridaDepartmentofNaturalResources,SpecialScientificReport37:1-11.Hendrickson,J.R.andE.Balasingam.1966.Nestingbeachpreferencesof.Malayanseaturtles.BulletinoftheNationalMuseumSingapore33(10):69-76.~~~~~~~~~Hi11estad,H.O.,J.I.Richardson,C.McYea,Jr.andJ.M.Watson,Jr.1982.Worldwideincidentalcaptureofseaturtles.Pages489-496inBjorndal,K.A.,ed.Biologyandconservationofseaturtles.SmithsonianInstitutionPress,Washington,D.C.Hirth,H.F.1980.Someaspectsofthenestingbehaviorandreproductivebiologyofseaturtles.AmericanZoologist20:507-523.Hopkins,S.R.,T.M.Murphy,Jr.,K.B.StansellandP.M.Wilkinson.1979.BioticandabioticfactorsaffectingnestmortalityintheAtlanticloggerheadturtle.ProceedingsAnnualConferenceofSoutheasternFishandWildlifeAgencies32:213-223.Hughes,G.R.1974.TheseaturtlesofsoutheastAfrica,1.Status,morphologyanddistribution's.SouthAfricanAssociationforMarineBiologicalResearch,OceanographicResearchInstitute,InvestigationalReportNo.35:1-144.1976.IrregularreproductivecyclesintheTongalandloggerheadseaturtle,Carettacaretta(L.)(Cryptodira:Chelonidae).ZoologicaAfricana11I2~285-291.Martin,R.E.,R.G.Ernest,N.W.WallsandJ.R.Wilcox.InPress.SizedistributionandseasonalabundanceofloggerheadandgreenturtlesinnearshorewatersoffHutchinsonIsland,Florida;Posterabstract.InProceedingsofSecondWesternAtlanticTurtleSymposium.Hayaguez,PuertoRico,12-16October1987.55
LITERATURECITED(continued)Mendonca,M.T.andL.M.Ehrhart.1982.Activity,populationsizeandstructureoftheimmatureChelonia~mdasandCarettacarettainMosquitoLagoon,Florida.Copeia1982:161-167.Moffler,M.D.andJ.F.VanBreedveld.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.X.Benthicalgaespecieslist.FloridaMarineResearchPublications34:118-122.Mortimer,J.A.1982.Factorsinfluencingbeachselectionbynestingseaturtles.Pages45-51inBjorndal,K.A.,ed.Biologyandconserva-tionofseaturtles.SmithsonianInstitutionPress.Washington,D.C.NMFS(NationalMarineFisheriesService).1978.FinalEISlistingandprotectingthegreenseaturtle(Chelonia~mdas),loggerheadseaturtle(Carettacaretta)andtilepac>f>cR>dleyseaturtle(Leidochelsoliv~aceaundertheEndangeredSpeciesActof1973.Rat>onemarinefssheriesService,Dept.ofCommerce,iiashington,D.C.NRC(U.S.NuclearRegulatoryCommission).1982.FinalenvironmentalstatementrelatedtotheoperationofSt.LuciePlantUnit2.DocketNo.50-389.O'ara,J.1980.Thermalinfluencesontheswimmingspeedofloggerheadturtlehatchlings.Copeia1980(4):773-780.Ogren,L.andC.McVea,Jr.1982.ApparenthibernationbyseaturtlesinNorthAmericanwaters.Pages127-132inBjorndal,K.A.,ed.Biologyandconservationofseaturtles.SmithsonianInstitutionPress,Washington,D.C.Owens,D.W.,J.R.Hendrickson,V.LanceandI.P.Cal1ard.1978.AtechniquefordeterminingsexofimmatureChelonia~mdasusingaradioimmunoassay.Herpetologica34:270-273.Owens,D.W.andG.J.Ruiz.1980.Newmethodsofobtainingbloodandcerebrospinalfluidfrommarineturtles.Herpetologica36:17-20.Pritchard,P.C.,P.R.Bacon,F.H.Berry,A.F.Carr,J.Fletemeyer,R.M.Gallagher,S.R.Hopkins,R.R.Lankford,R.MarquesM.,L.H.Ogren,W.G.Pringle,Jr.,H.A.ReichartandR.Witham.1983.Manualofseaturtleresearchandconservationtechniques.PreparedfortheWesternAtlanticTurtleSymposium,SanJose,CostaRica,July1983.126pp.Proffitt,C.E.,R.E.Martin,R.G.Ernest,B.J.Graunke,S.E.LeCroy,K.A.Muldoon,B.D.Peery,J.R.WilcoxandN.Williams-Walls.1986.Effectsofpowerplantconstructionandoperationonthenestingofthe1oggerheadseaturtle(Carettacaretta):1971-1984.Copeia1986(3):813-816.
LITERATURECITED(continued)Raymond,P.W.1984.TheeffectsofbeachrestorationonmarineturtlesnestinginsouthBrevardCounty,Florida.M.S.thesis,UniversityofCentralFlorida.Routa,R.A.1968.SeaturtlenestsurveyofHutchinsonIsland,Florida.quarterlyJournalFloridaAcademyofSciences30(4):287-294.Schulz,J.'P.1975.SeaturtlesnestinginSurinam.ZoologischeVerhandelingen,uitgegevendoorhetRijksmuseumvanNatuurlijkeHistoricteLeiden,No.143:1-144.Smith,N.P.1982.UpwellinginAtlanticshelfwatersofsouthFlorida.FloridaScientist45(2):125-138.Sokal,R.R.andF.J.Rohlf.1981.Biometry.Theprinciplesandprac-ticeofstatisticsinbiologicalresearch.W.H.FreemanandCompany,SanFrancisco.859pp.Stancyk,S.E.1982.Non-humanpredatorsofseaturtlesandtheircon-trol.Pages139-152inBjorndal,K.A.,ed.Biologyandconserva-tionofseaturtles.SmithsonianInstitutionPress.Washington,D.C.Talbert,O.R.,S.E.Stancyk,J.M.DeanandJ.M.Will.1980.Nestingactivityoftheloggerheadturtle(Carettacaretta)inSouthCarolina.I:Arookeryintransition.Copeia1980:709-718.Taylor,C.B.,andH.B.Stewart.1958.SummerupwellingalongtheeastcoastofFlorida.JournalofGeophysicalResearch64(1):33-40.Tester,L.A.andK.A.Ste'idinger.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.VII.Phytoplankton,1971-1973.FloridaMarineResearchPublications34:16-61.Walker,'.M.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.IX.Dielplankton,1973-1974.FloridaMarineResearchPublications34:99-117.Walker,L.M.,B.M.GlassandB.S.Roberts.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.VIII.Zooplankton,1971-1973.FloridaMarineResearchPublications34:62-98.Walker,L.M.'andK.A.Steidi,nger.1979.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.VI.Planktondynamics,1971-1973.FloridaMarineResearchPublications34:1-15.
LITERATURECITED(continued)Wibbels,T.,D.Owens,Y.MorrisandM.Amoss.1984.SexratiosofimmatureloggerheadseaturtlescapturedalongtheAtlanticcoastoftheUnitedStates.FinalReporttotheNationalMarineFisheriesService.,ContractNo.NA81-GA-C-0039.47pp.Williams-Walls,N.,J.O'ara,R.M.Gallagher,D.F.Worth,B.D.PeeryandJ.R.Wi1cox.1983.SpatialandtemporaltrendsofseaturtlenestingonHutchinsonIsland,Florida,1971-1979.BulletinofMarineScience33(1):55-66.Witherington,B.E.andL.M.Ehrhart.InPress.Statusandreproductivecharacteristicsofgreenturtles(Chelonia~mdas)nestinginFlorida.Posterabstract.InProceedingsofSecondWesternAtlanticTurtleSymposium.Mayaguez,PuertoRico,12-16October1987.Worth,D.F.andM.L.Hollinger.1977.NearshoremarineecologyatHutchinsonIsland,Florida:1971-1974.III.Physicalandchemicalenvironment.FloridaMarineResearchPublications23:25-85.Worth,D.F.,andJ.B.Smith.1976.MarineturtlenestingonHutchinsonIsland,Florida,in1973.FloridaMarineResearch.Publications18:1-17.58
GULFOFMEXICO0dOOVASSSKILOMDERSSCALE~~-N-St.LuciePlantFigure1.LocationoftheSt.LuciePlant.
l gegI~~P,::HUTCHINSONV\h~'La7~~V~OdVgH~ISLANDC~'I~tqP~'DISCHARGE@G'.:PIPES~qS'i.0v'9INTAKE'<:.INTAKE0+HEADWALL',WELLSINTAKESTRUCTURESINTRUSIONBARRIER:BARRIER,.NET;7";;':.':S',,Cl'vINTAKECANAL0250500METERS~~rFigure2.St.LuciePlantcoolingwaterintakeanddischargesystem.
L1 "i0'e~~'tPierceInletAAlgQQbb,eC7EaStateHwyA'0eH23LMN40FPLpSTLUCIEPLANTU.S.HwyI~n1eg4I0SkmR(VE,Rw/6YzQBBCCDDEE8FFHHGG~\ped1>.':e9~~St.LucleInletFigure3.Designationandlocationofnine1.25-kmsegmentsand~~~~~~thirty-six1-kmsegmentssurveyedforseaturtlenesting,HutchinsonIsland,1971-1987.
3000329250z0200z15010050123456789NORTHPOWERPLANTSOUTHFigure4.Heanannualnumberofloggerheadturtlenestsineachofthenine1.25-km-longsurveyareas,HutchinsonIsland,1971-1986,comparedwithnumberofnestsduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values(1980datawereexcludedbecausenotallareasweresurveyed).
0300250200R150Dz10050ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJABCDEFGHIJNORTH0POWERPLANTSOUTHFigure5.Heanannualnumberofloggerheadturtlenestsineachofthethirty-six1-km--longsurveyareas,HutchinsonIsland,1981-1986,comparedwithnumberofnestsduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values.
500g)400Oz300200100NORTHABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJABCDEFGHIJPOWERPLANTSOUTHFigure6.Heanannualnumberofloggerheadturtleemergencesineachofthethirty-six1-km-longsurveyareas,HutchinsonIsland,1981-1986,comparedwithnumberofemergencesduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values.
10080g(0COUJOOg60C9Z(0I-IIJz4020ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJABCDEFGHIJNORTHf'OWERPLANTSOUTHFigure7.Neanannualloggerheadturtlenestingsuccess(percentageofemergencesthatresultedinnests)foreachofthethirty-six1-km-longsurveyareas,HutchinsonIsland,1981-1986,comparedw'ithnestingsuccessduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values'
250o~Area4(PowerPlantSite)X--XArea5(ControlSite)200z150z100~XXX////XXx~N<x/K///X5071737577798081828384858687Figure8.NumberofloggerheadturtlenestsinAreas4and5,HutchinsonIsland,1971-1987.Arrowsdenoteyearsduringwhichintake/dischargeconstructionoccurredinArea4.
COI-COzDz50004000300020001000o10000z8000600040002000gCOCOLljOODCO(9zI-COUj8060402019811982198319841985198619879.Annualnumberofnests,numberofemergencesandnestingsuccessalongtheentire36.0-km-longAtlanticcoastlineofHutchinsonIsland,1981-1987.
~OujKDI-IZIllQ.ILjI-2826242220906030015305APR1530515305153051530515MAYJUNJULAUGSEPFigure10.Dailyloggerheadturtlenestingactivityandwatertemperature,HutchinsonIsland,1987.
50ALLAREASAREA150AREA250AREA3500-0W'o)50I-COLLIZAREA4AREA550I-Z50AREA650AREA750AREA8AREA9501971197319751977197919801981198219831984198519861987Figure11.Percentageofloggerheadturtlenestsdestroyedbyraccoonsinthenine1.25-km-longsurveyareas,HutchinsonIsland,1971-1987.
QDestroyedbyghostcrabsgDestroyedbyraccoonsandghostcrabsDestroyedbyraccoons50CIg40CO30z20z2?%1001%1%1%1A-BCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJABCDEFGHIJNORTH0POWERPLANTSOUTHFigure12.Numberofloggerheadturtlenestsdes'troyedbyraccoonsandghostcrabsandpercentageofnestsdestroyedineach1-km-longsurveyarea,HutchinsonIsland,1987.
60co45Zm30Z15p---pGreen(Cheloniamydas)8-+9Leatherback(Dermochelyscoriacea)rrpW-/Fs/Ii/I/I//I/Ix/~/IIIIIIIIIII19711973197519771979198119821983.1984198519861987Figure13.Numberofgreenturtleandleatherbackturtlenests,HutchinsonIsland,1971-1987.
~,
200~LOGGERHEAD(Carettacaretta)0---E3GREEN(Chelcniamidas)80175I-0150O125(901007550Z25I///0/I/I0////0x/0--000I)I5/\00070M6055040030.gD2010197619771978197919801981198219831984198519861987Figure14.Numberofloggerheadandgreenturtlesremovedeachyearfromtheintakecanal,St.LuciePlant,1976-1987.
5050Pv40030mZZ204030201010JANFEBMARAPRMAYJUNJULAUG.SEPOCTNOVDECMONTHOFCAPTUREFigure16.Heannumberofloggerheadscapturedeachmonth,St.LuciePlantintakecanal,1977-1986,comparedwithnumberofmonthlycapturesduring1987.Horizontallinesaremeans,boxesencloseplusorminusonestandarddeviation,verticallinesareranges,andclosedcirclesare1987values.
300200DO00z0KILJKlz100200.100c4041-4546-5051-5556-6061-6566-7071-7576-8081-8586-9091-9596-101-106-111-116-100105110115120STRAIGHTLINECARAPACELENGTH(cm)Figure16.Lengthdistribution(SLCL)ofliveloggerheadseaturtles(N=1,278)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1987.
18018016016014O0120Oz100Km8OD60140120100806040402020~2021-3031-4041-5051-6061-7071-8081-9091-100WEIGHT(Ibs)101-151-201-251-301-5350150200250300350figure17.Weightdistributionofliveloggerheadseaturtles(N=1,140)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1987.
8080COD060CIz0KlU40z60402020-1516-21-26-31-36-41-46-51-56-61-66-71-76-81-86-91-96-101-106-11120253035404550556065707580'859095100105110115STRAIGHTLINECARAPACELENGTH(cm)Figure18.Lengthdistribution(SLCL)oflivegreenturtles(N=209)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1987.
125125~100D00750K03D50.10075502525s1011-2021-3031-4041-5051-6061-7071-8081-9091-100WEIGHT(Ibs)101-151-201-251-i300150200250300Figure19.Weightdistributionoflivegreenturtles(N=205)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1987.
'-'-.MALESFEMALES4040MDO30Clz0KujK20Dz30201010JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECMONTHOFCAPTUREFigure20.Numbersofadultloggerheads(N=202),includingrecaptures,removedeachmonthfromtheintakecanal,St.LuciePlant,1976-1987.
400-0CANALCAPTURES300OKDOCOI-DO0KIDzDZZ3020100--~NESTS0Z'25PZ15075197619771978197919801981198219831984198519861987Figure21.Comparisonofcapturesofadultfemaleloggerheadsintheintakecanal,St.LuciePlant,1976-1987,andnumbersofloggerheadnestsinArea4adjacenttotheplant.Nonestingdatawerecollectedin1976and1978.
80z0.60)I-DDo4020/0//r00//0III0I0II0III0III0III0/J~0-----oIntervalbetweensuccessivecapturesIntervalbetweenfirstandlastcapture.806040201002003004005006007008009001000110012001300RECAPTUREINTERVAL(days)Figure22.Cumulativepercentageofallloggerheadrecapturesoccurringwithinvarioustimeintervalsbetweensuccessivecaptures(N=77)andfirstandlastcapture(N=45),St.LuciePlantintakecanal,1976-1987.
ESTIMATESOFTHENUMBERSOFLOGGERHEADTURTLENESTSONHUTCHINSONISLANDBASEDONSURVEYSOFNINE1.25-KM-LONGSURVEYAREAS,1971-1987,COMPAREDTOTHEACTUALNUMBEROFNESTSONTHEISLAND,1981-1987Year197119731975197719791981198219831984198519861987Numberofnestsinthenine1.25-km-longsurveyareas14201260149393214491031163415921439162318391645Extrapolationfromthenine418937174404274942753041482046964245478854254853surveyareastotheentireisland(seetext)Actualnumberofnestsontheentireisland3115469047434277487754834623 T2TOTALNUMBEROFSEATURTLEURESAND(NUMBEROFDEAD)TURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT1976-1987Year1976197719781979198019811982198319841985loerhead33(4)8o(s)138(19)173(13)116(5)62(s)101(16)119(4)148(3)157(4)Seciesreenleatherbacks(2)6(1)3(1)1O(3)32(2)23(4)69(2)14hawksbillKem'sridleTotal33(4)86(7)148(20)176(14)126(8)97(7)110(16)142(8)22O(S)172(4)19861987195(27)175(11)22(1)35Total1497(116)227(16)8(o)6(o)6(2)10(2)220(28)218(13)1748(134)AnnualMeana133.120.60.70.50.9158.9aExcludes1976(partialyearofplantoperation).
TABLETOTALNUMBERAND(NUMBEROFD0)LOGGERHEADTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT1976-1987Month19761977197819791980198119821983JanuaryFebruary131924(3)1611(1)6(2)398(1)11(2)29(1)21(2)11(3)1113(1)MarchAprilMay727(2)11145(2)19(5)17213(1)0761411014617(4)June05103(1)8(3)677(1)July7(1)4027(2)017August231217(2)12September115(l)18(1)19OctoberNovemberDecember9541079(1)17(2)15(3)75(3)515(7)12462(1)62(1)9(1)8(2)09(5)1704(2)531(1)12Total33(4)80(5)138(19)173(13)116(5)62(5)101(16)119(4)
TABL(continued)TOTALNUMBERAND(NUMBEROFDEAD)LOGGERHEADTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT1976-1987Month1984198519861987TotalMonthlyPercentofMeanTotalCatchaJanuaryFebruaryMarchApril111516(4)11157(14)14.362014(4)8(1)128(7)11.62(1)1320(2)24(3)124(13)11.3131115(2)26(3)193(11)17.513.210.78.78.5May7161223(1)98(6)8.26.6JuneJulyAugustSeptemberOctoberNovemberDecemberTotal16149(4)10711(2)938210106(10)8.8112(13)9.375(12)6.381(1)6.7148(3)157(4)195(27)175(11)1497(116)28(1)1720(1)26(1)137(8)11.412(1)20(3)26(2)19(1)130(10)10.82619(1)34(6)17(1)156(11)13.09.48.410.57.27.24.84.9aExcludes1976(partialyearofplantoperation).
TOTALNUMBERAND(NUMBEROFDEAD)GREENTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT1976-1987MonthJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember197619771978197919801981210020(1)2(1)215(1)70204(1)1(1)01(1)001(1)02(1)198219838(1)3(2)4(1)Total5(2)6(1)3(1)10(3)32(2)23(4)
TA4(continued)TOTALNUMBERAND(NUMBEROFDEAD)GREENTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT1976-1987MonthJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember1011116(1)34(1)198419851986198737(l)414Total78(3)34(2)20(4)13(2)4(1)10(1)9(1)1018(2)19MonthlyMean7.13.11.81.20.30.80.60.70.40.81.51.6PercentofTotalCatch34.415.08.85.71.84.43.14.02.2447.98.4Total69(2)1422(1)35227(16)
NUMBEROFMONTHLYCAPTURESBYSIZECLASSFORLIVELOGGERHEADTURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT1976-1987aMonthSizeclassesSLCLincmJuveniles/Sub-AdultsTransitionAdults41-5051-6061-70TotalPercentae71-80Percentae81-9091-100>100TotalPercentaeJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember3419363172214323631474591478615112075143101103637839342366443338023431676434190239317214.612.010.18.36.68.06.79.07.27.24.36.3221416161010181513.78.710.010.05.06.36.311.35.69.48.75.0232210200030105010115213162113020101435403614125.41.61.63.37.619.021.719.67.66.53.32.7Total76504424100474.516011.911661718413.6aNodatawerecollectedfor33individuals.
T6RELATIVECONDITIONSEATURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT1976-1987RelativeconditionLoerheadsNumberGreensNumberkNumberXNumberHawksbillsNumberAllseciesNumberTOTAL26017.434022.743829.325817.2765.11167.790.614976830.03917.27231.72310.162.6167.031.3227675.0112.522033011011022010112.5110466.633419.1116.638221.9116.652029.728316.2834.71347.7120.717481Excellent-normalorabovenormalweight,active,veryfewornobarnaclesorleeches,nowounds.2Verygood-intermediategoodtoexcellent.3Good-normalweight,active,lighttomediumcoverageofbarnaclesand/orleeches,woundsabsent,healedordonotappeartodebilitatetheanimal.4Fair5Poor-intermediatepoortogood.-emaciated,sloworinactive,heavybarnaclecoverageand/orleechinfestation,debilitatingwoundsormissingappendages.6Dead7Alivebutconditionotherwiseunknown.