ML17223B174: Difference between revisions
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
||
Line 17: | Line 17: | ||
=Text= | =Text= | ||
{{#Wiki_filter:APPLIEDBI0L'06Y,INC.AB-610I'LORIDAPOWER&LIGHTCOMPANYST. | {{#Wiki_filter:APPLIEDBI0L'06Y,INC.AB-610I'LORIDAPOWER&LIGHTCOMPANYST.LUCIEUNIT2ANNUALENVIRONMENTAL OPERATING REPORTVOLUMEI1990I2968ANORTHDECATURROAD9105070294 910025PDRADOCK05000389RPDR~ATLANTA,GEORGIA30033~404-296-3900 AB-610FLORIDAPOWER&LIGHTCOMPANYST.LUCIEUNIT2ANNUALENVIRONMENTAL OPERATING REPORT1990VOLUME1APRIL1991FLORIDAPOWER&LIGHTCOMPANYJUNOBEACH,FLORIDAAPPLIEDBIOLOGY,INC.ATLANTA,GEORGIA IIIIII ENVIRONMENTAL OPERATING REPORTTABLEOFCONTENTSTABLEOFCONVERSION FACTORSFORMETRICUNITSEXECUTIVE SUMMARYIntroduction TurtleNestingSurveyIntakeCanalMonitoring OtherRelatedActivities INTRODUCTION | ||
===Background=== | |||
AreaDescription PlantDescription TURTLESIntroduction Materials andMethodsNestingSurveyIntakeCanalMonitoring StudiestoEvaluateand/orMitigateIntakeEntrapment ResultsandDiscussion NestingSurveyDistribution ofLoggerhead NestsAlongHutchinson IslandEstimates ofTotalLoggerhead NestingonHutchinson IslandTemporalLoggerhead NestingPatternsPredation onLoggerhead TurtleNestsGreenandLeatherback TurtleNestingIntakeCanalMonitoring RelativeAbundance andTemporalDistribution Size-Class Distributions SexRatiosCaptureEfficiencies RelativeCondition Mortalities Recapture Incidents SummaryLITERATURE CITEDFIGURESTABLESIVIV10101415151518192021232326.28.3031333436404870 TABLEOFCONVERSION FACTORSFORMETRICUNITSToconvertcentigrade (degrees) centigrade (degrees) centimeters (cm)centimeters (cm)centimeters/second (cm/sec)cubiccentimeters (cm)grams(g)grams(g)hectares(ha)kilograms (kg)kilograms (kg)kilograms (kg)kilometers (km)kilometers (km)liters(I)liters(I)meters(m)meters(m)meters(m)milligrams (mg)milligrams/liters (mg/I)milliliters (ml)millimeters (mm)millimeters (mm)squarecentimeters (cm)squaremeters(m)squaremillimeters (mm)MultiIb(Cx1.8)+32C+273.183.937x103.281x103.281x101.0x102.205x103.527x102.4711.0x102.20463.5274x106.214x101.0x101.0x102.642x103.2813.937x101.0941.0x101.01.0x103.937x103.281x101.550x101.076x101.55x10Toobtainfahrenheit (degrees) kelvin(degrees) inchesfeetfeetpersecondliterspoundsounces(avoirdupois) acresgramspoundsounces(avoirdupois) miles(statute) millimetcrscubiccentimeters (cm)gallons(USliquid)feetinchesJJardsgramspartspermillionliters(USliquid)inchesfeetsquareinchessquarefeetsquareinches IIIrIe,t EXECUTlVE SUMMARYINTRODUCTION TheSt.LuciePlantisanelectricgenerating stationonHutchinson IslandinSt.LucieCounty,Florida.Theplantconsistsoftwonuclear-fueled 850-MWunits;Unit1wasplacedon-lineinMarch1976andUnit2inMay1983.Thisdocumenthasbeenpreparedtosatisfy.therequirements contained intheUnitedStatesNuclearRegulatory Commission's AppendixBEnvironmental Protection Plan(EPP)toSt.LucieUnit2FacilityOperating LicenseNo.NPF-16.Thisreportdiscusses environmental protection activities relatedtoseaturtlesasrequiredbySubsection 4.2oftheEPP.Otherroutineannualreporting requirements areaddressed inVolume2,alsoentitled"St.LucieUnit2AnnualEnvironmental Operating Report".TURTLENESTINGSURVEYTherehavebeenconsiderable year-to-year fluctuations inseaturtlenestingactivityonHutchinson Islandsincemonitoring beganin1971.Lownestingactivityin1975and1981-1983inthevicinityofthepowerplantwasattributed toconstruction ofplantin-takeanddischarge structures. | |||
Nestingreturnedtonormalorabovenormallevelsfol-lowingbothperiodsofconstruction. | |||
Powerplantoperation exclusive ofconstruction hashadnosignificant effectonnestingneartheplant.Datacollected through1990haveshownnolong-term reductions intotalnesting,totalemergences ornestingsuc-cessontheisland.Formalrequirements toconductthisprogramexpiredin1986butwerevoluntarily continued in1990withagreement fromfederalandstateagencies. | |||
INTAKECANALMONITORING Sinceplantoperation beganin1976,2,193seaturtles(including 100recaptures) representing fivedifferent specieshavebeenremovedfromtheintakecanal.Eighty-fourpercentofthesewereloggerheads. | |||
Differences inthenumbersofturtlesfoundduringdifferent monthsandyearswereattributed tonaturalvariation intheoccurren-cesofturtlesinthevicinityoftheplant,ratherthantoanyinfluence oftheplantitself.Themajorityofturtlesremovedfromtheintakecanal(about93percent)werecapturedaliveandreleasedbackintotheocean.TurtlesconfinedbetweentheA1Abarriernetandintakeheadwalls usuallyresidedinthecanalforarelatively shortperiodoftime,andmostwereingoodtoexcellent condition whencaught.OTHERRELATEDACTIVITIES Studiestoevaluatevariousintakedeterrent systems,asrequiredbytheNRC'sUnit2Environmental Protection Plan,wereconducted during1982and1983.Resultsandevaluations ofthosestudieswerepresented toregulatory agenciesduring1984,andtherequirement isnowconsidered completed. | |||
INTRODUCTION BACKGROUND Thisdocumenthasbeenpreparedtosatisfytherequirements contained intheUnitedStatesNuclearRegulatory Commission's (NRC)AppendixBEnvironmental Protection PlantoSt.LucieUnit2FacilityOperating LicenseNo.NPF-16.In1970,FloridaPower8LightCompany(FPL)wasissuedPermitNo.CPPR-74bytheUnitedStatesAtomicEnergyCommission, nowtheNuclearRegulatory Commis-sion,thatallowedconstruction ofUnit1oftheSt.LuciePlant,an850-MWnuclear-poweredelectricgenerating stationonHutchinson IslandinSt.LucieCounty,Florida.StLuciePlantUnit1wasplacedon-lineinMarch1976.InMay1977,FPLwasissuedPermitNo.CPPR-144bytheNRCfortheconstruction ofasecond850-MWnuclear-poweredunit.Unit2wasplacedon-lineinMay1983andbegancommercial operation inAugustofthatyear.St.LuciePlantUnits1and2usetheAtlanticOceanasasourceofwaterforonce-throughcondenser cooling.Since1971,thepotential environmental effectsresulting fromtheintakeanddischarge ofthiswaterhavebeenthesubjectofFPL-sponsored bioticstudiesatthesite.Baselineenvironmental studiesofthemarineenvironment adjacenttotheSt.LuciePlantweredescribed inaseriesofreportspublished bytheFloridaDepartment ofNaturalResources (Campetal.,1977;FutchandDwinell,1977;Gallagher, 1977;Gal-lagherandHollinger, 1977;WorthandHollinger, 1977;MofflerandVanBreedveld, 1979;TesterandSteidinger, 1979;Walker,1979;Walkeretal.,1979;WalkerandSteidinger, 1979;Lyons,1989).TheresultsofUnit1operational andUnit2preopera-tionalbioticmonitoring attheSt.LuciePlantwerepresented insixannualreports(ABI,1977,1978,1979,1980a,1981b,1982).InJanuary1982,aNationalPollutant Discharge Elimination System(NPDES)permitwasissuedtoFPLbytheUSEnvironmental Protec-tionAgency(EPA).TheEPAguidelines fortheSt.Luciesitebiological studieswerebasedonthedocumententitled"Proposed St.LuciePlantPreoperational andOpera-tionalBiological Monitoring Program-August1981"(ABI,1981c).Findingsfromthesestudieswerereportedinthreeannualreports(ABI,1983,1984a,1985a).TheEPAbioticmonitoring requirements weredeletedfromtheNPDESpermitin1985.Jurisdiction forseaturtlestudiesiswiththeNRC,whichisconsidered tobetheleadfederalagencyrelativetoconsultation undertheEndangered SpeciesAct.Previousresultsdealingexclusively withseaturtlestudiesarecontained insevenenvironmen-taloperating reports(ABI,1984b,1985b,1986,1987,1988,1989,1990).Thisreportdescribes the1990environmental protection activities relatedtoseaturtles,asrequiredbySubsection 4.2oftheSt.LuciePlantUnit2Environmental Protection Plan.AREADESCRIPTION TheSt.LuciePlantislocatedona457-hasiteonHutchinson IslandonFlorida's eastcoast(Figures1and2).Theplantisapproximately midwaybetweentheFt.PierceandSt.LucieInlets.ItisboundedonitseastsidebytheAtlanticOceanandonitswestsidebytheIndianRiverLagoon. | |||
IIIII Hutchinson Islandisabarrierislandthatextends36kmbetweeninletsandobtainsitsmaximumwidthof2kmattheplantsite.Elevations approach5matopdunesbor-deringthebeachanddecreasetosealevelinthemarigrove swampsthatarecommononmuchofthewesternside.Islandvegetation istypicalofsoutheastern Floridacoas-talareas;densestandsofAustralian pine,palmetto, seagrapeandSpanishbayonetarepresentatthehigherelevations, andmangroves aboundatthelowerelevations. | |||
Largestandsofblackmangroves, including someontheplantsite,havebeenkilledbyfloodingformosquitocontroloverpastdecades.TheAtlanticshoreline ofHutchinson Islandiscomposedofsandandshellhashwithintermittent rockypromontories protruding throughthebeachfacealongthesouthernendoftheisland.Submerged coquinoid rockformations parallelmuchoftheislandofftheoceanbeaches.Theoceanbottomimmediately offshorefromtheplantsitecon-sistsprimarily ofsandandshellsediments. | |||
Theunstablesubstrate limitstheestab-lishmentofrootedmacrophytes. | |||
TheFloridaCurrent,whichflowsparalleltothecontinental shelfmargin,beginstodivergefromthecoastline atWestPalmBeach.AtHutchinson Island,thecurrentisapproximately 33kmoffshore. | |||
Oceanicwaterassociated withthewesternboundaryofthecurrentperiodically meandersovertheinnershelf,especially duringsummermonths.PLANTDESCRIPTION TheSt.LuciePlantconsistsoftwo850-MWnuclear-fueled electricgenerating unitsthatusenearshore oceanwatersfortheplant'sonce-through condenser coolingwater system.Waterfortheplantentersthroughthreesubmerged intakestructures locatedabout365moffshore(Figure2).Eachoftheintakestructures isequippedwithavelocitycaptominimizefishentrainment. | |||
Horizontal intakevelocities arelessthan30cm/sec.Fromtheintakestructures, thewaterpassesthroughsubmerged pipes(two3.7mandone4.9mindiameter) underthebeachanddunesthatleadtoa1,500-mlongintakecanal.Thiscanaltransports thewatertotheplant.Afterpassingthroughtheplant,theheatedwaterisdischarged intoa670-mlongcanalthatleadstotwoburieddischarge pipelines. | |||
Thesepassunderneath thedunesandbeachandalongtheoceanfloortothesubmerged discharges, thefirstofwhichisapproximately 365moffshoreand730mnorthoftheintake.Heatedwaterleavesthefirstdischarge linefromaY-shapednozzle(diffuser) atadesignvelocityof396cm/sec.Thishigh-momentum jetentrainsambientwater,result-inginrapidheatdissipation. | |||
Theoceandepthintheareaofthefirstdischarge isabout6m.Heatedwaterleavestheseconddischarge linethroughaseriesof48equallyspacedhighvelocityjetsalonga323-mmanifold(multiport diffuser). | |||
Thisdiffuserstarts168mbeyondthefirstdischarge andterminates 856mfromshore.Theoceandepthatdischarge alongthisdiffuserisfromabout10to12m.Aswiththefirstdiffuser, thepurposeoftheseconddiffuseristoentrainambientwaterandrapidlydissipate heat.Fromthepointsofdischarge atbothdiffusers, thewarmerwaterrisestothesurfaceandformsasurfaceplumeofheatedwater.Theplumethenspreadsoutonthesur-faceoftheoceanundertheinfluence ofwindandcurrentsandtheheatdissipates totheatmosphere. | |||
>tIIIIII TURTLESTheNRC'sSt.LucieUnit2AppendixBEnvironmental Protection PlanissuedApril1983containsthefollowing technical specifications: | |||
4.2Terrestrial AuaticIssuesIssuesonendangered orthreatened seaturtlesraisedintheUnit2FES-OL[NRC,1982)andintheEndangered SpeciesBiological As-sessment(March1982)[Bellmund etal.,1982]willbeaddressed byprogramsasfollows:Beachnestingsurveysforallspeciesofseaturtleswillbeconducted onayearlybasisfortheperiodof1982through1986.Thesesur-veyswillbeconducted duringthenestingseasonfromap-proximately mid-April throughAugust.TheHutchinson Islandbeachwillbedividedinto36one-km-long surveyareas.Inaddition, thenine1.25-km-long surveyareasusedinpreviousstudies(1971-1979) willbemaintained forcomparison purposes. | |||
Surveyareaswillbemarkedwithnumberedwoodenpla-quesand/orexistinglandmarks. | |||
Theentirebeachwillbesurveyedsevendaysaweek.AIInewnestsandfalsecrawlswillbecountedandrecordedineacharea.Aftercounting, allcrawltrackswillbeobliterated toavoidrecounting. | |||
Predation onnestsbyraccoonsorotherpredators willberecordedasitoccurs.Recordswillbekeptofanyseasonalchangesinbeachtopography thatmayaffectthesuitability ofthebeachfornesting.4.2.2Aprogramthatemployslightand/orsoundtodeterturtlesfromtheintakestructure willbeconducted. | |||
Thestudywilldetermine withlaboratory andfieldexperiments ifsoundand/orlightwillresultinareduction oftotalturtleentrapment rate. | |||
Thestudyshallbeimplemented nolaterthanafterthefinalremovalfromtheoceanofequipment andstructures associated withcon-struction ofthethirdintakestructure andtheexperiments shallter-minate18monthslater.Fourmonthsaftertheconclusion oftheexperimental period,areportontheresultsofthestudywillbesub-mittedtoNRC,EPA,NationalMarineFisheries Service(NMFS),andtheUSFishandWildlifeService(USFWS)fortheirevaluation. | |||
Ifastatistically significant reduction inannualtotalturtleentrapment rateof80percentorgreatercanbedemonstrated, usingthedeveloped technology anduponFPLreceiving writtenconcurrence byNRC,EPA,NMFS,andUSFWSthenpermanent installation ofthedeterrent systemshallbecompleted andfunctioning nolaterthan18monthsaftertheagencies'oncurrence. | |||
Thedesignofthisstudyneedstotakeintoaccountthesignificant annualvariation inturtleentrapment observedinthepast.Ifan80percentreduction ofturtleentrapment cannotbeprojected toallthreeintakestructures, thenaninteragency taskforcecom-posedofNRC,EPA,NMFS,'USFWS, andFPLshallconvene18monthsaftercompletion ofthethirdintakeanddetermine ifothercoursesofactiontomitigateand/orreduceturtleentrapment arewarranted (suchasphysicalbarrier,emergence ofnewtechnology ormethodstodeterturtles). | |||
4.2.3Alternative methodsorprocedures forthecaptureofseaturtlesentrapped intheintakecanalwillbeevaluated. | |||
Ifamethodorpro-cedureisconsidered feasibleandcosteffective andmayreducecapturemortality rates,itwillbefieldtestedintheintakecanal.4.2.5CatureandReleaseProramSeaturtleremovalfromtheintakecanalwillbeconducted onacon-tinuingbasis.Theturtleswillbecapturedwithlargemeshnets,orothersuitablenondestructive device(s), | |||
ifdeemedappropriate. | |||
Aformalized dailyinspection, fromtheshoreline, ofthecaptul'Bdevice(s) willbemadebyaqualified individual whenthedevice(s) aredeployed. | |||
Theturtleswillbeidentified tospecies,measured, weighed(ifappropriate), | |||
taggedandreleasedbackintotheocean.Recordsofwounds,freshorold,andasubjective judgement onthecondition oftheturtle(e.g.,barnaclecoverage, underweight) willbemaintained. | |||
Methodsofobtaining additional biological/physiologi-caldata,suchasbloodanalysesandparasiteloads,fromcaptured IIIIII seaturtleswillbepursued.Deadseaturtleswillbesubjected toagrossnecropsy, iffoundinfreshcondition. | |||
INTRODUCTION Hutchinson Island,Florida,isanimportant rookeryfortheloggerhead turtle,Caret-tacarettaandalsosupportssomenestingofthegreenturtle,Chelonia~mdasandthIth5kttl.~OIII1915IIt1.,1959;5 t,1995;9I-lagheretal.,1972;WorthandSmith,1976;Williams-Walls etal.,1983).Allthreespeciesareprotected bystateandfederalstatutes. | |||
Thefederalgovernment classified thelog-gerheadturtleasathreatened species.Theleatherback turtleandtheFloridanestingpopulation ofthegreenturtlearelistedbythefederalgovernment asendangered species.Becauseofreductions inworldpopulations ofmarineturtlesresulting fromcoastaldevelopment andfishingpressure(NMFS,1978),maintaining thevitalityoftheHutchinson Islandrookeryisimportant. | |||
IthasbeenaprimeconcernofFPLthattheconstruction andsubsequent opera-tionoftheSt.LuciePlantwouldnotadversely affecttheHutchinson Islandrookery.Becauseofthisconcern,FPLhassponsored monitoring ofmarineturtlenestingac-tivityontheislandsince1971.Daytimesurveystoquantifynesting,aswellasnighttime turtletaggingprograms, wereconducted inoddnumberedyearsfrom1971through1979.Duringdaytimenest-ingsurveys,nine1.25-km-long surveyareasweremonitored fivedaysperweek(Figure3).TheSt.LuciePlantbeganoperation in1976;therefore, thefirstthreesurveyyears(1971,1973and1975)werepreoperational. | |||
Thoughthepowerplantwasnotoperat-ingduring1975,St.LuciePlantUnitNo.1oceanintakeanddischarge structures were IIIIII installed duringthatyear.Installation ofthesestructures includedconstruction activities conducted offshorefromandperpendicular tothebeach.Construction hadbeencom-pletedandtheplantwasinfulloperation duringthe1977and1979surveys.Amodifieddaytimenestingsurveywasconducted in1980duringthepreliminary construction oftheoceandischarge structure forSt.LuciePlantUnit2.Duringthisstudy,fourofthepreviously established 1.25-km-long surveyareasweremonitored. | |||
Additionally, eggsfromturtlenestspotentially endangered byconstruction activities wererelocated. | |||
Everyyearfrom1981through1990,361-km-long surveyareascomprising theen-tireislandweremonitored sevendaysaweekduringthenestingseason(Figure3).TheSt.LuciePlantUnit2discharge structure wasinstalled duringthe1981nestingseason.Offshoreandbeachconstruction oftheUnit2intakestructure proceeded throughout the1982nestingseasonandwascompleted neartheendofthe1983lseason.Construction activities associated withinstallation ofbothstructures weresimilartothoseconducted whenUnit1intakeanddischarge structures wereinstalled. | |||
Eggsfromturtlenestspotentially endangered byconstruction activities wererelocated duringallthreeyears.Requirement 4.2.1oftheNRC'sSt.LucieUnit2AppendixBEnvironmental Protec-tionPlanwascompleted withsubmission ofthe1986nestingsurveydata(ABI,1987).Thenestingsurveywascontinued voluntarily through1990withagreement fromfederalandstateagencies. | |||
Resultsarepresented inthisreportanddiscussed inrelationtopreviousfindings. | |||
I~pIIIIIII,)ClII Inadditiontomonitoring seaturtlenestingactivities andrelocating nestsawayfromplantconstruction areas,removalofturtlesfromtheintakecanalhasbeenanintegralpartoftheSt.LuciePlantenvironmental monitoring program.Turtlesenteringtheoceanintakestructures areentrained withcoolingwaterandrapidlytransported throughtheintakepipesintoanenclosedcanalsystemwheretheymustbemanuallycapturedandreturnedtotheocean.Sincetheplantbecameoperational in1976,turtlesentrapped intheintakecanalhavebeensystematically | |||
: captured, measured, weighed,taggedandreleased. | |||
Previouspublications andtechnical reportshavepresented findingsofthenestingsurveys,nestrelocation activities andcanalcaptureprogram(Gallagher etal.,1972;WorthandSmith,1976;ABI,1978,1980a,1981a,1982,1983,1984b,1985b,1986,1987,1988,1989,1990;Williams-Walls etal.,1983;Proffittetal.,1986;Ernestetal.,1988,1989;Martinetal.,1989a,1989b).Resultsofstudiestoassesstheeffectsofther-maldischarges onhatchling swimmingspeedhavealsobeenreported(ABI,1978;O'ara,1980).Thepurposeofthisreportisto1)present1990seaturtlenestingsur-veydataandsummarize observedspatialandtemporalnestingpatternssince1971,2)documentandsummarize predation onturtlenestssince1971,and3)present1990canalcapturedataandsummarize comparable datacollected since1976. | |||
IIIIIII MATERIALS ANDMETHODSNestinSurveMethodologies usedduringpreviousturtlenestingsurveysonHutchinson Islandweredescribed byGallagher etal.(1972),WorthandSmith(1976)andABI(1978,1981a,1982,1987,1988,1989).Methodsusedduringthe1990surveyweredesignedtoallowcomparisons withthesepreviousstudies.On11and13April1990,preliminary nestsurveyswereconducted alongHutchin-sonIslandfromtheFt.PierceInletsouthtotheSt.LucieInlet.From16Aprilthrough7September, nestsurveyswereconducted onadailybasis.After7September, severaladditional surveyswereconducted toconfirmthatnestinghadceased,thelastsurveybeingconducted on14September. | |||
Biologists usedsmalloff-roadmotorcycles tosur-veytheislandeachmorning.Newnests,non-nesting emergences (falsecrawls),andnestsdestroyed bypredators wererecordedforeachofthe361-km-long surveyareascomprising theentireisland(Figure3).Thenine1.25-km-long surveyareasestablished byGallagher etal.(1972)alsoweremonitored socomparisons couldbemadewithpreviousstudies.Duringthedailynestmonitoring, anymajorchangesintopography thatmayhaveaffectedthebeach'ssuitability fornestingwererecorded. | |||
Inaddition, eachofthe361-km-long surveyareashasbeensystematically analyzedandcategorized basedonbeachslope(steep,moderate, etc.),widthfromhightidelinetothedune,presenceofbenches(areasofabruptverticalrelief)andmiscellaneous characteristics (packed10 | |||
'lI sand,scattered rock,vegetation onthebeach,exposedrootsontheprimarydune,etc.).Inacooperative effort,datafromstrandedturtlesfoundduringbeachsurveyswereroutinely providedtotheNationalMaiineFisheries Service(NMFS)throughtheSeaTurtleStranding andSalvageNetwork.IntakeCanalMonitorin Mostturtlesentrapped intheSt.LuciePlantintakecanalwereremovedbymeansoflarge-mesh tanglenetsfishedbetweentheintakeheadwalls andabarriernetlocatedattheHighwayA1Abridge(Figure2).Netsusedduring1990werefrom30to40minlength,3to4mdeepandcomposedof40cmstretchmeshnylontwine.Largefloatswereattachedtothesurface,andunweighted linesusedalongthebottom.Turtlesen-tangledinthenetsgenerally remainedatthewater'ssurfaceuntilremoved.Sinceitsinception in1976,ABI'scanalcaptureprogramhasbeenundercontinual reviewandrefinement inanattempttominimizebothentrapment timesandin-juries/mortalities toentrapped seaturtles.PriortoApril1990,turtlenetswereusuallydeployedonMondaymorningsandretrieved onFridayafternoons. | |||
Duringperiodsofdeployment, thenetswereinspected forcapturesbyABIpersonnel atleasttwiceeachday(mornings andafternoons). | |||
Additionally, St.LuciePlantpersonnel checkedthenetsperiodically, andABIwasnotifiedimmediately ifacapturewasobserved. | |||
ABI'sseaturtlespecialists wereoncall24hoursadaytoretrievecapturedturtlesfromtheplant.11 I | |||
Beginning April1990,afterconsultation withNMFS,netdeployment wasscaledbacktodaylighthoursonly.Concurrently, surveillance oftheintakecanalwasin-creasedandABIpersonnel remainedonsiteforthedurationofeachday'snettingac-tivities. | |||
Thismeasuredecreased responsetimeforremovalofentangled turtlesfromnetsandprovidedanopportunity toimprovedailyassessments ofturtlelevelswithinthecanal.Recordsofdailycanalobservations werecomparedwithcapturedatatoas-sesscaptureefficiencies. | |||
TheA1Abarriernetisusedtoconfineturtlestotheeasternmost sectionofthein-takecanal,wherecapturetechniques havebeenmosteffective. | |||
Thisnetisconstructed oflargediameterpolypropylene ropeandhasameshsizeof30.5cmx30.5cm.Acableandseriesoflargefloatsareusedtokeepthetopofthenetabovethewater'surface,andthebottomisanchoredbyaseriesofheavyblocks.Thenetisinclinedataslopeof3:1,withthebottompositioned upstreamofthesurfacecable.Thisreducesbowinginthecenterandminimizes theriskofaweakorinjuredturtlebeingpinnedun-derwaterbystrongcurrents. | |||
Inthepast,theintegrity ofthebarriernetwasoccassionally compromised, andturtleswereabletomovewestofA1A.Theseturtleswerefurtherconstrained downstream byanunderwater intrusion detection system(UIDS)consisting, inpart,ofalargebarrierpositioned perpendicular tothenorth-south armofthecanal(Figure2).TheUIDSsecuritybarrieralsoconsistsof30.5cmx30.5cmmesh,butthenetisconstructed ofheavychainlinksratherthanrope.12 III Priortocompletion oftheUIDSinDecember1986,turtlesuncontained bytheA1AbarriernetwereusuallyremovedfromthecanalattheintakewellsofUnits1and2(Figure2).Theretheywereretrieved bymeansoflargemechanical rakesorspecially designednets.Following construction oftheUIDSbarrier,individuals withcarapacewidthslargerthan30.5cmwereunabletoreachtheintakewells.Thus,asrequired, tanglenetswerealsodeployedwestofA1A.Improvements madetotheA1Abarriernetduring1990shouldproveeffective inconfining allturtleslargerthan30.5cmtotheeasternendofthecanal.Formaldailyinspections oftheintakecanalweremadetodetermine thenumbers,locations andspeciesofturtlespresent.Surfaceobservations wereaugmented withperiodicunderwater inspections usingSCUBA,particularly inandaroundtheA1Abar-riernetandUIDSbarrier.Becauseofthereduction intotalnettinghoursduring1990,increased effortwasdirectedtowardhandcaptureofturtles.Thiswasaccomplished bydivinganduseofdipnets,anditprovedveryeffective whengoodwaterclaritycon-ditionsprevailed. | |||
Regardless ofcapturemethod,allturtlesremovedfromthecanalwereidentified tospecies,measured, weighed,tagged,andexaminedforoverallcondition (wounds,abnormalities, parasites, etc.).Healthyturtleswerereleasedintotheoceanthesamedayofcapture.Sickorinjuredturtlesweretreatedandoccasionally heldforobserva-tionpriortorelease.Whentreatment waswarranted, injections ofantibiotics andvitaminswereadministered byalocalveterinarian. | |||
Resuscitation techniques wereusedifaturtlewasfoundthatappearedtohavediedrecently. | |||
Beginning in1982,necrop-13 Ili~l sieswereconducted ondeadturtlesfoundinfreshcondition; onenecropsywasper-formedduring1990.Since1982,bloodsampleshavebeencollected andanalyzedtodetermine thesexofimmatureturtles.Bloodwasremovedfromthepaireddorsalcervicalsinusesofsub-jectturtlesusingthetechnique described byOwensandRuiz(1980).Thesamplesweremaintained oniceandlatercentrifuged for15minutestoseparatecellsandserum.Sexdeterminations weresubsequently madebyresearchers atTexasA8MUniver-sityusingradioimmunoassay forserumtestosterone (Owensetal.,1978).FloridaPower8LightCompanyandAppliedBiology,Inc.continued toassistotherseaturtleresearchers in1990.Data,specimens and/orassistance havebeengiventotheFloridaDepartment ofNaturalResources, NationalMarineFisheries Service,USFishandWildlifeService,USArmyCorpsofEngineers, Smithsonian Institution; SouthCarolinaWildlifeandMarineResources | |||
: Division, CenterforSeaTurtleResearch(University ofFlorida), | |||
TexasA&MUniversity, University ofRhodeIsland,University ofSouthCarolina, University ofIllinois, University ofCentralFlorida,University ofGeor-gia,VirginiaInstitute ofMarineScienceandtheWesternAtlanticTurtleSymposium. | |||
StudiestoEvaluateandorMitiateIntakeEntramentAprogramthatassessedthefeasibility ofusinglightand/orsoundtodeterturtlesfromenteringtheSt.LuciePlantintakestructures wasconducted in1982and1983andcompleted inJanuary1984.Asrequired, testresultsandevaluations werewrittenupandapresentation wasmadetotheNRC,NationalMarineFisheries ServiceandtheFloridaDepartment ofNaturalResources on11April1984.Requirement 4.2.2of Il1lI theNRC'sSt.LucieUnit2AppendixBEnvironmental Protection Planisconsidered completed withsubmission ofdeterrent studyfindings. | |||
RESULTSANDDISCUSSION NestinSurveDistribution ofLoerheadNestsAlonHutchinson IslandWhenseaturtlenestingsurveysbeganonHutchinson Island,nine1.25-km-long surveyareaswereusedtoestimateloggerhead nestingactivityfortheentireisland.Since1981,all361-km-long segmentscomprising theisland'scoastline havebeensurveyed. | |||
Regardless oftechnique, loggerhead nestdensities haveshowncon-siderable annualvariation withinindividual surveyareas(Figures4and5).Yet,theannualspatialdistribution ofthosenestsamongsurveyareashasproducedaratheruniformgradient, nestdensities consistently increasing fromnorthtosouth(ABI,1987).Thegradientappearstobelinearwhenonlythenine1.25-km-long surveyareasareused(Figure4),butbecomesnon-linear whenall361-km-long surveyareasarein-cludedintheanalysis(Figure5).During1990thedistribution ofloggerhead nestsalongtheislandwascharacterized byrecordhighnestingalongthenorthernandcentralpor-tionsoftheisland(Figure5).Inthepast,thepronounced gradientobservedonthenorthernendoftheislandwasoccasionally influenced byphysicalprocesses occurring there;periodsofheavyaccretion reducedthegradient, whileperiodsoferosionaccentuated it(WorthandSmith,1976;Williams-Walls etal.,1983).However,duringrecentyearsnoconsistent IIlI relationship wasapparentwhenfieldobservations ofbeachwidthswerecomparedtothespatialdistribution ofnestsalongtheisland(ABI,1987).Thus,eventhoughbeachdynamicsmaysometimes affecttheselection ofnestingsitesbyloggerhead turtles,otherfactorsmustalsocontribute totheselection process.Offshorebottomcontours, spatialdistribution ofnearshore reefs,typeandextentofdunevegetation, anddegreeofhumanactivityonthebeachatnighthavebeenidentified assomeofthefactorsaf-fectingnesting(Caldwell, 1962;Hendrickson andBalasingam, 1966;Bustard,1968;BustardandGreenham, 1968;Hughes,1974;DavisandWhiting,1977;Mortimer, 1982).Relationships betweenspatialnestingpatternsandspecificenvironmental con-ditionsareoftendifficult toestablish becauseoftheinterrelationship ofthefactorsin-volved.Notallventuresontothebeachbyafemaleturtleculminate insuccessful nests.These"falsecrawls"(non-nesting emergences) mayoccurformanyreasonsandarecommonlyencountered atotherrookeries (BaldwinandLofton,1959;Schulz,1975;DavisandWhiting,1977;Talbertetal.,1980;Raymond,1984).DavisandWhiting(1977)suggested thatrelatively highpercentages offalsecrawlsmayreflectdisturban-cesorunsatisfactory nestingbeachcharacteristics. | |||
Therefore, certainfactorsmayaf-fectaturtle'spreference toemergeonabeach,whileotherfactorsmayaffectaturtle'tendencytonestafterithasemerged.Anindexwhichrelatesthenumberofneststothenumberoffalsecrawlsinanareais.usefulinestimating thepost-emergence suitability ofabeachfornesting.Inthepresentstudythisindexistermed"nestingsuc-cess"andisdefinedasthepercentage oftotalemergences thatresultinnests. | |||
loHistorically, thepatternofloggerhead emergences ontheislandhasgenerally paral-leledthedistribution ofnests(ABI,1987,1988),andthissametrendwasapparentin1990(Figure6).Incontrast, nestingsuccessbyloggerheads alongtheislandhastypi-Pcallylackedgradients (Figure7).Thus,therelatively highnumbersofloggerhead nestsobservedincertainareasareusuallyaresultofmoreturtlescomingashoreinthoseareasratherthanofmorepreferable nestingconditions beingencountered bytheturtlesaftertheyemerged.Loggerhead nestingdensities during1990weregenerally highwhencomparedwithpreviously recordedvalues(Figures4and5).Recordhighnestingwasrecordedin21ofthe36one-kilometer-long surveyareasandwasmostnotableonthenorthernhalfoftheisland.Therewerenoapparentchangesinthephysicalcharacteristics ofthebeachthatwouldaccountforthisincreaseinnesting.Ingeneral,recordhighnestingwasduetorecordhighemergence rates,andthismayreflectanincreaseinthenum-berofnestingfemalesintheHutchinson Islandarea.NestingsurveysonHutchinson Islandwereinitiated inresponsetoconcernsthattheoperation oftheSt.LuciePlantmightnegatively impactthelocalseaturtlerookery.Previousanalysis, usinglog-likelihood testsofindependence (G-test;SokalandRohlf,1981)demonstrated thattheconstruction oftheplant'soffshoreintakeanddischarge structures significantly reducednestingattheplantsiteduringconstruction years-1975,1981,1982and1983(Proffitt etal.,1986;ABI,1987).However,nestingattheplantconsistently returnedtolevelssimilartoorgreaterthanthoseatacontrolsiteinyearsfollowing construction. | |||
Thistrendcontinued during1990(Figure8).Thus,power plantoperation exclusive ofintake/discharge construction hashadnoapparenteffectonnesting.Datacollected through1990haveshownnolong-term reduction inloggerhead nestdensities, totalemergences ornestingsuccessineitherthenine1.25-km-long surveyareasorthe361-km-long surveyareas(Table1;Figure9).EstimatesofTotaILo erheadNestin onHutchinsonlsland Variousmethodswereusedduringsurveyspriorto1981toestimatethetotalnum-berofloggerhead nestsonHutchinson Islandbasedonthenumberofnestsfoundinthenine1.25-km-long surveyareas(Gallagher etal.,1972;WorthandSmith,1976;ABI,1980a).Eachofthesemethodsweresubsequently foundtoconsistently overes-timateislandtotals(ABI,1987).Sincewhole-island surveysbeganin1981,ithasbeenpossibletodetermine theactualproportion oftotalnestsdeposited inthenineareas.Thishasthenallowedextrapolation fromtheninesurveyareastotheentireislandforyearspriorto1981.From1981through1990thetotalnumberofnestsinthenineareasvariedfrom32.5to35.6percentofthetotalnumberofnestsontheisland(Table1).Thisisslight-lyhigherthanthe31.3percentwhichwouldbeexpectedbasedstrictlyonthepropor-tionoflinearcoastline comprised bythenineareas.Usingtheten-yearmeanof33.8percent,estimates ofthetotalnumberofnestsonHutchinson Islandcanbecalculated bymultiplying thenumberofnestsinthenineareasby2.96.Thistechnique, whenap-pliedtotheninesurveyareasduringthetenyearsinwhichtheentireislandwassur-veyed,producedwhole-island estimates within5.3percentoftheactualnumberof18 IIl nestscounted.Becausetheproportion ofnestsrecordedintheninesurveyareasremainedrelatively constantoverthelasttenyears,thisextrapolation procedure shouldprovideafairlyaccurateestimateoftotalloggerhead nestingforyearspriorto1981.Itisclearthatloggerhead nestingactivityonHutchinson Islandfluctuates con-siderably fromyeartoyear(Table1).Annualvariations innestdensities alsoarecom-monatotherrookeries (Hughes,1976;DavisandWhiting,1977;Ehrhart,1980)andmayresultfromtheoverlapping ofnon-annual breedingpopulations. | |||
Nonetheless, datacollected through1990suggestanoverallincreaseinnestingonHutchinson Is-landsincesurveysbeganin1971.Totalnestingactivitywasgreatestduring1990when6,700loggerhead nestswererecorded. | |||
Norelationships betweentotalnestingactivityandpowerplantoperation orintake/discharge construction wereindicated byyear-to-yearvariations intotalnestingonHutchinson Island.TemoralLoerheadNestinPatternsTheloggerhead turtlenestingseasonusuallybeginsbetweenmid-April andearlyMay,attainsamaximumduringJuneorJuly,andendsbylateAugustorearlySep-tember(ABI,1987).Nestingactivityduring1990followedthissamepattern(Figure10).Coolwaterintrusions frequently occuroverthecontinental shelfofsoutheast Floridaduringthesummer(TaylorandStewart,1958;Smith,1982).WorthandSmith(1976),Williams-Walls etal.(1983)andABI(1982,1983,1984b,1985b,1986,1987,1988,1989,1990)suggested thattheseintrusions mayhavebeenresponsible forthetemporary declinesinloggerhead turtlenestingactivitypreviously observedonHutchinson Is-19 IIIIII land.Similarly, asubstantial decreaseinnestingduringmid-July1990wasapparently duetoanintrusion ofcoolwater(Figure10).Thoughnaturalfluctuations intemperature havebeenshowntoaffecttemporalnest-ingpatternsonHutchinson Island,therehasbeennoindication thatpowerplantopera-tionhasaffectedthesetemporalpatterns(ABI,1988)~Predation onLoerheadTurtleNestsSincenestsurveysbeganin1971,raccoonpredation probablyhasbeenthemajorcauseofturtlenestdestruction onHutchinson Island.Researchers atotherlocations havereportedraccoonpredation levelsashighas70tonearly100percent(DavisandWhiting,1977;Ehrhart,1979;Hopkinsetal.,1979;Talbertetal.,1980).Raccoonpreda-tionofloggerhead turtlenestsonHutchinson Islandhasnotapproached thislevelduringanystudyyear,thoughlevelsforindividual 1.25-km-long areashavebeenashighas80percent.Overallpredation ratesforsurveyyears1971through1977werebetween21and44percent,withahighof44percentrecordedin1973.Apronounced decreaseinraccoonpredation occurredafter1977,andoverallpredation ratesforthenineareashavenotexceeded10percentsince1979.Adeclineinpredation ratesonHutchinson Islandhasbeenvariously attributed totrappingprograms, construction activities, habitatlossanddisease(Williams-Walls etal.,1983;ABI,1987).During1990,sixpercent(406)oftheloggerhead nests(n=6,700)ontheislandweredepredated byraccoons. | |||
Asinpreviousyears(ABI,1989),predation ofturtlenestswasprimarily restricted tothemostundeveloped portionoftheisland(i.e.,AreasEthroughS;Figure11).20 IIIIIII Ghostcrabshavebeenreportedbynumerousresearchers asimportant predators ofseaturtlenests(BaldwinandLofton,1959;Schulz,1975;Diamond,1976;Fowler,1979;Hopkinsetal~,1979;Stancyk,1982).ThoughturtlenestsonHutchinson Islandprobablyhavebeendepredated byghostcrabssincenestingsurveysbeganin1971,thissourceofnestdestruction didnotbecomeapparentuntil1983.Quantification ofghostcrabpredation wasinitiated thesameyear.Overallpredation ratesbyghostcrabshavevariedfrom0.1to2.1percentfrom1983-1989(ABI,1990).During1990,0.4percent(27)oftheloggerhead nests(n=6,700)ontheislandweredestroyed byghostcrabs(Figure11).Nestsdestroyed byacombination ofraccoonandghostcrabpredation havebeenincludedasraccoonpredations inpreviousdiscussions. | |||
Whenthesecombination predations areincludedascrabpredations, theoverallpredation ratesbyghostcrabsrangefrom0.4to3.2percent.During1990,1.4percent(96nests)weredestroyed byeitherghostcrabsoracombination ofghostcrabsandraccoons. | |||
GreenandLeatherback TurtleNestinGl'eenandleatherback turtlesalsonestonHutchinson Island,butinfewernumbersthanloggerhead turtles.Priorto1981,bothsurvey(nine1.25-km-long sections) andinter-survey areasweremonitored forthepresenceofgreenandleatherback nests.Thirty-one kilometers ofbeachfromArea1southtotheSt.LucieInletwereincludedinthateffort.Duringwhole-island surveysfrom1981through1990,onlytwoof182Ieatherback nestsandonlysevenof601greennestswererecordedonthefivekilometers ofbeachnorthofArea1.Therefore, previouscountsofgreenandleather-21 III backnestswithinthe31kilometers surveyedwereprobablynotappreciably different fromtotaldensities fortheentireisland.Basedonthisassumption, greenandleather-backnestdensities maybecomparedamongallsurveyyears,except1980,whenlessthan15kilometers ofbeachweresurveyed. | |||
Priorto1990,thenumberofnestsobservedontheislandrangedfrom5to74forgreenturtlesandfrom1to36forleatherbacks (Figure12).Duringthe1990survey,132greenturtleand12leatherback turtlenestswererecordedonHutchinson Island.Temporalnestingpatternsforthesespeciesdifferfromthepatternforloggerhead turtles.Greenturtlestypically nestonHutchinson Islandfrommid-JunethroughthefirstorsecondweekofSeptember. | |||
During1990,greenturtlesnestedfrom28Maythrough11September. | |||
Leatherback'turtles usuallynestontheislandfrommid-April throughearlytomid-July. | |||
During1990thisspeciesnestedfrom10Aprilthrough3July.Considerable fluctuations ingreenturtlenestingontheislandhaveoccurredamongsurveyyears(Figure12).Thisisnotunusualsincetherearedrasticyear-to-year fluc-tuationsinthenumbersofgreenturtlesnestingatotherbreedinggrounds(Carretal.,1982).Despitethesefluctuations, datacollected through1990suggestanoverallin-creaseinnestingsince1971andmayreflectanincreaseinthenumberofnestingfemalesintheHutchinson Islandarea.During1990,greenturtlesnestedmost frequent-lyalongthesouthernhalfoftheisland.Thisisconsistent withresultsofprevioussur-veys.Leatherback turtlenestdensities haveremainedlowonHutchinson Island;however,increased nestingduringrecentyears(Figure12)mayreflectanoverallincreaseinthe22 numberofnestingfemalesintheHutchinson Islandarea.During1990,leatherback turtlesprimarily nestedonthesouthernhalfoftheisland.IntakeCanalMonitorin Entrainment ofseaturtlesattheSt.LuciePlanthasbeenattributed tothepresumedphysicalattractiveness oftheoffshorestructures housingtheintakepipesratherthantoplantoperating characteristics (ABI,1980band1986).Evenwhenbothunitsareoperating atfullcapacity, turtlesmustactivelyswimintothemouthofoneoftheintakepipesbeforetheyencounter currentvelocities sufficiently strongtoeffectentrainment. | |||
Consequently, aturtle'sentrapment relatesprimarily totheprobability thatitwilldetectandsubsequently enteroneoftheintakestructures. | |||
Assumingthatdetection distan-cesdonotvaryappreciably overtimeandthatallturtles(oraconstantproportion) areequallyattracted tothestructures, capturerateswillvaryproportionally tothenumberofturtlesoccurring inthevicinityofthestructures. | |||
Ifthisassumption istrue,datafromthecanalcaptureprogramshouldreflectnaturalvariability inthestructure ofthepopula-tionbeingsampled.RelativeAbundance andTemoralDistribution During1990,132seaturtlecapturestookplaceintheintakecanaloftheSt.LuciePlant(Table2).Ofthefivespeciesofseaturtlesinhabiting coastalwatersofthesoutheastern UnitedStates,onlytwowererepresented inthisyear'scatches:112log-gerheadsand20greenturtles.Sinceintakecanalmonitoring beganinMay1976,1,853loggerhead (including 99recaptures), | |||
306green(including 1recapture), | |||
9leatherback, 8hawksbill and17Kemp'sridleycaptureshavetakenplaceattheSt.LuciePlant.23 Annualcatchesofloggerheads increased steadilyfromalowof33in1976(partialyearofplantoperation andmonitoring) to172in1979(Figure13).Afterdeclining be-tween1979and1981,yearlycatchesofloggerheads againrosesteadily, reachingahighof195during1986.Captureshavebeenindeclinesince1986,decreasing morethan40percentoverthelastfouryears.Twooffshoreintakestructures wereinplacepriortoUnit1start-upin1976;thethirdandlargeststructure wasinstalled during1982-1983. | |||
Eventhoughallthreestructures areinrelatively closeproximity, theadditionofanotherpipemayhaveincreased theprobability ofaturtlebeingentrained. | |||
Becausethischangecannotbequantified, datacollected priorto1982maynotbecomparable withthatcollected after1983.Addition-ally,theinfluence oftheconstruction itselfonseaturtleentrainment during1982and1983isunknown.Withtheseconsiderations inmind,neitheralong-term increasenordecreaseinthenumberofloggerheads capturedattheSt.LuciePlantcanbeinferredfromthedata.During1990,themonthlycatchofloggerheads rangedfrom1(November) to25(June),withamonthlymeanof9.3(+7.0;Table3).ThenumberofcapturesduringMay,JuneandJulywereconsiderably aboveaverage,whilecapturesthroughout theIremainder oftheyearweremoderately toconsiderably lowerthanaverage(Figure14).Overtheentiremonitoring period,monthlycatcheshaverangedfrom0to39;thegreatestnumberofcapturesoccurredduringJanuary1983.Whendatafromallfullyearsofmonitoring (1977-1990) werecombined, thehighestnumberofloggerhead capturesoccurredinJanuary(11.8percent); | |||
fewestcaptures24 IlIlII wererecordedinNovemberandDecember(Table3).However,monthlycatcheshaveshownconsiderable annualvariability. | |||
Monthshavingrelatively lowcatchesoneyearoftenhavehadrelatively highcatchesinanother.Catchesofgreenturtlesalsohavevariedwidelyamongyears,rangingfrom0in1976(partialyearofsampling) to69in1984(Table4).During1990,20individuals werecaptured. | |||
Theaverageannualcatchofgreenturtles,excluding 1976,was21.9(+18.0).Althoughhighlyvariable, annualcapturedataforgreenturtlessuggestalong-term in-creaseinthenumberofindividuals inhabiting thenearshore coastalareaadjacenttotheplant(Figure13).Again,however,theinfluence oftheadditionofathirdintakepipeduring1982-1983 onthesedataisnotknown.Greenturtleshavebeencaughtduringeverymonthoftheyear,withaveragemonth-lycatchesforallyearscombinedrangingfrom0.3inSeptember to7.1inJanuary(Table4).Seasonalabundance patternsofgreensaremuchmorepronounced thanforlog-gerheads, nearly60percentofallcapturesoccurring duringthethreemonthperiodbetweenJanuaryandMarch.During1990,thelargestnumberofgreens(6)werecap-turedinJanuary.Themostgreensevercaughtinonemonthwas37inJanuary1984.Catchesofleatherbacks, hawksbills andKemp'sridleyshavebeeninfrequent andscattered throughout the15yearstudyperiod(Table2).Eachspecieshasshownratherpronounced seasonaloccurrences; allbuttwoofthenineleatherbacks werecollected betweenFebruaryandMay,sevenoftheBighthawksbills werecollected betweenJuneandSeptember, andallbuttwoofthe17Kemp'sridleyswerecaughtbetweenNovemberandApril.25 Size-lassDistribtionAlthoughseveralstraight-line andcurvedmeasurements wererecordedforturtlesremovedfromtheintakecanal,onlyonestraight-line measurement hasbeenusedinanalysespresented here.Straight-line carapacelength(SLCL)wasmeasuredfromtheprecentral scutetothenotchbetweenthepostcentral scutes(minimumcarapacelengthofPritchard etal.,1983).Todate,loggerheads removedfromtheintakecanalhaverangedinlength(SLCL)from40.2to112.0cm(x=66.8+13.7cm)andinweightfrom10.7kgto169.6kg(x=49.2+31.0kg;Figures15and16).Acarapacelengthof70cmapproximates thesmallestsizeofnestingloggerhead femalesobservedalongtheAtlanticeastcoast(Hirth,1980).However,adultscanonlybereliablysexedonexternalmorphological characteristics (e.g.,relativetaillength)afterobtaining alengthofabout85cm.Previously, 80.0cmwasusedasthelowerlimitforadultturtles.However,recentdatasuggestthatsomemalesmaynotmature,andthusmightnotbedistinguishable fromfemales,untiltheyattainaslightlylargersize.Basedonthesedivisions, dataweresegregated intothreegroups:juveniles | |||
(<70cm),adults(>85cm)andtransitional (71-85cm).Thelattergroupprobablyincludessomematureandsomeimmatureindividuals. | |||
Ofthe1,744capturesbetween1977and1990forwhichlengthdatawerecollected, 69percentwerejuveniles, themajorityofthesemeasuring between50and70cmSLCL(Table5).Adultsaccounted forabout15percentofallcaptures, withtheremaining 16percentcomprised ofanimalsinthetransitional sizeclass.Similarsize-frequency distributions, indicating apreponderance ofjuveniles, havebeenreportedforthe26 IIII Mosquito/Indian RiverLagoon(Mendonca andEhrhart,1982),theCanaveral shipchannel(Henwood, 1987),andGeorgiaandSouthCarolina(Hillestad etal.,1982).Thesedatasuggestthatcoastalwatersofthesoutheastern UnitedStatesconstitute animportant developmental habitatforCarettacaretta.Seasonalpatternsofabundance forvarioussizeclassesindicated thatjuvenilelog-gerheadswereslightlymoreabundantduringthewinterthanatothertimesoftheyear(Table5).About45percentofthejuveniles werecapturedbetweenJanuaryandApril.Abundances decreased inspringandremainedrelatively constantduringthesummerandearlyfallbeforedecreasing againtolowestlevelsinNovemberandDecember. | |||
Theseasonaldistribution ofadultloggerheads wasmuchmorepronounced, 76per-centofallcapturesoccurring betweenMayandAugust,Thisrepresents themajorpro-tionofthenestingseasononHutchinson Island.Greenturtlesremovedfromtheintakecanalovertheentirestudyperiodrangedinsizefrom20.0to108.0cmSLCL(x=35.8+14.3cm)and0.9kgto177.8kg(x=9.4+20.2kg;Figures17and18)~Nearlyall(96percent)werejuveniles. | |||
About80per-centwere40cmorlessinlength,and66percentweighed5kilograms orless.Theseimmatureturtlesexhibited distinctwinterpulsessuggesting migratory behavior(Table4).However,someimmaturegreenturtleswerepresentthroughout theyear.Todate,onlyeightadultgreenturtles(SLCL>83cm;Witherington andEhrhart,1989)havebeenremovedfromthecanal;ailwerecapturedduringorshortlyafterthenestingseason.27 IIl Theeighthawksbills removedfromthecanalrangedinsizefrom34.0to70.0cmSLCL(x=46.2+12.9cm)andinweightfrom6.4to52.2kg(x=17.3+16.6kg).Allbutonewerejuveniles (SLCL<63cm;Witzell,1983).Similarly, allbutoneofthe17Kemp'sridleyscapturedattheSt.LuciePlantwerejuveniles (SLCL<60.0cm;Hirth,1980).Carapacelengthsfortheridleysrangedfrom27.0to62.0cmSLCL(x=36.1+9.7cm)andweightsfrom3.1to31.8kg(x=8.0+8.1kg).Thenineleatherbacks removedfromthecanalrangedinlengthfrom112.5to150.0cm,andatleastsevenwereadults(SLCL>121cm;Hirth,1980).Thelargestleatherback forwhichanac-curateweightwasobtained, afemalewithacurvedcarapacelengthof158.5cm,weighed334.8kg.~SxRatiosSinceintakecanalmonitoring beganin1976,255adultloggerheads (SLCL>85.0cm)havebeensexed.Femalespredominated malesbyaratioof5.4:1.0,whichsig-nificantly departsfroma1:1ratio(X,P<0.05).Consequently, temporalpatternsinthenumberofadultloggerhead captureswereheavilyinfluenced bythenumbersoffemalespresent.Whensexeswereseparated, itisevidentthatmaleswererelatively evenlydistributed amongmonths,whereas90percentofthefemalesweretakenduringthenestingseason(MaythroughSeptember; Figure19).Thenumberofadultfemaleloggerheads capturedattheSt.LuciePlanthasin-creasedsteadilyoverthelastsevenyears.From1977through1983,anaverageof4.4adultfemales(+3.2;range=1-10)wereentrapped eachyear,whereassincethen,anaverageof26.3femalesperyear(+6.7;range=16-35)werecaptured. | |||
Thisin-28 creasecorresponds toageneralriseinloggerhead nestingactivityneartheplant(Figure20).Increased nearshore movementassociated withnestingincreases theprobability ofaturtledetecting oneoftheintakestructures andhencetheprobability ofentrainment. | |||
Althoughtheadditionofthethirdoffshoreintakestructure mayhaveaccounted forsomeoftheincreaseinthenumberofadultsentrained since1983,thecontinued riseoverthelastsevenyearssuggestsagenuineincreaseinthenumberoffemalesoccurring inthevicinityoftheplant.BetweenSeptember 1982andDecember1986,267individual juvenileandsub-adult loggerhead turtlescapturedinthecanalweresexedbyTexasA8MUniversity re-searchers usingabioimmunoassay technique forbloodserumtestosterone. | |||
Aspre-viouslyreported, femalesoutnumbered malesbyaratioof2.3:1.0(ABI,1989).Thesefindingsareconsistent withthosereportedforsamplestakenfromtheCapeCanaveral shipchannel(1.7:1.0) andtheIndianRiverLagoon(1.4:1.0), | |||
wheresexratiosarealsosignificantly skewedinfavoroffemales(Wibbelsetal.,1984).Bloodsamplescollected since1986arecurrently beinganalyzedandtheseresultswillprovideavaluabletoolforassessing temporalvariability inthesexratiosofthelocalloggerhead population. | |||
Oftheeightadultgreenturtlescapturedsincemonitoring began,sixweremalesandtwowerefemales.Siximmaturegreenturtleshavebeensexedthroughbloodwork;allhavebeenfemales.Ofthesixadultleatherback turtlesforwhichsexwasrecorded, threewerefemalesandthreeweremales.Theadulthawksbill andKemp'sridleywerebothfemales.Nosexinformation existsforjuveniles ofthesespecies.29 CatureEfficiencies Capturemethodologies havebeenundercontinual reviewandrefinement asnetmaterials, configurations andplacement werevariedinanefforttominimizeseaturtleentrapment times.Concurrently, alternative capturetechniques wereevaluated andpotential deterrent systemstestedinthelaboratory. | |||
Duringthisperiod,captureefficien-ciesvariedinrelationtonettingeffortandtheeffectiveness ofthesystemsdeployed. | |||
Acapture/recapture studyconducted intheintakecanalbetweenOctober1980andJanuary1981indicated thatmostturtlesconfinedbetweentheA1Abridgeandtheintakeheadwalls werecapturedwithintwoweeksoftheirentrainment (ABI,1983)~Basedonmorerecentformaldailyinspections, itappearsthatcaptureefficiencies havefurtherimproved. | |||
Nearly50percentoftheturtlesenteringthecanalarenowcaughtwithin24hoursoffirstsighting, andalmost90percentarecapturedduringtheirfirstweekofentrapment (Figure21).Averagecaptureefficiency, expressed aselapseddaysbetweenfirstsightingandcapture,duringtheperiodfromAprilthroughDecem-ber1990was3.9days(+6.8days;range=1-50days).Betterutilization ofcurrentsandeddies,adjustments totethering lines,multi-net deployments andincreased ef-fortstohandcaptureturtleshavecontributed toreducedentrapment times.Entrapment timesmaybeextendedforturtlesswimmingpasttheA1Abarriernet(ABI,1987).Occasionally, thetopofthenethasbeensubmerged ortheanchorcablepulledfreefromthebottom,allowinglargerturtlestopass;turtleswithcarapacewidthslessthanabout30.5cmcanswimthroughthelargemesh.BecausecaptureeffortswestoftheA1Abridgehavegenerally beenlesseffective thanthoseneartheintake30 headwalls, mostturtlesbreaching thebarriernetwerenotcaughtuntiltheyenteredtheintakewellsofUnits1and2.Priortoinstallation oftheUIDSbarrierin1986,about15percentofallturtlesentrapped inthecanalwereremovedfromtheintakewells.Be-causeoftheirrelatively smallsizes,amuchlargerproportion ofgreens(51.6percent)reachedtheplantthanloggerheads (10.1pel'cent). | |||
Since1986,thepercentage ofgreenscaughtattheintakewellshasdecreased slightly(35.1percent), | |||
whilealllog-gerheadshavebeenprevented fromreachingtheplant.Majorrenovations weremadetotheA1Abarriernetduring1990tofurtherreducethepotential forturtleslargerthan30.5cmbecomingtrappedbetweenA1AandtheUIDS.Twologgerheads (lessthan2percentofallloggerhead captures) breachedtheA1Abarriernetpriortocompletion ofthesemodifications. | |||
BothwereremovedfromthecanalattheUIDSbarrier.Additionally, twosmallgreenturtlespassedthroughtheA1Abarriernetandwereremovedattheplant'sintakewells.Thus,nearly97percentofallturtlesentrapped inthecanalduring1990werecapturedbynettingorbyhandeastoftheA1Abridge.Theeffective confinement ofturtleseastofA1Awasanothermajorcontributor tothehighcaptureefficiency achievedduring1990.RelativeCondition TurtlescapturedaliveintheintakecanaloftheSt.LuciePlantwereassignedarela-tivecondition basedonweight,activity, parasiteinfestation, barnaclecoverage, wounds,injuriesandanyotherabnormalities whichmighthaveaffectedoverallwell-being.During1990,92.9percent(104)ofallloggerheads foundinthecanalwerealiveandingoodtoexcellent condition. | |||
Only6.3percent(7)ofloggerhead capturesin-31 IIIII volvedindividuals infairorpoorcondition; oneloggerhead wasdeadwhenremovedfromthecanal.Ofthe20greenturtlesremovedfromtheintakecanalduring1990,16wereingoodtoexcellent condition, twowereinfaircondition andtwoweredead.Overtheentiremonitoring period,about76and78percent,respectively, ofalllog-gerheadandgreencaptureshaveinvolvedturtlesingoodtoexcellent condition (Table6).Capturesofindividuals infairtopoorcondition haveoccurredabout16percentofthetimeforloggerheads and14percentofthetimeforgreens.Allofthehawksbills andleatherbacks havebeenremovedfromthecanalingoodtoexcellent condition, whileabouthalfoftheKemp'sridleyshavefallenintothesecategories. | |||
Relativecondition ratingscanbeinfluenced byanumberoffactors,somerelatedandothersunrelated toentrainment and/orentrapment intheintakecanal.Ratingsofgoodtoexcellent indicatethatturtleshavenotbeennegatively impactedbytheirentrap-mentinthecanal,atleastasevidenced byphysicalappearance. | |||
Althoughratingsoffairorpoorimplyreducedvitality, theextenttowhichentrainment/entrapment isresponsible isoftenindeterminable. | |||
Insomeinstances, conditions responsible forlowerratings,suchasinjuries, obviously weresustained priortoentrainment. | |||
During1990,aboutninepercent(10)ofallloggerhead capturesinvolvedindividuals withnoticeable | |||
: injuries, suchasmissingappendages, brokenormissingpiecesofcarapaceanddeeplacerations. | |||
Mostofthesewereold,well-healed wounds,andnonewereseriousenoughtorequiremedicalattention. | |||
Noneofthegreenturtlescapturedduring1990hadmajorinjuries. | |||
32 IIIIIIII | |||
~Mrtalitie Mortalities havebeencloselymonitored throughout thelifeofthecanalcaptureprograminanattempttoassignprobablecausesandtakeappropriate remedialac-tiontominimizefutureoccurrences. | |||
Previousanalysesofcapturedataidentified drown-inginnets(A1Abarriernet,UIDSbarrier,andtanglenets),drowningintheintakepipesduringperiodsofreducedintakeflow,injuriessustained fromdredgingoperations andinjuriessustained fromthemechanical rakesusedintheintakewellsasprobablemor-talityfactors(ABI,1987).Althoughdifficult toquantify, theentrapment andsubsequent demiseofinjuredorsickturtleshasprobablyaccounted foraportionofobservedmor-talities. | |||
Overtheentire15yearmonitoring period,127(6.9percent)ofthe1,853logger-headsand21(6.9percent)ofthe306greenturtlesentrapped inthecanalwerefounddead(Table6).Mortalities spannedtherangeofsizeclassesforloggerheads (SLCL=47.5-103cm),whileallgreenturtlemortalities involvedjuveniles lessthan42cminlength.ThefourKemp'sridleymortalities documented attheplantduring1987and1988wel'etheonlydeathsforthisspeciestodate;noleatherback orhawksbill mor-talitieshaveoccurredattheSt.LuciePlant.Modifications tocaptureprocedures, improvements totheA1Abarriernetandvir-tualelimination oflowflowconditions withinthecanalhaveresultedinasubstantial reduction inseaturtlemortalities overthelifeofthecanalcaptureprogram.Mortality rates,expressed asthepercentage oftotalcapturesinvolving deadanimals,declined42percentbetweenthefirst(1976-1983) andsecond(1984-1990) halvesofthe33 IIIIIIIIII program.During1990,onlythreemortalities (2.3percentoftotalcaptures) wererecorded, oneloggerhead andtwogreenturtles.Thisrepresents thefewestannualmortalities sincethecanalcaptureprogrambeganin1976.Previousobservations suggestthatsickorinjuredturtlesmaybesusceptible todrowningattheUIDSbarrier.Theloggerhead mortality recordedduring1990occurredatthislocation. | |||
Eventhoughthecarcasswastoodecomposed toassessitsphysicalcondition ordetermine causeofdeath,drowningissuspected. | |||
Additional improve-mentstotheA1Abarriernetduringthelaterpartof1990shouldpreventfuturelogger-headmovements westofA1Aandtherebyeliminate theUIDSbarrierasapotential mortality source.Thetwogreenturtlemortalities during1990resultedfromdrowninginABI'stanglenets.Oneofthesewasresuscitated, butitlatersuccumbed whileunderobservation. | |||
Anecropsywasperformed todetermine ifitwasinpoorhealthatthetimeofcapture;resultsoftissueanalyseshavenotyetbeencompleted. | |||
Toeliminate thepotential forfuturenetdrownings, ABIhasbeguncontinual monitoring ofitstanglenetsduringperiodsofdeployment. | |||
RecatureIncidentSincetheSt.LuciePlantcaptureprogrambegan,mostturtlesremovedalivefromtheintakecanalhavebeentaggedandreleasedintotheoceanatvariouslocations alongHutchinson Island.Consequently, individual turtlescanbeidentified aslongastheyretaintheirtags.Overthe15yearhistoryofturtleentrapment attheSt.LuciePlant,61individuals (60loggerheads and1green)havebeenremovedfromthecanalmore34 thanonce.Severalotherturtleswithtagscarshavealsobeenrecovered, indicating thattheactualnumberofrecaptures maybehigher.Ofthe60individual loggerheads knowntohavebeencaughtmorethanonce,42werecaughttwice,9werecaughtthreetimes,5werecaughtfourtimes,2werecap-turedsixtimes,1wascaughtseventimesand1wascaughtonnineseparateoc-casions,yieldingatotalof99recapture incidents. | |||
Releasesitedidnotappeartohaveanyeffectonaturtle'sprobability ofbeingrecaptured. | |||
Turtlesreleasedbothnorthandsouthoftheplantreturned. | |||
Recaptures alsodidnotappeartoberelatedtosize,asbothjuveniles andadultswerecapturedmorethanonce(rangeofSLCL=47-89cm).However,themajorityofrecapture incidents involvedjuveniles (SLCL<70cm).Recapture intervals forloggerheads rangedfromfourto858days,withameanof157days(+174.0days).Theonlygreenturtlecaughtmorethanoncewascapturedontwooccasions, returning tothecanal59daysafterfirstbeingreleasedintotheocean.About56percentofallloggerhead recapture incidents occurredwithin90daysofpreviouscaptureand89percentwithinoneyear(Figure22).Theaverageintervalbetweenfirstandlastcapturewas262days(+329.7days).Thelongestperiodbe-tweenfirstandlastcapturewas5.3years.Thesedatasuggestthatresidency timesofloggerheads withinthenearshore habitatadjacenttotheSt.LuciePlantarerelatively short.Similarfindingshavebeenreportedforloggerheads inhabiting theMosquito/In-dianRiverLagoonsofeast-central Florida(Mendonca andEhrhart,1982).35 SUMMARYAgradientofincreasing loggerhead turtlenestdensities fromnorthtosouthalongthenorthernhalfofHutchinson Islandhasbeenshownduringmostsurveyyears.Thisgradientmayresultfromvariations inbeachtopography, offshoredepthcontours, dis-tribution ofnearshore reefs,onshoreartificial lightingandhumanactivityonthebeachatnight.Lownestingactivityinthevicinityofthepowerplantduring1975andfrom1981through1983wasattributed toconstruction ofpowerplantintakeanddischarge systems.Nestingreturnedtonormalorabovenormallevelsfollowing bothperiodsofconstruction. | |||
Powerplantoperation, exclusive ofintake/discharge construction, hashadnosignificant effectonnestdensities. | |||
Therehavebeenconsiderable year-to-year fluctuations inloggerhead nestingac-tivityonHutchinson Islandfrom1971through1990.Fluctuations arecommonatotherrookeries andmayresultfromoverlapping ofnon-annual breedingpopulations. | |||
Despitethesefluctuations, loggerhead nestingactivityhasremainedhighduringrecentyearsandmayreflectanoverallincreaseinthenumberofnestingfemalesintheHutchinson Islandarea.Norelationship betweentotalnestingontheislandandpowerplantoperation orintake/discharge construction wasindicated. | |||
Temporary declinesinloggerhead nestingactivityhavebeenattributed tocoolwaterintrusions thatfrequently occuroverthecontinental shelfofsoutheast Florida.ThoughtemporalnestingpatternsoftheHutchinson Islandpopulation maybeinfluenced bynaturalfluctuations inwatertemperature, nosignificant effectsduetopowerplantoperation havebeenindicated. | |||
36 Sincenestingsurveysbeganin1971,raccoonpredation wasconsidered themajorcauseofturtlenestdestruction onHutchinson Island.From1971through1977,over-allpredation ratesintheninesurveyareaswerebetween21and44percent.However,apronounced decreaseinraccoonpredation occurredafter1977,andoverallpreda-tionratesintheninesurveyareashavenotexceededtenpercentsince1979.Decreased predation byraccoonsprobablyreflectsadeclineintheraccoonpopula-tion.During1990,132greenturtleand12leatherback turtlenestswererecordedonHutchinson Island.Nestingactivitybythesetwospeciesexhibited considerable annualfluctuations, ashasbeenrecordedatotherrookeries, buthasremainedrelatively highduringrecentyears.Thismayreflectanoverallincreaseinthenumberofnestinggreenandleatherback turtlesintheHutchinson Islandarea.During1990,112loggerheads and20greenturtleswereremovedfromtheSt.LuciePlantintakecanal.Sincemonitoring beganinMay1976,1,843loggerhead, 306green,9leatherback, 8hawksbill and17Kemp'sridleyturtleshavebeencaptured. | |||
Overthelifeofthemonitoring program,annualcatchesforloggerhead turtleshaverangedfrom33in1976(partialyearofplantoperation andmonitoring) toahighof195in1986.Yearlycatchesofgreenturtleshaverangedfrom0in1976to69in1984.Differences inthenumberofturtlesentrapped duringdifferent yearsandmonthsareattributed tonaturalvariation intheoccurrence ofturtlesinthevicinityoftheoffshoreintakestruc-tures,ratherthantoanyinfluence oftheplantitself.37 IIII Size-class distributions ofloggerhead turtlesremovedeachyearfromthecanalhaveconsistently beenpredominated byjuveniles between50and70cminstraightlinecarapacelength.Mostgreenturtlesentrapped inthecanal(about80percent)werejuveniles 40cmorlessinlength.Forbothspecies,thelargestnumberofcapturesforallyearscombinedoccurredduringthewinter,buttheseseasonalpeaksweremuchmorepronounced forgreenturtles.Sexratiosofbothadultandimmatureloggerheads caughtinthecanalcontinued tobebiasedtowardsfemales.During1990,about93and80percent,respectively, ofallloggerheads andgreenturtlesremovedfromthecanalwerecategorized byphysicalappearance asbeingingoodtoexcellent condition. | |||
Overtheentire15yearmonitoring period,76and78per-cent,respectively, ofallloggerhead andgreenturtlecaptureshaveinvolvedindividuals inthesecategories; 16percentoftheloggerheads and14percentofthegreenturtlesremovedfromthecanalhavebeeninfairorpoorcondition. | |||
Aboutninepercentoftheturtlesremovedfromtheintakecanalduring1990hadsubstantial injuries. | |||
However,mostoftheseinjuriesweresustained priortoentrap-ment.Onceinthecanal,turtlesconfinedeastofA1Ausuallyhadverybriefresidency timesandthustherelativecondition ofmostturtleswasnotaffectedbytheirentrap-ment.During1990,oneloggerhead andtwogreenturtlemortalities occurredintheintakecanal.Thesedeathsprobablyresultedfromdrowning: | |||
twoinABItanglenets,oneattheUIDSbarrier.Programmodifications topermitcontinual surveillance oftanglenets38 IIII duringperiodsofdeployment andimprovements totheA1Abarriernetwereinitiated tofurtherreducethepotential forsimilarmortalities inthefuture.Sinceintakecanalmonitoring beganin1976,6.9percentoftheloggerheads andasimilarpercentage ofgreenturtlesremovedfromthecanalweredead.ThefourKemp'sridleymortalities in1987and1988weretheonlydeathsrecordedforthisspeciessincemonitoring began.Alloftheleatherbacks andhawksbills entrapped intheintakecanalattheSt.LuciePlanthavebeencapturedaliveandreleasedintotheocean.Modifica-tionstocaptureprocedures, improvements totheA1Abarriernetandvirtualelimina-tionoflowflowconditions inthecanalhasresultedina42percentreduction inseaturtlemortality ratesoverthelifeofthecanalcaptureprogram.39 IIIIIII LITERATURE CITEDABI(AppliedBiology,Inc).1977.Ecological monitoring attheFloridaPower&LightCo.St.LuciePlant,annualreport1976.VolumesIandII.AB-44.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1978.Ecological monitoring attheFloridaPower8LightCo.St.LuciePlant,annualreport1977.VolumesIandII.AB-101.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami..1979.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1978.VolumesIIandIII,Bioticmonitoring. | |||
AB-177.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1980a.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1979.VolumesIIandIII,Bioticmonitoring. | |||
AB-244.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1980b.Turtleentrainment deterrent study.AB-290.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1981a.Successful relocation ofseaturtlenestsneartheSt.LuciePlant,Hutchinson Island,Florida.AB-317.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1981b.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1980.VolumesIIandIII,Bioticmonitoring. | |||
AB-324.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1981c.ProposedSt.LuciePlantpreoperational andoperational biological monitoring program-August1981.AB-358.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1982.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1981.VolumesIIandIII,Bioticmonitoring. | |||
AB-379.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1983.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calaquaticmonitoring report1982.VolumesIandII.AB-442.PreparedbyAppliedBiol-ogy,Inc.forFloridaPower8LightCo.,Miami.40 IIII ABI(AppliedBiology,Inc.).1984a.FloridaPower8LightCompany,St.LuciePlantannualnon-radiological environmental monitoring report1983.VolumesIandII.AB-530.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1984b.FloridaPower&LightCompany,St.LucieUnit2annualenviron-mentaloperating report1983.AB-533.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami..1985a.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1984.AB-553.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,JunoBeach..1985b.FloridaPower&LightCompany,St.LucieUnit2annualenviron-mentaloperating report1984.AB-555.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,JunoBeach..1986.FloridaPower&LightCompany,St.LucieUnit2annualenvironmen-taloperating report1985.AB-563.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,JunoBeach..1987.FloridaPower&LightCompany,St.LucieUnit2annualenvironmen-taloperating report1986.AB-579.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,JunoBeach..1988.FloridaPower8LightCompany,St.LucieUnit2annualenvironmen-taloperating report1987.AB-595.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,JunoBeach..1989.FloridaPower&LightCompany,St.LucieUnit2annualenvironmen-taloperating report1988.AB-596.PreparedbyAppliedBiology,Inc.forFloridaPower&.LightCo.,JunoBeach..1990.FloridaPower8LightCompany,St.LucieUnit2annualenvironmen-taloperating report1989.AB-603.PreparedbyApplied,Biology,Inc.forFloridaPower&LightCo.,JunoBeach.Baldwin,W.P.,Jr.andJ.P.Lofton,Jr.1959.Theloggerhead turtlesofCapeRomain,SouthCarolina. | |||
Previously unpublished manuscript abridgedandannotated byD.K.Caldwell, withouttheauthors.InD.K.CaldwellandA.Carr,coordinators, TheAtlanticlogger-headeeaturtle,Carettacaretta~carett(L.),inAmerica.BulletinoftheFloridaStateMuseum,Biological | |||
: Sciences, 4(10):319-348. | |||
41 IIII | |||
: Bellmund, S.,M.T.MasnikandG.LaRoche.1982.Assessment oftheimpactsoftheSt.Lucie2NuclearStationonthreatened orendangered species.USNuclearRegulatory Com-mission,OfficeofNuclearReactorRegulation. | |||
Bustard,H.R.1968.Protection forarookery:Bundaberg seaturtles.WildlifeinAustralia 5:43-44Bustard,H.R.andP.Greenham. | |||
1968.Physicalandchemicalfactorsaffecting hatchinginthe=-greenaeaturtle,Chelonia~mdaa(L.).Ecology49(2):269-276. | |||
: Caldwell, D.K.1962.CommentsonthenestingbehaviorofAtlanticloggerhead seaturtles,basedprimarily ontaggingreturns.Quarterly JournaloftheFloridaAcademyofScien-ces25(4):287-302. | |||
: Caldwell, D.K.,A.CarrandL.H.Ogren.1959.Nestingandmigration oftheAtlanticlogger-headturtle.InD.K.CaldwellandA.Carr,coordinators, TheAtlanticloggerhead seaturtleCarettacarettacaretta(L.),inAmerica.BulletinoftheFloridaStateMuseum,Biological | |||
: Sciences, 4(10):295-308. | |||
Camp,D.K.,N.W.WhitingandR.E.Martin.1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
V.Arthropods. | |||
FloridaMarineResearchPublications 25:1-63.Carr,A.,A.Meylan,J.Mortimer, K.BjorndalandT.Carr.1982.Surveysofseaturtlepopula-tionsandhabitatsintheWesternAtlantic. | |||
NOAATechnical Memorandum NMFS-SEFC-91:1-82.Davis,G.E.,andM.C.Whiting.1977.Loggerhead seaturtlenestinginEverglades NationalPark,Florida,U.S.A.Herpetologica 33:18-28. | |||
dtdAWtdtg9dtgttIgtdttIHtttllt~I,~WAIimbricata L.,onCousinIsland,Seychelles. | |||
Biological Conservation 9:199-215. | |||
Ehrhart,L.M.1979.Reproductive characteristics andmanagement potential oftheseaturtlerookeryatCanaveral NationalSeashore, Florida.Pages397-399inLinn,R.M.,ed.Proceedings oftheFirstConference onScientific ResearchintheNationalParks,9-12November, 1976,NewOrleans,La.NPSTrans.andProc.Ser.No.5.Ehrhart,L.M.1980.Threatened andendangered speciesoftheKennedySpaceCenter:marineturtlestudies.InAcontinuation ofbaselinestudiesforenvironmentally monitor-ingspacetransportation systems(STS)atJohnF.KennedySpaceCenter.ContractNo.NAS-10-8986. | |||
Vol.IV,NASAReport163122.September 1980.42 Ernest,R.G.,R.E.Martin,B.D.Peery,D.G.Strom,J.R.WilcoxandN.W.Walls.1988.Seaturtleentrapment atacoastalpowerplant.Pages270-301inMahadevan, K.,R.K.Evans,P.Behrens,T.BiffarandL.Olsen,eds.Proceedings, Southeastern WorkshoponAquaticEcological EffectsofPowerGeneration. | |||
ReportNo.124,MoteMarineLaboratory, | |||
: Sarasota, Florida.Ernest,R.G.,R.E.Martin,N.W.WallsandJ.R.Wilcox.1989.Population dynamicsofseaturtlesutilizing shallowcoastalwatersoffHutchinson Island,Florida.Pages57-59inEckert,S.A.,K.L.EckertandT.H.Richardson, compilers. | |||
Proceedings oftheNinthAnnualWorkshoponSeaTurtleConservation andBiology.NOAATechnical Memorandum NMFS-SEFC-232. | |||
Fowler,L.E.1979.Hatchingsuccessandnestpredation inthegreenseaturtle,Chelonia~mdasatTortuguero, CostaRica.Ecology60(5):945-955. | |||
Futch,C.R.andS.E.Dwinell.1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
IV.Lancelets andFishes.FloridaMarineResearchPublications 24:1-23.Gallagher, R.M.1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
II.Sediments. | |||
FloridaMarineResearchPublications 23:6-24.Gallagher, R.M.andM.L.Hollinger. | |||
1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
I.Introduction andrationale. | |||
FloridaMarineResearchPublications 23:1-5.Gallagher, R.M.,M.L.Hollinger, R.M.IngleandC.R.Futch.1972.MarineturtlenestingonHutchinson Island,Floridain1971.FloridaDepartment ofNaturalResources, SpecialScientific Report37:1-11.Hendrickson, J.R.andE.Balasingam. | |||
1966.Nestingbeachpreferences ofMalayanseaturtles.BulletinoftheNationalMuseumSingapore 33(10):69-76. | |||
Henwood,T.A.1987.Movements andseasonalchangesinloggerhead turtle,Carettacaret-taaggregations inthevicinityofCapeCanaveral, Florida(1978-84). | |||
Biological Con-servation 40:191-202. | |||
Hillestad, H.O.,J.I~Richardson, C.McVea,Jr.andJ.M.Watson,Jr.1982.Worldwide inciden-talcaptureofseaturtles.Pages489-496inBjorndal, K.A.,ed.Biologyandconserva-tionofseaturtles.Smithsonian Institution Press,Washington, D.C.Hirth,H.F.1980.Someaspectsofthenestingbehaviorandreproductive biologyofseaturtles.AmericanZoologist 20:507-523. | |||
43 III Hopkins,S.R.,T.M.Murphy,Jr.,K.B.StansellandP.M.Wilkinson. | |||
1979.Bioticandabioticfactorsaffecting nestmortality intheAtlanticloggerhead turtle.Proceedings AnnualConference ofSoutheastern FishandWildlifeAgencies32:213-223. | |||
Hughes,G.R.1974.Theseaturtlesofsoutheast Africa,1.Status,morphology anddistribu-tions.SouthAfricanAssociation forMarineBiological | |||
: Research, Oceanographic ResearchInstitute, Investigational ReportNo.35:1-144. | |||
.1976.Irregular reproductive cyclesintheTongaland loggerhead seaturtle,Carettacaretta(L.)(Cryptodira: | |||
Chelonidae). | |||
Zoologica Africana11(2):285-291. | |||
Lyons,W.G.1989.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
PartXI.Mollusks. | |||
FloridaMarineResearchPublication 47:1-131. | |||
Martin,R.E.,R.G.Ernest,N.W.WallsandJ.R.Wilcox.1989a.Sizedistribution andseasonalabundance ofloggerhead andgreenturtlesinnearshore watersoffHutchinson Island,Florida.Pages334-335inOgren,L.,F.Berry,K.Bjorndal, H.Kumpf,R.Mast,G.Medina,H.ReichartandR.Witham,editors.Proceedings oftheSecondWesternAt-lanticTurtleSymposium. | |||
: Mayaguez, PuertoRico,12-16October1987.NOAATechni-calMemorandum NMFS-SEFC-226. | |||
.1989b.Long-term trendsinseaturtlenestingonHutchin-sonIsland,Florida.Pages111-113inEckert,S.A.,K.L.EckertandT.H.Richardson, compilers. | |||
Proceedings oftheNinthAnnualWorkshoponSeaTurtleConservation andBiology.NOAATechnical Memorandum NMFS-SEFC-232. | |||
: Mendonca, M.T.andL.M.Ehrhart.1982.Activity, population sizeandstructure oftheimma-tureChelonia~mdas andCarettacarettainMosquitoLagoon,Florida.Copeia1982:(1)161-167.Moffler,M.D.andJ.F.VanBreedveld. | |||
1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.X. | |||
Benthicalgaespecieslist.FloridaMarineResearchPublications 34:118-122.Mortimer, J.A.1982.Factorsinfluencing beachselection bynestingseaturtles.Pages45-51inBjorndal, K.A.,ed.BiologyandConservation ofSeaTurtles.Smithsonian Institution Press.Washington, D.C.NMFS(National MarineFisheries Service). | |||
1978.FinalEISlistingandprotecting thegreenseaturtle(Chelonia~mdas, loggerhead seaturtle(CGartta~cretta andthePacificRidleytttid3ptt~lidI3d9dgpI9t11913.3ttalMarineFisheries Service,Dept.ofCommerce, Washington, D.C. | |||
IIII NRC(USNuclearRegulatory Commission). | |||
1982.Finalenvironmental statement relatedtotheoperation ofSt.LuciePlantUnit2.DocketNo.50-389.O'ara,J.1980.Thermalinfluences ontheswimmingspeedofloggerhead turtlehatchlings. | |||
Copeia1980(4):773-780. | |||
Owens,D.W.,J.R.Hendrickson, V.LanceandI.P.Callard.1978.Atechnique fordetermin-ingsexofimmatureChelonia~md~ausingaradioimmunoassay. | |||
Herpetologica 34:270-273. | |||
Owens,D.W.andG.J.Ruiz.1980.Newmethodsofobtaining bloodandcerebrospinal fluidfrommarineturtles.Herpetologica 36:17-20. | |||
Pritchard, P.C.,P.R.Bacon,F.H.Berry,A.F.Carr,J.Fletemeyer, R.M.Gallagher, S.R.Hop-kins,R.R.Lankford, R.MarquesM.,L.H.Ogren,W.G.Pringle,Jr.,H.A.ReichartandR.Witham.1983.Manualofseaturtleresearchandconservation techniques. | |||
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.Effectsofpowerplantconstruction andopera-tiononthenestingoftheloggerhead seaturtle(Caretta~caretta:t97t-t984. | |||
Copeia1986(3):813-816.Raymond,P.W.1984.Theeffectsofbeachrestoration onmarineturtlesnestinginsouthBrevardCounty,Florida.M.S.thesis,University ofCentralFlorida.Routa,R.A.1968.SeaturtlenestsurveyofHutchinson Island,Florida.Quarterly JournalFloridaAcademyofSciences30(4):287-294. | |||
Schulz,J.P.1975.SeaturtlesnestinginSurinam.Zoologische Verhandelingen, uitgegeven doorhetRijksmuseum vanNatuurlijke HistoricteLeiden,No.143:1-144. | |||
Smith,N.P.1982.Upwelling inAtlanticshelfwatersofsouthFlorida.FloridaScientist 45(2):125-138.Sokal,R.R.andF.J.Rohlf.1981.Biometry. | |||
Theprinciples andpracticeofstatistics inbiologi-calresearch. | |||
W.H.FreemanandCompany,SanFrancisco. | |||
859pp.Stancyk,S.E.1982.Non-human predators ofseaturtlesandtheircontrol.Pages139-152inBjorndal, K.A.,ed.BiologyandConservation ofSeaTurtles.Smithsonian Institution Press.Washington, D.C. | |||
IIIIIII Talbert,O.R.,S.E.Stancyk,J.M.DeanandJ.M.Will.1980.Nestingactivityoftheloggerhead turtle(Caretta~carettainSouthCarolina. | |||
I:Arookeryintransition. | |||
Copeia1950:(4)709-718.Taylor,C.B.,andH.B.Stewart.1958.Summerupwelling alongtheeastcoastofFlorida.Jour-nalofGeophysical Research64(1):33-40. | |||
Tester,L.A.andK.A.Steidinger. | |||
1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
Vll.Phytoplankton, 1971-1973. | |||
FloridaMarineResearchPublica-tions34:16-61~Walker,L.M.1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
IX.Dielplankton, 1973-1974. | |||
FloridaMarineResearchPublications 34:99-117.Walker,L.M.,B.M.GlassandB.S.Roberts.1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
Vill.Zooplankton, 1971-1973. | |||
FloridaMarineResearchPublications 34:62-98.Walker,L.M.andK.A.Steidinger. | |||
1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
Vl.Planktondynamics, 1971-1973. | |||
FloridaMarineResearchPublications 34:1-15.Wibbels,T.,D.Owens,Y.MorrisandM.Amoss.1984.Sexratiosofimmatureloggerhead seaturtlescapturedalongtheAtlanticcoastoftheUnitedStates.FinalReporttotheNa-tionalMarineFisheries Service.ContractNo.NA81-GA-C-0039. | |||
47pp.Williams-Walls, N.,J.O'ara,R.M.Gallagher, D.F.Worth,B.D.PeeryandJ.R.Wilcox.1983.SpatialandtemporaltrendsofseaturtlenestingonHutchinson Island,Florida,1971-1979.BulletinofMarineScience33(1):55-66. | |||
Witherington, B.E.andL.M.Ehrhart.1989.Statusandreproductive characteristics ofgreenturtles(Chelonia | |||
~mdasnestinginFlorida.Pages351-352inOgren,L.,F.Berry,K.Bjorndal, H.Kumpf,R.Mast,G.Medina,H.ReichartandR.Witham,editors.Proceed-ingsoftheSecondWesternAtlanticTurtleSymposium. | |||
: Mayaguez, PuertoRico,12-16October1987.NOAATechnical Memorandum NMFS-SEFC-226. | |||
Wi*II,WN.'l983.98 3IIdiIpiIdI83till~I~~EhI(Linnaeus, 1766).FAOFisheries | |||
: Synopsis, 137:1-78. | |||
Worth,D.F.andM.L.Hollinger. | |||
1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974. | |||
III.Physicalandchemicalenvironment. | |||
FloridaMarineResearchPublica-tions23:25-85.46 Worth,D.F.,andJ.B.Smith.1976.MarineturtlenestingonHutchinson Island,Florida,in1973.FloridaMarineResearchPublications 18:1-17.47 GULFOFMEXICO00YAROSKILOMETERS SCALEr~~StLuciaPlantFigure1.LocationoftheSt.LuciePlant. | |||
IIIIIIIII V~g~t'~gW.:,::HUTCHINSON ISLAND~o0'F~~IJi7.~iS'~Oc2G'5~.L-....i~00250500METERS~~tr~5pp,>r~DISCHARGE | |||
~gG+'..PIPES0G"oi~gAv'~'l"r2VQ9INTAKE'<:.:.c,".'NTAKE HEADWALL'; | |||
4~':-,.'.'ELLS~'.",STRUCTURES UIDSA1A'-'.:. | |||
BARRIERBARRIER:. | |||
,,NET;.~;~b~',,'1'a'84'NTAKECANALFigure2.St.LuciePlantcoolingwaterintakeanddischarge system. | |||
II FLPierceInlet10A\~~'aFaStateGHwyA0a7~'t~aeaaAIg0Q0bb,oOaloH2V+F+3N40FPLST.LUCIEPU.S.HwyId0SkmRtV6.RVw6AA4BBCCDDEFFGGda+HHOdQuSLLudoInletFigure3.Designation andlocationofnine1.25-kmsegmentsandthirty-six 1-kmsegmentssurveyedforseaturtlenesting.Hutchinson Island,1971-1990. | |||
350300250z0200Dz1501005012NORTH3456789POWERPLANTSOUTHFigure4.Meanannualnumberofloggerhead turtlenestsineachofthenine1.25-km-long surveyareas,Hutchinson Island,1971-1989, comparedwithnumberofnestsduring1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values(1980datawereexcludedbecausenotallareasweresurveyed). | |||
IIIIIIIIIIII 350300~~250200(0I-V)z150Dz~~~10050ABCDEFGHIJKLMNOPQRSTUVWXYZABCDE FGHIJABCDEFGHIJNORTH1'OWERPLANTSOUTHFigure5.Meanannualnumberofloggerhead turtlenestsineachofthethirty-six 1-km-long surveyareas,Hutchinson Island,1981-1989, comparedwithnumberofnestsduring1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values. | |||
IIIIIIIII 700600500400Oz300D200~~100ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHI JABCDEFGHIJNORTHPOWERPLANTSOUTHFigure6.Meanannualnumberofloggerhead turtleemergences ineachofthethirty-six 1-km-long surveyareas,Hutchinson Island,1981-1989, comparedwiththenumberofemergences during1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values. | |||
IIIIIII 10080gM(0LIJOOP)60(9ZI-0)ILJZ4020ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGH IJABCDEFGHIJNORTH0POWERPLANTSOUTHFigure7.Meanannualloggerhead turtlenestingsuccess(percentage ofemergences thatresultedinnests)foreachofthethirty-six 1-km-longsurveyareas,Hutchinson Island,1981-1989, comparedwithnestingsuccessduring1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values. | |||
300250o-oArea4(PowerPlantSite)e--~Area5(ControlSite)200V)I-Z0150Dz100~Or%rr/////////50TTT19711972197319741975197619771978197919801981198219831984198519861987198819891990Figure8.Numberofioggerhead turtlenestsinAreas4and5,Hutchinson Isiand,1971-1990. | |||
Arrowsdenoteyearsduringwhichintake/discharge construction occurredinArea4. | |||
I 6000CD(DI-zDz50004000300020001000CDOz0CCDz12000100008000600040002000gCDCOLIJOO(0(9zCDUJ806040201981198219831984198519861987198819891990Figure9.Annualnumberofnests,numberofemergences andnestingsuccessalongtheentire36.0-km-long Atlanticcoastline ofHutchinson Island,198t-1990. | |||
3130O29285272625Q.242322212012090(0z060z30305153051530515APRMAYJUNJULFigure10.Dailyloggerhead turtlenestingactivityandwatertemperature, Hutchinson Island,1990.30515AUG30515SEP 27%7060Destroyed byghostcrabsgDestroyed byraccoonsandghostcrabsQDestroyed byraccoons50O0-0KI-Uj40O(0I-(0zrt-30Dz201015%.?~Vxm:('?iAMh((.:9X'~egZps:K(:N<:e.'.gg.r,'(?Fp?'m~$+11%Y??r','my~?(m,:(g~18%r'(I(pjmr~'r'..vÃr'.rg~b;s(:r.ggCi(5'$.::$p~.?s?:.'$p$j~g>?~PI5%?.'A'(iM:'A?g(;@A;('(?g(??.:N~??jPAQsE(g?gr.m(mi14%Wg'kg$.$yg?gmmeE(.:VP8:.:~a??::,g:)>%!4~?>?:'(pY,~4'.($NScYA(Ã~(??APg.(g'.?'.spi'g~Q4?ih(1%rr:.(1%1%2'/oABCDEFGHIJKLMNOPQRS TUVWXYZABCDEFGHIJABCDEFGHIJNORTH0POWERPLANTSOUTHFigure11.Numberofloggerhead turtlenestsdestroyed byraccoonsandghostcrabsandpercentage ofnestsdestroyed ineach1-km-long surveyarea,Hutchinson Island,1990. | |||
140120100COIzO80z604020Q--QGreen(Chelonia mydas)O-~Leatherback (Dermochelys coriacea) pQpHgoIIIIIIlIIIpqII/xIIiIy/XgIIIIII197119731975197719791981198219831984198519861987198819891990Figure12.Annualnumbersofgreenturtleandleatherback turtlenests,Hutchinson Island,1971-1990. | |||
200~-eLOGGERHEAD (Carettacaretta)0---wGREEN(Chelccia m~das)80175150O125K1007550z25////r0IIIIIIpi\'I70860O50z40(930mmD2010197619771978197919801981198219831984198519861987198819891990Figure13.Numberofloggerhead andgreenturtlesremovedeachyearfromtheintakecanal,St.LuciePlant,19764990. | |||
40403030I-20z201010JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECMONTHOFCAPTUREFigure14.Meannumberofloggerheads capturedeachmonth,St.LuciePlantintakecanal,1977-1989, comparedwithnumberofmonthlycapturesduring1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values. | |||
IIIIIII 400400300300(0DO)0zu-2000KUJlZlDz200100100~4041-4546-5051-5556-6061-6566-7071-7576-8081-8586-9091-9596-101-106->110STRAIGHTLINECARAPACELENGTH(cm)100105110Figure15.Lengthdistribution (SLCL)ofloggerhead turtles(N=1,673) removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1990. | |||
Nodatacollected for81individuals. | |||
400400300300(0DO)DZ2000KIllCODZ200100100+1011-2021-3031-4041-5051-6061-7071-8081-9091-100101-111-121-131-141-i150'I/EiGHT(kg)110120130140150Figure1LWeightdistribution ofliveloggerhead turtles(¹1,487)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1990. | |||
Nodatacollected for267individuals. | |||
12012010010080COD0)0600K(9408060402020-1516-21-26-31-36-41-46-51-56-61-66-71-76-81-86-91-96-101-106->11020253035404550556065707580859095100105110STRAIGHTLINECARAPACELENGTH(cm)Figure17.Lengthdistribution (SLCL)ofgreenturtles(N=295)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1990. | |||
Nodatacollected for10individuals. | |||
200200180180160160(D140D9120Dz010080z601401201008060404020201-56-1011-1516-2021-2526-3031-3536-4041-4546-5051-101-151-)200WEIGHT(kg)100150200Figure18.Weightdistribution ofgreenturtles(N=291)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1990. | |||
Nodatacollected for14individuals. | |||
IIIIIIII MALESFEMALES60505040V)DCI0300KILJKDz204030201010JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECMONTHOFCAPTUREFigure19.Numbersofadultloggerheads (SLCL)85.0 cm),including recaptures, removedeachmonthfromtheintakecanal,St.LuciePlant,1977-1990 (N=255;sexnotrecordedforsixindividuals)85.0 cm). | |||
50~-eCANALCAPTURES 50040302010o---oEMERGENCES 00//////]y////r/400300200100ZV)OzGK0zzz19771978197919801981198219831984198519861987198819891990Figure20.Comparison ofcapturesofadultfemaleloggerheads (SLCL>85.0cm)intheintakecanal,St.LuciePlant,1977-1990, andnumbersofloggerhead emergences inarea4adjacenttotheplant.Nestingactivitywasnotmonitored in1978. | |||
JLJCCI-CLOCIJCJCIZ0I-ZILJOIZILJQ.ILJI-O10080604020'100806040201020304050DAYSBETWEENFIRSTSIGHTINGANDCAPTUREFigure21.Captureefficiency, expressed asdaysbetweenfirstsightingandcapture,forloggerhead turtlesentrapped intheintakecanal,St.LuciePlant,April-December, 1990(N=90). | |||
TABLE3TOTALNUMBEROF(ANDNUMBEROFDEAD) | 100100~80(9za-60I-DD<40fIt///80604020IIIIIt~-----~Intervalbetweensuccessive capturesIntervalbetweenfirstandlastcapture20500250175075010001250RECAPTURE INTERVAL(days)Figure22.Cumulative percentage ofallloggerhead recaptures occurring withinvarioustimeintervals betweensuccessive captures(¹97jandfirstandlastcapture(¹58),St.LuciePlantintakecanal1976-1990. | ||
IIII TABLE4TOTALNUMBEROF(ANDNUMBEROFDEAD)GREENTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPIANT,1976- | |||
IIIIII | WTABLE1ESTIMATES OFTHENUMBERSOFLOGGERHEAD TURTLENESTSONHUTCHINSON ISLANDBASEDONSURVEYSOFNINE1.25-KM-LONG SURVEYAREAS,1971-1990,COMPAREDTOTHEACTUALNUMBEROFNESTSONTHEISLAND,1981-1990197119731975197719791981198219831984198519861987198819891990Numberofnestsinthenine1420126014939321449103115921439162318391645170117742177Extrapolation fromtheninesurveyareastotheiI4203373044192759428930524837471242594804486950355251Actualnumberofnestsonthe311546904743427748775483462351936700 IIIII TABLE2TOTALNUMBEROFSEATURTLECAPTURESAND(NUMBEROFDEAD)TURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT,1976-1990 19761977197819791980198119821983198419851986198719881989TotalAnnualMean's(4) 80(5)138(19)172(13)116(5)62(5)101(16)119(4)148(3)157(4)195(27)175(11)134(6)111(4)112(1)1853(127)130.05(2)6(1)3(1)10(3)32(2)823(4)69(2)1422(1)3542(2)17(1)20(2)306(21)21.99(0)0.6will8(0)0.6Km'l16(2)5(2)217(4)1.2ss(4)86(7)148(20)175(14)126(8)97(7)110(16)142(8)220(5)172(4)220(28)218(13)181(10)133(5)1s2(s)2193(152)154.3Excludes1976(partialyearofplantoperation). | ||
TABLE3TOTALNUMBEROF(ANDNUMBEROFDEAD)LOGGERHEAD TURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT,1976-1990 1976197713s(1)2075(2)157(1)75(3)15(1)9(1)5933(4)580(5)19781911(2)27(2)19(5)3(1)101217(2)15(7)4138(19)19791980198119824&1983198419851986198719881989199024(3)29(1)111703(1)1621(2)14078(3)11(1)11(3)6106627(2)16(2)8(1)12192(1)15(3)1274006(2)141417(4)72(1)9(1)9(5)4(2)391313(1)047(1)62(1)728(1)12(1)26s(2)16152013161720(3)19(1)1426(3)8(1)24(3)23(1)26(1)19(1)17(1)1751097311(2)83510(3)1113(2)283011(1)-254(2)11131699232521(1)15167(1)35(1)4115(2)16(4)14(4)20(2)1220(1)26(2)34(6)9(4)10172(13)8116(5)362(5)1(1)101(16)12119(4)8148(3)2157(4)10195(27)9175(11)9134(6)2111(4)3112(1)Total219(11)178(17)152(9)157(15)162(6)208(8)172(11)177(11)126(12)121(13)86(13)95(1)1853(127) | |||
MonthlyMean15.6%TotalCatch11.812.79.611.58.28.58.711.29.310.911.210.813.911.89.68.46.86.54.68.15.76.35.1eludes1976(partialyearofplantoperation). | |||
IIII TABLE4TOTALNUMBEROF(ANDNUMBEROFDEAD)GREENTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPIANT,1976-1990 1976197719781979198019811982198310018(1)43(2)22(1)01(1)012201(1)0101(1)00,5(1)4(1)0020(1)7110000000101(1)000000000002(1)02.04(1)5(2)6(1)3(1)10(3)32(2)23(4)1984198537(1)1041121986116(1)31198741332198819891990Total12114233(1)06316(1)3(1)31199(5)48(3)33(4)19(2)9(1)MonthlyMean7.13.42.41.40.62.9%TotalCatch32.415.710.86.25.92.60211316(2)1101018(3)81.20.59(1)0.62.90.31.6140.94.64(1)51102022120(2)241.31.66.57.869(2)1422(1)3542(2)17(1)20(2)306(21) | |||
IIIIII TABLE5NUMBEROFMONTHLYCAPTURESBYSIZECLASSFORLOGGERHEAD TURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT,1977-1990 SizeclassesSLCLincm)JanuaryFebruaryMarch16AprilMayJune13Total101%ofTotalJulyAugustSeptember 4October8November4December473475150'24248352034592765648523835483832242651717812011210010581977548121014.711.69.99.38.38.76.78.07.46.24.05.369.42621182717262835162?19132739.57.76.6996.29.510.312.85.9997.04.815.772022006150132613826321294191815825114414011613114406738152613.41.52.72.315.325.720.714.65.72.73.41.915.0Excludes1976(partialyearofdata).Nodatawerecollected for76individuals. | |||
TABLE6RELATIVECONDITION OFSEATURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT,1976-1990RelativeTotal39321.251127.650327.122111.9713.81276.9271.5185312841.85919.35116.73511.472.3216.951.6306111.1111.1777.8211.8317631763176211.8423.51775.025.053024.257626.356425.725911.8803.61526.9321.521931Excellent: | |||
normalorabovenormalweight,active,veryfewornobarnacles orleeches,nowounds.2Verygood:intermediate goodtoexcellent. | |||
3Good:normalweight,active,lighttomediumcoverageofbarnacles and/orleeches,woundsabsent,healedordonotappeartodebilitate theanimal.4Fair:intermediate poortogood.5Poor:emaciated, sloworinactive, heavybarnaclecoverageand/orleechinfestation, debilitating woundsormissingappendages. | |||
6Dead7Alivebutotherwise condition notrecorded. | |||
IIII}} | IIII}} |
Revision as of 16:26, 29 June 2018
ML17223B174 | |
Person / Time | |
---|---|
Site: | Saint Lucie ![]() |
Issue date: | 12/31/1990 |
From: | APPLIED BIOLOGY, INC. |
To: | |
Shared Package | |
ML17223B173 | List: |
References | |
NUDOCS 9105070294 | |
Download: ML17223B174 (128) | |
Text
APPLIEDBI0L'06Y,INC.AB-610I'LORIDAPOWER&LIGHTCOMPANYST.LUCIEUNIT2ANNUALENVIRONMENTAL OPERATING REPORTVOLUMEI1990I2968ANORTHDECATURROAD9105070294 910025PDRADOCK05000389RPDR~ATLANTA,GEORGIA30033~404-296-3900 AB-610FLORIDAPOWER&LIGHTCOMPANYST.LUCIEUNIT2ANNUALENVIRONMENTAL OPERATING REPORT1990VOLUME1APRIL1991FLORIDAPOWER&LIGHTCOMPANYJUNOBEACH,FLORIDAAPPLIEDBIOLOGY,INC.ATLANTA,GEORGIA IIIIII ENVIRONMENTAL OPERATING REPORTTABLEOFCONTENTSTABLEOFCONVERSION FACTORSFORMETRICUNITSEXECUTIVE SUMMARYIntroduction TurtleNestingSurveyIntakeCanalMonitoring OtherRelatedActivities INTRODUCTION
Background
AreaDescription PlantDescription TURTLESIntroduction Materials andMethodsNestingSurveyIntakeCanalMonitoring StudiestoEvaluateand/orMitigateIntakeEntrapment ResultsandDiscussion NestingSurveyDistribution ofLoggerhead NestsAlongHutchinson IslandEstimates ofTotalLoggerhead NestingonHutchinson IslandTemporalLoggerhead NestingPatternsPredation onLoggerhead TurtleNestsGreenandLeatherback TurtleNestingIntakeCanalMonitoring RelativeAbundance andTemporalDistribution Size-Class Distributions SexRatiosCaptureEfficiencies RelativeCondition Mortalities Recapture Incidents SummaryLITERATURE CITEDFIGURESTABLESIVIV10101415151518192021232326.28.3031333436404870 TABLEOFCONVERSION FACTORSFORMETRICUNITSToconvertcentigrade (degrees) centigrade (degrees) centimeters (cm)centimeters (cm)centimeters/second (cm/sec)cubiccentimeters (cm)grams(g)grams(g)hectares(ha)kilograms (kg)kilograms (kg)kilograms (kg)kilometers (km)kilometers (km)liters(I)liters(I)meters(m)meters(m)meters(m)milligrams (mg)milligrams/liters (mg/I)milliliters (ml)millimeters (mm)millimeters (mm)squarecentimeters (cm)squaremeters(m)squaremillimeters (mm)MultiIb(Cx1.8)+32C+273.183.937x103.281x103.281x101.0x102.205x103.527x102.4711.0x102.20463.5274x106.214x101.0x101.0x102.642x103.2813.937x101.0941.0x101.01.0x103.937x103.281x101.550x101.076x101.55x10Toobtainfahrenheit (degrees) kelvin(degrees) inchesfeetfeetpersecondliterspoundsounces(avoirdupois) acresgramspoundsounces(avoirdupois) miles(statute) millimetcrscubiccentimeters (cm)gallons(USliquid)feetinchesJJardsgramspartspermillionliters(USliquid)inchesfeetsquareinchessquarefeetsquareinches IIIrIe,t EXECUTlVE SUMMARYINTRODUCTION TheSt.LuciePlantisanelectricgenerating stationonHutchinson IslandinSt.LucieCounty,Florida.Theplantconsistsoftwonuclear-fueled 850-MWunits;Unit1wasplacedon-lineinMarch1976andUnit2inMay1983.Thisdocumenthasbeenpreparedtosatisfy.therequirements contained intheUnitedStatesNuclearRegulatory Commission's AppendixBEnvironmental Protection Plan(EPP)toSt.LucieUnit2FacilityOperating LicenseNo.NPF-16.Thisreportdiscusses environmental protection activities relatedtoseaturtlesasrequiredbySubsection 4.2oftheEPP.Otherroutineannualreporting requirements areaddressed inVolume2,alsoentitled"St.LucieUnit2AnnualEnvironmental Operating Report".TURTLENESTINGSURVEYTherehavebeenconsiderable year-to-year fluctuations inseaturtlenestingactivityonHutchinson Islandsincemonitoring beganin1971.Lownestingactivityin1975and1981-1983inthevicinityofthepowerplantwasattributed toconstruction ofplantin-takeanddischarge structures.
Nestingreturnedtonormalorabovenormallevelsfol-lowingbothperiodsofconstruction.
Powerplantoperation exclusive ofconstruction hashadnosignificant effectonnestingneartheplant.Datacollected through1990haveshownnolong-term reductions intotalnesting,totalemergences ornestingsuc-cessontheisland.Formalrequirements toconductthisprogramexpiredin1986butwerevoluntarily continued in1990withagreement fromfederalandstateagencies.
INTAKECANALMONITORING Sinceplantoperation beganin1976,2,193seaturtles(including 100recaptures) representing fivedifferent specieshavebeenremovedfromtheintakecanal.Eighty-fourpercentofthesewereloggerheads.
Differences inthenumbersofturtlesfoundduringdifferent monthsandyearswereattributed tonaturalvariation intheoccurren-cesofturtlesinthevicinityoftheplant,ratherthantoanyinfluence oftheplantitself.Themajorityofturtlesremovedfromtheintakecanal(about93percent)werecapturedaliveandreleasedbackintotheocean.TurtlesconfinedbetweentheA1Abarriernetandintakeheadwalls usuallyresidedinthecanalforarelatively shortperiodoftime,andmostwereingoodtoexcellent condition whencaught.OTHERRELATEDACTIVITIES Studiestoevaluatevariousintakedeterrent systems,asrequiredbytheNRC'sUnit2Environmental Protection Plan,wereconducted during1982and1983.Resultsandevaluations ofthosestudieswerepresented toregulatory agenciesduring1984,andtherequirement isnowconsidered completed.
INTRODUCTION BACKGROUND Thisdocumenthasbeenpreparedtosatisfytherequirements contained intheUnitedStatesNuclearRegulatory Commission's (NRC)AppendixBEnvironmental Protection PlantoSt.LucieUnit2FacilityOperating LicenseNo.NPF-16.In1970,FloridaPower8LightCompany(FPL)wasissuedPermitNo.CPPR-74bytheUnitedStatesAtomicEnergyCommission, nowtheNuclearRegulatory Commis-sion,thatallowedconstruction ofUnit1oftheSt.LuciePlant,an850-MWnuclear-poweredelectricgenerating stationonHutchinson IslandinSt.LucieCounty,Florida.StLuciePlantUnit1wasplacedon-lineinMarch1976.InMay1977,FPLwasissuedPermitNo.CPPR-144bytheNRCfortheconstruction ofasecond850-MWnuclear-poweredunit.Unit2wasplacedon-lineinMay1983andbegancommercial operation inAugustofthatyear.St.LuciePlantUnits1and2usetheAtlanticOceanasasourceofwaterforonce-throughcondenser cooling.Since1971,thepotential environmental effectsresulting fromtheintakeanddischarge ofthiswaterhavebeenthesubjectofFPL-sponsored bioticstudiesatthesite.Baselineenvironmental studiesofthemarineenvironment adjacenttotheSt.LuciePlantweredescribed inaseriesofreportspublished bytheFloridaDepartment ofNaturalResources (Campetal.,1977;FutchandDwinell,1977;Gallagher, 1977;Gal-lagherandHollinger, 1977;WorthandHollinger, 1977;MofflerandVanBreedveld, 1979;TesterandSteidinger, 1979;Walker,1979;Walkeretal.,1979;WalkerandSteidinger, 1979;Lyons,1989).TheresultsofUnit1operational andUnit2preopera-tionalbioticmonitoring attheSt.LuciePlantwerepresented insixannualreports(ABI,1977,1978,1979,1980a,1981b,1982).InJanuary1982,aNationalPollutant Discharge Elimination System(NPDES)permitwasissuedtoFPLbytheUSEnvironmental Protec-tionAgency(EPA).TheEPAguidelines fortheSt.Luciesitebiological studieswerebasedonthedocumententitled"Proposed St.LuciePlantPreoperational andOpera-tionalBiological Monitoring Program-August1981"(ABI,1981c).Findingsfromthesestudieswerereportedinthreeannualreports(ABI,1983,1984a,1985a).TheEPAbioticmonitoring requirements weredeletedfromtheNPDESpermitin1985.Jurisdiction forseaturtlestudiesiswiththeNRC,whichisconsidered tobetheleadfederalagencyrelativetoconsultation undertheEndangered SpeciesAct.Previousresultsdealingexclusively withseaturtlestudiesarecontained insevenenvironmen-taloperating reports(ABI,1984b,1985b,1986,1987,1988,1989,1990).Thisreportdescribes the1990environmental protection activities relatedtoseaturtles,asrequiredbySubsection 4.2oftheSt.LuciePlantUnit2Environmental Protection Plan.AREADESCRIPTION TheSt.LuciePlantislocatedona457-hasiteonHutchinson IslandonFlorida's eastcoast(Figures1and2).Theplantisapproximately midwaybetweentheFt.PierceandSt.LucieInlets.ItisboundedonitseastsidebytheAtlanticOceanandonitswestsidebytheIndianRiverLagoon.
IIIII Hutchinson Islandisabarrierislandthatextends36kmbetweeninletsandobtainsitsmaximumwidthof2kmattheplantsite.Elevations approach5matopdunesbor-deringthebeachanddecreasetosealevelinthemarigrove swampsthatarecommononmuchofthewesternside.Islandvegetation istypicalofsoutheastern Floridacoas-talareas;densestandsofAustralian pine,palmetto, seagrapeandSpanishbayonetarepresentatthehigherelevations, andmangroves aboundatthelowerelevations.
Largestandsofblackmangroves, including someontheplantsite,havebeenkilledbyfloodingformosquitocontroloverpastdecades.TheAtlanticshoreline ofHutchinson Islandiscomposedofsandandshellhashwithintermittent rockypromontories protruding throughthebeachfacealongthesouthernendoftheisland.Submerged coquinoid rockformations parallelmuchoftheislandofftheoceanbeaches.Theoceanbottomimmediately offshorefromtheplantsitecon-sistsprimarily ofsandandshellsediments.
Theunstablesubstrate limitstheestab-lishmentofrootedmacrophytes.
TheFloridaCurrent,whichflowsparalleltothecontinental shelfmargin,beginstodivergefromthecoastline atWestPalmBeach.AtHutchinson Island,thecurrentisapproximately 33kmoffshore.
Oceanicwaterassociated withthewesternboundaryofthecurrentperiodically meandersovertheinnershelf,especially duringsummermonths.PLANTDESCRIPTION TheSt.LuciePlantconsistsoftwo850-MWnuclear-fueled electricgenerating unitsthatusenearshore oceanwatersfortheplant'sonce-through condenser coolingwater system.Waterfortheplantentersthroughthreesubmerged intakestructures locatedabout365moffshore(Figure2).Eachoftheintakestructures isequippedwithavelocitycaptominimizefishentrainment.
Horizontal intakevelocities arelessthan30cm/sec.Fromtheintakestructures, thewaterpassesthroughsubmerged pipes(two3.7mandone4.9mindiameter) underthebeachanddunesthatleadtoa1,500-mlongintakecanal.Thiscanaltransports thewatertotheplant.Afterpassingthroughtheplant,theheatedwaterisdischarged intoa670-mlongcanalthatleadstotwoburieddischarge pipelines.
Thesepassunderneath thedunesandbeachandalongtheoceanfloortothesubmerged discharges, thefirstofwhichisapproximately 365moffshoreand730mnorthoftheintake.Heatedwaterleavesthefirstdischarge linefromaY-shapednozzle(diffuser) atadesignvelocityof396cm/sec.Thishigh-momentum jetentrainsambientwater,result-inginrapidheatdissipation.
Theoceandepthintheareaofthefirstdischarge isabout6m.Heatedwaterleavestheseconddischarge linethroughaseriesof48equallyspacedhighvelocityjetsalonga323-mmanifold(multiport diffuser).
Thisdiffuserstarts168mbeyondthefirstdischarge andterminates 856mfromshore.Theoceandepthatdischarge alongthisdiffuserisfromabout10to12m.Aswiththefirstdiffuser, thepurposeoftheseconddiffuseristoentrainambientwaterandrapidlydissipate heat.Fromthepointsofdischarge atbothdiffusers, thewarmerwaterrisestothesurfaceandformsasurfaceplumeofheatedwater.Theplumethenspreadsoutonthesur-faceoftheoceanundertheinfluence ofwindandcurrentsandtheheatdissipates totheatmosphere.
>tIIIIII TURTLESTheNRC'sSt.LucieUnit2AppendixBEnvironmental Protection PlanissuedApril1983containsthefollowing technical specifications:
4.2Terrestrial AuaticIssuesIssuesonendangered orthreatened seaturtlesraisedintheUnit2FES-OL[NRC,1982)andintheEndangered SpeciesBiological As-sessment(March1982)[Bellmund etal.,1982]willbeaddressed byprogramsasfollows:Beachnestingsurveysforallspeciesofseaturtleswillbeconducted onayearlybasisfortheperiodof1982through1986.Thesesur-veyswillbeconducted duringthenestingseasonfromap-proximately mid-April throughAugust.TheHutchinson Islandbeachwillbedividedinto36one-km-long surveyareas.Inaddition, thenine1.25-km-long surveyareasusedinpreviousstudies(1971-1979) willbemaintained forcomparison purposes.
Surveyareaswillbemarkedwithnumberedwoodenpla-quesand/orexistinglandmarks.
Theentirebeachwillbesurveyedsevendaysaweek.AIInewnestsandfalsecrawlswillbecountedandrecordedineacharea.Aftercounting, allcrawltrackswillbeobliterated toavoidrecounting.
Predation onnestsbyraccoonsorotherpredators willberecordedasitoccurs.Recordswillbekeptofanyseasonalchangesinbeachtopography thatmayaffectthesuitability ofthebeachfornesting.4.2.2Aprogramthatemployslightand/orsoundtodeterturtlesfromtheintakestructure willbeconducted.
Thestudywilldetermine withlaboratory andfieldexperiments ifsoundand/orlightwillresultinareduction oftotalturtleentrapment rate.
Thestudyshallbeimplemented nolaterthanafterthefinalremovalfromtheoceanofequipment andstructures associated withcon-struction ofthethirdintakestructure andtheexperiments shallter-minate18monthslater.Fourmonthsaftertheconclusion oftheexperimental period,areportontheresultsofthestudywillbesub-mittedtoNRC,EPA,NationalMarineFisheries Service(NMFS),andtheUSFishandWildlifeService(USFWS)fortheirevaluation.
Ifastatistically significant reduction inannualtotalturtleentrapment rateof80percentorgreatercanbedemonstrated, usingthedeveloped technology anduponFPLreceiving writtenconcurrence byNRC,EPA,NMFS,andUSFWSthenpermanent installation ofthedeterrent systemshallbecompleted andfunctioning nolaterthan18monthsaftertheagencies'oncurrence.
Thedesignofthisstudyneedstotakeintoaccountthesignificant annualvariation inturtleentrapment observedinthepast.Ifan80percentreduction ofturtleentrapment cannotbeprojected toallthreeintakestructures, thenaninteragency taskforcecom-posedofNRC,EPA,NMFS,'USFWS, andFPLshallconvene18monthsaftercompletion ofthethirdintakeanddetermine ifothercoursesofactiontomitigateand/orreduceturtleentrapment arewarranted (suchasphysicalbarrier,emergence ofnewtechnology ormethodstodeterturtles).
4.2.3Alternative methodsorprocedures forthecaptureofseaturtlesentrapped intheintakecanalwillbeevaluated.
Ifamethodorpro-cedureisconsidered feasibleandcosteffective andmayreducecapturemortality rates,itwillbefieldtestedintheintakecanal.4.2.5CatureandReleaseProramSeaturtleremovalfromtheintakecanalwillbeconducted onacon-tinuingbasis.Theturtleswillbecapturedwithlargemeshnets,orothersuitablenondestructive device(s),
ifdeemedappropriate.
Aformalized dailyinspection, fromtheshoreline, ofthecaptul'Bdevice(s) willbemadebyaqualified individual whenthedevice(s) aredeployed.
Theturtleswillbeidentified tospecies,measured, weighed(ifappropriate),
taggedandreleasedbackintotheocean.Recordsofwounds,freshorold,andasubjective judgement onthecondition oftheturtle(e.g.,barnaclecoverage, underweight) willbemaintained.
Methodsofobtaining additional biological/physiologi-caldata,suchasbloodanalysesandparasiteloads,fromcaptured IIIIII seaturtleswillbepursued.Deadseaturtleswillbesubjected toagrossnecropsy, iffoundinfreshcondition.
INTRODUCTION Hutchinson Island,Florida,isanimportant rookeryfortheloggerhead turtle,Caret-tacarettaandalsosupportssomenestingofthegreenturtle,Chelonia~mdasandthIth5kttl.~OIII1915IIt1.,1959;5 t,1995;9I-lagheretal.,1972;WorthandSmith,1976;Williams-Walls etal.,1983).Allthreespeciesareprotected bystateandfederalstatutes.
Thefederalgovernment classified thelog-gerheadturtleasathreatened species.Theleatherback turtleandtheFloridanestingpopulation ofthegreenturtlearelistedbythefederalgovernment asendangered species.Becauseofreductions inworldpopulations ofmarineturtlesresulting fromcoastaldevelopment andfishingpressure(NMFS,1978),maintaining thevitalityoftheHutchinson Islandrookeryisimportant.
IthasbeenaprimeconcernofFPLthattheconstruction andsubsequent opera-tionoftheSt.LuciePlantwouldnotadversely affecttheHutchinson Islandrookery.Becauseofthisconcern,FPLhassponsored monitoring ofmarineturtlenestingac-tivityontheislandsince1971.Daytimesurveystoquantifynesting,aswellasnighttime turtletaggingprograms, wereconducted inoddnumberedyearsfrom1971through1979.Duringdaytimenest-ingsurveys,nine1.25-km-long surveyareasweremonitored fivedaysperweek(Figure3).TheSt.LuciePlantbeganoperation in1976;therefore, thefirstthreesurveyyears(1971,1973and1975)werepreoperational.
Thoughthepowerplantwasnotoperat-ingduring1975,St.LuciePlantUnitNo.1oceanintakeanddischarge structures were IIIIII installed duringthatyear.Installation ofthesestructures includedconstruction activities conducted offshorefromandperpendicular tothebeach.Construction hadbeencom-pletedandtheplantwasinfulloperation duringthe1977and1979surveys.Amodifieddaytimenestingsurveywasconducted in1980duringthepreliminary construction oftheoceandischarge structure forSt.LuciePlantUnit2.Duringthisstudy,fourofthepreviously established 1.25-km-long surveyareasweremonitored.
Additionally, eggsfromturtlenestspotentially endangered byconstruction activities wererelocated.
Everyyearfrom1981through1990,361-km-long surveyareascomprising theen-tireislandweremonitored sevendaysaweekduringthenestingseason(Figure3).TheSt.LuciePlantUnit2discharge structure wasinstalled duringthe1981nestingseason.Offshoreandbeachconstruction oftheUnit2intakestructure proceeded throughout the1982nestingseasonandwascompleted neartheendofthe1983lseason.Construction activities associated withinstallation ofbothstructures weresimilartothoseconducted whenUnit1intakeanddischarge structures wereinstalled.
Eggsfromturtlenestspotentially endangered byconstruction activities wererelocated duringallthreeyears.Requirement 4.2.1oftheNRC'sSt.LucieUnit2AppendixBEnvironmental Protec-tionPlanwascompleted withsubmission ofthe1986nestingsurveydata(ABI,1987).Thenestingsurveywascontinued voluntarily through1990withagreement fromfederalandstateagencies.
Resultsarepresented inthisreportanddiscussed inrelationtopreviousfindings.
I~pIIIIIII,)ClII Inadditiontomonitoring seaturtlenestingactivities andrelocating nestsawayfromplantconstruction areas,removalofturtlesfromtheintakecanalhasbeenanintegralpartoftheSt.LuciePlantenvironmental monitoring program.Turtlesenteringtheoceanintakestructures areentrained withcoolingwaterandrapidlytransported throughtheintakepipesintoanenclosedcanalsystemwheretheymustbemanuallycapturedandreturnedtotheocean.Sincetheplantbecameoperational in1976,turtlesentrapped intheintakecanalhavebeensystematically
- captured, measured, weighed,taggedandreleased.
Previouspublications andtechnical reportshavepresented findingsofthenestingsurveys,nestrelocation activities andcanalcaptureprogram(Gallagher etal.,1972;WorthandSmith,1976;ABI,1978,1980a,1981a,1982,1983,1984b,1985b,1986,1987,1988,1989,1990;Williams-Walls etal.,1983;Proffittetal.,1986;Ernestetal.,1988,1989;Martinetal.,1989a,1989b).Resultsofstudiestoassesstheeffectsofther-maldischarges onhatchling swimmingspeedhavealsobeenreported(ABI,1978;O'ara,1980).Thepurposeofthisreportisto1)present1990seaturtlenestingsur-veydataandsummarize observedspatialandtemporalnestingpatternssince1971,2)documentandsummarize predation onturtlenestssince1971,and3)present1990canalcapturedataandsummarize comparable datacollected since1976.
IIIIIII MATERIALS ANDMETHODSNestinSurveMethodologies usedduringpreviousturtlenestingsurveysonHutchinson Islandweredescribed byGallagher etal.(1972),WorthandSmith(1976)andABI(1978,1981a,1982,1987,1988,1989).Methodsusedduringthe1990surveyweredesignedtoallowcomparisons withthesepreviousstudies.On11and13April1990,preliminary nestsurveyswereconducted alongHutchin-sonIslandfromtheFt.PierceInletsouthtotheSt.LucieInlet.From16Aprilthrough7September, nestsurveyswereconducted onadailybasis.After7September, severaladditional surveyswereconducted toconfirmthatnestinghadceased,thelastsurveybeingconducted on14September.
Biologists usedsmalloff-roadmotorcycles tosur-veytheislandeachmorning.Newnests,non-nesting emergences (falsecrawls),andnestsdestroyed bypredators wererecordedforeachofthe361-km-long surveyareascomprising theentireisland(Figure3).Thenine1.25-km-long surveyareasestablished byGallagher etal.(1972)alsoweremonitored socomparisons couldbemadewithpreviousstudies.Duringthedailynestmonitoring, anymajorchangesintopography thatmayhaveaffectedthebeach'ssuitability fornestingwererecorded.
Inaddition, eachofthe361-km-long surveyareashasbeensystematically analyzedandcategorized basedonbeachslope(steep,moderate, etc.),widthfromhightidelinetothedune,presenceofbenches(areasofabruptverticalrelief)andmiscellaneous characteristics (packed10
'lI sand,scattered rock,vegetation onthebeach,exposedrootsontheprimarydune,etc.).Inacooperative effort,datafromstrandedturtlesfoundduringbeachsurveyswereroutinely providedtotheNationalMaiineFisheries Service(NMFS)throughtheSeaTurtleStranding andSalvageNetwork.IntakeCanalMonitorin Mostturtlesentrapped intheSt.LuciePlantintakecanalwereremovedbymeansoflarge-mesh tanglenetsfishedbetweentheintakeheadwalls andabarriernetlocatedattheHighwayA1Abridge(Figure2).Netsusedduring1990werefrom30to40minlength,3to4mdeepandcomposedof40cmstretchmeshnylontwine.Largefloatswereattachedtothesurface,andunweighted linesusedalongthebottom.Turtlesen-tangledinthenetsgenerally remainedatthewater'ssurfaceuntilremoved.Sinceitsinception in1976,ABI'scanalcaptureprogramhasbeenundercontinual reviewandrefinement inanattempttominimizebothentrapment timesandin-juries/mortalities toentrapped seaturtles.PriortoApril1990,turtlenetswereusuallydeployedonMondaymorningsandretrieved onFridayafternoons.
Duringperiodsofdeployment, thenetswereinspected forcapturesbyABIpersonnel atleasttwiceeachday(mornings andafternoons).
Additionally, St.LuciePlantpersonnel checkedthenetsperiodically, andABIwasnotifiedimmediately ifacapturewasobserved.
ABI'sseaturtlespecialists wereoncall24hoursadaytoretrievecapturedturtlesfromtheplant.11 I
Beginning April1990,afterconsultation withNMFS,netdeployment wasscaledbacktodaylighthoursonly.Concurrently, surveillance oftheintakecanalwasin-creasedandABIpersonnel remainedonsiteforthedurationofeachday'snettingac-tivities.
Thismeasuredecreased responsetimeforremovalofentangled turtlesfromnetsandprovidedanopportunity toimprovedailyassessments ofturtlelevelswithinthecanal.Recordsofdailycanalobservations werecomparedwithcapturedatatoas-sesscaptureefficiencies.
TheA1Abarriernetisusedtoconfineturtlestotheeasternmost sectionofthein-takecanal,wherecapturetechniques havebeenmosteffective.
Thisnetisconstructed oflargediameterpolypropylene ropeandhasameshsizeof30.5cmx30.5cm.Acableandseriesoflargefloatsareusedtokeepthetopofthenetabovethewater'surface,andthebottomisanchoredbyaseriesofheavyblocks.Thenetisinclinedataslopeof3:1,withthebottompositioned upstreamofthesurfacecable.Thisreducesbowinginthecenterandminimizes theriskofaweakorinjuredturtlebeingpinnedun-derwaterbystrongcurrents.
Inthepast,theintegrity ofthebarriernetwasoccassionally compromised, andturtleswereabletomovewestofA1A.Theseturtleswerefurtherconstrained downstream byanunderwater intrusion detection system(UIDS)consisting, inpart,ofalargebarrierpositioned perpendicular tothenorth-south armofthecanal(Figure2).TheUIDSsecuritybarrieralsoconsistsof30.5cmx30.5cmmesh,butthenetisconstructed ofheavychainlinksratherthanrope.12 III Priortocompletion oftheUIDSinDecember1986,turtlesuncontained bytheA1AbarriernetwereusuallyremovedfromthecanalattheintakewellsofUnits1and2(Figure2).Theretheywereretrieved bymeansoflargemechanical rakesorspecially designednets.Following construction oftheUIDSbarrier,individuals withcarapacewidthslargerthan30.5cmwereunabletoreachtheintakewells.Thus,asrequired, tanglenetswerealsodeployedwestofA1A.Improvements madetotheA1Abarriernetduring1990shouldproveeffective inconfining allturtleslargerthan30.5cmtotheeasternendofthecanal.Formaldailyinspections oftheintakecanalweremadetodetermine thenumbers,locations andspeciesofturtlespresent.Surfaceobservations wereaugmented withperiodicunderwater inspections usingSCUBA,particularly inandaroundtheA1Abar-riernetandUIDSbarrier.Becauseofthereduction intotalnettinghoursduring1990,increased effortwasdirectedtowardhandcaptureofturtles.Thiswasaccomplished bydivinganduseofdipnets,anditprovedveryeffective whengoodwaterclaritycon-ditionsprevailed.
Regardless ofcapturemethod,allturtlesremovedfromthecanalwereidentified tospecies,measured, weighed,tagged,andexaminedforoverallcondition (wounds,abnormalities, parasites, etc.).Healthyturtleswerereleasedintotheoceanthesamedayofcapture.Sickorinjuredturtlesweretreatedandoccasionally heldforobserva-tionpriortorelease.Whentreatment waswarranted, injections ofantibiotics andvitaminswereadministered byalocalveterinarian.
Resuscitation techniques wereusedifaturtlewasfoundthatappearedtohavediedrecently.
Beginning in1982,necrop-13 Ili~l sieswereconducted ondeadturtlesfoundinfreshcondition; onenecropsywasper-formedduring1990.Since1982,bloodsampleshavebeencollected andanalyzedtodetermine thesexofimmatureturtles.Bloodwasremovedfromthepaireddorsalcervicalsinusesofsub-jectturtlesusingthetechnique described byOwensandRuiz(1980).Thesamplesweremaintained oniceandlatercentrifuged for15minutestoseparatecellsandserum.Sexdeterminations weresubsequently madebyresearchers atTexasA8MUniver-sityusingradioimmunoassay forserumtestosterone (Owensetal.,1978).FloridaPower8LightCompanyandAppliedBiology,Inc.continued toassistotherseaturtleresearchers in1990.Data,specimens and/orassistance havebeengiventotheFloridaDepartment ofNaturalResources, NationalMarineFisheries Service,USFishandWildlifeService,USArmyCorpsofEngineers, Smithsonian Institution; SouthCarolinaWildlifeandMarineResources
- Division, CenterforSeaTurtleResearch(University ofFlorida),
TexasA&MUniversity, University ofRhodeIsland,University ofSouthCarolina, University ofIllinois, University ofCentralFlorida,University ofGeor-gia,VirginiaInstitute ofMarineScienceandtheWesternAtlanticTurtleSymposium.
StudiestoEvaluateandorMitiateIntakeEntramentAprogramthatassessedthefeasibility ofusinglightand/orsoundtodeterturtlesfromenteringtheSt.LuciePlantintakestructures wasconducted in1982and1983andcompleted inJanuary1984.Asrequired, testresultsandevaluations werewrittenupandapresentation wasmadetotheNRC,NationalMarineFisheries ServiceandtheFloridaDepartment ofNaturalResources on11April1984.Requirement 4.2.2of Il1lI theNRC'sSt.LucieUnit2AppendixBEnvironmental Protection Planisconsidered completed withsubmission ofdeterrent studyfindings.
RESULTSANDDISCUSSION NestinSurveDistribution ofLoerheadNestsAlonHutchinson IslandWhenseaturtlenestingsurveysbeganonHutchinson Island,nine1.25-km-long surveyareaswereusedtoestimateloggerhead nestingactivityfortheentireisland.Since1981,all361-km-long segmentscomprising theisland'scoastline havebeensurveyed.
Regardless oftechnique, loggerhead nestdensities haveshowncon-siderable annualvariation withinindividual surveyareas(Figures4and5).Yet,theannualspatialdistribution ofthosenestsamongsurveyareashasproducedaratheruniformgradient, nestdensities consistently increasing fromnorthtosouth(ABI,1987).Thegradientappearstobelinearwhenonlythenine1.25-km-long surveyareasareused(Figure4),butbecomesnon-linear whenall361-km-long surveyareasarein-cludedintheanalysis(Figure5).During1990thedistribution ofloggerhead nestsalongtheislandwascharacterized byrecordhighnestingalongthenorthernandcentralpor-tionsoftheisland(Figure5).Inthepast,thepronounced gradientobservedonthenorthernendoftheislandwasoccasionally influenced byphysicalprocesses occurring there;periodsofheavyaccretion reducedthegradient, whileperiodsoferosionaccentuated it(WorthandSmith,1976;Williams-Walls etal.,1983).However,duringrecentyearsnoconsistent IIlI relationship wasapparentwhenfieldobservations ofbeachwidthswerecomparedtothespatialdistribution ofnestsalongtheisland(ABI,1987).Thus,eventhoughbeachdynamicsmaysometimes affecttheselection ofnestingsitesbyloggerhead turtles,otherfactorsmustalsocontribute totheselection process.Offshorebottomcontours, spatialdistribution ofnearshore reefs,typeandextentofdunevegetation, anddegreeofhumanactivityonthebeachatnighthavebeenidentified assomeofthefactorsaf-fectingnesting(Caldwell, 1962;Hendrickson andBalasingam, 1966;Bustard,1968;BustardandGreenham, 1968;Hughes,1974;DavisandWhiting,1977;Mortimer, 1982).Relationships betweenspatialnestingpatternsandspecificenvironmental con-ditionsareoftendifficult toestablish becauseoftheinterrelationship ofthefactorsin-volved.Notallventuresontothebeachbyafemaleturtleculminate insuccessful nests.These"falsecrawls"(non-nesting emergences) mayoccurformanyreasonsandarecommonlyencountered atotherrookeries (BaldwinandLofton,1959;Schulz,1975;DavisandWhiting,1977;Talbertetal.,1980;Raymond,1984).DavisandWhiting(1977)suggested thatrelatively highpercentages offalsecrawlsmayreflectdisturban-cesorunsatisfactory nestingbeachcharacteristics.
Therefore, certainfactorsmayaf-fectaturtle'spreference toemergeonabeach,whileotherfactorsmayaffectaturtle'tendencytonestafterithasemerged.Anindexwhichrelatesthenumberofneststothenumberoffalsecrawlsinanareais.usefulinestimating thepost-emergence suitability ofabeachfornesting.Inthepresentstudythisindexistermed"nestingsuc-cess"andisdefinedasthepercentage oftotalemergences thatresultinnests.
loHistorically, thepatternofloggerhead emergences ontheislandhasgenerally paral-leledthedistribution ofnests(ABI,1987,1988),andthissametrendwasapparentin1990(Figure6).Incontrast, nestingsuccessbyloggerheads alongtheislandhastypi-Pcallylackedgradients (Figure7).Thus,therelatively highnumbersofloggerhead nestsobservedincertainareasareusuallyaresultofmoreturtlescomingashoreinthoseareasratherthanofmorepreferable nestingconditions beingencountered bytheturtlesaftertheyemerged.Loggerhead nestingdensities during1990weregenerally highwhencomparedwithpreviously recordedvalues(Figures4and5).Recordhighnestingwasrecordedin21ofthe36one-kilometer-long surveyareasandwasmostnotableonthenorthernhalfoftheisland.Therewerenoapparentchangesinthephysicalcharacteristics ofthebeachthatwouldaccountforthisincreaseinnesting.Ingeneral,recordhighnestingwasduetorecordhighemergence rates,andthismayreflectanincreaseinthenum-berofnestingfemalesintheHutchinson Islandarea.NestingsurveysonHutchinson Islandwereinitiated inresponsetoconcernsthattheoperation oftheSt.LuciePlantmightnegatively impactthelocalseaturtlerookery.Previousanalysis, usinglog-likelihood testsofindependence (G-test;SokalandRohlf,1981)demonstrated thattheconstruction oftheplant'soffshoreintakeanddischarge structures significantly reducednestingattheplantsiteduringconstruction years-1975,1981,1982and1983(Proffitt etal.,1986;ABI,1987).However,nestingattheplantconsistently returnedtolevelssimilartoorgreaterthanthoseatacontrolsiteinyearsfollowing construction.
Thistrendcontinued during1990(Figure8).Thus,power plantoperation exclusive ofintake/discharge construction hashadnoapparenteffectonnesting.Datacollected through1990haveshownnolong-term reduction inloggerhead nestdensities, totalemergences ornestingsuccessineitherthenine1.25-km-long surveyareasorthe361-km-long surveyareas(Table1;Figure9).EstimatesofTotaILo erheadNestin onHutchinsonlsland Variousmethodswereusedduringsurveyspriorto1981toestimatethetotalnum-berofloggerhead nestsonHutchinson Islandbasedonthenumberofnestsfoundinthenine1.25-km-long surveyareas(Gallagher etal.,1972;WorthandSmith,1976;ABI,1980a).Eachofthesemethodsweresubsequently foundtoconsistently overes-timateislandtotals(ABI,1987).Sincewhole-island surveysbeganin1981,ithasbeenpossibletodetermine theactualproportion oftotalnestsdeposited inthenineareas.Thishasthenallowedextrapolation fromtheninesurveyareastotheentireislandforyearspriorto1981.From1981through1990thetotalnumberofnestsinthenineareasvariedfrom32.5to35.6percentofthetotalnumberofnestsontheisland(Table1).Thisisslight-lyhigherthanthe31.3percentwhichwouldbeexpectedbasedstrictlyonthepropor-tionoflinearcoastline comprised bythenineareas.Usingtheten-yearmeanof33.8percent,estimates ofthetotalnumberofnestsonHutchinson Islandcanbecalculated bymultiplying thenumberofnestsinthenineareasby2.96.Thistechnique, whenap-pliedtotheninesurveyareasduringthetenyearsinwhichtheentireislandwassur-veyed,producedwhole-island estimates within5.3percentoftheactualnumberof18 IIl nestscounted.Becausetheproportion ofnestsrecordedintheninesurveyareasremainedrelatively constantoverthelasttenyears,thisextrapolation procedure shouldprovideafairlyaccurateestimateoftotalloggerhead nestingforyearspriorto1981.Itisclearthatloggerhead nestingactivityonHutchinson Islandfluctuates con-siderably fromyeartoyear(Table1).Annualvariations innestdensities alsoarecom-monatotherrookeries (Hughes,1976;DavisandWhiting,1977;Ehrhart,1980)andmayresultfromtheoverlapping ofnon-annual breedingpopulations.
Nonetheless, datacollected through1990suggestanoverallincreaseinnestingonHutchinson Is-landsincesurveysbeganin1971.Totalnestingactivitywasgreatestduring1990when6,700loggerhead nestswererecorded.
Norelationships betweentotalnestingactivityandpowerplantoperation orintake/discharge construction wereindicated byyear-to-yearvariations intotalnestingonHutchinson Island.TemoralLoerheadNestinPatternsTheloggerhead turtlenestingseasonusuallybeginsbetweenmid-April andearlyMay,attainsamaximumduringJuneorJuly,andendsbylateAugustorearlySep-tember(ABI,1987).Nestingactivityduring1990followedthissamepattern(Figure10).Coolwaterintrusions frequently occuroverthecontinental shelfofsoutheast Floridaduringthesummer(TaylorandStewart,1958;Smith,1982).WorthandSmith(1976),Williams-Walls etal.(1983)andABI(1982,1983,1984b,1985b,1986,1987,1988,1989,1990)suggested thattheseintrusions mayhavebeenresponsible forthetemporary declinesinloggerhead turtlenestingactivitypreviously observedonHutchinson Is-19 IIIIII land.Similarly, asubstantial decreaseinnestingduringmid-July1990wasapparently duetoanintrusion ofcoolwater(Figure10).Thoughnaturalfluctuations intemperature havebeenshowntoaffecttemporalnest-ingpatternsonHutchinson Island,therehasbeennoindication thatpowerplantopera-tionhasaffectedthesetemporalpatterns(ABI,1988)~Predation onLoerheadTurtleNestsSincenestsurveysbeganin1971,raccoonpredation probablyhasbeenthemajorcauseofturtlenestdestruction onHutchinson Island.Researchers atotherlocations havereportedraccoonpredation levelsashighas70tonearly100percent(DavisandWhiting,1977;Ehrhart,1979;Hopkinsetal.,1979;Talbertetal.,1980).Raccoonpreda-tionofloggerhead turtlenestsonHutchinson Islandhasnotapproached thislevelduringanystudyyear,thoughlevelsforindividual 1.25-km-long areashavebeenashighas80percent.Overallpredation ratesforsurveyyears1971through1977werebetween21and44percent,withahighof44percentrecordedin1973.Apronounced decreaseinraccoonpredation occurredafter1977,andoverallpredation ratesforthenineareashavenotexceeded10percentsince1979.Adeclineinpredation ratesonHutchinson Islandhasbeenvariously attributed totrappingprograms, construction activities, habitatlossanddisease(Williams-Walls etal.,1983;ABI,1987).During1990,sixpercent(406)oftheloggerhead nests(n=6,700)ontheislandweredepredated byraccoons.
Asinpreviousyears(ABI,1989),predation ofturtlenestswasprimarily restricted tothemostundeveloped portionoftheisland(i.e.,AreasEthroughS;Figure11).20 IIIIIII Ghostcrabshavebeenreportedbynumerousresearchers asimportant predators ofseaturtlenests(BaldwinandLofton,1959;Schulz,1975;Diamond,1976;Fowler,1979;Hopkinsetal~,1979;Stancyk,1982).ThoughturtlenestsonHutchinson Islandprobablyhavebeendepredated byghostcrabssincenestingsurveysbeganin1971,thissourceofnestdestruction didnotbecomeapparentuntil1983.Quantification ofghostcrabpredation wasinitiated thesameyear.Overallpredation ratesbyghostcrabshavevariedfrom0.1to2.1percentfrom1983-1989(ABI,1990).During1990,0.4percent(27)oftheloggerhead nests(n=6,700)ontheislandweredestroyed byghostcrabs(Figure11).Nestsdestroyed byacombination ofraccoonandghostcrabpredation havebeenincludedasraccoonpredations inpreviousdiscussions.
Whenthesecombination predations areincludedascrabpredations, theoverallpredation ratesbyghostcrabsrangefrom0.4to3.2percent.During1990,1.4percent(96nests)weredestroyed byeitherghostcrabsoracombination ofghostcrabsandraccoons.
GreenandLeatherback TurtleNestinGl'eenandleatherback turtlesalsonestonHutchinson Island,butinfewernumbersthanloggerhead turtles.Priorto1981,bothsurvey(nine1.25-km-long sections) andinter-survey areasweremonitored forthepresenceofgreenandleatherback nests.Thirty-one kilometers ofbeachfromArea1southtotheSt.LucieInletwereincludedinthateffort.Duringwhole-island surveysfrom1981through1990,onlytwoof182Ieatherback nestsandonlysevenof601greennestswererecordedonthefivekilometers ofbeachnorthofArea1.Therefore, previouscountsofgreenandleather-21 III backnestswithinthe31kilometers surveyedwereprobablynotappreciably different fromtotaldensities fortheentireisland.Basedonthisassumption, greenandleather-backnestdensities maybecomparedamongallsurveyyears,except1980,whenlessthan15kilometers ofbeachweresurveyed.
Priorto1990,thenumberofnestsobservedontheislandrangedfrom5to74forgreenturtlesandfrom1to36forleatherbacks (Figure12).Duringthe1990survey,132greenturtleand12leatherback turtlenestswererecordedonHutchinson Island.Temporalnestingpatternsforthesespeciesdifferfromthepatternforloggerhead turtles.Greenturtlestypically nestonHutchinson Islandfrommid-JunethroughthefirstorsecondweekofSeptember.
During1990,greenturtlesnestedfrom28Maythrough11September.
Leatherback'turtles usuallynestontheislandfrommid-April throughearlytomid-July.
During1990thisspeciesnestedfrom10Aprilthrough3July.Considerable fluctuations ingreenturtlenestingontheislandhaveoccurredamongsurveyyears(Figure12).Thisisnotunusualsincetherearedrasticyear-to-year fluc-tuationsinthenumbersofgreenturtlesnestingatotherbreedinggrounds(Carretal.,1982).Despitethesefluctuations, datacollected through1990suggestanoverallin-creaseinnestingsince1971andmayreflectanincreaseinthenumberofnestingfemalesintheHutchinson Islandarea.During1990,greenturtlesnestedmost frequent-lyalongthesouthernhalfoftheisland.Thisisconsistent withresultsofprevioussur-veys.Leatherback turtlenestdensities haveremainedlowonHutchinson Island;however,increased nestingduringrecentyears(Figure12)mayreflectanoverallincreaseinthe22 numberofnestingfemalesintheHutchinson Islandarea.During1990,leatherback turtlesprimarily nestedonthesouthernhalfoftheisland.IntakeCanalMonitorin Entrainment ofseaturtlesattheSt.LuciePlanthasbeenattributed tothepresumedphysicalattractiveness oftheoffshorestructures housingtheintakepipesratherthantoplantoperating characteristics (ABI,1980band1986).Evenwhenbothunitsareoperating atfullcapacity, turtlesmustactivelyswimintothemouthofoneoftheintakepipesbeforetheyencounter currentvelocities sufficiently strongtoeffectentrainment.
Consequently, aturtle'sentrapment relatesprimarily totheprobability thatitwilldetectandsubsequently enteroneoftheintakestructures.
Assumingthatdetection distan-cesdonotvaryappreciably overtimeandthatallturtles(oraconstantproportion) areequallyattracted tothestructures, capturerateswillvaryproportionally tothenumberofturtlesoccurring inthevicinityofthestructures.
Ifthisassumption istrue,datafromthecanalcaptureprogramshouldreflectnaturalvariability inthestructure ofthepopula-tionbeingsampled.RelativeAbundance andTemoralDistribution During1990,132seaturtlecapturestookplaceintheintakecanaloftheSt.LuciePlant(Table2).Ofthefivespeciesofseaturtlesinhabiting coastalwatersofthesoutheastern UnitedStates,onlytwowererepresented inthisyear'scatches:112log-gerheadsand20greenturtles.Sinceintakecanalmonitoring beganinMay1976,1,853loggerhead (including 99recaptures),
306green(including 1recapture),
9leatherback, 8hawksbill and17Kemp'sridleycaptureshavetakenplaceattheSt.LuciePlant.23 Annualcatchesofloggerheads increased steadilyfromalowof33in1976(partialyearofplantoperation andmonitoring) to172in1979(Figure13).Afterdeclining be-tween1979and1981,yearlycatchesofloggerheads againrosesteadily, reachingahighof195during1986.Captureshavebeenindeclinesince1986,decreasing morethan40percentoverthelastfouryears.Twooffshoreintakestructures wereinplacepriortoUnit1start-upin1976;thethirdandlargeststructure wasinstalled during1982-1983.
Eventhoughallthreestructures areinrelatively closeproximity, theadditionofanotherpipemayhaveincreased theprobability ofaturtlebeingentrained.
Becausethischangecannotbequantified, datacollected priorto1982maynotbecomparable withthatcollected after1983.Addition-ally,theinfluence oftheconstruction itselfonseaturtleentrainment during1982and1983isunknown.Withtheseconsiderations inmind,neitheralong-term increasenordecreaseinthenumberofloggerheads capturedattheSt.LuciePlantcanbeinferredfromthedata.During1990,themonthlycatchofloggerheads rangedfrom1(November) to25(June),withamonthlymeanof9.3(+7.0;Table3).ThenumberofcapturesduringMay,JuneandJulywereconsiderably aboveaverage,whilecapturesthroughout theIremainder oftheyearweremoderately toconsiderably lowerthanaverage(Figure14).Overtheentiremonitoring period,monthlycatcheshaverangedfrom0to39;thegreatestnumberofcapturesoccurredduringJanuary1983.Whendatafromallfullyearsofmonitoring (1977-1990) werecombined, thehighestnumberofloggerhead capturesoccurredinJanuary(11.8percent);
fewestcaptures24 IlIlII wererecordedinNovemberandDecember(Table3).However,monthlycatcheshaveshownconsiderable annualvariability.
Monthshavingrelatively lowcatchesoneyearoftenhavehadrelatively highcatchesinanother.Catchesofgreenturtlesalsohavevariedwidelyamongyears,rangingfrom0in1976(partialyearofsampling) to69in1984(Table4).During1990,20individuals werecaptured.
Theaverageannualcatchofgreenturtles,excluding 1976,was21.9(+18.0).Althoughhighlyvariable, annualcapturedataforgreenturtlessuggestalong-term in-creaseinthenumberofindividuals inhabiting thenearshore coastalareaadjacenttotheplant(Figure13).Again,however,theinfluence oftheadditionofathirdintakepipeduring1982-1983 onthesedataisnotknown.Greenturtleshavebeencaughtduringeverymonthoftheyear,withaveragemonth-lycatchesforallyearscombinedrangingfrom0.3inSeptember to7.1inJanuary(Table4).Seasonalabundance patternsofgreensaremuchmorepronounced thanforlog-gerheads, nearly60percentofallcapturesoccurring duringthethreemonthperiodbetweenJanuaryandMarch.During1990,thelargestnumberofgreens(6)werecap-turedinJanuary.Themostgreensevercaughtinonemonthwas37inJanuary1984.Catchesofleatherbacks, hawksbills andKemp'sridleyshavebeeninfrequent andscattered throughout the15yearstudyperiod(Table2).Eachspecieshasshownratherpronounced seasonaloccurrences; allbuttwoofthenineleatherbacks werecollected betweenFebruaryandMay,sevenoftheBighthawksbills werecollected betweenJuneandSeptember, andallbuttwoofthe17Kemp'sridleyswerecaughtbetweenNovemberandApril.25 Size-lassDistribtionAlthoughseveralstraight-line andcurvedmeasurements wererecordedforturtlesremovedfromtheintakecanal,onlyonestraight-line measurement hasbeenusedinanalysespresented here.Straight-line carapacelength(SLCL)wasmeasuredfromtheprecentral scutetothenotchbetweenthepostcentral scutes(minimumcarapacelengthofPritchard etal.,1983).Todate,loggerheads removedfromtheintakecanalhaverangedinlength(SLCL)from40.2to112.0cm(x=66.8+13.7cm)andinweightfrom10.7kgto169.6kg(x=49.2+31.0kg;Figures15and16).Acarapacelengthof70cmapproximates thesmallestsizeofnestingloggerhead femalesobservedalongtheAtlanticeastcoast(Hirth,1980).However,adultscanonlybereliablysexedonexternalmorphological characteristics (e.g.,relativetaillength)afterobtaining alengthofabout85cm.Previously, 80.0cmwasusedasthelowerlimitforadultturtles.However,recentdatasuggestthatsomemalesmaynotmature,andthusmightnotbedistinguishable fromfemales,untiltheyattainaslightlylargersize.Basedonthesedivisions, dataweresegregated intothreegroups:juveniles
(<70cm),adults(>85cm)andtransitional (71-85cm).Thelattergroupprobablyincludessomematureandsomeimmatureindividuals.
Ofthe1,744capturesbetween1977and1990forwhichlengthdatawerecollected, 69percentwerejuveniles, themajorityofthesemeasuring between50and70cmSLCL(Table5).Adultsaccounted forabout15percentofallcaptures, withtheremaining 16percentcomprised ofanimalsinthetransitional sizeclass.Similarsize-frequency distributions, indicating apreponderance ofjuveniles, havebeenreportedforthe26 IIII Mosquito/Indian RiverLagoon(Mendonca andEhrhart,1982),theCanaveral shipchannel(Henwood, 1987),andGeorgiaandSouthCarolina(Hillestad etal.,1982).Thesedatasuggestthatcoastalwatersofthesoutheastern UnitedStatesconstitute animportant developmental habitatforCarettacaretta.Seasonalpatternsofabundance forvarioussizeclassesindicated thatjuvenilelog-gerheadswereslightlymoreabundantduringthewinterthanatothertimesoftheyear(Table5).About45percentofthejuveniles werecapturedbetweenJanuaryandApril.Abundances decreased inspringandremainedrelatively constantduringthesummerandearlyfallbeforedecreasing againtolowestlevelsinNovemberandDecember.
Theseasonaldistribution ofadultloggerheads wasmuchmorepronounced, 76per-centofallcapturesoccurring betweenMayandAugust,Thisrepresents themajorpro-tionofthenestingseasononHutchinson Island.Greenturtlesremovedfromtheintakecanalovertheentirestudyperiodrangedinsizefrom20.0to108.0cmSLCL(x=35.8+14.3cm)and0.9kgto177.8kg(x=9.4+20.2kg;Figures17and18)~Nearlyall(96percent)werejuveniles.
About80per-centwere40cmorlessinlength,and66percentweighed5kilograms orless.Theseimmatureturtlesexhibited distinctwinterpulsessuggesting migratory behavior(Table4).However,someimmaturegreenturtleswerepresentthroughout theyear.Todate,onlyeightadultgreenturtles(SLCL>83cm;Witherington andEhrhart,1989)havebeenremovedfromthecanal;ailwerecapturedduringorshortlyafterthenestingseason.27 IIl Theeighthawksbills removedfromthecanalrangedinsizefrom34.0to70.0cmSLCL(x=46.2+12.9cm)andinweightfrom6.4to52.2kg(x=17.3+16.6kg).Allbutonewerejuveniles (SLCL<63cm;Witzell,1983).Similarly, allbutoneofthe17Kemp'sridleyscapturedattheSt.LuciePlantwerejuveniles (SLCL<60.0cm;Hirth,1980).Carapacelengthsfortheridleysrangedfrom27.0to62.0cmSLCL(x=36.1+9.7cm)andweightsfrom3.1to31.8kg(x=8.0+8.1kg).Thenineleatherbacks removedfromthecanalrangedinlengthfrom112.5to150.0cm,andatleastsevenwereadults(SLCL>121cm;Hirth,1980).Thelargestleatherback forwhichanac-curateweightwasobtained, afemalewithacurvedcarapacelengthof158.5cm,weighed334.8kg.~SxRatiosSinceintakecanalmonitoring beganin1976,255adultloggerheads (SLCL>85.0cm)havebeensexed.Femalespredominated malesbyaratioof5.4:1.0,whichsig-nificantly departsfroma1:1ratio(X,P<0.05).Consequently, temporalpatternsinthenumberofadultloggerhead captureswereheavilyinfluenced bythenumbersoffemalespresent.Whensexeswereseparated, itisevidentthatmaleswererelatively evenlydistributed amongmonths,whereas90percentofthefemalesweretakenduringthenestingseason(MaythroughSeptember; Figure19).Thenumberofadultfemaleloggerheads capturedattheSt.LuciePlanthasin-creasedsteadilyoverthelastsevenyears.From1977through1983,anaverageof4.4adultfemales(+3.2;range=1-10)wereentrapped eachyear,whereassincethen,anaverageof26.3femalesperyear(+6.7;range=16-35)werecaptured.
Thisin-28 creasecorresponds toageneralriseinloggerhead nestingactivityneartheplant(Figure20).Increased nearshore movementassociated withnestingincreases theprobability ofaturtledetecting oneoftheintakestructures andhencetheprobability ofentrainment.
Althoughtheadditionofthethirdoffshoreintakestructure mayhaveaccounted forsomeoftheincreaseinthenumberofadultsentrained since1983,thecontinued riseoverthelastsevenyearssuggestsagenuineincreaseinthenumberoffemalesoccurring inthevicinityoftheplant.BetweenSeptember 1982andDecember1986,267individual juvenileandsub-adult loggerhead turtlescapturedinthecanalweresexedbyTexasA8MUniversity re-searchers usingabioimmunoassay technique forbloodserumtestosterone.
Aspre-viouslyreported, femalesoutnumbered malesbyaratioof2.3:1.0(ABI,1989).Thesefindingsareconsistent withthosereportedforsamplestakenfromtheCapeCanaveral shipchannel(1.7:1.0) andtheIndianRiverLagoon(1.4:1.0),
wheresexratiosarealsosignificantly skewedinfavoroffemales(Wibbelsetal.,1984).Bloodsamplescollected since1986arecurrently beinganalyzedandtheseresultswillprovideavaluabletoolforassessing temporalvariability inthesexratiosofthelocalloggerhead population.
Oftheeightadultgreenturtlescapturedsincemonitoring began,sixweremalesandtwowerefemales.Siximmaturegreenturtleshavebeensexedthroughbloodwork;allhavebeenfemales.Ofthesixadultleatherback turtlesforwhichsexwasrecorded, threewerefemalesandthreeweremales.Theadulthawksbill andKemp'sridleywerebothfemales.Nosexinformation existsforjuveniles ofthesespecies.29 CatureEfficiencies Capturemethodologies havebeenundercontinual reviewandrefinement asnetmaterials, configurations andplacement werevariedinanefforttominimizeseaturtleentrapment times.Concurrently, alternative capturetechniques wereevaluated andpotential deterrent systemstestedinthelaboratory.
Duringthisperiod,captureefficien-ciesvariedinrelationtonettingeffortandtheeffectiveness ofthesystemsdeployed.
Acapture/recapture studyconducted intheintakecanalbetweenOctober1980andJanuary1981indicated thatmostturtlesconfinedbetweentheA1Abridgeandtheintakeheadwalls werecapturedwithintwoweeksoftheirentrainment (ABI,1983)~Basedonmorerecentformaldailyinspections, itappearsthatcaptureefficiencies havefurtherimproved.
Nearly50percentoftheturtlesenteringthecanalarenowcaughtwithin24hoursoffirstsighting, andalmost90percentarecapturedduringtheirfirstweekofentrapment (Figure21).Averagecaptureefficiency, expressed aselapseddaysbetweenfirstsightingandcapture,duringtheperiodfromAprilthroughDecem-ber1990was3.9days(+6.8days;range=1-50days).Betterutilization ofcurrentsandeddies,adjustments totethering lines,multi-net deployments andincreased ef-fortstohandcaptureturtleshavecontributed toreducedentrapment times.Entrapment timesmaybeextendedforturtlesswimmingpasttheA1Abarriernet(ABI,1987).Occasionally, thetopofthenethasbeensubmerged ortheanchorcablepulledfreefromthebottom,allowinglargerturtlestopass;turtleswithcarapacewidthslessthanabout30.5cmcanswimthroughthelargemesh.BecausecaptureeffortswestoftheA1Abridgehavegenerally beenlesseffective thanthoseneartheintake30 headwalls, mostturtlesbreaching thebarriernetwerenotcaughtuntiltheyenteredtheintakewellsofUnits1and2.Priortoinstallation oftheUIDSbarrierin1986,about15percentofallturtlesentrapped inthecanalwereremovedfromtheintakewells.Be-causeoftheirrelatively smallsizes,amuchlargerproportion ofgreens(51.6percent)reachedtheplantthanloggerheads (10.1pel'cent).
Since1986,thepercentage ofgreenscaughtattheintakewellshasdecreased slightly(35.1percent),
whilealllog-gerheadshavebeenprevented fromreachingtheplant.Majorrenovations weremadetotheA1Abarriernetduring1990tofurtherreducethepotential forturtleslargerthan30.5cmbecomingtrappedbetweenA1AandtheUIDS.Twologgerheads (lessthan2percentofallloggerhead captures) breachedtheA1Abarriernetpriortocompletion ofthesemodifications.
BothwereremovedfromthecanalattheUIDSbarrier.Additionally, twosmallgreenturtlespassedthroughtheA1Abarriernetandwereremovedattheplant'sintakewells.Thus,nearly97percentofallturtlesentrapped inthecanalduring1990werecapturedbynettingorbyhandeastoftheA1Abridge.Theeffective confinement ofturtleseastofA1Awasanothermajorcontributor tothehighcaptureefficiency achievedduring1990.RelativeCondition TurtlescapturedaliveintheintakecanaloftheSt.LuciePlantwereassignedarela-tivecondition basedonweight,activity, parasiteinfestation, barnaclecoverage, wounds,injuriesandanyotherabnormalities whichmighthaveaffectedoverallwell-being.During1990,92.9percent(104)ofallloggerheads foundinthecanalwerealiveandingoodtoexcellent condition.
Only6.3percent(7)ofloggerhead capturesin-31 IIIII volvedindividuals infairorpoorcondition; oneloggerhead wasdeadwhenremovedfromthecanal.Ofthe20greenturtlesremovedfromtheintakecanalduring1990,16wereingoodtoexcellent condition, twowereinfaircondition andtwoweredead.Overtheentiremonitoring period,about76and78percent,respectively, ofalllog-gerheadandgreencaptureshaveinvolvedturtlesingoodtoexcellent condition (Table6).Capturesofindividuals infairtopoorcondition haveoccurredabout16percentofthetimeforloggerheads and14percentofthetimeforgreens.Allofthehawksbills andleatherbacks havebeenremovedfromthecanalingoodtoexcellent condition, whileabouthalfoftheKemp'sridleyshavefallenintothesecategories.
Relativecondition ratingscanbeinfluenced byanumberoffactors,somerelatedandothersunrelated toentrainment and/orentrapment intheintakecanal.Ratingsofgoodtoexcellent indicatethatturtleshavenotbeennegatively impactedbytheirentrap-mentinthecanal,atleastasevidenced byphysicalappearance.
Althoughratingsoffairorpoorimplyreducedvitality, theextenttowhichentrainment/entrapment isresponsible isoftenindeterminable.
Insomeinstances, conditions responsible forlowerratings,suchasinjuries, obviously weresustained priortoentrainment.
During1990,aboutninepercent(10)ofallloggerhead capturesinvolvedindividuals withnoticeable
- injuries, suchasmissingappendages, brokenormissingpiecesofcarapaceanddeeplacerations.
Mostofthesewereold,well-healed wounds,andnonewereseriousenoughtorequiremedicalattention.
Noneofthegreenturtlescapturedduring1990hadmajorinjuries.
32 IIIIIIII
~Mrtalitie Mortalities havebeencloselymonitored throughout thelifeofthecanalcaptureprograminanattempttoassignprobablecausesandtakeappropriate remedialac-tiontominimizefutureoccurrences.
Previousanalysesofcapturedataidentified drown-inginnets(A1Abarriernet,UIDSbarrier,andtanglenets),drowningintheintakepipesduringperiodsofreducedintakeflow,injuriessustained fromdredgingoperations andinjuriessustained fromthemechanical rakesusedintheintakewellsasprobablemor-talityfactors(ABI,1987).Althoughdifficult toquantify, theentrapment andsubsequent demiseofinjuredorsickturtleshasprobablyaccounted foraportionofobservedmor-talities.
Overtheentire15yearmonitoring period,127(6.9percent)ofthe1,853logger-headsand21(6.9percent)ofthe306greenturtlesentrapped inthecanalwerefounddead(Table6).Mortalities spannedtherangeofsizeclassesforloggerheads (SLCL=47.5-103cm),whileallgreenturtlemortalities involvedjuveniles lessthan42cminlength.ThefourKemp'sridleymortalities documented attheplantduring1987and1988wel'etheonlydeathsforthisspeciestodate;noleatherback orhawksbill mor-talitieshaveoccurredattheSt.LuciePlant.Modifications tocaptureprocedures, improvements totheA1Abarriernetandvir-tualelimination oflowflowconditions withinthecanalhaveresultedinasubstantial reduction inseaturtlemortalities overthelifeofthecanalcaptureprogram.Mortality rates,expressed asthepercentage oftotalcapturesinvolving deadanimals,declined42percentbetweenthefirst(1976-1983) andsecond(1984-1990) halvesofthe33 IIIIIIIIII program.During1990,onlythreemortalities (2.3percentoftotalcaptures) wererecorded, oneloggerhead andtwogreenturtles.Thisrepresents thefewestannualmortalities sincethecanalcaptureprogrambeganin1976.Previousobservations suggestthatsickorinjuredturtlesmaybesusceptible todrowningattheUIDSbarrier.Theloggerhead mortality recordedduring1990occurredatthislocation.
Eventhoughthecarcasswastoodecomposed toassessitsphysicalcondition ordetermine causeofdeath,drowningissuspected.
Additional improve-mentstotheA1Abarriernetduringthelaterpartof1990shouldpreventfuturelogger-headmovements westofA1Aandtherebyeliminate theUIDSbarrierasapotential mortality source.Thetwogreenturtlemortalities during1990resultedfromdrowninginABI'stanglenets.Oneofthesewasresuscitated, butitlatersuccumbed whileunderobservation.
Anecropsywasperformed todetermine ifitwasinpoorhealthatthetimeofcapture;resultsoftissueanalyseshavenotyetbeencompleted.
Toeliminate thepotential forfuturenetdrownings, ABIhasbeguncontinual monitoring ofitstanglenetsduringperiodsofdeployment.
RecatureIncidentSincetheSt.LuciePlantcaptureprogrambegan,mostturtlesremovedalivefromtheintakecanalhavebeentaggedandreleasedintotheoceanatvariouslocations alongHutchinson Island.Consequently, individual turtlescanbeidentified aslongastheyretaintheirtags.Overthe15yearhistoryofturtleentrapment attheSt.LuciePlant,61individuals (60loggerheads and1green)havebeenremovedfromthecanalmore34 thanonce.Severalotherturtleswithtagscarshavealsobeenrecovered, indicating thattheactualnumberofrecaptures maybehigher.Ofthe60individual loggerheads knowntohavebeencaughtmorethanonce,42werecaughttwice,9werecaughtthreetimes,5werecaughtfourtimes,2werecap-turedsixtimes,1wascaughtseventimesand1wascaughtonnineseparateoc-casions,yieldingatotalof99recapture incidents.
Releasesitedidnotappeartohaveanyeffectonaturtle'sprobability ofbeingrecaptured.
Turtlesreleasedbothnorthandsouthoftheplantreturned.
Recaptures alsodidnotappeartoberelatedtosize,asbothjuveniles andadultswerecapturedmorethanonce(rangeofSLCL=47-89cm).However,themajorityofrecapture incidents involvedjuveniles (SLCL<70cm).Recapture intervals forloggerheads rangedfromfourto858days,withameanof157days(+174.0days).Theonlygreenturtlecaughtmorethanoncewascapturedontwooccasions, returning tothecanal59daysafterfirstbeingreleasedintotheocean.About56percentofallloggerhead recapture incidents occurredwithin90daysofpreviouscaptureand89percentwithinoneyear(Figure22).Theaverageintervalbetweenfirstandlastcapturewas262days(+329.7days).Thelongestperiodbe-tweenfirstandlastcapturewas5.3years.Thesedatasuggestthatresidency timesofloggerheads withinthenearshore habitatadjacenttotheSt.LuciePlantarerelatively short.Similarfindingshavebeenreportedforloggerheads inhabiting theMosquito/In-dianRiverLagoonsofeast-central Florida(Mendonca andEhrhart,1982).35 SUMMARYAgradientofincreasing loggerhead turtlenestdensities fromnorthtosouthalongthenorthernhalfofHutchinson Islandhasbeenshownduringmostsurveyyears.Thisgradientmayresultfromvariations inbeachtopography, offshoredepthcontours, dis-tribution ofnearshore reefs,onshoreartificial lightingandhumanactivityonthebeachatnight.Lownestingactivityinthevicinityofthepowerplantduring1975andfrom1981through1983wasattributed toconstruction ofpowerplantintakeanddischarge systems.Nestingreturnedtonormalorabovenormallevelsfollowing bothperiodsofconstruction.
Powerplantoperation, exclusive ofintake/discharge construction, hashadnosignificant effectonnestdensities.
Therehavebeenconsiderable year-to-year fluctuations inloggerhead nestingac-tivityonHutchinson Islandfrom1971through1990.Fluctuations arecommonatotherrookeries andmayresultfromoverlapping ofnon-annual breedingpopulations.
Despitethesefluctuations, loggerhead nestingactivityhasremainedhighduringrecentyearsandmayreflectanoverallincreaseinthenumberofnestingfemalesintheHutchinson Islandarea.Norelationship betweentotalnestingontheislandandpowerplantoperation orintake/discharge construction wasindicated.
Temporary declinesinloggerhead nestingactivityhavebeenattributed tocoolwaterintrusions thatfrequently occuroverthecontinental shelfofsoutheast Florida.ThoughtemporalnestingpatternsoftheHutchinson Islandpopulation maybeinfluenced bynaturalfluctuations inwatertemperature, nosignificant effectsduetopowerplantoperation havebeenindicated.
36 Sincenestingsurveysbeganin1971,raccoonpredation wasconsidered themajorcauseofturtlenestdestruction onHutchinson Island.From1971through1977,over-allpredation ratesintheninesurveyareaswerebetween21and44percent.However,apronounced decreaseinraccoonpredation occurredafter1977,andoverallpreda-tionratesintheninesurveyareashavenotexceededtenpercentsince1979.Decreased predation byraccoonsprobablyreflectsadeclineintheraccoonpopula-tion.During1990,132greenturtleand12leatherback turtlenestswererecordedonHutchinson Island.Nestingactivitybythesetwospeciesexhibited considerable annualfluctuations, ashasbeenrecordedatotherrookeries, buthasremainedrelatively highduringrecentyears.Thismayreflectanoverallincreaseinthenumberofnestinggreenandleatherback turtlesintheHutchinson Islandarea.During1990,112loggerheads and20greenturtleswereremovedfromtheSt.LuciePlantintakecanal.Sincemonitoring beganinMay1976,1,843loggerhead, 306green,9leatherback, 8hawksbill and17Kemp'sridleyturtleshavebeencaptured.
Overthelifeofthemonitoring program,annualcatchesforloggerhead turtleshaverangedfrom33in1976(partialyearofplantoperation andmonitoring) toahighof195in1986.Yearlycatchesofgreenturtleshaverangedfrom0in1976to69in1984.Differences inthenumberofturtlesentrapped duringdifferent yearsandmonthsareattributed tonaturalvariation intheoccurrence ofturtlesinthevicinityoftheoffshoreintakestruc-tures,ratherthantoanyinfluence oftheplantitself.37 IIII Size-class distributions ofloggerhead turtlesremovedeachyearfromthecanalhaveconsistently beenpredominated byjuveniles between50and70cminstraightlinecarapacelength.Mostgreenturtlesentrapped inthecanal(about80percent)werejuveniles 40cmorlessinlength.Forbothspecies,thelargestnumberofcapturesforallyearscombinedoccurredduringthewinter,buttheseseasonalpeaksweremuchmorepronounced forgreenturtles.Sexratiosofbothadultandimmatureloggerheads caughtinthecanalcontinued tobebiasedtowardsfemales.During1990,about93and80percent,respectively, ofallloggerheads andgreenturtlesremovedfromthecanalwerecategorized byphysicalappearance asbeingingoodtoexcellent condition.
Overtheentire15yearmonitoring period,76and78per-cent,respectively, ofallloggerhead andgreenturtlecaptureshaveinvolvedindividuals inthesecategories; 16percentoftheloggerheads and14percentofthegreenturtlesremovedfromthecanalhavebeeninfairorpoorcondition.
Aboutninepercentoftheturtlesremovedfromtheintakecanalduring1990hadsubstantial injuries.
However,mostoftheseinjuriesweresustained priortoentrap-ment.Onceinthecanal,turtlesconfinedeastofA1Ausuallyhadverybriefresidency timesandthustherelativecondition ofmostturtleswasnotaffectedbytheirentrap-ment.During1990,oneloggerhead andtwogreenturtlemortalities occurredintheintakecanal.Thesedeathsprobablyresultedfromdrowning:
twoinABItanglenets,oneattheUIDSbarrier.Programmodifications topermitcontinual surveillance oftanglenets38 IIII duringperiodsofdeployment andimprovements totheA1Abarriernetwereinitiated tofurtherreducethepotential forsimilarmortalities inthefuture.Sinceintakecanalmonitoring beganin1976,6.9percentoftheloggerheads andasimilarpercentage ofgreenturtlesremovedfromthecanalweredead.ThefourKemp'sridleymortalities in1987and1988weretheonlydeathsrecordedforthisspeciessincemonitoring began.Alloftheleatherbacks andhawksbills entrapped intheintakecanalattheSt.LuciePlanthavebeencapturedaliveandreleasedintotheocean.Modifica-tionstocaptureprocedures, improvements totheA1Abarriernetandvirtualelimina-tionoflowflowconditions inthecanalhasresultedina42percentreduction inseaturtlemortality ratesoverthelifeofthecanalcaptureprogram.39 IIIIIII LITERATURE CITEDABI(AppliedBiology,Inc).1977.Ecological monitoring attheFloridaPower&LightCo.St.LuciePlant,annualreport1976.VolumesIandII.AB-44.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1978.Ecological monitoring attheFloridaPower8LightCo.St.LuciePlant,annualreport1977.VolumesIandII.AB-101.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami..1979.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1978.VolumesIIandIII,Bioticmonitoring.
AB-177.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1980a.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1979.VolumesIIandIII,Bioticmonitoring.
AB-244.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1980b.Turtleentrainment deterrent study.AB-290.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1981a.Successful relocation ofseaturtlenestsneartheSt.LuciePlant,Hutchinson Island,Florida.AB-317.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1981b.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1980.VolumesIIandIII,Bioticmonitoring.
AB-324.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1981c.ProposedSt.LuciePlantpreoperational andoperational biological monitoring program-August1981.AB-358.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1982.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1981.VolumesIIandIII,Bioticmonitoring.
AB-379.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1983.FloridaPower8LightCompany,St.LuciePlantannualnon-radiologi-calaquaticmonitoring report1982.VolumesIandII.AB-442.PreparedbyAppliedBiol-ogy,Inc.forFloridaPower8LightCo.,Miami.40 IIII ABI(AppliedBiology,Inc.).1984a.FloridaPower8LightCompany,St.LuciePlantannualnon-radiological environmental monitoring report1983.VolumesIandII.AB-530.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,Miami..1984b.FloridaPower&LightCompany,St.LucieUnit2annualenviron-mentaloperating report1983.AB-533.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,Miami..1985a.FloridaPower&LightCompany,St.LuciePlantannualnon-radiologi-calenvironmental monitoring report1984.AB-553.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,JunoBeach..1985b.FloridaPower&LightCompany,St.LucieUnit2annualenviron-mentaloperating report1984.AB-555.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,JunoBeach..1986.FloridaPower&LightCompany,St.LucieUnit2annualenvironmen-taloperating report1985.AB-563.PreparedbyAppliedBiology,Inc.forFloridaPower8LightCo.,JunoBeach..1987.FloridaPower&LightCompany,St.LucieUnit2annualenvironmen-taloperating report1986.AB-579.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,JunoBeach..1988.FloridaPower8LightCompany,St.LucieUnit2annualenvironmen-taloperating report1987.AB-595.PreparedbyAppliedBiology,Inc.forFloridaPower&LightCo.,JunoBeach..1989.FloridaPower&LightCompany,St.LucieUnit2annualenvironmen-taloperating report1988.AB-596.PreparedbyAppliedBiology,Inc.forFloridaPower&.LightCo.,JunoBeach..1990.FloridaPower8LightCompany,St.LucieUnit2annualenvironmen-taloperating report1989.AB-603.PreparedbyApplied,Biology,Inc.forFloridaPower&LightCo.,JunoBeach.Baldwin,W.P.,Jr.andJ.P.Lofton,Jr.1959.Theloggerhead turtlesofCapeRomain,SouthCarolina.
Previously unpublished manuscript abridgedandannotated byD.K.Caldwell, withouttheauthors.InD.K.CaldwellandA.Carr,coordinators, TheAtlanticlogger-headeeaturtle,Carettacaretta~carett(L.),inAmerica.BulletinoftheFloridaStateMuseum,Biological
- Sciences, 4(10):319-348.
41 IIII
- Bellmund, S.,M.T.MasnikandG.LaRoche.1982.Assessment oftheimpactsoftheSt.Lucie2NuclearStationonthreatened orendangered species.USNuclearRegulatory Com-mission,OfficeofNuclearReactorRegulation.
Bustard,H.R.1968.Protection forarookery:Bundaberg seaturtles.WildlifeinAustralia 5:43-44Bustard,H.R.andP.Greenham.
1968.Physicalandchemicalfactorsaffecting hatchinginthe=-greenaeaturtle,Chelonia~mdaa(L.).Ecology49(2):269-276.
- Caldwell, D.K.1962.CommentsonthenestingbehaviorofAtlanticloggerhead seaturtles,basedprimarily ontaggingreturns.Quarterly JournaloftheFloridaAcademyofScien-ces25(4):287-302.
- Caldwell, D.K.,A.CarrandL.H.Ogren.1959.Nestingandmigration oftheAtlanticlogger-headturtle.InD.K.CaldwellandA.Carr,coordinators, TheAtlanticloggerhead seaturtleCarettacarettacaretta(L.),inAmerica.BulletinoftheFloridaStateMuseum,Biological
- Sciences, 4(10):295-308.
Camp,D.K.,N.W.WhitingandR.E.Martin.1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
V.Arthropods.
FloridaMarineResearchPublications 25:1-63.Carr,A.,A.Meylan,J.Mortimer, K.BjorndalandT.Carr.1982.Surveysofseaturtlepopula-tionsandhabitatsintheWesternAtlantic.
NOAATechnical Memorandum NMFS-SEFC-91:1-82.Davis,G.E.,andM.C.Whiting.1977.Loggerhead seaturtlenestinginEverglades NationalPark,Florida,U.S.A.Herpetologica 33:18-28.
dtdAWtdtg9dtgttIgtdttIHtttllt~I,~WAIimbricata L.,onCousinIsland,Seychelles.
Biological Conservation 9:199-215.
Ehrhart,L.M.1979.Reproductive characteristics andmanagement potential oftheseaturtlerookeryatCanaveral NationalSeashore, Florida.Pages397-399inLinn,R.M.,ed.Proceedings oftheFirstConference onScientific ResearchintheNationalParks,9-12November, 1976,NewOrleans,La.NPSTrans.andProc.Ser.No.5.Ehrhart,L.M.1980.Threatened andendangered speciesoftheKennedySpaceCenter:marineturtlestudies.InAcontinuation ofbaselinestudiesforenvironmentally monitor-ingspacetransportation systems(STS)atJohnF.KennedySpaceCenter.ContractNo.NAS-10-8986.
Vol.IV,NASAReport163122.September 1980.42 Ernest,R.G.,R.E.Martin,B.D.Peery,D.G.Strom,J.R.WilcoxandN.W.Walls.1988.Seaturtleentrapment atacoastalpowerplant.Pages270-301inMahadevan, K.,R.K.Evans,P.Behrens,T.BiffarandL.Olsen,eds.Proceedings, Southeastern WorkshoponAquaticEcological EffectsofPowerGeneration.
ReportNo.124,MoteMarineLaboratory,
- Sarasota, Florida.Ernest,R.G.,R.E.Martin,N.W.WallsandJ.R.Wilcox.1989.Population dynamicsofseaturtlesutilizing shallowcoastalwatersoffHutchinson Island,Florida.Pages57-59inEckert,S.A.,K.L.EckertandT.H.Richardson, compilers.
Proceedings oftheNinthAnnualWorkshoponSeaTurtleConservation andBiology.NOAATechnical Memorandum NMFS-SEFC-232.
Fowler,L.E.1979.Hatchingsuccessandnestpredation inthegreenseaturtle,Chelonia~mdasatTortuguero, CostaRica.Ecology60(5):945-955.
Futch,C.R.andS.E.Dwinell.1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
IV.Lancelets andFishes.FloridaMarineResearchPublications 24:1-23.Gallagher, R.M.1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
II.Sediments.
FloridaMarineResearchPublications 23:6-24.Gallagher, R.M.andM.L.Hollinger.
1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
I.Introduction andrationale.
FloridaMarineResearchPublications 23:1-5.Gallagher, R.M.,M.L.Hollinger, R.M.IngleandC.R.Futch.1972.MarineturtlenestingonHutchinson Island,Floridain1971.FloridaDepartment ofNaturalResources, SpecialScientific Report37:1-11.Hendrickson, J.R.andE.Balasingam.
1966.Nestingbeachpreferences ofMalayanseaturtles.BulletinoftheNationalMuseumSingapore 33(10):69-76.
Henwood,T.A.1987.Movements andseasonalchangesinloggerhead turtle,Carettacaret-taaggregations inthevicinityofCapeCanaveral, Florida(1978-84).
Biological Con-servation 40:191-202.
Hillestad, H.O.,J.I~Richardson, C.McVea,Jr.andJ.M.Watson,Jr.1982.Worldwide inciden-talcaptureofseaturtles.Pages489-496inBjorndal, K.A.,ed.Biologyandconserva-tionofseaturtles.Smithsonian Institution Press,Washington, D.C.Hirth,H.F.1980.Someaspectsofthenestingbehaviorandreproductive biologyofseaturtles.AmericanZoologist 20:507-523.
43 III Hopkins,S.R.,T.M.Murphy,Jr.,K.B.StansellandP.M.Wilkinson.
1979.Bioticandabioticfactorsaffecting nestmortality intheAtlanticloggerhead turtle.Proceedings AnnualConference ofSoutheastern FishandWildlifeAgencies32:213-223.
Hughes,G.R.1974.Theseaturtlesofsoutheast Africa,1.Status,morphology anddistribu-tions.SouthAfricanAssociation forMarineBiological
- Research, Oceanographic ResearchInstitute, Investigational ReportNo.35:1-144.
.1976.Irregular reproductive cyclesintheTongaland loggerhead seaturtle,Carettacaretta(L.)(Cryptodira:
Chelonidae).
Zoologica Africana11(2):285-291.
Lyons,W.G.1989.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
PartXI.Mollusks.
FloridaMarineResearchPublication 47:1-131.
Martin,R.E.,R.G.Ernest,N.W.WallsandJ.R.Wilcox.1989a.Sizedistribution andseasonalabundance ofloggerhead andgreenturtlesinnearshore watersoffHutchinson Island,Florida.Pages334-335inOgren,L.,F.Berry,K.Bjorndal, H.Kumpf,R.Mast,G.Medina,H.ReichartandR.Witham,editors.Proceedings oftheSecondWesternAt-lanticTurtleSymposium.
- Mayaguez, PuertoRico,12-16October1987.NOAATechni-calMemorandum NMFS-SEFC-226.
.1989b.Long-term trendsinseaturtlenestingonHutchin-sonIsland,Florida.Pages111-113inEckert,S.A.,K.L.EckertandT.H.Richardson, compilers.
Proceedings oftheNinthAnnualWorkshoponSeaTurtleConservation andBiology.NOAATechnical Memorandum NMFS-SEFC-232.
- Mendonca, M.T.andL.M.Ehrhart.1982.Activity, population sizeandstructure oftheimma-tureChelonia~mdas andCarettacarettainMosquitoLagoon,Florida.Copeia1982:(1)161-167.Moffler,M.D.andJ.F.VanBreedveld.
1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.X.
Benthicalgaespecieslist.FloridaMarineResearchPublications 34:118-122.Mortimer, J.A.1982.Factorsinfluencing beachselection bynestingseaturtles.Pages45-51inBjorndal, K.A.,ed.BiologyandConservation ofSeaTurtles.Smithsonian Institution Press.Washington, D.C.NMFS(National MarineFisheries Service).
1978.FinalEISlistingandprotecting thegreenseaturtle(Chelonia~mdas, loggerhead seaturtle(CGartta~cretta andthePacificRidleytttid3ptt~lidI3d9dgpI9t11913.3ttalMarineFisheries Service,Dept.ofCommerce, Washington, D.C.
IIII NRC(USNuclearRegulatory Commission).
1982.Finalenvironmental statement relatedtotheoperation ofSt.LuciePlantUnit2.DocketNo.50-389.O'ara,J.1980.Thermalinfluences ontheswimmingspeedofloggerhead turtlehatchlings.
Copeia1980(4):773-780.
Owens,D.W.,J.R.Hendrickson, V.LanceandI.P.Callard.1978.Atechnique fordetermin-ingsexofimmatureChelonia~md~ausingaradioimmunoassay.
Herpetologica 34:270-273.
Owens,D.W.andG.J.Ruiz.1980.Newmethodsofobtaining bloodandcerebrospinal fluidfrommarineturtles.Herpetologica 36:17-20.
Pritchard, P.C.,P.R.Bacon,F.H.Berry,A.F.Carr,J.Fletemeyer, R.M.Gallagher, S.R.Hop-kins,R.R.Lankford, R.MarquesM.,L.H.Ogren,W.G.Pringle,Jr.,H.A.ReichartandR.Witham.1983.Manualofseaturtleresearchandconservation techniques.
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.Effectsofpowerplantconstruction andopera-tiononthenestingoftheloggerhead seaturtle(Caretta~caretta:t97t-t984.
Copeia1986(3):813-816.Raymond,P.W.1984.Theeffectsofbeachrestoration onmarineturtlesnestinginsouthBrevardCounty,Florida.M.S.thesis,University ofCentralFlorida.Routa,R.A.1968.SeaturtlenestsurveyofHutchinson Island,Florida.Quarterly JournalFloridaAcademyofSciences30(4):287-294.
Schulz,J.P.1975.SeaturtlesnestinginSurinam.Zoologische Verhandelingen, uitgegeven doorhetRijksmuseum vanNatuurlijke HistoricteLeiden,No.143:1-144.
Smith,N.P.1982.Upwelling inAtlanticshelfwatersofsouthFlorida.FloridaScientist 45(2):125-138.Sokal,R.R.andF.J.Rohlf.1981.Biometry.
Theprinciples andpracticeofstatistics inbiologi-calresearch.
W.H.FreemanandCompany,SanFrancisco.
859pp.Stancyk,S.E.1982.Non-human predators ofseaturtlesandtheircontrol.Pages139-152inBjorndal, K.A.,ed.BiologyandConservation ofSeaTurtles.Smithsonian Institution Press.Washington, D.C.
IIIIIII Talbert,O.R.,S.E.Stancyk,J.M.DeanandJ.M.Will.1980.Nestingactivityoftheloggerhead turtle(Caretta~carettainSouthCarolina.
I:Arookeryintransition.
Copeia1950:(4)709-718.Taylor,C.B.,andH.B.Stewart.1958.Summerupwelling alongtheeastcoastofFlorida.Jour-nalofGeophysical Research64(1):33-40.
Tester,L.A.andK.A.Steidinger.
1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
Vll.Phytoplankton, 1971-1973.
FloridaMarineResearchPublica-tions34:16-61~Walker,L.M.1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
IX.Dielplankton, 1973-1974.
FloridaMarineResearchPublications 34:99-117.Walker,L.M.,B.M.GlassandB.S.Roberts.1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
Vill.Zooplankton, 1971-1973.
FloridaMarineResearchPublications 34:62-98.Walker,L.M.andK.A.Steidinger.
1979.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
Vl.Planktondynamics, 1971-1973.
FloridaMarineResearchPublications 34:1-15.Wibbels,T.,D.Owens,Y.MorrisandM.Amoss.1984.Sexratiosofimmatureloggerhead seaturtlescapturedalongtheAtlanticcoastoftheUnitedStates.FinalReporttotheNa-tionalMarineFisheries Service.ContractNo.NA81-GA-C-0039.
47pp.Williams-Walls, N.,J.O'ara,R.M.Gallagher, D.F.Worth,B.D.PeeryandJ.R.Wilcox.1983.SpatialandtemporaltrendsofseaturtlenestingonHutchinson Island,Florida,1971-1979.BulletinofMarineScience33(1):55-66.
Witherington, B.E.andL.M.Ehrhart.1989.Statusandreproductive characteristics ofgreenturtles(Chelonia
~mdasnestinginFlorida.Pages351-352inOgren,L.,F.Berry,K.Bjorndal, H.Kumpf,R.Mast,G.Medina,H.ReichartandR.Witham,editors.Proceed-ingsoftheSecondWesternAtlanticTurtleSymposium.
- Mayaguez, PuertoRico,12-16October1987.NOAATechnical Memorandum NMFS-SEFC-226.
Wi*II,WN.'l983.98 3IIdiIpiIdI83till~I~~EhI(Linnaeus, 1766).FAOFisheries
- Synopsis, 137:1-78.
Worth,D.F.andM.L.Hollinger.
1977.Nearshore marineecologyatHutchinson Island,Florida:1971-1974.
III.Physicalandchemicalenvironment.
FloridaMarineResearchPublica-tions23:25-85.46 Worth,D.F.,andJ.B.Smith.1976.MarineturtlenestingonHutchinson Island,Florida,in1973.FloridaMarineResearchPublications 18:1-17.47 GULFOFMEXICO00YAROSKILOMETERS SCALEr~~StLuciaPlantFigure1.LocationoftheSt.LuciePlant.
IIIIIIIII V~g~t'~gW.:,::HUTCHINSON ISLAND~o0'F~~IJi7.~iS'~Oc2G'5~.L-....i~00250500METERS~~tr~5pp,>r~DISCHARGE
~gG+'..PIPES0G"oi~gAv'~'l"r2VQ9INTAKE'<:.:.c,".'NTAKE HEADWALL';
4~':-,.'.'ELLS~'.",STRUCTURES UIDSA1A'-'.:.
BARRIERBARRIER:.
,,NET;.~;~b~',,'1'a'84'NTAKECANALFigure2.St.LuciePlantcoolingwaterintakeanddischarge system.
II FLPierceInlet10A\~~'aFaStateGHwyA0a7~'t~aeaaAIg0Q0bb,oOaloH2V+F+3N40FPLST.LUCIEPU.S.HwyId0SkmRtV6.RVw6AA4BBCCDDEFFGGda+HHOdQuSLLudoInletFigure3.Designation andlocationofnine1.25-kmsegmentsandthirty-six 1-kmsegmentssurveyedforseaturtlenesting.Hutchinson Island,1971-1990.
350300250z0200Dz1501005012NORTH3456789POWERPLANTSOUTHFigure4.Meanannualnumberofloggerhead turtlenestsineachofthenine1.25-km-long surveyareas,Hutchinson Island,1971-1989, comparedwithnumberofnestsduring1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values(1980datawereexcludedbecausenotallareasweresurveyed).
IIIIIIIIIIII 350300~~250200(0I-V)z150Dz~~~10050ABCDEFGHIJKLMNOPQRSTUVWXYZABCDE FGHIJABCDEFGHIJNORTH1'OWERPLANTSOUTHFigure5.Meanannualnumberofloggerhead turtlenestsineachofthethirty-six 1-km-long surveyareas,Hutchinson Island,1981-1989, comparedwithnumberofnestsduring1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values.
IIIIIIIII 700600500400Oz300D200~~100ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHI JABCDEFGHIJNORTHPOWERPLANTSOUTHFigure6.Meanannualnumberofloggerhead turtleemergences ineachofthethirty-six 1-km-long surveyareas,Hutchinson Island,1981-1989, comparedwiththenumberofemergences during1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values.
IIIIIII 10080gM(0LIJOOP)60(9ZI-0)ILJZ4020ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGH IJABCDEFGHIJNORTH0POWERPLANTSOUTHFigure7.Meanannualloggerhead turtlenestingsuccess(percentage ofemergences thatresultedinnests)foreachofthethirty-six 1-km-longsurveyareas,Hutchinson Island,1981-1989, comparedwithnestingsuccessduring1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values.
300250o-oArea4(PowerPlantSite)e--~Area5(ControlSite)200V)I-Z0150Dz100~Or%rr/////////50TTT19711972197319741975197619771978197919801981198219831984198519861987198819891990Figure8.Numberofioggerhead turtlenestsinAreas4and5,Hutchinson Isiand,1971-1990.
Arrowsdenoteyearsduringwhichintake/discharge construction occurredinArea4.
I 6000CD(DI-zDz50004000300020001000CDOz0CCDz12000100008000600040002000gCDCOLIJOO(0(9zCDUJ806040201981198219831984198519861987198819891990Figure9.Annualnumberofnests,numberofemergences andnestingsuccessalongtheentire36.0-km-long Atlanticcoastline ofHutchinson Island,198t-1990.
3130O29285272625Q.242322212012090(0z060z30305153051530515APRMAYJUNJULFigure10.Dailyloggerhead turtlenestingactivityandwatertemperature, Hutchinson Island,1990.30515AUG30515SEP 27%7060Destroyed byghostcrabsgDestroyed byraccoonsandghostcrabsQDestroyed byraccoons50O0-0KI-Uj40O(0I-(0zrt-30Dz201015%.?~Vxm:('?iAMh((.:9X'~egZps:K(:N<:e.'.gg.r,'(?Fp?'m~$+11%Y??r','my~?(m,:(g~18%r'(I(pjmr~'r'..vÃr'.rg~b;s(:r.ggCi(5'$.::$p~.?s?:.'$p$j~g>?~PI5%?.'A'(iM:'A?g(;@A;('(?g(??.:N~??jPAQsE(g?gr.m(mi14%Wg'kg$.$yg?gmmeE(.:VP8:.:~a??::,g:)>%!4~?>?:'(pY,~4'.($NScYA(Ã~(??APg.(g'.?'.spi'g~Q4?ih(1%rr:.(1%1%2'/oABCDEFGHIJKLMNOPQRS TUVWXYZABCDEFGHIJABCDEFGHIJNORTH0POWERPLANTSOUTHFigure11.Numberofloggerhead turtlenestsdestroyed byraccoonsandghostcrabsandpercentage ofnestsdestroyed ineach1-km-long surveyarea,Hutchinson Island,1990.
140120100COIzO80z604020Q--QGreen(Chelonia mydas)O-~Leatherback (Dermochelys coriacea) pQpHgoIIIIIIlIIIpqII/xIIiIy/XgIIIIII197119731975197719791981198219831984198519861987198819891990Figure12.Annualnumbersofgreenturtleandleatherback turtlenests,Hutchinson Island,1971-1990.
200~-eLOGGERHEAD (Carettacaretta)0---wGREEN(Chelccia m~das)80175150O125K1007550z25////r0IIIIIIpi\'I70860O50z40(930mmD2010197619771978197919801981198219831984198519861987198819891990Figure13.Numberofloggerhead andgreenturtlesremovedeachyearfromtheintakecanal,St.LuciePlant,19764990.
40403030I-20z201010JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECMONTHOFCAPTUREFigure14.Meannumberofloggerheads capturedeachmonth,St.LuciePlantintakecanal,1977-1989, comparedwithnumberofmonthlycapturesduring1990.Horizontal linesaremeans,boxesencloseplusorminusonestandarddeviation, verticallinesareranges,andclosedcirclesare1990values.
IIIIIII 400400300300(0DO)0zu-2000KUJlZlDz200100100~4041-4546-5051-5556-6061-6566-7071-7576-8081-8586-9091-9596-101-106->110STRAIGHTLINECARAPACELENGTH(cm)100105110Figure15.Lengthdistribution (SLCL)ofloggerhead turtles(N=1,673) removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1990.
Nodatacollected for81individuals.
400400300300(0DO)DZ2000KIllCODZ200100100+1011-2021-3031-4041-5051-6061-7071-8081-9091-100101-111-121-131-141-i150'I/EiGHT(kg)110120130140150Figure1LWeightdistribution ofliveloggerhead turtles(¹1,487)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1990.
Nodatacollected for267individuals.
12012010010080COD0)0600K(9408060402020-1516-21-26-31-36-41-46-51-56-61-66-71-76-81-86-91-96-101-106->11020253035404550556065707580859095100105110STRAIGHTLINECARAPACELENGTH(cm)Figure17.Lengthdistribution (SLCL)ofgreenturtles(N=295)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1990.
Nodatacollected for10individuals.
200200180180160160(D140D9120Dz010080z601401201008060404020201-56-1011-1516-2021-2526-3031-3536-4041-4546-5051-101-151-)200WEIGHT(kg)100150200Figure18.Weightdistribution ofgreenturtles(N=291)removedforthefirsttimefromtheintakecanal,St.LuciePlant,1976-1990.
Nodatacollected for14individuals.
IIIIIIII MALESFEMALES60505040V)DCI0300KILJKDz204030201010JANFEBMARAPRMAYJUNJULAUGSEPOCTNOVDECMONTHOFCAPTUREFigure19.Numbersofadultloggerheads (SLCL)85.0 cm),including recaptures, removedeachmonthfromtheintakecanal,St.LuciePlant,1977-1990 (N=255;sexnotrecordedforsixindividuals)85.0 cm).
50~-eCANALCAPTURES 50040302010o---oEMERGENCES 00//////]y////r/400300200100ZV)OzGK0zzz19771978197919801981198219831984198519861987198819891990Figure20.Comparison ofcapturesofadultfemaleloggerheads (SLCL>85.0cm)intheintakecanal,St.LuciePlant,1977-1990, andnumbersofloggerhead emergences inarea4adjacenttotheplant.Nestingactivitywasnotmonitored in1978.
JLJCCI-CLOCIJCJCIZ0I-ZILJOIZILJQ.ILJI-O10080604020'100806040201020304050DAYSBETWEENFIRSTSIGHTINGANDCAPTUREFigure21.Captureefficiency, expressed asdaysbetweenfirstsightingandcapture,forloggerhead turtlesentrapped intheintakecanal,St.LuciePlant,April-December, 1990(N=90).
100100~80(9za-60I-DD<40fIt///80604020IIIIIt~-----~Intervalbetweensuccessive capturesIntervalbetweenfirstandlastcapture20500250175075010001250RECAPTURE INTERVAL(days)Figure22.Cumulative percentage ofallloggerhead recaptures occurring withinvarioustimeintervals betweensuccessive captures(¹97jandfirstandlastcapture(¹58),St.LuciePlantintakecanal1976-1990.
WTABLE1ESTIMATES OFTHENUMBERSOFLOGGERHEAD TURTLENESTSONHUTCHINSON ISLANDBASEDONSURVEYSOFNINE1.25-KM-LONG SURVEYAREAS,1971-1990,COMPAREDTOTHEACTUALNUMBEROFNESTSONTHEISLAND,1981-1990197119731975197719791981198219831984198519861987198819891990Numberofnestsinthenine1420126014939321449103115921439162318391645170117742177Extrapolation fromtheninesurveyareastotheiI4203373044192759428930524837471242594804486950355251Actualnumberofnestsonthe311546904743427748775483462351936700 IIIII TABLE2TOTALNUMBEROFSEATURTLECAPTURESAND(NUMBEROFDEAD)TURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT,1976-1990 19761977197819791980198119821983198419851986198719881989TotalAnnualMean's(4) 80(5)138(19)172(13)116(5)62(5)101(16)119(4)148(3)157(4)195(27)175(11)134(6)111(4)112(1)1853(127)130.05(2)6(1)3(1)10(3)32(2)823(4)69(2)1422(1)3542(2)17(1)20(2)306(21)21.99(0)0.6will8(0)0.6Km'l16(2)5(2)217(4)1.2ss(4)86(7)148(20)175(14)126(8)97(7)110(16)142(8)220(5)172(4)220(28)218(13)181(10)133(5)1s2(s)2193(152)154.3Excludes1976(partialyearofplantoperation).
TABLE3TOTALNUMBEROF(ANDNUMBEROFDEAD)LOGGERHEAD TURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPLANT,1976-1990 1976197713s(1)2075(2)157(1)75(3)15(1)9(1)5933(4)580(5)19781911(2)27(2)19(5)3(1)101217(2)15(7)4138(19)19791980198119824&1983198419851986198719881989199024(3)29(1)111703(1)1621(2)14078(3)11(1)11(3)6106627(2)16(2)8(1)12192(1)15(3)1274006(2)141417(4)72(1)9(1)9(5)4(2)391313(1)047(1)62(1)728(1)12(1)26s(2)16152013161720(3)19(1)1426(3)8(1)24(3)23(1)26(1)19(1)17(1)1751097311(2)83510(3)1113(2)283011(1)-254(2)11131699232521(1)15167(1)35(1)4115(2)16(4)14(4)20(2)1220(1)26(2)34(6)9(4)10172(13)8116(5)362(5)1(1)101(16)12119(4)8148(3)2157(4)10195(27)9175(11)9134(6)2111(4)3112(1)Total219(11)178(17)152(9)157(15)162(6)208(8)172(11)177(11)126(12)121(13)86(13)95(1)1853(127)
MonthlyMean15.6%TotalCatch11.812.79.611.58.28.58.711.29.310.911.210.813.911.89.68.46.86.54.68.15.76.35.1eludes1976(partialyearofplantoperation).
IIII TABLE4TOTALNUMBEROF(ANDNUMBEROFDEAD)GREENTURTLESREMOVEDEACHMONTHFROMTHEINTAKECANALST.LUCIEPIANT,1976-1990 1976197719781979198019811982198310018(1)43(2)22(1)01(1)012201(1)0101(1)00,5(1)4(1)0020(1)7110000000101(1)000000000002(1)02.04(1)5(2)6(1)3(1)10(3)32(2)23(4)1984198537(1)1041121986116(1)31198741332198819891990Total12114233(1)06316(1)3(1)31199(5)48(3)33(4)19(2)9(1)MonthlyMean7.13.42.41.40.62.9%TotalCatch32.415.710.86.25.92.60211316(2)1101018(3)81.20.59(1)0.62.90.31.6140.94.64(1)51102022120(2)241.31.66.57.869(2)1422(1)3542(2)17(1)20(2)306(21)
IIIIII TABLE5NUMBEROFMONTHLYCAPTURESBYSIZECLASSFORLOGGERHEAD TURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT,1977-1990 SizeclassesSLCLincm)JanuaryFebruaryMarch16AprilMayJune13Total101%ofTotalJulyAugustSeptember 4October8November4December473475150'24248352034592765648523835483832242651717812011210010581977548121014.711.69.99.38.38.76.78.07.46.24.05.369.42621182717262835162?19132739.57.76.6996.29.510.312.85.9997.04.815.772022006150132613826321294191815825114414011613114406738152613.41.52.72.315.325.720.714.65.72.73.41.915.0Excludes1976(partialyearofdata).Nodatawerecollected for76individuals.
TABLE6RELATIVECONDITION OFSEATURTLESREMOVEDFROMTHEINTAKECANALST.LUCIEPLANT,1976-1990RelativeTotal39321.251127.650327.122111.9713.81276.9271.5185312841.85919.35116.73511.472.3216.951.6306111.1111.1777.8211.8317631763176211.8423.51775.025.053024.257626.356425.725911.8803.61526.9321.521931Excellent:
normalorabovenormalweight,active,veryfewornobarnacles orleeches,nowounds.2Verygood:intermediate goodtoexcellent.
3Good:normalweight,active,lighttomediumcoverageofbarnacles and/orleeches,woundsabsent,healedordonotappeartodebilitate theanimal.4Fair:intermediate poortogood.5Poor:emaciated, sloworinactive, heavybarnaclecoverageand/orleechinfestation, debilitating woundsormissingappendages.
6Dead7Alivebutotherwise condition notrecorded.
IIII