oral presentation at national conference on beach preservation technology (2012)
TRANSCRIPT
Examiningdifferentbeachnourishmentdesignstounderstandchangesinmarineturtlenesting
AllisonHaysandLlewellynEhrhartUniversityofCentralFlorida
Marineturtles
LoggerheadFederallythreatened
73,702nests
GreenturtleFederallyendangered
13,225nests
Marineturtles
Marineturtles
DataandmapcopyrightSTC
Marineturtles
Marineturtles
GeneticallydistinctregionalrookerygroupingsShamblinetal2011
Loop Bodypit Eggchamber
Non‐nestingemergence(Falsecrawl)
Marineturtles
Marineturtles
• Capitalbreeders– Storednutrients
• Unexpectedfalsecrawls?
Marineturtles
Photo:KellyMartin
Beachnourishment
• Temporaryinloggerheadnestingsuccessrates(#nests/total#emergences)
• 1greenturtlestudy• Nonewithalternatetemplatedesigns
BrevardCounty,FL
DDR
ArchieCarrNWR
Nourishmentdesigns
Full‐scalerestoration(FSR)
DDR
2005,2010
ArchieCarrNWR
Photo:TownofLongboatKey
FSR
Nourishmentdesigns
Full‐scalerestoration(FSR)
2005,2010 2005,2006,2008,2009
Dunerestoration(DR)
Photo:TownofLongboatKey
Methods
• Before‐After‐Control‐ImpactPairedSeriesModel
• Pairedt‐test• Holm’stest
CONTROL IMPACT DELTA
BEFOREDAY1
(1997‐2001average)
60% 60% 0%
AFTERDAY1
(2005)60% 10% 50%
DRResultsLoggerhead Greenturtle
YOC=yearofconstructionErrorbars=SE*significance<0.05,**<0.01,and***<0.001
Nestin
gsuccessrate
Nestin
gsuccessrate
FullScaleRestorationResultsLoggerhead Greenturtle
Nestin
gsuccessrate
Nestin
gsuccessrate
Nestin
gsuccessrate
Nestin
gsuccessrate
YOC=yearofconstructionErrorbars=SE*significance<0.05,**<0.01,and***<0.001
Loggerheadeffectsizes
YOC 1YEARPOSTEffectsize
p‐value Effectsize
p‐value
DR ‐0.11 >0.05 ‐0.05 <0.001*FSR ‐0.13 ‐0.16
Greenturtleeffectsizes
YOC 1YEARPOSTEffectsize
p‐value Effectsize
p‐value
DR ‐0.15 0.002* ‐0.08 <0.001*FSR ‐0.29 ‐0.32
Objectives
• Objective1:Determinebeachcharacteristicsthatserveasnestingcues
• Objective2:Determineifalteringkeycharacteristicsthroughbeachrestorationaffectstheirroleasnestingcues
Studysites
• photos
• 6studysites(3treatments)– Natural– DR– FSR:flat
Studysites
• photos
• 6studysites(3treatments)– Natural– DR– FSR:sloped
Photo:EcologicalAssociates,Inc
Methods• Loggerheads• Nests• Unobstructedloopingfalsecrawls
Methods
Methods
Objective1:StatisticsNestingcues
• Logisticregressionmodelselection– Beachspecific:
• Beachslope• Beachwidth• Moisturecontent• Grainsize
– Turtlespecific:• Slopewhereturtlestopped• Distancetraveled
– Createmodelstopredictifturtlenests
Objective1:ResultsNestingcues
• R2=0.75• Beachslopeandwidth• Sandmoisturecontentandgrainsize
• Distanceturtletraveled• Slopewhereturtlestopped
Objective1:ResultsNestingcues
• R2=0.75• Beachslopeandwidth• Sandmoisturecontentandgrainsize
• Distanceturtletraveled• Slopewhereturtlestopped
Objectives
• Objective1:Determinebeachcharacteristicsthatserveasnestingcues– Beachslopeandwidth– Sandmoisturecontentandgrainsize
Objectives
• Objective1:Determinebeachcharacteristicsthatserveasnestingcues– Beachslopeandwidth– Sandmoisturecontentandgrainsize
• Objective2:Determinehowalteringkeycharacteristicsthroughbeachrestorationaffectsnesting
1
4
3
2
Objective2:MethodsAlteringbeachcharacteristics
• Dividedcrawlintoquarters
• Averageddataforeachquarter
• Slope,moisturecontent,grainsize
CrawlQuarter
Elevation(m
)Objective2:Results
Alteringbeachcharacteristics
Allfalsecrawls(n=25)
Allnests(n=49)
Objective2:ResultsAlteringbeachcharacteristics
CrawlQuarter
Elevation(m
)
Naturalnests(n=19)
Naturalfalsecrawls(n=7)
FSR:flatnests(n=8)
FSR:flatfalsecrawls(n=4)
Objective2:ResultsAlteringbeachcharacteristics
CrawldistancesonFSR:flat
CrawlType
Distancefrom
water(m
)
Falsecrawln=4Nestn=8
Objective2:ResultsAlteringbeachcharacteristics
CrawlQuarter
Elevation(m
)
Naturalnests(n=19)Naturalfalsecrawls(n=7)FSR:flatnests(n=8)FSR:flatfalsecrawls(n=4)
FSR:slopednests(n=5)FSR:slopedfalsecrawls(n=8)
Objective2:MethodsAlteringbeachcharacteristics
• Referencepoint• Rateofchange(change/1.5m)
• Profile,moisturecontent,grainsize
Objective2:ResultsAlteringbeachcharacteristics
• Differenceinnestsandfalsecrawls1.5mfromhead
Nests Falsecrawls
Distancefromhead(m) Distancefromhead(m)
Changeperunit(m)
Changeperunit(m)
• Objective2:Determineifalteringkeycharacteristicsthroughbeachnourishmentaffectstheirroleasnestingcues– Slope– Tooflat/toosloped=morefalsecrawls– Affectsitsabilitytofunctionasaneffectivenestingcue
Objective2:ConclusionAlteringbeachcharacteristics
Summary
• Biggereffectsizeafterfull‐scalerestoration• Beachslope/widthandsandmoisturecontent/grainsize=loggerheadnestingcues
• Alteringbeachslopeaffectsitsabilitytofunctionasanestingcue
Whyisthisimportant?
• 1stdatatoshowtheimportanceofslope• Laysgroundworkforfurtherresearch• Experimentwithalternatetemplatedesigns
Acknowledgments
• Committee:Drs.LlewellynEhrhart,RossHinkle,MarioMota,JohnWeishampel
• Fieldcrew:MeredithHickman,SarahKrieg,RobynLee,GregNorris
• Labmates:SimonaCeriani,JenniferElliot,ChrisLong,CherylSanchez,JenniferSolis,AndrewSterner,TerryWilliamson
• UCFMarineTurtleResearchGroup• EcologicalAssociates,Inc.,RickHerren,KristenKneifl,MikeMcGarry
• UCFDepartmentofEngineering