PacificPacific--Atlantic Sea Turtle Atlantic Sea Turtle AssessmentAssessment

(PASTA) (PASTA) Working Group Meeting IIWorking Group Meeting II

Report for PFRP Meeting Report for PFRP Meeting November 14 November 14 –– 17, 200617, 2006

Honolulu, HawaiiHonolulu, Hawaii

SelinaSelina HeppellHeppellMolly LutcavageMolly Lutcavage

Purpose of PASTAPurpose of PASTA

Develop a framework for comparative Develop a framework for comparative analysis of loggerhead and leatherback analysis of loggerhead and leatherback populations in the North Atlantic and North populations in the North Atlantic and North Pacific.Pacific.Involve modelers, oceanographers, Involve modelers, oceanographers, fisheries scientists and sea turtle biologists fisheries scientists and sea turtle biologists

New skills, new ideas, new synthesis!New skills, new ideas, new synthesis!

PASTA IIPASTA IIPIPI’’ss: Molly Lutcavage, Selina Heppell: Molly Lutcavage, Selina Heppell

Steering committee: Steering committee: David Kirby, David Kirby, Rebecca Lewison ,Rebecca Lewison ,YonatYonat Swimmer, Swimmer, Melissa Melissa SnoverSnover, , TomoTomo EguchiEguchi

Abby McCarthy, Jay VaughnAbby McCarthy, Jay Vaughn

Funded by PFRPFunded by PFRP

Inspiration John Inspiration John SibertSibert

PASTA II ParticipantsPASTA II ParticipantsDavid KirbyDavid Kirby ModelingModeling SPC Ocean Fisheries ProgramSPC Ocean Fisheries ProgramRebecca LewisonRebecca Lewison Bycatch Bycatch San Diego State UniversitySan Diego State UniversityMelissa Melissa SnoverSnover ModelerModeler Pacific Islands Fisheries Science CenterPacific Islands Fisheries Science CenterYonatYonat Swimmer Pelagic Fisheries SW FisheriSwimmer Pelagic Fisheries SW Fisheries Science Centeres Science CenterTomo EguchiTomo Eguchi GeneticsGenetics SW Fisheries Science CenterSW Fisheries Science CenterMartin Hall Martin Hall Fisheries Fisheries InterInter--American Tropical Tuna CommissionAmerican Tropical Tuna CommissionJeanette Wyneken Jeanette Wyneken PhysiologyPhysiology Florida Atlantic UniversityFlorida Atlantic UniversityMark Maunder Mark Maunder Fisheries Fisheries InterInter--American Tropical Tuna CommissionAmerican Tropical Tuna CommissionFrancois Royer Fisheries Francois Royer Fisheries OceanogrOceanogr. UNH Large Pelagics Lab. UNH Large Pelagics LabAndy Myers Ecology, Andy Myers Ecology, OceangrOceangr. UNH Large Pelagics Lab. UNH Large Pelagics LabJeffrey Seminoff Jeffrey Seminoff Coastal fisheriesCoastal fisheries SW Fisheries Science CenterSW Fisheries Science CenterFrancisco Chavez Francisco Chavez OceanographyOceanography Monterey Bay Aquarium Research InstituteMonterey Bay Aquarium Research InstituteVince SabaVince Saba Biol. Biol. OceanogrOceanogr. . Virginia Institute of Marine ScienceVirginia Institute of Marine ScienceKate MansfieldKate Mansfield Coastal fisheriesCoastal fisheries Virginia Institute of Marine ScienceVirginia Institute of Marine ScienceYoshiYoshi MatsuzawaMatsuzawa BiologyBiology Sea Turtle Association of JapanSea Turtle Association of JapanJay VaughanJay Vaughan BiologyBiology Oregon State UniversityOregon State UniversityAbby McCarthyAbby McCarthy OceanographyOceanography Oregon State UniversityOregon State UniversityBryan WallaceBryan Wallace BiologyBiology Duke UniversityDuke UniversityIrene Irene KinanKinan Pelagic FisheriesPelagic Fisheries Western Pacific Regional Fishery Management CouncilWestern Pacific Regional Fishery Management CouncilShaleylaShaleyla KelezKelez Coastal FisheriesCoastal Fisheries Duke UniversityDuke UniversityJenny PurcellJenny Purcell Jellyfish BiologyJellyfish Biology Western Washington UniversityWestern Washington University

Project GoalsProject Goals

Develop hypotheses to determine what drives Develop hypotheses to determine what drives sea turtle pop dynamics and role of human and sea turtle pop dynamics and role of human and environmental impacts, (ocean basin and environmental impacts, (ocean basin and species levels)species levels)

Design assessment tools to test those Design assessment tools to test those hypotheseshypotheses

Provide guidance for research, management Provide guidance for research, management and mitigationand mitigation

Why ?Why ?Arguably, we should promote all possible Arguably, we should promote all possible means to reduce human impacts on means to reduce human impacts on declining populations of sea turtles, declining populations of sea turtles, BUTBUT

Elimination of impacts is not possible, nor Elimination of impacts is not possible, nor likely necessarylikely necessaryLimited time, money for research and Limited time, money for research and monitoringmonitoringNeed to know Need to know ““how much is enough?how much is enough?””

Meeting objectivesMeeting objectives

Identify the likely impacts of human & natural Identify the likely impacts of human & natural stressors on abundance, vital rates, distribution stressors on abundance, vital rates, distribution and size structure. and size structure.

Synthesize over broad spatial and temporal scalesSynthesize over broad spatial and temporal scales

Compare impacts and expected population Compare impacts and expected population dynamics for loggerhead and leatherback turtles dynamics for loggerhead and leatherback turtles

Develop testable hypotheses for identifying Develop testable hypotheses for identifying drivers of population changedrivers of population change

Fine tune assessment tools, fill data gaps Fine tune assessment tools, fill data gaps required to test hypotheses, eliminate some!required to test hypotheses, eliminate some!

Species lifeSpecies life--history differenceshistory differences

Primary habitat is lifePrimary habitat is life--stage specificstage specificAge at maturity: 25Age at maturity: 25--30 30 yearsyearsSmaller body size= Smaller body size= susceptibility to cold susceptibility to cold shock, smaller niche shock, smaller niche sizesizeSlower early growth Slower early growth raterate

Primary habitat is Primary habitat is pelagicpelagicAge at maturity:10Age at maturity:10--15 15 yrsyrsLarge body size= Large body size= greater physiological greater physiological tolerance, larger niche tolerance, larger niche size, warmsize, warm--bodiedbodiedFast early growth rateFast early growth rate

http://tofino.ex.ac.uk/euroturtler.htm

Loggerhead (Loggerhead (Caretta carettaCaretta caretta)) Leatherback (Leatherback (DermochelysDermochelys coriaceacoriacea))

Leatherbacks in the PacificLeatherbacks in the PacificMexico (Pacific)

y = 8961.2e-0.279x

R2 = 0.7292

y = 1487.5e-0.2552x

R2 = 0.6179

0100020003000400050006000

1984

1986

1988

1990

1992

1994

1996

1998

Mexiquillo

Chacahua

Malaysia

y = 9297.9e-0.1511x

R2 = 0.922

02000400060008000

100001200014000

1968

1971

1974

1977

1980

1983

1986

1989

1992

1995

1998

Leatherback females Playa Grande, Costa Rica

0200400600800

1000120014001600

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

French Guiana y = 13625e0.0359x

R2 = 0.1509

0

10000

20000

30000

40000

50000

60000

70000

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

Nes

ting

fem

ales

St. Croix y = 17.79e0.0869x

R2 = 0.7087

020406080

100120140160180200

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

Florida y = 87.691e0.1376x

R2 = 0.8793

0100200300400500600700800900

1000

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

Leatherbacks in Leatherbacks in the Atlantic / the Atlantic / CaribbeanCaribbean

StressorsStressorsTo nesting To nesting

beaches:beaches:Egg/female harvestEgg/female harvestCoastal Coastal

development, development, human human population population growthgrowth

Nest predation by Nest predation by native & native & introduced introduced predatorspredators

Catastrophic Catastrophic natural events, natural events, e.g. hurricanese.g. hurricanes

To pelagic habitat:To pelagic habitat:

LargeLarge--scale shifts scale shifts in current/ wind in current/ wind patterns, patterns, temperature that temperature that may affect may affect forage qualityforage quality

Marine debris Marine debris aggregations, aggregations, both direct and both direct and indirectindirect

Fishing, shifting Fishing, shifting gear types and gear types and location of effort

To coastal habitat:To coastal habitat:

Fishing: gillnet, Fishing: gillnet, trawl, trawl, longlinelongline, , othersothers

Entanglement Entanglement Boat strikesBoat strikesMarine debrisMarine debrisPollution Pollution

location of effort

Pacific BasinPacific Basin•• Higher density of pelagic hooks (4.4 hooks/ kmHigher density of pelagic hooks (4.4 hooks/ km22), ), more hooks (718 million) but lower turtle CPUEmore hooks (718 million) but lower turtle CPUE•• Higher concentration of fishing near beachesHigher concentration of fishing near beaches•• Less bycatch management/ monitoringLess bycatch management/ monitoring•• Larger basin, longer migration lengthsLarger basin, longer migration lengths•• More variation in nesting beach productivityMore variation in nesting beach productivity•• Lower adult female recapture rateLower adult female recapture rate•• More nesting beach development More nesting beach development •• Greater climate change impacts, leads to: Greater climate change impacts, leads to:

•• Higher variability in availability of prey? Higher variability in availability of prey? •• Longer reLonger re--migration interval for leatherbacks?migration interval for leatherbacks?

Fisheries in AtlanticFisheries in AtlanticAtlantic BasinAtlantic Basin•• Lower density of pelagic hooks than Pacific Lower density of pelagic hooks than Pacific (3.4 hooks/ km(3.4 hooks/ km22), fewer hooks (316 million ), fewer hooks (316 million hooks), but higher turtle CPUE hooks), but higher turtle CPUE •• More bycatch management and monitoring More bycatch management and monitoring than Pacificthan Pacific•• More nests and higher number of eggs per More nests and higher number of eggs per nestnest•• Larger female body sizeLarger female body size•• More variable migration patterns for More variable migration patterns for leatherbacksleatherbacks•• More nests per season for leatherbacksMore nests per season for leatherbacks•• Better nesting beach dataBetter nesting beach data

Mapping ProductsMapping Products

GIS maps nesting beach locations, trends GIS maps nesting beach locations, trends > 3 decades for leatherbacks and > 3 decades for leatherbacks and loggerheads.loggerheads.

GIS maps of fishing effort GIS maps of fishing effort (# of boats)(# of boats)by countryby countryby size of boat (by size of boat (grtgrt))•• small= coastal?small= coastal?•• large= pelagic?large= pelagic?

Assessment of fishing intensityAssessment of fishing intensityIn collaboration with Project GLOBAL, Duke In collaboration with Project GLOBAL, Duke UnivUniv, we, we’’ve ve

collated data on major fisheries in each basin:collated data on major fisheries in each basin:

Maps showing distribution of gear types. Maps showing distribution of gear types.

BycatchBycatch rates for each fishery have been calculated.rates for each fishery have been calculated.

Estimate of post encounter mortality from bycatch events Estimate of post encounter mortality from bycatch events examined.examined.

Next steps: examine differences in fishing pressure, Next steps: examine differences in fishing pressure, bycatch mortality rates, overlap of turtles and fisheries bycatch mortality rates, overlap of turtles and fisheries between basinsbetween basins

Satellite Tracking SynthesisSatellite Tracking Synthesis

Available satellite tracking data compiled from published Available satellite tracking data compiled from published literature, literature, Seaturtle.orgSeaturtle.org, OBIS, OBIS--SEAMAP, TOPP SEAMAP, TOPP websites.websites.

Tracks revealed some patterns of movement from Tracks revealed some patterns of movement from specific nesting locations, but no obvious differences in specific nesting locations, but no obvious differences in patterns between basins.patterns between basins.

More detailed analysis necessary to determine if More detailed analysis necessary to determine if migration distance, availability of suitable habitat are migration distance, availability of suitable habitat are potential drivers between the two populations.potential drivers between the two populations.

Modeling ProductsModeling ProductsAgeAge--structured population model to examine impacts of structured population model to examine impacts of past perturbations on both species. past perturbations on both species.

Ability to input 5 different sets of life history Ability to input 5 different sets of life history parametersparametersExplore effects of time lags on population responseExplore effects of time lags on population response

•• e.g., Loggerhead response in Japan (recent e.g., Loggerhead response in Japan (recent increase) could be a rebound following cessation increase) could be a rebound following cessation of driftnetsof driftnets

Examine responses in nesting female counts that Examine responses in nesting female counts that may be due to changes in nesting frequency rather may be due to changes in nesting frequency rather than population sizethan population size

•• e.g., Atlantic leatherback increase (in part) due to e.g., Atlantic leatherback increase (in part) due to large number of annual nesterslarge number of annual nesters

Modeling ProductsModeling Products

Simulation of hatchling drift trajectories for the Simulation of hatchling drift trajectories for the Pacific and Atlantic basinPacific and Atlantic basin

““hatchlingshatchlings”” are released from nesting beach are released from nesting beach locations during peak time of emergencelocations during peak time of emergence

Model disperses passive drifting hatchlings Model disperses passive drifting hatchlings based on basin wide currents, behavior, based on basin wide currents, behavior, physiologyphysiology

Future workFuture workParticipants will acknowledge PASTA Participants will acknowledge PASTA meetings (and PFRP) on manuscripts as meetings (and PFRP) on manuscripts as appropriateappropriate

Collaboration across disciplines fostered !Collaboration across disciplines fostered !

Possible future PASTA meetingsPossible future PASTA meetings

Synthesis symposia at sea turtle and/or Synthesis symposia at sea turtle and/or fisheries meetings, fisheries meetings, CliotopCliotop? ?