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Chapter 11 Sea Turtles© Linda SchonknechtSelection of Target SpeciesThe three species of sea turtle selected for the assessmentare currently found within the Northwest Atlantic region:• Green sea turtle (Chelonia mydas)• Leatherback (Dermochelys coriacea)• Loggerhead (Caretta caretta)The Kemp’s ridley turtle (Lepidochelys kempii) is the fourthspecies of turtle found in the region. Currently, there isnot adequate information on the distribution of this speciesin the region to include it in this report.Population Status and the Importance ofNorthwest Atlantic regionIn the United States, all three target species are federallylisted as endangered or threatened species. Loggerheadturtles are considered threatened throughout their range;green sea turtles are listed as endangered in Florida andthe Pacific Coast of Mexico and threatened for all otherpopulations; leatherback turtles are listed as endangeredthroughout their range. According to the InternationalUnion for Conservation of Nature (IUCN) Red List(2007a, b, c), both the loggerhead and green turtles arecategorized as “Endangered” while the leatherback is considered“Critically Endangered.” These species are protectedagainst international trade (CITES 1979).Variable and/or sporadic survey efforts coupled withspecies specific sources of variation (e.g., remigrationintervals and clutch frequency) have precluded a comprehensiveglobal population abundance and trend analysisover long periods for these species. For the loggerhead,the two primary global nesting aggregations with greaterthan 10,000 nesting females per year are South Florida(United States) and Masirah (Oman, Arabian Sea)(Baldwin et al. 2003; NMFS USFWS 2008). Over thepast decade, estimates for United States nesting aggregationshave fluctuated between 47,000 and 90,000 nestsper year, with 80% of nesting occurring in eastern Florida(NMFS USFWS 2008). Over an 18 year period, the totalnumber of nests in Florida has declined by 28% witha more pronounced decline of 43% since 1998. Decliningpopulation trends have also been reported over the pastdecade for nesting aggregations outside Florida includingthe southeastern United States, the Bahamas, andMexico (NMFS USFWS 2008). For the green turtle,the mean annual number of nesting females has declinedby approximately 48% (173,429 to 90,403 individuals) to67% (266,133 to 88,499 individuals) over the last threegenerations across 32 globally distributed subpopulations(IUCN Marine Turtle Specialist Group 2004). Despitethe global decline of green turtles over the past 150 years,all but one of the subpopulation index sites (Venezuela,Aves Island) in the IUCN’s Western Atlantic Ocean andCaribbean Region witnessed percentage increases includingthe United States (Florida). This IUCN region representsapproximately 30% of the overall global populationof nesting females. For the leatherback, population decreasesand collapse have been documented in major nestingareas globally. A recent assessment puts the currentadult population in the North Atlantic between 34,000and 94,000 adult females (Turtle Expert Working Group2007). For seven Atlantic Ocean populations with a minimumof 10 years of nesting data, populations appear tobe stable or increasing with the exception of West Africaand Western Caribbean (Turtle Expert Working Group2007). Standardized nest counts suggest that the Floridapopulation has increased from 98 nests (1989) to 900nests per season (2006).11-Northwest Atlantic Marine Ecoregional Assessment • Phase 1 Report