Hawaii FEP - Western Pacific Fishery Council

seem to have a more carnivorous diet. Analysis of stomach contents of green turtles found offPeru revealed a large percentage of mollusks and polychaetes, while fish and fish eggs, jellyfish,and commensal amphipods made up a smaller percentage (Bjorndal 1997). Seminoff et al.(2000) found that 5.8 percent of gastric samples and 29.3 percent of the fecal samples of eastPacific green turtles foraging in the northern Sea of Cortéz, Mexico, contained the remains of thefleshy sea pen (Ptilosarcus undulatus).Green sea turtles are a circumglobal and highly migratory species, nesting and feeding intropical/subtropical regions. Their range can be defined by a general preference for watertemperature above 20° C. Green sea turtles are known to live in pelagic habitats asposthatchlings/juveniles, feeding at or near the ocean surface. The non-breeding range of thisspecies can lead a pelagic existence many miles from shore while the breeding population livesprimarily in bays and estuaries, and are rarely found in the open ocean. Most migration fromrookeries to feeding grounds is via coastal waters, with females migrating to breed only onceevery two years or more (Bjorndal 1997).Tag returns of eastern Pacific green turtles (often reported as black turtles) establish that theseturtles travel long distances between foraging and nesting grounds. In fact, 75 percent of tagrecoveries from 1982–1990 were from turtles that had traveled more than 1,000 kilometers fromMichoacán, Mexico. Even though these turtles were found in coastal waters, the species is notconfined to these areas, as indicated by sightings recorded in 1990 from a NOAA research ship.Observers documented green turtles 1,000–2,000 statute miles from shore (Eckert 1993). Theeast Pacific green is also the second-most sighted turtle in the east Pacific during tuna cruises;they frequent a north–south band from 15° N to 5° S along 90° W and an area between theGalapagos Islands and the Central American Coast (NMFS and USFWS 1998a).The non-breeding range of green turtles is generally tropical, and can extend approximately 500–800 miles from shore in certain regions (Eckert 1993). The underwater resting sites include coralrecesses, undersides of ledges, and sand bottom areas that are relatively free of strong currentsand disturbance from natural predators and humans. In the Pacific, the only major (> 2,000nesting females) populations of green turtles occur in Australia and Malaysia. Smaller coloniesoccur in the insular Pacific islands of Polynesia, Micronesia, and Melanesia (Wetherall 1993)and on six small sand islands at French Frigate Shoals, a long atoll situated in the middle of theHawaii Archipelago (Balazs et al. 1994).Green turtles were listed as threatened under the ESA on July 28, 1978, except for breedingpopulations found in Florida and the Pacific coast of Mexico, which were listed as endangered.Using a precautionary estimate, the number of nesting female green turtles has declined by 48percent to 67 percent over the last three generations (~150 years; Troeng and Rankin 2005).Causes for this decline include harvest of eggs, subadults, and adults; incidental capture byfisheries; loss of habitat; and disease. The degree of population change is not consistent amongall index nesting beaches or among all regions. Some nesting populations are stable or increasing(Balazs and Chaloupka 2004; Chaloupka and Limpus 2001; Troeng and Rankin 2005). However,other populations or nesting stocks have markedly declined. Because many of the threats thathave led to these declines have not yet ceased, it is evident that green turtles face a measurablerisk of extinction (Troeng and Rankin 2005).74