EPA's Vessel General Permit and Small Vessel General

in leatherbacks and can block gastrointestinal tracts leading to death (Mrosovsky et al. 2009).
Although global climate change may expand foraging habitats into higher latitude waters,
increasing temperatures may increase feminization of nests (Mrosovsky et al. 1984, James et al.
2006, McMahon and Hays 2006, Hawkes et al. 2007b). It may also result in rising sea levels,
which may inundate nests on some beaches. Natural threats include: predation on adults by
sharks and killer whales (Pitman and Dutton 2004); predation on hatchlings by seabirds, land
predators, and sharks; and tidal inundation of nests (Caut et al. 2009).
Life history
Both males and females exhibit some degree of philopatry, returning to their natal beaches for
breeding and nesting (James et al. 2005b). Age to maturity remains elusive, with estimates
ranging from 5 to 29 years (Spotila et al. 1996, Avens et al. 2009). Females lay up to seven
clutches per season, with more than 65 eggs per clutch and eggs weighing >80 g (Reina et al.
2002, Wallace et al. 2007). Females remigrate every 1-7 years, with most turtles returning every
two years to nest in French Guiana (Rivalan et al. 2005) and every three years in Las Baulas,
Costa Rica (Reina et al. 2002). The remigration interval for western Pacific leatherbacks is
unknown but estimated as “several years” (Benson et al. 2011). According to Wallace (2007),
high seasonal and lifetime fecundity likely reflect compensation for high and unpredictable
mortality during early life history stages.
Migration and movement
Leatherback sea turtles migrate long distances between tropical nesting beaches temperate forage
areas (i.e., remigration). Leatherbacks weigh ~33 percent more on their foraging grounds than at
nesting, indicating that they probably catabolize fat reserves to fuel migration and subsequent
reproduction (James et al. 2005a, Wallace et al. 2006). Sea turtles must meet an energy
threshold before returning to nesting beaches (Rivalan et al. 2005, Sherrill-Mix and James 2008,
Casey et al. 2010). Therefore, their remigration intervals (the time between breeding seasons)
are dependent upon foraging success and duration (Hays 2000, Price et al. 2004). Eastern Pacific
leatherbacks use a consistent migration corridor to forage in the South Pacific Gyre, a lowproductivity
region (Shillinger et al. 2008). Western Pacific turtles that nest during the boreal
summer migrate to forage in temperate waters of the North Pacific or tropical waters of the South
China Sea; those that nest during the boreal winter forage in temperate and tropical waters of the
southern hemisphere (Benson et al. 2011). Post-nesting, western Atlantic leatherbacks migrate
to foraging areas in the North Atlantic or the equatorial eastern Atlantic (Ferraroli et al. 2004,
Hays et al. 2004, Eckert et al. 2006, Eckert 2006). Eastern Atlantic leatherbacks migrate to
foraging areas in the equatorial Atlantic, temperate waters off South America, or temperate
waters off southern Africa (Witt et al. 2011).
Diet
Leatherbacks feed primarily on jellyfish, such as Stomolophus, Chryaora, and Aurelia (Rebel
1974), and tunicates (salps, pyrosomas). These gelatinous zooplankton are relatively nutrientpoor
(Doyle et al. 2007), such that leatherbacks must consume large quantities to support their
body weight.
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