EPA's Vessel General Permit and Small Vessel General

sea turtles over the last half century (TEWG 2009). Shrimp trawls were the major source of
mortality until 2003 when turtle excluder devices were mandated. Pelagic longline, finfish trawl,
gill net, drift net, and pound net fisheries are additional sources of mortality. Estimated mean
annual bycatch in the Atlantic is 26,500 loggerheads, of which an estimated 1,400 die
(Finkbeiner et al. 2011b). The TEWG (2009) concludes that incidental capture of loggerheads in
these commercial fisheries “may certainly be playing a role in the recent apparent decrease in the
numbers of adult female loggerheads in the Western North Atlantic.” Commercial harvest of
turtles and eggs also plays a role. Threats to nesting habitat include: coastal development and
construction, placement of erosion control structures, beachfront lighting, vehicular and
pedestrian traffic, sand extraction, beach erosion, beach nourishment, beach pollution, removal
of native vegetation, and planting of non-native vegetation (Baldwin 1992, USFWS 1998,
Margaritoulis et al. 2003, Mazaris et al. 2009). Loggerhead sea turtles face numerous threats in
the marine environment as well, including oil and gas exploration, marine pollution, trawl, purse
seine, hook and line, gill net, pound net, longline, and trap fisheries, underwater explosions,
dredging, offshore artificial lighting, power plant entrapment, entanglement in debris, ingestion
of marine debris, marina and dock construction and operation, boat collisions, and poaching.
Climate change may also have significant implications on loggerhead populations worldwide. In
addition to potential loss of nesting habitat due to sea level rise, loggerhead sea turtles are very
sensitive to temperature as a determinant of sex while incubating. Ambient temperature increase
by just 1º-2º C can potentially change hatchling sex ratios to all or nearly all female in tropical
and subtropical areas (Hawkes et al. 2007a). Increasing ocean temperatures may also lead to
reduced primary productivity and food availability. Natural threats include predation by sharks,
seabirds, raccoons, and crabs (Barton and Roth 2008).
Life History
Loggerhead females mature at 15 – 38 years of age (Frazer and Ehrhart 1985, NMFS 2001,
Witherington et al. 2006, Casale et al. 2009). They breed approximately every 2-3 years
(Richardson et al. 1978, Dodd 1988), and lay 4 – 5 nests per season, which generally lasts from
March until August (Murphy and Hopkins 1984, Tucker 2010). The average clutch size is 100-
130 eggs (Dodd 1988). There are five life stages for the loggerhead: year one (terrestrial to
oceanic hatchlings); juvenile one (exclusively oceanic), juvenile two (oceanic or neritic, 41 – 82
cm standard carapace length), juvenile three (oceanic or neritic, 63 – 100 cm standard carapace
length), and adult (TEWG 2009).
Diet
Loggerhead sea turtles are omnivorous and opportunistic feeders through their lifetimes (Parker
et al. 2005). Hatchling loggerheads feed on macroplankton associated with Sargassum spp.
communities (NMFS and USFWS 1991b). Pelagic and benthic juveniles forage on crabs,
mollusks, jellyfish, and vegetation at or near the surface (Dodd 1988, Wallace et al. 2009).
Loggerheads in the deep, offshore waters of the western North Pacific feed on jellyfish, salps,
and other gelatinous animals (Dodd 1988, Hatase et al. 2002). Sub-adult and adult loggerheads
prey on benthic invertebrates such as gastropods, mollusks, and decapod crustaceans in hardbottom
habitats, although fish and plants are also occasionally eaten (NMFS and USFWS
1998d). Stable isotope analysis and study of organisms on turtle shells has recently shown that
although a loggerhead population may feed on a variety of prey, individuals have specialized
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