Chapter 3 - Natural Resources - Marine Corps Base Camp Pendleton

Integrated Natural Resources Management Plan [March 2012 - Update]
ventral (plastral) surfaces, as well as the dorsal surface of the head whenever possible to
assist in the identification of the species (Holland 1998b).
The Pacific loggerhead turtle is the least common aquatic reptile to pass through ocean
waters off Base, and only a single record of observation is known (Holland 1998b).
Loggerheads were named for their relatively large heads, which support powerful jaws and
enable them to feed on hard-shelled prey, such as whelks and conch. The carapace (top
shell) is slightly heart-shaped and reddish-brown in adults and sub-adults, while the
plastron (bottom shell) is generally a pale-yellowish color. The neck and flippers are
usually dull-brown to reddish-brown on top and medium to pale-yellow on the sides and
bottom. Carapace length of adults is approximately 36 in (92 cm) long; corresponding
weight is about 250 lbs (113 kg) (USFWS 2009c). The only know breeding locations in the
North Pacific are in Japan (USFWS 2007g). On 22 September 2011, the USFWS issued a
final rule which divided existing loggerhead turtle populations into 9 distinct population
segments; the potential loggerhead habitat offshore of the Base is considered part of the
Northern Pacific Distinct Population Segment (DPS) (USFWS 2011g).
There is a resident foraging population of green sea turtles in the San Diego Bay area that
breed throughout Mexico; no know breeding sites are along the coast of California
(USFWS 2007h). The species is known to pass through the ocean waters off Base,
however, the quantity and frequency is unknown without further study (Holland 1998b).
The green sea turtle grows to a maximum length of about 4 feet and a weight of 440
pounds. It has a heart-shaped shell, small head, and single-clawed flippers. Color is
variable. Hatchlings generally have a black carapace, white plastron, and white margins on
the shell and limbs. The adult carapace is smooth, keelless, and light to dark brown with
dark mottling; the plastron is whitish to light-yellow. Adult heads are light-brown with
yellow markings. Identifying characteristics include four pairs of costal scutes, none of
which borders the nuchal scute, and only one pair of prefrontal scales between the eyes
(USFWS 2009d).
Leatherback sea turtle records are scarce, but it is likely that the species passes through the
offshore waters of the Base on a frequent basis; however, further study would have to be
conducted to affirm the frequency of its presence (Holland 1998b). No know breeding sites
are along the coast of California (USFWS 2007i). The leatherback is the largest, deepest
diving, most migratory and widest ranging of all sea turtles. The adult leatherback can
reach 4 to 8 feet in length and 500 to 2000 pounds in weight, and is the largest living reptile
in the world. Its shell is composed of a mosaic of small bones covered by firm, rubbery,
oil-saturated skin with seven longitudinal ridges or keels. The skin is predominantly black
with varying degrees of pale spotting; including a notable pink spot on the dorsal surface of
the head in adults. A toothlike cusp is located on each side of the gray upper jaw; the lower
jaw is hooked anteriorly. The paddle-like clawless limbs are black with white margins and
pale spotting (USFWS 2009e).
The olive ridley was named for the olive color of its heart-shaped shell, and is one of the
smallest of the sea turtles, with adults reaching 2 to 2.5 feet in length and weighing 80 to
110 pounds. The species may be identified by the uniquely high and variable numbers of
vertebral and costal scutes. Although some individuals have only five pairs of costals, in
nearly all cases some division of costal scutes occurs, so that as many as six to nine pairs
Chapter 3 – Natural Resources 3-29