The leatherback turtle was listed as endangered throughout its range on June 2, 1970. Nesting populations of leatherback sea turtles are especially difficult to discern because the females frequently change beaches. However, current estimates are that 20,000-30,000 female leatherbacks exist worldwide.
Leatherbacks do not nest frequently enough in the United States to assess an accurate trend. The recovery plan for the leatherback sea turtle concludes that nesting trends in the United States appear stable, but the population faces significant threats from incidental take in commercial fisheries and marine pollution. Populations have declined in Mexico, Costa Rica, Malaysia, India, Sri Lanka, Thailand, Trinidad, Tobago, and Papua New Guniea. Leatherbacks are seriously declining at all major nesting beaches throughout the Pacific. The decline is dramatic along the Pacific coasts of Mexico and Costa Rica and coastal Malaysia. Nesting along the Pacific coast of Mexico declined at an annual rate of 22% over the last 12 years, and the Malaysian population represents 1% of the levels recorded in the 1950s. The collapse of these nesting populations was precipitated by a tremendous overharvest of eggs, direct harvest of adults, and incidental mortality from fishing. In the Atlantic and Caribbean, the largest nesting assemblages are found in the U.S. Virgin Islands, Puerto Rico, and Florida. Nesting data for these locations have been collected since the early 1980's and indicate that the annual number of nests is likely stable; however, information regarding the status of the entire leatherback population in the Atlantic is lacking. Nesting activity has also declined in French Guiana due to erosion of nesting beaches, the population appears to have shifted to Surinam, where annual numbers of nests have risen from less than 100 in 1967 to 5,565 in 1977 and 9,816 in 1987. Habitat destruction, incidental catch in commercial fisheries, the harvest of eggs and flesh are the greatest threats to the survival of the leatherback.
The leatherback is the largest living turtle, and is so distinctive
as to be placed in a separate taxonomic family, Dermochelyidae.
The carapace is distinguished by a rubber-like texture, about 4
cm thick, and made primarily of tough, oil-saturated connective
tissue. No sharp angle is formed between the carapace and the plastron,
resulting in the animal being somewhat barrel-shaped. The average
curved carapace length for adult turtles is 155 cm and weight ranges
from 200-700 kg. Hatchlings are dorsally mostly black and are covered
with tiny scales; the flippers are margined in white, and rows of
white scales appear as stripes along the length of the back. Hatchlings
average 61.3 mm long and 45.8 g in weight.
In the adult, the skin is black and scaleless. The undersurface is mottled pinkish-white and black. The front flippers are proportionally longer than in any other sea turtle, and may span 270 cm in an adult. In both adults and hatchlings, the upper jaw bears two tooth-like projections at the premaxillary-maxillary sutures. Age at sexual maturity is unknown.
The leatherback turtle's range extends from Cape Sable, Nova Scotia, south to Puerto Rico and the U.S. Virgin Islands. Critical habitat for the leatherback includes the waters adjacent to Sandy Point, St. Croix, U.S. Virgin Islands, up to and inclusive of the waters from the hundred fathom curve shoreward to the level of mean high tide with boundaries at 17¡42'12" N and 64¡50'00" W. Nesting occurs from February - July with sites located from Georgia to the U.S. Virgin Islands. During the summer, leatherbacks tend to be found along the east coast of the U.S. from the Gulf of Maine south to the middle of Florida.
Leatherbacks are commonly seen by fishermen in Hawaiian offshore waters, generally beyond the 100-fathom curve but within sight of land. Sightings often take place off the north coast of Oahu and the Kona coast of Hawaii. North of the Hawaiian Islands, a high seas aggregation of leatherbacks is known to occur at 35¡-45¡N, 175¡-180¡W.
Leatherback turtles feed mostly on jellyfish, but also eat fish and other smaller sea creatures.
Human Impacts on the Leatherback Sea Turtle's Nesting Environment
Human Impacts on the Leatherback Sea Turtle's Marine Environment
Commercial Fishing Impacts
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