Proceedings of the International Technical Expert Workshop on Marine Turtle Baycatch in Longline Fisheries, Seattle, Washington, 11-13 February, 2003

摘要

Marine turtle populations have declined worldwide over the last century. All species have been listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since the Convention entered into force in 1975. The leatherback (Dermochelys coriacea), hawksbill (Eretmochelys imbricata), and Kemps ridley (Lepidochelys kempii) are listed as Critically Endangered under the Red List of the International Union for the Conservation of Nature (IUCN). The loggerhead (Caretta caretta), olive ridley (Lepidochelys olivacea), and green turtle (Chelonia mydas) are listed as Endangered and the flatback (Natator depressus) is listed as Vulnerable on the IUCN Red List. Except for the flatback, which is indigenous to Australia, all species are listed under the U.S. Endangered Species Act of 1973. Population declines have been documented in specific nesting assemblages of the loggerhead in the Atlantic and Pacific as well as the green turtle in the eastern Pacific. Of particular concern is the leatherback, which is seriously declining throughout the Pacific and has experienced an overall decline in the Atlantic. Once numbering in the tens of thousands, a 1996 study of the four major nesting beaches for the Pacific leatherback in Mexico, which sustained perhaps as much as half of all global nesting for this species, revealed that the population had collapsed. Annual surveys conducted since 1996 have revealed precipitously low population levels with only a few hundred females nesting annually along the entire Pacific coast of Mexico. The decline in these populations is due primarily to human-related causes, including incidental capture in commercial and artisanal fisheries and poaching of eggs and nesting females.