Sea Turtles

There are seven species of sea turtles: olive ridley (Lepidochelys olivacea); Kemp's ridley (Lepidochelys kempii); green (Chelonia mydas); logger head (Caretta caretta); leatherback (Dermochelys coriacea); hawksbill (Eretmochelys imbricata); and flatback (Natator depressus). Sea turtles are protected under several international agreements, including the Convention on International Trade in Species of Wild Fauna and Flora (CITES), the Convention on the Conservation of Migratory Species of Wild Animals, and the Inter-American Convention for the Protection and Conservation of Sea Turtles.

Sea turtles are listed in the Red List of the World Conservation Union (IUCN), with Kemp's ridleys, hawksbills, Mediterranean greens, and leatherbacks classified as “critically endangered,” greens, olive ridleys, and loggerheads as “endangered,” and flatbacks as “data deficient.” Because of the difficulties associated with assessing population status for long-lived, globally distributed species, where large portions of the population are difficult to monitor (that is, at sea), these listings have been controversial and the value of the Red List for sea turtles has been questioned.

Sea turtles are vulnerable to predators at all life stages. Eggs and hatchlings are taken for food by small mammals, crabs, and fish, and juvenile and adult turtles are preyed on by large fish, including sharks, and mammals (for example, jaguars on nesting beaches). At all sizes, turtles are taken by humans. Both subsistence and commercial uses of sea turtles, as well as international trade in turtle products, has historically been widespread. International trade has been greatly reduced in the post – World War II era.

For example, a Caribbean-based green turtle fishery that supplied European and U.S. markets with turtle meat and soup had significant impacts on turtle populations before trade fell off in the 1960s and was eventually eliminated in the 1970s. Traditional Japanese jewelry is made from hawksbill shell and was supported by international trade until 1994. Olive ridley leather is used in manufacturing boots and handbags, and in Mexico, an extensive olive ridley fishery existed until 1990. Local subsistence and commercial use has also declined, but to a lesser extent.

The role that sea turtles have played, and continue to play, in traditional coastal and sea-faring communities has been documented by archaeologists, historians, anthropologists, and geographers. [Page 1578]In some places, they remain a central part of cultural identity (for example, for the Miskito Indians in Nicaragua). While most of the conventions cited above make allowances for the continued use of sea turtles for economic subsistence purposes of traditional communities, these terms are undefined and the use of sea turtles continues to be a controversial issue in the conservation community. This issue is likely to become more contentious as some sea turtle populations increase as a result of protection activities.

Indirect impacts of human activities on sea turtles are also of concern. Nesting sea turtles have become popular as tourist attractions, and the impacts of turtle viewing on nesting behavior and success are mostly unknown. Changes in habitat pose threats to sea turtles; as coastal development progresses, hatchling mortality can be increased by artificial beach lighting, and adult females face nesting obstacles such as beach renourishment and coastal armoring. Pollution is also of growing concern, as sea turtles ingest plastic and oil. Further habitat degradation is anticipated via global climate change and associated sea level rise.

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