Chelonia mydas

The Black Turtle of the Pacific Ocean has been considered a separate species (Chelonia agassizii) by some authors (e.g., Pritchard and Trebbau 1984, Okamato and Kamezaki 2014), a subspecies of Chelonia mydas by others (Kamezaki and Matsui 1995), and synonymous with Chelonia mydas by others (e.g., Bowen et al. 1992) (Crother 2017). Crother (2017) and the Turtle Taxonomy Working Group (2021) do not recognize it.

This species is distributed across the globe in tropical and subtropical oceans. The population declined by approximately 50% until protections were afforded beginning in the 1970s. The population has since begun to rebound. It remains threatened primarily by nesting habitat degradation and poaching.

Distribution is pantropical in the Atlantic, Pacific, and Indian oceans. In some areas this species occurs in higher temperate latitudes due to drifting in ocean currents in conjunction with above-normal sea temperatures or as a normal life history event; young turtles regularly range as far north as New England. Major nesting activity occurs on Ascension Island (British Overseas Territory), Aves Island (Venezuela), Tortuguero, Costa Rica, and in Suriname (CSTC 1990). See Hirth (1980) for a map of major nesting beaches.

In U.S. Atlantic waters, green sea turtles occur around the U.S. Virgin Islands and Puerto Rico, where small numbers nest (islas Mona, Vieques, and Culebra, and St. Thomas, St. John, St. Croix), and a juvenile population exists in eastern portion of Puerto Rican Bank (Collazo et al. 1992), and from Texas to Massachusetts. Relatively small numbers nest in Florida, particularly in Brevard, Indian River, St. Lucie, Martin, Palm Beach, and Broward counties (CSTC 1990), mostly from Volusia County to Dade County (Ehrhart and Witherington 1992), with rare recent nesting on the Gulf Coast in Santa Rosa County (Ehrhart and Witherington 1992); important feeding areas in Florida include the Indian River, Florida Bay, Homossassa Bay, Crystal River, and Cedar Key (CSTC 1990). Rarely nests in Georgia, North Carolina, and Texas.

What constitutes an occurrence for sea turtles is challenging. Seminoff et al. (2015) identified 11 distinct population segments (DPS) across the range and documented 428 nesting sites worldwide.

Major threats, which vary throughout the range, include degradation of nesting habitat, including beach lighting, which may disorient hatchlings and/or nesting females; human predation on nesting females and turtles in foraging areas (e.g., for meat and use in commercial products); collection of eggs for human consumption; predation on eggs and hatchlings by raccoons, dogs, etc.; mortality in fishing gear and other entangling debris; collisions with power boats; contact with chemical pollutants; and epidemic outbreaks of fibropapilloma or "tumor" infections (Mitchell 1991, Ehrhart and Witherington 1992, Tuato`o-Bartley et al. 1993, Losey et al. 1994, Barrett 1996, NMFS and USFWS 2007, Seminoff et al. 2015). In the north, juveniles experience periodic mortality due to cold-stunning associated with rapid temperature declines in fall. See USFWS (1998) and NMFS and USFWS (2007) for further information on certain threats, including beach erosion, beach armoring, beach nourishment, artificial lighting, beach cleaning, increased human presence, recreational beach equipment, exotic dune and beach vegetation, nest loss to abiotic factors, predation, poaching, and disease. Restrepo et al. (2023) gives a brief review of human consumption in the Caribbean.