10,000 - 1,000,000 individuals
Comments: Pritchard (1982) estimated 115,000 breeding females worldwide, though his estimates may have been too high, especially for Mexico. Estimated world population in the early 1990s was reported as 136,000 breeding females by Pritchard (1992). In contrast, Spotila et al. (1996) estimated the worldwide population of nesting females at 26,200-42,000, with the majority of animals occurring in the Atlantic Ocean and Caribbean Sea where the population was estimated at 27,608. An estimated 100-900 leatherbacks occur in summer in waters off the northeastern U.S. (Shoop and Kenney 1992). See Cook (1981) for information on status in Canada.
Spotila et al. (2000) estimated total adult (breeding) population at 1,690 females in the eastern Pacific (down from an estimated 4,600-6,500 in 1996) and concluded leatherbacks are on the verge of extinction in the Pacific. Another estimate suggested a total of 2,300 adult females in the entire Pacific (Crowder 2000).
In Florida, between 1988 and 1992, annual reported leatherback nests varied between 98 and 188 (USFWS 1998). In the 1980s and early 1990s, about 18-55 females nested each year on St. Croix in the U.S. Virgin Islands (Boulon et al. 1996); increased to 100+ in 1997. In 1997, more than 80 females nested at Culebra Island, Puerto Rico.
Nest counts at the largest nesting colony in Mexico reported less than 250 in 1998-1999 (Eckert unpubl. results in Spotila et al. 2000). Spotila et al. (2000) predicted that without protection the population breeding at Playa Grande, Costa Rica (once the 4th largest nesting colony in the world), would be reduced to around 50 nesting females by 2003-2004.
In the mid-1990s, few beaches had more than a few hundred nesting females (Spotila et al. 1996). Only four nesting areas presently support more than 1,000 breeding females: the Pacific coast of Mexico probably fewer than 5,000 though formerly many more; Pacific coast of French Guiana, 4,500-6,500; peninsular Malaysia, 1,000-2,000; and the Kepala Burung region of Indonesia (UNEP 2003).