Threatened and Endangered Species - Status Reports
Date Published: July 1999
Number of Pages: 21
Author(s): Scott Richardson
Olive ridley sea turtles are graceful saltwater reptiles with streamlined bodies and flipper-like limbs. They measure up to 73 cm and weigh up to 45 kg. Their distribution is limited primarily to tropical oceans and beaches.
Most olive ridleys nest in large, synchronized aggregations known as arribadas. In the eastern tropical Pacific, large arribadas are found in Costa Rica and Mexico. Females typically lay two clutches, each numbering about 100 eggs, separated by 2 to 4 weeks. Eggs hatch after 7 to 10 weeks. Olive ridleys probably require more than 7 years to attain sexual maturity.
Olive ridleys are primarily carnivorous. They eat fish, shellfish, jellyfish, and other marine animals. In some areas, algae may be an important dietary component.
Threats to olive ridleys include poorly-regulated and illegal harvesting of adults and eggs, floating plastics, oil pollution, and incidental take in fishing nets. In areas where recreational boating and ship traffic are intense, propeller and collision injuries are not uncommon.
The olive ridley may be the most abundant sea turtle in the Pacific Ocean. However, the number of olive ridleys at most arribadas has declined considerably during the past 30 years or more. Currently, several hundred thousand nest along the Mexican and Costa Rican coasts. The Bay of Bengal in India also supports several hundred thousand nesters.
Ocean temperature restricts olive ridleys to waters well south of Washington. The state has only a single olive ridley record, a turtle that was found dead in Grays Harbor County. Oregon has two records.
The Mexican nesting population of the olive ridley sea turtle is listed as federally endangered under the Endangered Species Act. All other populations are listed as threatened. The National Marine Fisheries Service has suggested the Atlantic population may deserve to be uplisted to endangered.
Although Washington Administration Code 232-12-297 dictates that federally-listed species will be listed by the state, the olive ridley's range apparently does not include Washington coastal waters. It is therefore recommended that the Washington Fish and Wildlife Commission not list the olive ridley sea turtle as endangered, threatened, or sensitive.
Richardson, S. 1997. Washington State Status Report for the Olive Ridley Sea Turtle. Wash. Dept. Fish and Wildl., Olympia. 14pp.