The illegal harvest of olive ridley eggs in the Central American region continues, and there is also high mortality of adults due to coastal fisheries that do not yet use Turtle Excluder Devices (TEDs) in their nets.
The olive ridley looks very similar to the Kemp's ridley, but has a deeper body and slightly up-turned edges to its carapace (shell).
The average length is 70cm, and adults weigh approximately 45kg.
Rusty coloured carapace.
After reaching sexual maturity when they are about 12 years old, many thousands of females emerge from the sea and nest simultaneously over a period of 2 to 3 days. These arribadas (a Spanish word meaning 'mass arrivals') may be an adaptation against predation, and one reason for the success of this species.
However, the olive ridley often chooses small, narrow beaches and their nests may be so closely packed that subsequent waves of females often dig up other nests in efforts to lay their own eggs. Arribadas may be repeated 2 to 7 times a season.
This species feeds essentially on crabs and shrimps, but also jellyfish, small invertebrates, tunicates, small invertebrates and fish eggs. Individuals have been captured in prawn trawls at depths of 80 to 110m, and are therefore considered capable of foraging at these depths.
Current Population and Distribution
Olive ridleys occur through the Antilles, around the north coast of South America, in West Africa, the Indian Ocean, Australia and southeast Asia. There are also many important nesting and feeding grounds on the east Pacific coast from as far north as Canada to as far south as southern Peru.
Nesting occurs at low frequency throughout much of its range, with the highest concentrations of the olive ridley found on the coast of Orissa state, India. The principal beaches are Garhimatha, Ruchikulya and Devi River mouths. On the Pacific coast of Costa Rica, the main nesting beaches are Nancite and Ostional, and La Escobilla on the coast of Oaxaca, Mexico. Populations in northern Australia and south-east Asia are known to be different genetic stock to the Orissa turtles. Populations of olive ridleys are reported to have declined in Pakistan, Myanmar, Malaysia and Thailand, and possibly on the east coast of India, south of Orissa and in the Andaman and Nicobar islands.
A recent estimate of 800,000+ female olive ridleys has been made.