Olive ridley sea turtle (Lepidochelys olivacea)

TAXONOMY AND NAMING

Class : Reptilia
Order : Testudines
Family : Cheloniidae
Genus : Lepidochelys
Species : L. olivacea
Common names :
English : Olive ridley sea turtle
Spanish : Tortuga olivácea
French : Tortue olivâtre

Olive ridley sea turtle (E. imbricata)© Joëlle Dufour

ANATOMY AND MORPHOLOGY

Growing to about 61 cm (2 ft) in carapace length (measured along the curve), the olive ridley sea turtle gets its common name from its olive-colored carapace, which is heart-shaped and rounded. Males and females grow to the same size, but females have a slightly more rounded carapace as compared to males.

DISTRIBUTION AND LIFE HISTORY

The olive ridley turtle has a circumtropical distribution, living in tropical and warm waters of the Pacific and Indian Oceans. Olive ridleys are occasionally found in open waters. The multiple habitats and geographical localities used by this species vary throughout its lifecycle. Migratory movements have been studied less intensely in olive ridleys than other species of marine turtles, but they are believed to use the coastal waters of over 80 countries. Historically, this species has been widely regarded as the most abundant sea turtle in the world.

Olive ridley turtles are best known for their behavior of synchronized nesting in mass numbers, termed arribadas. Females return to the same beach from where they hatched, to lay their eggs. Mating is often assumed to occur in the vicinity of nesting beaches, but copulating pairs have been reported over 1,000 km from the nearest beach. The olive ridley is predominantly carnivorous, especially in immature stages of its lifecycle. Animal prey consists of protochordates or invertebrates, which can be caught in shallow marine waters or estuarine habitats.

Olive ridley sea turtle (E. imbricata) geographic range©IUCN red list

THREATS

Humans are still listed as the leading threat to L. olivacea, responsible for unsustainable egg collection, slaughtering nesting females on the beach, and direct harvesting adults at sea for commercial sale of both the meat and hides. Moreover, olive Ridley have many predators. Other major threats include mortality associated with boat collisions, and incidental takes in fisheries.

Some of the olive ridley’s foraging grounds near Southern California are contaminated due to sewage, agricultural runoff, pesticides, solvents, and industrial discharges. These contaminants have been shown to decrease the productivity of the benthic community, which negatively affects these turtles, which feed from these communities.[6 Another threat to these turtles is power plants, which have documented juvenile and subadult turtles becoming entrained and entrapped within the saltwater cooling intake systems.

PROTECTION AND CONSERVATION STATUS

Olive ridley sea turtles are considered the most abundant, yet globally they have declined by more than 30% from historic levels.[citation needed] These turtles are considered endangered because of their few remaining nesting sites in the world. The olive ridley is classified as vulnerable according to the International Union for Conservation of Nature and Natural Resources. The Convention on Migratory Species and the Inter-American Convention for the Protection and Conservation of Sea Turtles have also provided olive ridleys with protection, leading to increased conservation and management for this marine turtle.

CITES : yes_Annex I

SPAW Protocol  : yes since 1991_Annex II

Tab 1. International convention and protection for olive ridley sea turtle

Sea turtle national protection status in SPAW parties ©SPAW RAC

Bibliography

"Archived copy". Archived from the original on November 28, 2010. Retrieved October 25, 2010. STRP Hawksbill Sea Turtle
Boulon, R. (1994). Growth Rates of Wild Juvenile Hawksbill Turtles, Eretmochelys imbricata, in St. Thomas, United States Virgin Islands. Copeia, 1994 : 3 pp 811-814
"Species Booklet : Hawksbill sea turtle". Virginia Fish and Wildlife Information Service. Virginia Department of Game & Inland Fisheries. Archived from the original on 2006-09-24. Retrieved 2007-02-06.
"Hawksbill turtle – Eretmochelys imbricata : More information". Wildscreen. Archived from the original on 2007-03-28. Retrieved 2007-02-05.
UNEP-WCMC. "Eretmochelys imbricata". UNEP-WCMC Species Database : CITES-Listed Species. United Nations Environment Programme - World Conservation Monitoring Centre. A-301.003.003.001. Retrieved 2007-02-05.
Van Dam, R. P. ; Diez, C. E. (1997). "Diving behavior of immature hawksbill turtles (Eretmochelys imbricata) in a Caribbean reef habitat". Coral Reefs. 16 (2) : 133–8. doi:10.1007/s003380050067. S2CID 2307103.