The Olive Ridley Sea Turtle, also known as the Pacific Ridley Sea Turtle, is a member of the Sea Turtle family. This species is the second smallest and most abundant sea turtle in the world. This turtle is found in the warm tropical waters of the Indian and Pacific Oceans and the Atlantic Ocean. The Kemp’s turtle, which is associated with this turtle, is best known for its unique mass nesting site called Alibada. Here, thousands of females gather on the same beach to lay their eggs.
Highlights
The olive-green Ridley sea turtle grows to about 61 inches (61 cm) in length (measured along a curve) and is commonly known for its heart-shaped, rounded olive shell. Females and males are the same size, but females have a slightly rounded shell compared to males. Carapace which is heart shaped is characterized by four pairs of sub marginal scutes with pores on the bridge, two pairs of prefrontal scutes, and up to nine side scutes on each side. L. olivacea is unique in that it has variable and asymmetric lateral graduations in the range of 5-9 plates on each side, with 6-8 being the most commonly observed. There are 12-14 edge scutes on each side of the shell.
Young turtles are dark gray with light scars on the yolk, but appear completely black when wet. The shell length of a freshly hatched child ranges from 37 to 50 mm. Thin white lines line the shell and trailing edge of the anterior and posterior fins. Both freshly hatched pups and juveniles have serrated trailing edge shields that become smoother with age. There are also three back keels in adolescence. The central longitudinal keel gives young turtles a serrated profile that is retained until sexual maturity.
Distribution of Olive Ridley Turtles
Olive ridley turtles are distributed in the tropics and inhabit the tropical and warm waters of the Indian and Pacific Oceans from India, Japan, Arabia and Micronesia to Australia, southern Africa and New Zealand. It has been observed in the Atlantic Ocean off the west coast of Africa and on the northern coast of Brazil, in Guyana, Suriname, Venezuela and French Guiana. In addition, olive ridley turtles have been found in the Caribbean Sea north of Puerto Rico.
Nesting
Ridley turtles are best known for their synchronized nesting behavior, known as arribada. The female returns to the same beach, hatches and lays eggs. They lay eggs in a conical nest about 1.5 meters deep, which is difficult to dig in the hind fins. In the Indian Ocean, most olive ridley turtles nest in two or three large groups near Gahirmatha in the state of Orissa. The coast of Orissa, India, along with the coasts of Costa Rica and Mexico, is one of the largest nesting sites for olive ridley turtles. In the year 1991, more than 6,00,000 turtles nested on the coast of Orissa in a week. Nesting occurs along the Coromandel Coast and elsewhere in Sri Lanka, but in isolated locations. However, olive ridley turtles are considered rare in most parts of the Indian Ocean.
Eating Habits
Olive ridley turtles are predominantly carnivorous, especially during the immature stages of their life cycle. Animal prey consists of protocodes or invertebrates that can be caught in shallow sea waters and estuary habitats. Common prey are tunicates, jellyfish, bryozoa, sea urchins, snails, clams, crabs, shrimp, worms and red shrimp. Captive studies have shown several levels of cannibalism of this type.
Threats faced
Loss or change of nesting beaches due to She-oak plantations. Gillnet fishing; development of fishing grounds in potential nesting and breeding grounds. Strong lighting around the nesting beach confuses both adult turtles and juveniles. Large vessel movements in the assembly zone severely disrupt mating and breeding. Nests and eggs are destroyed by predators such as dogs, jackals and hyenas and coastal erosion.
Conservation
The International Union for Conservation of Nature classifies Ridley olives as endangered by and are listed in CITES Appendix I. These lists were the main causes of the suspension of large-scale commercial exploitation and trading of olive ridley sea turtle skins.
