Жасыл қабықты теңіз тасбақасы: Әлемдегі ең көп кездесетін түрлердің бірі

One of the most abundant living sea turtle in the world

The olive ridley sea turtle (Lepidochelys olivacea), also known commonly as the Pacific ridley sea turtle, is a species of turtle in the family Cheloniidae. The species is the second smallest and most abundant of all sea turtles found in the world. L. olivacea is found in warm and tropical waters, primarily in the Pacific and Indian Oceans, but also in the warm waters of the Atlantic Ocean. However, the origin of "ridley" is unknown, perhaps derived from "riddle". Lepidochelys is the only genus of sea turtles containing more than one extant species: L. olivacea and the closely related L. kempii (Kemp's ridley).

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. Each side of the carapace has 12–14 marginal scutes. The carapace is flattened dorsally and highest anterior to the bridge. it has a medium sized, broad head that appears triangular from above. The head's concave sides are most obvious on the upper part of the short snout. It has paddle like fore limbs, each having two anterior claws. The upper parts are grayish green to olive in color, but sometimes appear reddish due to algae growing on the carapace. The bridge and hingeless plastron of an adult vary from greenish white in younger individuals to a creamy yellow in older specimens (maximum age is up to 50 years). Hatchlings are dark gray with a pale yolk scar, but appear all black when wet. A juvenile female was found off the coast of Sussex in 2020. The olive ridley is also found in the eastern Pacific Ocean from the Galápagos Islands and Chile north to the Gulf of California, and along the Pacific coast to at least Oregon. 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. The population of Pacific Mexico was estimated to be at least 10 million prior to the era of mass exploitation. More recently, the global population of annual nesting females has been reduced to about two million by 2004, and was further reduced to 852,550 by 2008. This indicated a dramatic decrease of 28 to 32% in the global population within only one generation (i. e., 20 years).

Olive ridley turtles exhibit two different nesting behaviours, the most prevalent solitary nesting, but also the behaviour they are best known for, the synchronized mass nesting, termed arribadas. They are also rare in the western and central Pacific, with known arribadas occurring only within the tropical eastern Pacific, in Central America and Mexico. In Costa Rica, they occur at Nancite and Ostional beach, and a third arribada beach seems to be emerging at Corozalito. Two active arribada beaches are located in Nicaragua, Chacocente and La Flor, with a smaller arribada beach of unknown status on the Pacific coast of Panama. Historically, arribadas happened at several beaches in Mexico, but in the present arribadas are only observed at Playa Escobilla and Morro Ayuda in Oaxaca, and Ixtapilla in Michoacan.

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. Beach fidelity is common, but not absolute. Nesting events are usually nocturnal, but diurnal nesting has been reported, especially during large arribadas. On land, nesting females may be attacked by jaguars. Notably, the jaguar is the only cat with a strong enough bite to penetrate a sea turtle's shell, thought to be an evolutionary adaption from the Holocene extinction event. In observations of jaguar attacks, the cats consumed the neck muscles of the turtle and occasionally the flippers, but left the remainder of the turtle carcass for scavengers as most likely, despite the strength of its jaws, a jaguar still cannot easily penetrate an adult turtle's shell to reach the internal organs or other muscles. In recent years, increased predation on turtles by jaguars has been noted, perhaps due to habitat loss and fewer alternative food sources. Sea turtles are comparatively defenseless in this situation, as they cannot pull their heads into their shells like freshwater and terrestrial turtles. Females are often plagued by mosquitos during nesting. 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. In addition, entanglement and ingestion of marine debris is listed as a major threat for this species. Coastal development, natural disasters, climate change, and other sources of beach erosion have also been cited as potential threats to nesting grounds. Hatchlings which use light cues to orient themselves to the sea are now misled into moving towards land, and die from dehydration or exhaustion, or are killed on roads. The greatest single cause of olive ridley egg loss, though, results from arribadas, in which the density of nesting females is so high, previously laid nests are inadvertently dug up and destroyed by other nesting females. In March 2023, in Honnavar, India, local fishers sighted 86 sea turtle nests, with over 5,000 eggs in them, along a 3 km stretch of beach between Apsarakonda and Pavinkorava. The highest number of nests previously recorded in the area, 34, was in 2008.