Scientific Name: Lepidochelys olivacea
Category: Sea Turtles
The Olive Ridley sea turtle, also called the Pacific Ridley Turtle, is the most abundant of all the sea turtles. It has a heart-shaped and smallest shell whose top is olive green and underside is yellow-green. Its name comes from its color. It lives in the Atlantic, Pacific and Indian Oceans. Although these turtles are usually found close to shore, ships sailing in the middle of the Pacific Ocean, as far as 2,400 miles from the coast, have reported seeing them. The Olive Ridley Turtle migrates great distances between its feeding grounds and its breeding beaches in the various oceans. The turtle spends most of its life within 15km of the shore, as it prefers the shallow areas for feeding and sunbathing. It is estimated there are 800,000 nesting females worldwide. The Olive Ridley Turtle weighs about 45-50kg (100 lbs) and has a large head. Their shell is called a carapace and is about 65cm long, (2.5 feet) but its shell is thinner than the shells of the other sea turtles. The way you can distinguish a male from a female is by the tail. The male tail can be seen beyond the edge of the shell and the female tail is shorter and cannot be seen. Each of their four limbs has two claws.
The female turtles nest on the same beach where they hatched and they find these beaches by using their sense of smell. The females are at least 15 years old before they lay any eggs. Mating takes place offshore in the water during spring and summer. Females are then washed ashore to nest, with several thousand coming ashore at the same time. This migration ashore is called an arribada which in Spanish means "arrival by sea." Scientists have many theories, but really do not know what leads the females to head for the beach at the same time. When they arrive, the mothers crawl ashore and dig a hole in the sand that is 30-55 cm deep, depositing more than 100 eggs in the nest. After the eggs are laid, the mother piles sand over them, flattens the sand with her underbelly and throws more sand around with her flippers to disguise the location of the nest. After completing her work she swims back out to sea. The females can nest several times in one season. The eggs are round and look like ping pong balls, they weigh only 30g (1 ounce). The eggs hatch after about 50-60 days. As with other sea turtles, the sex of the Olive Ridley Turtle is determined by the temperature at which the eggs are incubated. If the temperature is colder than 29.50 °C (850 °F), the turtles that hatch will be mostly male. In view of the rising temperatures in our warming climate, there is a significant chance that future generations will be mostly female. The hatchlings move out to sea at night and use light reflecting off the water to find their way. It is thought that only about 10% of the hatchlings will survive. Some will not make it to the sea before daylight and will die in the hot sun. However, thousands make this journey successfully by instinct.
The turtle usually eats in the morning hours and sunbathes in the afternoon as it floats on the surface of the ocean. Sometimes in colder waters, turtles can be seen on the surface sunbathing together, trying to keep warm. In warmer climates, the turtle does not need to sunbathe. The Olive Ridley Turtle primarily feeds on shrimp, jellyfish, crabs, fish, sea grass, snails, and sometimes algae, but it eats other animals as well. Their variety of diet allows the turtles to play an important role in many marine ecosystems. This means that the ocean pollution of plastic bags and other trash create a significant hazard for all the sea turtles. When predators, sharks and humans, approach a turtle, it will try to swim away or dive deep in the ocean. Snakes, opossums, birds, and pigs eat the turtle eggs.
The Olive Ridley Turtle is on the US endangered species list because the populations in the Atlantic Ocean are dwindling. Scientists and volunteers are trying to save the turtles by moving the nests to a hatchery, and once they are hatched, helping them back to the ocean. Many other people are also working to save the turtle. In one village in India, children who read about the turtle eggs being eaten by predators organized Turtle Walks during the nesting season to safeguard the nests. These turtles are also impacted by human coastal development, especially in the areas of nesting beaches which throw off too much light at night. This disrupts the internal timing mechanisms of the hatchlings that tells them it is dark enough to return to the sea.
Numbers of turtles are declining because in man cultures, humans collect and eat the eggs. Turtles are often part of the bycatch of commercial fishermen who drag trawling nets behind their boats. A special invention called the Turtle Excluder Device (TED) has been designed to allow small animals, like shrimp, to pass into the catch net, but will keep out larger animals like the Olive Ridley Turtles. The turtle habitats are disturbed by construction near their nesting beaches. Since the Olive Ridley Turtle has such a wide range, and feeds and nests in many countries, the coordination of conservation efforts is very difficult. It is estimated that the population of Olive Ridley Turtles worldwide has decreased 50% since the 1960s.
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