Initiated in the early 1980s, every year Coast Guards rescue operation named Operation Olivia helps to safeguard Olive Ridley turtles as they assemble along the coasts of Odisha in November and December.
Extensive fishing along the coasts of Andhra Pradesh, Odisha, and West Bengal, especially ocean-going trawlers, boat propellers, and gill-netters pose a grave threat to the species.
Olive Ridley sea turtles (Lepidochelys olivacea) are also known as Pacific Olive Ridley sea turtles. They are medium-sized carnivorous species found mainly in the warm waters of the Pacific, Indian, and Atlantic Oceans. Jellyfish, tunicates, sea urchins, bryozoans, bivalves, snails, shrimp, crabs, rock lobsters, and sipunculid worm forms part of their prey.
The International Union for Conservation of Nature, the oldest and largest institution working for environmental protection, lists them as vulnerable species in its Red List. Schedule 1 of the Indian Wildlife Protection Act, 1972, includes all the five species found in India. Appendix 1 of the Convention of International Trade in Endangered Species of Wild Fauna and Flora prohibits trade in turtle by the signatory countries.
The Olive turtles' noteworthy feature is their mass nesting called Arribadas. It means that the female turtles travel back to the coast from where they hatched to lay eggs. The coast of Odisha has three arribada beaches-Gahirmatha, the mouth of the river Devi and Rushikulya. These beaches together house nearly 1 lakh such nests annually.
As per the U.S. National Oceanic and Atmospheric Administration (NOAA) Fisheries, a new mass nesting site is found in the Andaman Nicobar Islands with more than 5,000 nests reported in a season.
A coast guard official stated, “For optimal results, round-the-clock surveillance is conducted from November till May utilizing Coast Guard assets such as fast patrol vessels, air cushion vessels, interceptor craft and Dornier aircraft to enforce laws near the rookeries.”
The officer added, “From November 2020 to May 2021, the Coast Guard devoted 225 ship days and 388 aircraft hours to protect 3.49 lakh turtles that laid eggs along the Odisha coast.”
Usually, the breeding grounds in the offshore waters are the place for mating. The females come ashore to the nest several times during the season. They trail ashore, dig a flask-shaped nest about 1.5 to 2 feet deep, and lay 100 to 150 eggs in each cluster. Hatchlings pop out from their nests in about seven to 10 weeks.
The officer added, “Between the arrival of the mother and the hatchlings retreat to the sea, they go through various challenges. According to an estimation, only one in a thousand survives to adulthood.”
The officer further explained, "Studies have found three main factors that damage Olive Ridley turtles and their eggs — heavy predation of eggs by dogs and wild animals, indiscriminate fishing with trawlers and gill nets, and beach soil erosion”.
Gahirmatha is the largest nesting ground for these endangered species in the world. According to a report, over 1.48 crore turtles have hatched at the Gahirmatha beach recently. Their eggs are guarded against humans and other animal intrusions by the officials. This year, around 3.49 lakh female turtles crawled ashore for mass nesting.
Predators of its eggs include raccoons, coyotes, feral dogs and pigs, opossums, coatimundi, caimans, ghost crabs, and the sunbeam snake. Vultures, frigate birds, crabs, raccoons, coyotes, iguanas, and snakes prey upon the young hatchlings. In the water, oceanic fishes, sharks, and crocodiles prey on the hatchlings. The adult turtles have less chance of being preyed upon except for occasional attacks by sharks and killer whales.
Olive Ridleys are of significant economic importance and are mainly hunted for food, bait, oil, leather, and fertilizer. Their egg collection is valued everywhere and therefore prohibited in many countries. The prime cause of olive ridley egg loss results from arribadas wherein a higher density of nesting females leads the previously laid nests dug up and ravaged by other nesting females.
The legal egg harvest at Ostional, Costa Rica, is viewed as both biologically sustainable and economically viable to increase hatching success. The villagers are allowed to gather eggs during the first 36 hours of the nesting period, as many of these eggs would be damaged by later nesting females.
The Convention on Migratory Species and the Inter-American Convention for the Protection and Conservation of Sea Turtles have also protected Olive Ridleys for increased conservation and management of the marine turtle. Managing the Arribada has also played a crucial role in the protection of olive ridleys.
But their species remain unattended at a global level. Therefore, the requirement of an effective international conservation policy for the conservation of vulnerable species becomes imperative.
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