Context: 

In the past two weeks, several dead olive ridley turtles have been found washed ashore in Tamil Nadu, especially in Chennai.

More on the News: 

• Experts have estimated that so far, between 300 and 350 turtles have been found dead.
• While turtle deaths during nesting season are common, the high number of carcasses found in Neelankarai, Besant Nagar, and Kovalam has raised concerns.

Causes of the Deaths: 

• Turtles often mate and nest near the shore, where they are vulnerable to getting trapped in commercial fishing nets, particularly those used by trawlers. 
• Post-mortem examinations of the dead turtles have revealed signs of suffocation, such as lesions on the lungs, indicating that the turtles likely drowned. 

Olive Ridley Turtle

• Scientifically known as Lepidochelys olivacea, they are one of the smallest and most abundant sea turtles in the world. 
• These turtles are omnivorous and named for their olive-coloured, heart-shaped shells. 
• They are primarily found in the warm waters of the Pacific, Atlantic, and Indian Oceans.
• They grow up to 80 cm, weigh less than 50 kg, and live up to around 62 years.
• It is classified as "Vulnerable" on the IUCN Red List. 
• It is also listed under Schedule 1 of the Wildlife Protection Act, 1972.
• International trade of these turtles and their products is prohibited under CITES Appendix I.

Nesting season 

• They have unique mass nesting behaviour, known as "arribada," where thousands of females come together on the same beach to lay their eggs. 
• Their nesting season begins in late November and ends in March.
• Olive ridley turtles lay their eggs on sandy beaches, and India is home to some of the most important nesting sites. 

• Odisha's Gahirmatha and Rushikulya beaches see the arrival of lakhs of female turtles each year, where they lay between 100-110 eggs in shallow nests. 

• Gahirmatha Marine Sanctuary is the world's largest and most important nesting beach for olive ridley sea turtles. 

• The turtles cover the nests with sand to protect the eggs from predators before returning to the sea. After 45-60 days, the hatchlings emerge and make their way to the ocean. 

• Only one in about 1,000 turtle hatchlings survive to adulthood.

Potential Solutions: 

• There is a need for stricter enforcement of turtle-excluding devices (TEDs) in fishing nets. These devices allow accidental bycatch, such as turtles, to escape from the nets, reducing the risk of entanglement.
• To protect the eggs from predators and human disturbance, Forest Departments sometimes create hatcheries. 
• The eggs are carefully moved from the nests to these hatcheries, and once the hatchlings emerge, they are released near the sea to start their journey.