The recent surge in the deaths of olive ridley turtles along Tamil Nadu’s coastline has raised significant environmental concerns among conservationists and the public. Over the past two weeks, around 300 to 350 turtle carcasses have washed ashore near Chennai and its surrounding areas. These developments come at the beginning of their nesting season, a critical period for the survival of this vulnerable species.
What Is Causing the Spike in Mortalities?
Olive ridley turtles are most vulnerable during their breeding and nesting seasons, which typically begin in late November and extend until March. Although it is not uncommon for some turtles to die during this period, the current high mortality rate has alarmed experts.
One of the leading causes of these deaths is their inadvertent entanglement in fishing nets used by commercial trawlers. As olive ridleys swim to the surface to breathe, they often get trapped in long nets designed for catching fish. This entanglement leads to asphyxiation. The findings of post-mortem examinations corroborate this, revealing symptoms such as lesions on the lungs, bulging eyes, and swollen necks—clear indicators of drowning.
Several experts attribute this year’s increase in deaths to the abundance of fish near shorelines, which has attracted a larger number of fishing vessels to areas frequented by the turtles. With an increase in trawler activity, the likelihood of turtles getting ensnared in fishing nets has surged. These nets do not employ turtle-excluder devices (TEDs), which are specialized mechanisms designed to allow turtles and other bycatch to escape.
Where Have the Carcasses Been Found?
Carcasses of olive ridley turtles have been discovered across Chennai’s beaches, including areas such as Neelankarai, Besant Nagar, and Kovalam, extending to neighboring regions in Kancheepuram district. Reports of turtle mortalities have also come from Pulicat in Thiruvalluvar district, north of Chennai. Conservation groups and volunteers have noted increased sightings of dead turtles, with citizens frequently reporting them on beaches in and around Chennai.
How Does the Nesting Season of Olive Ridley Turtles Typically Unfold?
Olive ridley turtles are renowned for their synchronized nesting behavior, known as arribada, which occurs across various Indian coastal states. While Odisha’s Gahirmatha and Rushikulya beaches are celebrated for hosting the largest nesting grounds, states like Tamil Nadu and Andhra Pradesh also play crucial roles during this period.
During the nesting season, female olive ridleys travel long distances to their preferred sandy beaches. They dig nests using their flippers and lay anywhere between 100 and 110 eggs, carefully covering them with sand to protect against predators. After about 45 to 60 days, the hatchlings emerge and instinctively head to the sea. Recognizing the risks of predation and human interference at nesting sites, many Forest Departments establish hatcheries where eggs are safeguarded until they hatch. Juvenile turtles are later released into the ocean, ensuring a higher survival rate.
What Measures Are Being Suggested to Mitigate the Mortality Rates?
The rising death toll among olive ridley turtles necessitates immediate intervention to protect this vulnerable species through strict enforcement of turtle-excluder devices (TEDs) in fishing nets. These devices have proven effective in other regions and are instrumental in reducing incidental bycatch of non-target species.
Sivakumar also highlighted the importance of conducting a comparative analysis of fish catch data over the years. A surge in fish landings from Chennai’s harbors this season could corroborate the theory that an unusually high number of trawlers have been operating in turtle gathering areas, inadvertently causing their deaths.
In addition, volunteers and conservation organizations advocate for community awareness programs to educate fishing communities about sustainable practices and the importance of using turtle-friendly gear. Increased patrolling of coastal areas during the nesting season and stringent regulations on fishing activities near known turtle habitats are crucial.
Why Is the Conservation of Olive Ridley Turtles Important?
Olive ridley turtles, listed as vulnerable under the International Union for Conservation of Nature (IUCN), are an integral part of marine ecosystems. Their decline poses a threat to the health of ocean habitats. As omnivores, they help maintain the balance of marine life by feeding on jellyfish, algae, and small invertebrates. Ensuring their survival is not only an ecological imperative but also a cultural one, given the species’ historical significance in coastal communities.
These turtles face myriad threats, ranging from plastic pollution to coastal development, which disrupts their nesting grounds. Adding to their plight is climate change, which alters beach temperatures and affects the gender ratio of hatchlings—a critical factor for their reproductive success.
What Has Been Done to Protect Olive Ridley Turtles in India?
India has long been at the forefront of olive ridley conservation efforts. Protected areas such as Odisha’s Gahirmatha Marine Sanctuary provide a safe haven for nesting turtles. Programs such as Operation Kachhapa, launched in Odisha in 1998, have focused on protecting turtles during arribada and curbing illegal fishing practices in nesting zones. Additionally, community involvement through awareness drives and turtle walks has helped highlight the importance of these species.
Conservationists in Tamil Nadu are working alongside government agencies to mitigate the crisis. The involvement of non-profits, such as the Tree Foundation, has been instrumental in rescuing, rehabilitating, and monitoring turtles during the nesting season. Despite these efforts, challenges persist, underscoring the need for stringent measures and collective action.