- With the arribada season underway, olive ridley turtles are migrating to the Odisha coast for mass nesting.
- Solo nesting of the turtles in new locations is also capturing attention, raising hopes among conservationists.
- As olive ridley nesting patterns are threatened, experts emphasise on sustainable fishing practices and local participation in conservation efforts.
The Arabian Sea often remains calm on the cool nights following Christmas in Thiruvananthapuram, the capital of the southernmost state of Kerala. The sandy shores glimmer under the starlit sky. It’s during these nights that sea turtles come ashore to nest.
On February 8, as if in response to the prayers of nature lovers, a single olive ridley turtle made its way onto the shores of Veli, a village near the Thumba Equatorial Rocket Launching Station, and laid 126 eggs. “Three local boys discovered the turtle and the eggs,” says Ajith Shanghumukham, a fisherman-turned-conservationist.
“After a brief disagreement between those who wanted to take the eggs as a delicacy and the others who wanted to take it to the police station, the boys managed to conserve them on the beach. They are now protecting them as they hatch, in a secure location, away from stray dogs and the threat of high waves,” he informs Mongabay India.
Last year, Ajith, who works with the conservation group Wildlife Trust of India, tried to save 81 olive ridley turtle eggs in a makeshift hatchery on the severely eroded shores of his native village, Shanghumukham, near the domestic airport. Unfortunately, he failed. “The eggs were exposed to the rains because they came late in the season,” explains Ajith. The turtle arrived on April 7, and the monsoon rains began before the 60-day hatching period had passed.
Thiruvananthapuram’s coast, home to over 50,000 seagoing fishers, is gaining attention from conservationists. The youth have taken up activities such as beach walks, diving, and birdwatching along the shores. Rare instances of sea turtles nesting here spark the interest of these young enthusiasts.
The residents of the coastal villages in the area recall that sea turtles used to come regularly in the past, but now they likely only visit secluded beaches, like the one adjacent to the rocket station. “When I was a child, one or a few turtles, with a white line on their shells (olive ridleys), would come every year. They would hide in a shed where we stored dried fish or simply nest under coconut palms. The hatchlings would crawl back into the sea,” recalls Aloysius Gomez, a retired schoolteacher in his 60s from Puthukurichy village on Thiruvananthapuram city’s northern fringes. “They just disappeared, but a few came three years ago.”
Six kilometres south, Davidson Anthony Adima, a fisherman in his 40s, enjoys spotting them in the sea. “They swim alongside or float in the shadow of driftwood, but they never come ashore,” he says. Fishers in the southern parts of Thiruvananthapuram remember a time when turtles nested there. “They came in hordes, nested, laid eggs, and left,” recalls Mariyannii Miyyelpillai, a fisherman in his 70s from Pozhiyoor village.
Researcher Al Badush of Oceans and Coasts Programme, Nature Conservation Foundation explains that the nesting that happens on Kerala coasts are considered solitary nesting, meaning, they don’t nest in groups. “Turtles come and nest sporadically,” he says, adding, “Kerala is a sporadic nesting site, unlike the east coast of Tamil Nadu, which serves as a moderate nesting ground, and places in Odisha, which are mass nesting sites.”
The rare event of mass nesting
As the 2025 mass nesting season, known as arribada — the Spanish term for arrival — begins, conservationists and local communities are gearing up to welcome thousands of female sea turtles. These turtles belong to several species, including the leatherback (Dermochelys coriacea), green (Chelonia mydas), hawksbill (Eretmochelys imbricata), loggerhead (Caretta caretta), and the smallest and most abundant of the group, the olive ridley (Lepidochelys olivacea).
Olive ridleys, named for their olive-green shell or carapace, thrive in the warm waters of the Indian Ocean, Pacific, and Atlantic. They primarily feed on jellyfish, shrimp, snails, crabs, and fish eggs. Conservationists estimate that only one in 1,000 hatchlings survives to adulthood, with the rest falling prey to predators, including jackals, birds, hyenas, fiddler crabs, stray dogs, and some fishing activities like trawling.
This high mortality rate is partly offset by the large number of eggs a single female can lay — 80 to 120 eggs, sometimes twice a season — enhancing the chances of hatchling survival. Once the eggs hatch, the tiny turtles crawl to the sea, disappear into the blue, swim great distances, and eventually return to their nest, continuing the cycle.
Olive ridley arribada sites are scarce, with most located along the Pacific coasts of Mexico and Central America, as well as India’s east coast. In contrast, solitary nesting beaches are found scattered across the tropics, on every continent and in many island chains.
In India, Odisha’s Gahirmatha, Rushikulya, and the mouths of the Devi river remain the primary nesting grounds for olive ridleys. Over 6.5 lakh (650,000) olive ridley turtles have arrived at the Rushikulya beach in the Ganjam district of Odisha for mass nesting this year.
Along the coast of Cuddalore in Tamil Nadu, another nesting site, a group of fishermen works to protect turtles and their eggs. Meanwhile, in Chennai, the recent deaths of around 1,000 olive ridleys in January and February have sparked debate and prompted government action. Another case of nesting on the beaches of Mangaluru after a gap of close to two decades suggests a revival of some of the old and wider nesting range.
Mysterious journeys
Olive ridleys use both coastal waters and the open ocean, following various paths in search of food. Their ability to roam and adapt may help them survive in a changing environment, which is likely why they are the most abundant of all sea turtle species, as scientists observe.
“Olive ridleys mate close to the shore, sometimes in large congregations, and the females come ashore to nest,” says scientist Anant Pande, senior scientist at the Wildlife Conservation Society-India’s marine programme. “We still don’t know exactly where they go after nesting, but they are known to swim great distances,” he adds. Olive ridley turtles from India’s east coast have been tracked as far as the Sri Lankan coast and even to the west coast of India.
A 2023 study of the Rushikulya and Gahirmatha nesting sites revealed that the turtles’ nesting patterns are influenced by factors such as the lunar phase, tidal cycles, rainfall, wind conditions, and temperature. Arribadas at both sites occurred during cooler months, particularly following or coinciding with the fast southern winds.
Threats they face
At Pozhiyoor village on the southern edge of Thiruvananthapuram, sitting amid the rubble of homes washed away by the sea, village residents recall the days when turtles used to come ashore. They also remember the taste of turtle curry and roasted turtle blood, considered delicacies with medicinal value. “Some would make a stew out of the eggs and burst the shells for the popping sound,” recalls Gomez, who is also present there. Ajith shares stories of turtles found dead in the coastal waters, with ropes tied around their necks.
Sea turtles face many similar threats. Trawl nets and ghost gear — mostly discarded fishing nets — pose additional dangers. In India’s Odisha alone, trawlers kill around 10,000 turtles annually. Climate change, plastic pollution, and coastal development further exacerbate the pressure on turtle populations, scientists report.
“It’s the trawl nets operated close to the shore that trap the turtles, not the artisanal hook and line gear,” notes Pande. Turtle excluder devices attached to the nets allow turtles to escape, but fishers often avoid using them because these devices also allow large fish to escape. “Designers, fishermen, and conservationists should collaborate to redesign these devices,” Pande suggests. He adds, “Conservation efforts such as nest protection, fishing bans, and restrictions on turtle trade have helped reduce turtle deaths.”
People’s participation
Kartik Shanker, a professor at the Centre for Ecological Studies at the Indian Institute of Science (IISc), points out that turtle deaths are not a new phenomenon. The upward trend in solitary nesting sites sought by olive ridley populations may be the result of long-term conservation efforts.
If this is the case, he suggests, the solution to occasional turtle deaths may not necessarily lie in more stringent and exclusive conservation measures. “A better approach is to blend coastal conservation with sustainable fishing and local participation,” he adds.
Shanker, who began his conservation efforts in the 1980s on the Chennai shores as a student, highlights two success stories: the Students’ Sea Turtle Conservation Network in Chennai, which has been conserving eggs and managing hatcheries with local involvement since 1988, and fishers protecting turtle eggs while restoring mangroves in Kerala’s Kottapuzha estuary. In contrast, turtle conservation in Odisha and other areas where fishing restrictions are imposed often meets with local resistance.
“Successful programmes,” he wrote in 2005, “have gone beyond their turtle focus to using the species to drive social and environmental changes. On the other hand, the most spectacular population in India, arguably the most important in terms of genetic distinctiveness… and in terms of size, not to mention the biological and cultural value of the arribada, has had less success, at least locally.”
While Shanker notes that the traditional conservationist approach has not evolved in 20 years, he believes the hope lies in new local initiatives.
As Ajith defines the policy of coastal conservationist youth in Thiruvananthapuram, “Strict protection alone won’t work. Success lies in blending conservation with sustainable fishing and awareness-building, ensuring that both turtles and fishers thrive.”
Read more: Tracking an elusive turtle with genetic clues from nature
Banner image: An olive ridley turtle in the Sundarbans, West Bengal. As the 2025 mass nesting season begins, thousands of female sea turtles of various species are set to arrive along India’s coastline. Image by Anirnoy via Wikimedia Commons (CC BY-SA 4.0).
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