Over 1,000 nests of Leatherback turtles recorded every year: Report
Surveys conducted in 2016 and 2019 confirm that important nesting beaches have re-formed after the 2004 Indian Ocean earthquake and tsunami caused widespread destruction.
The Andaman and Nicobar Islands host a globally significant nesting population of vulnerable leatherback turtles, supporting over 1,000 nests annually, according to a recent report by Dakshin Foundation. While records of leatherback turtles existed on mainland India in the early 1900s, their nesting population is now entirely restricted to these islands.
The report, “Monitoring Sea Turtles in India 2008-2024”, highlights that these islands, along with one site in Sri Lanka, are the only locations with significant leatherback nesting between Southeast Asia and South Africa.
“The population appears to be stable, with some inter-annual variation. It remains the most significant population of nesting leatherbacks in the northern Indian Ocean,” the report states. While the International Union for Conservation of Nature (IUCN) categorises leatherbacks as “vulnerable” globally, many sub-populations are “critically endangered”.
Surveys conducted in 2016 and 2019 confirm that important nesting beaches have re-formed after the 2004 Indian Ocean earthquake and tsunami caused widespread destruction. The beaches of Great and Little Nicobar Islands exhibit the highest nesting density, with over 94% of leatherback nests in the Nicobar islands found in these two locations.
These findings carry particular significance given the ₹81,800 crore Great Nicobar Holistic Development Project, which includes an International Container Transshipment Terminal, international airport, power plant, and township. Parts of the project cover critical nesting areas like Galathea Bay.
The Hindustan Times reported on May 12, 2021, that the environment ministry’s expert appraisal committee had recommended terms of reference for the Great Nicobar township proposal despite concerns about impacts on turtle nesting sites, megapodes, and coral reefs.
The Nicobar Islands fall within the Sundaland Biodiversity Hotspot, covering the western half of the Indonesian archipelago. In 2016, a survey by Dakshin Foundation and the Andaman and Nicobar Forest Department identified important nesting sites including Galathea, Alexandria, and Dagmar Bay on Great Nicobar Island and Kiyang.
Leatherback conservation faces multiple challenges. According to the National Oceanic and Atmospheric Administration (NOAA), coastal development and rising seas from climate change are destroying nesting habitats. Human-related threats include beachfront lighting, shoreline armoring, and beach driving. Shoreline hardening can eliminate dry sand needed for successful nesting.
The global leatherback population has declined by 40% over the past 60 years. The decline is particularly stark in Malaysia, where nesting dropped from about 10,000 nests in 1953 to only one or two annually since 2003. Pacific leatherback populations face the highest extinction risk.
The report also documents increasing green turtle numbers in Lakshadweep since the early 2000s, attributed to successful conservation efforts at nesting beaches. However, this population growth has led to ecological changes, particularly the loss of seagrass meadows through overgrazing. Researchers found that green turtles move between islands after depleting their food sources.
India’s mainland coast and island territories serve as nesting grounds for four marine turtle species: olive ridley, green, leatherback, and hawksbill. Loggerhead turtles occasionally appear in mainland coastal waters. Hawksbill turtles nest primarily in the Andaman group, with sporadic nesting in Nicobar and Lakshadweep.
Odisha’s Gahirmatha and Rushikulya beaches are among the world’s largest olive ridley rookeries, comparable only to sites in Mexico and Costa Rica. Last week, Rushikulya witnessed one of the largest arribadas (mass nestings) in recent years, with 400,000 to 500,000 turtles nesting within days. Observers reported beaches so densely packed with turtles that walking space was scarce.
“The overall trend from nearly two decades of monitoring is that the ridley population is stable or increasing. The fact that arribadas don’t occur in some years is puzzling, as our offshore monitoring indicates that there are large numbers of turtles in the water, but it may not be a cause for immediate alarm,” said professor Kartik Shanker from Indian Institute of Science and Dakshin Foundation.
The monitoring programme for leatherbacks began in 2000 when Harry Andrews of the Andaman Nicobar Environment Team and Madras Crocodile Bank Trust initiated work at Galathea, Great Nicobar Island.
