The leather turtles once nested across the shores of mainland Indian, but lately their habitats have shifted to only the beaches of India’s Andaman and Nicobar Islands.
The Andaman and Nicobar Islands are home to a globally important nesting population of vulnerable leatherback turtles, supporting over 1,000 nests each year, according to a report by the Dakshin Foundation. Leatherback turtles were once known to nest across the mainland India shores in the early 20th century, their habitat is now limited exclusively to these islands in the Indian Ocean.
The report — Monitoring Sea Turtles in India 2008–2024 highlights that these islands, alongside one site in Sri Lanka, represent the only significant nesting grounds for leatherbacks 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 notes. While the International Union for Conservation of Nature (IUCN) lists leatherbacks as “vulnerable” on a global scale, many regional populations are “critically endangered”.
Nesting beaches make a comeback
Surveys carried out in 2016 and 2019 confirmed that vital nesting beaches had recovered following the devastation caused by the 2004 Indian Ocean earthquake and tsunami. The Great and Little Nicobar Islands recorded the highest nesting densities, with over 94% of leatherback nests in the Nicobar region found in these two locations.
These insights gain particular relevance in the context of the Rs 81,800 crore Great Nicobar Holistic Development Project, which includes an International Container Transshipment Terminal, an international airport, a power plant, and a township. Parts of the proposed development overlap with critical nesting habitats such as Galathea Bay.
According to a Hindustan Times report in May 2021, the environment ministry’s expert appraisal committee had approved terms of reference for the township project despite concerns about its potential impacts on turtle nesting sites, endemic bird species like megapodes, and coral reefs.
The Nicobar Islands fall within the Sundaland Biodiversity Hotspot, which includes the western part of the Indonesian archipelago. A 2016 survey by the Dakshin Foundation and the Andaman and Nicobar Forest Department identified key nesting beaches at Galathea, Alexandria, and Dagmar Bay on Great Nicobar Island, as well as Kiyang.
Declining leatherback turtle population
Leatherback turtle conservation faces numerous challenges. The U.S. National Oceanic and Atmospheric Administration (NOAA) notes that coastal development and sea-level rise due to climate change are eroding nesting habitats. Other threats include artificial lighting near beaches, coastal infrastructure, and vehicle movement on shorelines, all of which can disrupt or prevent successful nesting.
Globally, leatherback turtle numbers have declined by 40% over the past six decades. The drop is particularly severe in Malaysia, where nesting numbers have plummeted from around 10,000 nests in 1953 to just one or two a year since 2003. Pacific leatherback populations face the highest risk of extinction.
The report also records a notable rise in green turtle numbers in Lakshadweep since the early 2000s, credited to effective conservation at nesting beaches. However, this population boom has led to ecological strain, especially the degradation of seagrass meadows caused by overgrazing. Researchers observed that green turtles move between islands once local food sources are depleted.
India’s mainland coast and island territories are nesting sites for four marine turtle species: olive ridley, green, leatherback, and hawksbill turtles. Loggerhead turtles are occasionally spotted in mainland waters. Hawksbill turtles primarily nest in the Andaman group, with sporadic nesting in the Nicobar and Lakshadweep islands.