Five of the seven species of marine turtles are found in Indian coastal waters and at least four have significant nesting beaches and/or feeding areas. We are studying leatherback turtles in Little Andaman Island, olive ridley turtles in Orissa, and have initiated studies on green turtles in the Lakshadweep islands. We have been carrying out studies on population distributions through nesting beach monitoring, satellite telemetry and offshore surveys. We have also carried out studies on their feeding behaviours as well as population genetics. We have also initiated a collaborative effort with NGOs along the mainland coast to monitor temperatures, and potential impact of climate change on sea turtle populations through its impact on sex ratios.We are also actively involved in socio-ecological research on the political ecology of sea turtle conservation, conflict and their management. For a brief history of research at these locations, see here.
Olive ridley turtles in Orissa
Olive ridley turtles (Lepidochelys olivacea) are known to nest en masse only in Pacific Costa Rica and Mexico, and Orissa on the east coast of India The olive ridley population on the east coast of India is also believed to be an evolutionary source for ridleys found across the world. We initiated a long term monitoring programme for olive ridleys at Rushikulya rookery on the southern Orissa coast. We monitor solitary and mass nesting populations at this site each season; a census of the mass nesting event is carried out in collaboration with the Forest Department. We also monitor the in-water population at this rookery. We have studied the effect of light pollution on the mis-orientation of hatchlings in Rushikulya. In order to examine the impacts of climate change, we translocate nests to a hatchery to monitor nest temperature profiles and collect dead hatchlings to estimate sex ratios (we also collect temperature data and hatchlings from other site on the mainland coast in collaboration with other partners). In addition, we study the phylogeography of olive ridley turtles along the east and west coast of India.
Leatherback turtles in Little Andaman Island
The leatherback turtle (Dermochelys coriacea) is the largest and widest ranging sea turtle. Leatherback turtle nesting in India is currently restricted to the Andaman and Nicobar Islands and very little is known about nesting trends. Since January 2008, we have monitored nesting populations on Little Andaman Island. We also profile the habitat and collect air and sand temperatures to assess the impact of climate change. We are conducting genetic analysis to study phylogeography and have also initiated a project on monitoring post-nesting movements of leatherback turtles using satellite transmitters. Of the ten turtles we tracked, many went southeast along the coast of Sumatra, some traveling as far as Western Australia. A few traveled west, reaching the coasts of Mozambique and Madagascar.
Green turtles in the Lakshadweep Islands
The Lakshadweep Archipelago, an important foraging and nesting habitat for sea turtles, has seen a steep increase in green turtle numbers in the last decade. This has caused intensive grazing of the two major seagrass species (Thalassia hemprichii and Cymodacea rotundata) and a reduction in the associated fish species important for the subsistence of local fisher communities leading to fisher-turtle conflict. To help inform the management of green turtle populations and encourage seagrass recovery, we are studying the distribution of the green turtle populations, monitoring their diets and investigating seagrass characteristics and distribution in the lagoons of Agatti, Kadmat and Kalpeni. We also plan to establish a monitoring programme to study green turtle movement between islands through a combination of radio telemetry, and photo-identification of individuals. Indigenous radio tags are being developed in collaboration with a Bangalore based tech company, Arcturus Inc.