WII satellite telemetry study on olive ridley turtles to track the migratory route
Thirteen years after it conducted a satellite telemetry study on the biological and behavioral aspects of olive ridley sea turtles off the coast of Odisha, the Dehradun-based Wildlife Institute of India proposed another such study. next year to find out if there have been any changes to your migration route.
The study, the third conducted by the institute, would examine whether there has been any change in the traditional migration route of sea turtles from the coast of Odisha to Sri Lanka. I would also find out if some of these turtles remain near the Odisha coast instead of migrating after the nesting season ends in March-April.
“We know that one group of the olive population goes to Sri Lanka while another group goes to the coast of Myanmar facing the Andaman Sea. They travel about 3,000 km and return to the coast of Odisha. Through this new study, we want to confirm the presence of some turtles along the Indian coast that do not migrate and stay within 100 nautical miles of the Indian coast. Although we do not expect any change in the migratory route, we need to study if there have been any changes in their migratory routes and their reason. It is going to be a very useful study, ”said Kuppusamy Sivakumar, scientist at WII Endangered Species Management department, Dehradun.
Named after English biologist Henry Nicholas Ridley, who first reported on the sighting of turtles in Brazil in 1887, omnivorous olive ridley turtles are among the smallest species of sea turtles in the world. They can dive to great depths and are highly migratory, covering thousands of kilometers between feeding and nesting grounds. Its teardrop-shaped shell has an olive green color. They grow to an average of 70 cm long, while the adults weigh about 45 kg.
The most fascinating feature of the Olive Ridleys is their massive nesting called ‘arribada’ that occurs off the coast of Odisha when thousands of gravid females choose narrow beaches near estuaries to lay eggs. Each adult female lays approximately 100 to 140 eggs at a time. In India, the arrival takes place in the state of Orissa, on the east coast, in three Gahirmatha nesting areas, the mouth of the Devi River and the mouth of the Rushikulya River. Forest department officials estimated that as of March this year, around 8 lakh of turtles had laid eggs at the Rushikulya and Gahirmatha sites.
The first satellite telemetry study of olive ridley turtles was conducted in April 2001, when WII with the Odisha Forest Department and turtle biologist Jack Frazier of the Smithsonian Institution installed platform transmitter terminals on four turtles on the nesting beach of Devi for online monitoring of migration routes. Of the four turtles with TTP, only one migrated to Sri Lanka. However, all four turtles stopped transmitting within two to four months due to technical problems or trawler-related mortality.
In the second study carried out between 2007 and 2010 by WII and financed by the Ministry of Oil and Natural Gas, 70 TTPs were used which showed that the turtles undertook migrations in the open sea in the Bay of Bengal and exhibited a migratory corridor between Sri Lanka and nesting . sites along the coast of Odisha in India. Sivakumar said the study not only provided a lot of information about their migration route, but also helped the Odisha government to consolidate its measures on the 7-month ban on the coast between November and May to prevent turtle mortality during the season of mating and nesting.
“After our study, the Odisha government announced a one-time notification prohibiting offshore fishing activity for 7 months,” Sivakumar said.
He said that through the new study using 30 PTTs to be conducted during the nesting season in April-May, the WII would try to find out developments in the migratory routes of the turtles and study how turtle tourism can be carried out on the site Rushikulya nesting site.
“We need some understanding of the current situation. More and more activities are being planned in the Bay of Bengal and many changes are taking place on the coast of Odisha. As many fishermen are unhappy due to the loss of their livelihoods during the closed season, we want to know if we can improve our action plan so that the turtles are safe and the fishermen can continue their livelihoods. Based on the telemetry studies, we would see if it is necessary to reduce the fishing closure period or increase it. We would also see if any changes can be made in the no-fishing zone, ”said the WII scientist.
The study will be carried out over a period of three years.
As WII has no money to finance the studies, it has proposed to the Odisha government to finance them. Odisha’s secretary for forests and the environment, Mona Sharma, said money would not be an issue. “We are waiting for your proposal,” Sharma said.
Through the studies, the WII will also partner with the Odisha government to carry out research at the upcoming Sea Turtle Research and Conservation Center which will likely be located on 5 acres in the Gorakhakuda village near the nesting site. Rushikulya turtle farm from Ganjam district.