Bengaluru May 22, 2018, (Research Matters):
In March 2018, the city of Mumbai woke up to long bygone visitors—the Olive Ridley turtles were crawling on the Versova beach after two decades! Mumbai beaches, infamous for being a pile of garbage, was being cleaned for years for this grand welcome. What’s so remarkable about these turtles, you ask? Well, turtles are the oldest reptiles inhabiting the earth and can live for up to a hundred years. Many of them are classified as ‘endangered’ or ‘critically endangered’, making their sightings a feast.
Turtles are found in both freshwater and seawater, and lay eggs on land. For this, they travel miles between their feeding ground and nesting ground. Some sea turtles are known to go as long as 1400 miles! In some cases, these turtles migrate great distances to nest on the same beach year after year, and lay eggs in pits laboriously dug with their flippers. The phenomenal ‘arribada’, Spanish for arrival, where thousands of female turtles visit one of the eight shores of Odisha for mass nesting during October and April, is a fascinating event observed only in two species of turtles across the world—Olive Ridley and Kemp’s Ridley turtles.
India is home to five species of sea turtles; Olive Ridley (Lepidochelys olivacea), Green (Chelonia mydas), Hawksbill (Eretmochelys imbricata), Loggerhead (Caretta caretta) and Leatherback (Dermochelys coriacea) turtles can be found all along the coastline spanning 7500 km. Although Loggerhead turtles are found in India, there is very little information about their nesting. There are about 25 species of freshwater turtles distributed across West Bengal, Madhya Pradesh, Assam and Mizoram.
Turtles - A vital link in the food chain
Turtles play a crucial role in nutrient cycling as they transport nutrients from the water to dunes that are nutrient-deficit, resulting in healthy beaches. Their shells are home to epibionts—organisms that live on the surface of another organism—and are eaten by seabirds. Sea turtles feed on seagrass—flowering plants that grow in the sea—thereby preventing their overgrowth that can hinder the water current and result in their decay. “In the Lakshadweep, green turtles have been doing the damnedest thing. They have been destroying seagrass meadows. In Agatti, an island in Lakshadweep, about 550 turtles counted a few years ago decimated the meadows”, says Mr. Muralidharan M, a Field Director at Dakshin Foundation, who works on turtle conservation projects in India.
Hawksbill turtles are known to feed on sponges in the ocean, making space for the growth of healthy coral populations. As the top predator of jellyfishes, turtles help in maintaining the balance in the food web.
However, all is not well with these magnificent and versatile creatures. In recent times, their survival is threatened by many factors. They are often victims of incidental catch in trawler fishing vessels and gill nets that scoop fish (and many other organisms) from the bottom of the sea. Their nesting spaces are destroyed by casuarina trees planted to reduce calamities during strong winds and for timber. Feral dogs, raptor birds such as eagles and kites, and a few communities eat their eggs. Unplanned beach developments involving the construction of resorts is a threat due to expanding tourism. Hunting and exploitation of turtles for meat and climate change are other woes these turtles face.
With their dwindling population, the ability of turtles to maintain the health of the world’s oceans goes down. There are also misconceptions about how turtles affect the fish in the sea. In Agatti, for example, the local fishermen believe that the decline in fish catch is due to the increase in green turtles.
Realising the importance of turtles, they are now ‘protected’ under Schedule 1 of the Wildlife Protection Act, 1972, which prevents their hunting and trade. The Convention on International Trade in Endangered Species (CITES) agreement provides absolute protection by banning some species of turtles from being involved in any trade, with offences prescribed with highest penalties. The forest departments in many states are trying to push the belief that turtles are an incarnation of Lord Vishnu according to Indian mythology, and hence they need to be conserved. However, these steps seem to be inadequate as hundreds of turtles are found dead on the coasts for various reasons.
A step towards saving India’s turtles
Realising the importance of turtles, many researchers, organisations and individuals have come together to address their declining numbers in the country and to protect coastal ecosystems. There are conservation efforts at multiple scales and levels, including educating local communities of the benefits of these turtles. One such effort is by Ms. Madhuri Ramesh from the Ashoka Trust for Research in Ecology and Environment (ATREE), Bangalore. She advocates ‘conservation governance’ of turtles that involves identification of the threatened species and associated management practices, creation and maintenance of spatial enclosures in the form of ‘protected areas’ and identification of certain human activities as ‘threats’.
Turtle Action Group is a nationwide network of sea turtle conservation organisations, established by Dakshin Foundation, Bengaluru and headed by Dr. Kartik Shanker. It monitors leatherback turtles, a threatened species, in the Andaman and Nicobar Islands. They also perform genetic studies and track turtles using satellite telemetry. “Our transmitter attachment procedure involves drilling through the ridge on the back of the turtle, and tying the transmitter in place with wires that are threaded through plastic tubing”, explains Mr. Muralidharan.
The Students’ Sea Turtle Conservation Network (SSTCN), a voluntary group in Chennai mainly comprising of students, is providing a unique opportunity for all to help conserve turtles through its citizen science initiatives. Mr. Arun Venkataraman, a coordinator of SSTCN, proudly says “This conservation work has been going on since the early 1970's when Romulus Whitaker, a well-known Indian herpetologist, and Zai Whitaker initiated it. If not for the work of this group and its predecessors and the forest department, many species of turtles would have gone locally extinct.”
SSTCN is actively involved in collecting the eggs and incubating them in a hatchery. Since volunteers run the entire activity, a small contribution of checking the hatchery in the middle of the night by someone returning from work is a significant one. “Over the last 30 years, a few hundred youths have carried the responsibility of the programme. Many of them are now involved in environmental work as researchers, conservationists, activists, journalists, environmental filmmakers, etc.”, says Mr. Venkataraman.
Most conservation efforts focus on involving not only researchers and ecologists but also local communities and helping them understand how small steps can help rebuild the population of turtles to healthy levels in India. Collection of eggs and setting up of hatcheries on the shores, turning off lights when hatchlings emerge and conducting various awareness programmes for the local community goes a long way in helping the survival of these turtles.
Aldo Leopold, an American ecologist, and conservationist famously said, “Conservation is a state of harmony between men and land”. It is this harmony many individuals and organisations are working towards, in the hope that we can preserve many forms of lives from being wiped off from the face of our planet.