The ridleys return

The arribada has begun at Odisha’s Gahirmatha, the world’s largest nesting beach for olive ridleys

March 09, 2019 04:10 pm | Updated 04:10 pm IST

Only one in a thousand hatchlings survives to reach adulthood.

Only one in a thousand hatchlings survives to reach adulthood.

It is almost midnight and we are standing behind a long makeshift fence in Rushikulya beach south of Odisha. We are waiting for the arrival of an annual marine visitor. The ‘arribada’ is about to begin: this is when thousands of olive ridley turtles will emerge from the sea, clamber up the beach, dig nesting holes in the sand, lay eggs en masse, and then vanish into the waters as suddenly as they appeared. Some 45-60 days later, the hatchlings will emerge and make their way uncannily towards the sea, hazarding predators and poachers.

Security is tight. We are cautioned not to use any kind of light, even the light on our mobile phone screens could be a disturbance The 5-km-long fence is to protect the ridleys and eggs from predators like dogs and jackals.

As we watch, unmistakable saucer-shaped silhouettes appear on the moonlit sand. Forest officials tell us to be silent. The shadowy figures grow in number. There must be 250 of them. Their heads stooping so low their nostrils are almost touching the sands, the pregnant ridleys are making their way up the beach looking for a suitable spot to lay eggs. We can hear their collective, laboured breathing from metres away, as they dig nest holes with their flippers and lower their bodies into them. They could lay 70 to 190 eggs each.

Once done, they begin their arduous journey back to the sea. This time they are moving much slower than they did when they arrived, but their heads are raised. As they drag their bodies across the sand, they leave distinct track marks. And just like that they are gone, back into the dark waters. The eggs will incubate in the heat of the sand. Only one in a thousand hatchlings will survive to reach adulthood.

Another nest-egg

But the real arribada is taking place at Gahirmatha Marine Sanctuary in northern Odisha, where more that 4 lakh turtles have arrived since February 27. This is the world’s biggest nesting beach for ridleys. Much has been done to protect these Schedule 1 animals during nesting season, but they are still up against several odds.

Some 50 years ago, ridleys nested en masse on the Odisha coast in winter, between November and December. This has gradually shifted to February and March and no one is quite sure why. There have been speculations about climate change impacting their breeding and nesting, but no studies have been done yet to confirm this theory.

One nesting site, at the Devi river mouth, has been all but abandoned by the ridleys because mechanised fishing poses a huge threat to them. But at the Rushikulya rookery coast, their numbers have dramatically increased: last year, this rookery witnessed the rare phenomenon of ‘double mass nesting’ in February and April.

Unplanned coastal development along the coastline has taken a toll on the turtles, with sea erosion also reducing the nesting beach stretch at Gahirmatha from 3.2 km in 1993-94 to less than a kilometre today, says Bivash Pandav, a scientist at the Wildlife Institute of India. Light pollution also impacts the animals, disorienting the hatchlings as they make their way to the sea at night.

“The government needs to regularly assess nesting beaches. A proper illumination policy is needed to keep a check on light pollution, and we need trawlers fitted with turtle excluder devices,” says Pandav. A deep-water sea port and a township near Dhamra, and a missile testing centre are not far from Gahirmatha, he says. The scientist is also critical of casuarina plantations planted along the beach since nesting beaches need to be kept open.

Selfie menace

Then, there is a distinctly 21st century problem: selfies. Phone-toting tourists who throng the Rushikulya beach to watch the breeding are a big disturbance.

But some important measures have been taken. The government has been trying to keep the beach pollution-free, and mechanised fishing has been banned from November to May. There’s regular patrolling as well against predators who destroy eggs or hunt the hatchlings. This year, the forest department is preparing to protect a 3-km stretch near the Bahuda river, south of the Rushikulya rookery, as an alternative nesting site. As for tourists, anyone taking selfies with ridleys or trying to touch them may now face legal action.

A special weather station has been set up at Gokharkuda in the Rushikulya rookery to study the impact of weather on mass nesting. And on the anvil is a sea turtle research centre.

Happily, the turtle population in Odisha is “stable or increasing,” says Kartik Shanker, an Associate Professor at the Centre for Ecological Sciences, Indian Institute of Science. “We still need to be concerned about unplanned coastal development. Ports can have a long-term impact on turtle populations.”

Meanwhile, in Gahirmatha, the forest department is hoping for a second nesting by the end of next month. Vast stretches of beach were lost to erosion here. Then last year, Nasi-II Island’s nesting beach, which had becomes less than a kilometre long, grew by 500 metres due to accretion. And this year, it’s become 2,600 metres long.

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