Kendrapara: The endangered Olive Ridley female turtles have started arriving at the Gahirmatha beach in Kendrapara district, the world's largest known rookery of these species, to lay eggs, a phenomenon otherwise called 'arribada', officials said on Wednesday.

Arribada, a Spanish term that describes the unique natural heritage of millions of these marine species converging on the nesting ground for laying eggs.

The annual mass nesting of these delicate marine species began on Tuesday night in Nasi-2 beach of the Gahirmatha nesting ground. The number of female turtles that crawled onto the beach to dig pits by flippers and lay eggs was on a lesser scale. We are expecting a large turnout of turtles in the coming days for the arribada, said Debashis Bhoi, the forest range officer, Gahirmatha forest range.

The officials are yet to count the number of nests dug by the turtles so far. However, around 2,000 turtles had turned up to lay eggs. The mass nesting is likely to continue for at least 10 days.

The intensity of the number of turtles turning up to lay eggs will pick up pace in the next three to four days, they said.

Around 7.30 lakh Olive Ridley turtles had turned up for mass nesting in the 2019-20 nesting season in Odisha with Gahirmatha beach playing host to 4.50 lakh turtles for mass nesting. We are expecting this year's mass nesting figure to get better than last year's, the official said.

The forest department is now prioritising the safety of turtles' nests. To ensure the safety of turtle eggs, a 600 metre net barricade has been installed along the casiruanna forest cover that is close to nesting ground. Wildlife staff are on the round-the-clock vigil to keep the predators like jackals, hyena and wild dogs at bay, he said.

"The presence of forest personnel on the nesting ground did not bother the turtles as they maintained a distance from the animals. Emphasis is on to provide privacy to the marine animals during the egg-laying process. On their seaward journey, they moved past the forest guards at hand- shaking distance", said the officials who witnessed mass nesting.

It's only the female turtles that invade the nesting beaches usually at the dead of the night for laying eggs.

After indulgence in instinctive egg-laying, the turtles leave the nesting ground to stride into the deep sea water.

Hatchlings emerge from these eggs after 45-60 days. It is a rare natural phenomenon where the babies grow without their mother, said officials.

The Olive ridley turtles turn up in millions for mass nesting along the Odisha coast every year. Gahirmatha beach off the Bay of Bengal coast in Kendrapara district is incidentally acclaimed as World's largest-known nesting ground of these animals.

Apart from Gahirmatha, these threatened aquatic animals turn up at Rushikulya river mouth and Devi river mouth for mass nesting, otherwise called arribada.

An Olive Ridley turtle usually lays about 120 to 150 eggs from which hatchlings emerge after about 45 to 50 days.

But not all eggs remain intact as predators devour them.

Besides, eggs are also washed away by sea waves during high tide. The eggs are incubated in the nest and grow, sans mother, to emerge as hatchlings, they said.