Over one lakh endangered Olive Ridley sea turtles have laid eggs on the beach adjoining the Rushikulya river mouth since Monday as scientists observed the phenomenon with interest.

The eggs are expected to hatch in the first week of May, about 45 days after the mass nesting.

While 6,000 turtles emerged from the sea to lay eggs in the wee hours of Monday, around 65,000 swarmed the four—km long sandy beach between Gokharakuda and Kantiagada the next day. The number of nesting turtles came down thereafter.

Kartik Shanker, a turtle biologist from the Indian Institute of Science — Bangalore and Basudeb Tripathy of the Wildlife Institute of India, who are here to study the pattern of mass nesting, said the laying of eggs could continue sporadically for a few more days.

The hatching will take place around the first week of May when the temperature will be high.

Mr. Shanker said that the gender of the new—born turtles would determined by several factors including the prevailing temperature of the time.

“If the temperature is high, more number of female hatchings are expected to emerge from the eggs,” said Mr. Shanker adding it could happen in the Rushikulya beach as the day temperature was on the rise.

Wildlife activists said mass nesting at Rushikulya beach had been delayed by about a month compared to last year. Last year the mass nesting took place from February 14 and over 2 lakh turtles had converged for mass nesting.

More male turtle babies were likely to hatch in the Nasi Island off Gahiramatha beach where an estimated 1.87 lakh turtles had laid eggs about a fortnight ago, Mr. Shanker said.

The scientists, however, said there was no delay in the mass nesting in the Rushikulya beach. Olive Ridley turtles generally come for mass nesting any time between January and April, Mr. Shanker said.

Nesting in the second week of March usually damage eggs because of rough sea and strong winds that erode the beach, experts observe.

When mass nesting had taken place in the second week of March in the past, a large number of eggs had been destroyed, they said.

The Divisional Forest Officer (Berhampur) A. K. Jena said measures had been taken to protect the eggs till the hatching occurred. Besides providing nets, the forest personnel, local volunteers and police had been deployed in the area for enhanced protection and guarding the eggs from kites, jackals and stray dogs, the DFO said.

Orissa Governor M. C. Bhandare had visited the beach on Wednesday to witness the mass nesting.