KENDRAPARA: Beach erosion is threatening the very existence of three major mass-nesting sites of the endangered Olive Ridley turtles at the Rushikulya beach, the Devi river mouth and the Gahirmatha beach. The 4.5-km beach from Rushikulya to Kantiagada was 500-metre wide two years back but due to erosion the width has been narrowed down to only 50 to 60 metre. It will affect nesting of turtles this year, said Rabindra Nath Sahoo, turtle researcher and president of Rushikulya Sea Turtle Protection Committee (RSTPC). Last year, 3.5 lakh turtles laid eggs in Rushikulya and 2.75 lakh in Gahirmatha beach, added Sahoo. At present, the beach is occupied by fishermen who have constructed makeshift huts and covered the beach with boats. The beach is also littered with damaged fishing nets, broken boats and garbage which may hamper the mass arrival of the turtles, said Sahoo. The topography of another mass nesting site near the Devi river mouth has also undergone several changes over the years. The super cyclone in 1999 resulted in the formation of a new river mouth. This river mouth is now getti0ng sand-cast, said Sudhansu Parida, environmentalist. The 12-km Gahirmatha beach, world