Gahirmatha sanctuary is the only marine sanctuary of Orissa. It extends from Ekakula Nasi Island from North to Telanga Muhana in the South. It has a width of 20k.m. towards the sea. Located slightly further away is the coastal area of Gahirmatha, where the giant Pacific Ridely Sea Turtle, travelling annually from as far away from South America nest by the million. A sanctuary is a restricted area where as per provision of Wildlife Act, the living beings including Turtles, Dolphins, Fishes, Sharks etc. have a right to survive. These animals are allowed to propagate, perpetuate and flourish in this restricted area irrespective of their direct economic concern for human beings. Special arrangements were made to ensure their protection as the turtles were preyed upon by the local folk many years. The Gahirmatha is unique because it is the only mass nesting site for Olive-ridley sea turtles in the whole world. This area too is a potential breeding and feeding ground for many marine fishes.

The sea turtle ARRIBADA, in a clear moonlit winter night, big turtles crawling out of deep sea in hundred and thousands, puffing and laboring, selecting a site, digging a hole in the sand with hind flippers, laying nearly 200 eggs, covering and compacting by their own body weight, sweeping out of all traces and crawling back to sea, all within 45 minutes, is an event to be seen to be believed.