Abundance of Olive Ridleys Along Odisha Coast: Sources of Mortality and Relative Importance of Fisheries Impacts

Abstract

Despite international and national protection, sea turtles continue to be caught incidentally in large numbers along the coastal waters of Odisha. This chapter examines the mortality of sea turtles in three arribada site of Odisha, focusing on offshore distribution and number of carcasses of olive ridley found along the three zones. A total of 14,035 and 3,481 turtles were washed ashore dead along the three important arribada sites of Odisha in two consecutive study period 2008–2009 and 2009–2010 due to trawling activity. We compared the number of turtles stranded on beaches adjacent to the fishing grounds with the near shore fishing activity within 6 km from the coast and at a depth of 30 m. The objective was to correlate the beach stranding with degree of fishing activities and to evaluate beach stranding as an indicator of fishery-induced mortality. The mortality and trawling activity was further classified into pre-mating, mating, and post-mating seasons for comparison. There was a positive significant correlation with the seasons in trawling and mortality of turtles. The findings conclude that turtle stranding during the mating period is highest in the turtle abundance zones in comparison to adjoining areas. In places where near shore trawling was more mortality of turtles and where the fishing activities were moderate or low the turtle mortalities was found to be less. The high trawling near shore coincide with the mating period of turtles due to which large number of mortality occurs.