Impact of tuna longline fishery on the sea turtles of Indian seas

Longline fishery is exerting an impact on the sea turtle populations of the seas around India, as in the case of many longline fisheries operating in other parts of the world. During the tuna longline survey conducted by four research vessels of Fishery Survey of India, 87 sea turtles were caught incidentally from the Arabian Sea, Bay of Bengal and Andaman and Nicobar waters of the Indian exclusive economic zone (EEZ) during 2005-08, registering an overall hooking rate of 0.108 turtles per 1000 hooks operated. There were marked differences in the hooking rates of turtles recorded from these three regions of the Indian EEZ, the maximum hooking rate being recorded from the Bay of Bengal (0.302), followed by the Arabian Sea (0.068) and Andaman and Nicobar waters (0.008). The species of sea turtles recorded in the bycatch, in order of abundance, were olive ridley (Lepidochelys olivacea), green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles. This study provides quantitative data on the magnitude of sea turtle incidental catch of the tuna longline fishery in the Indian EEZ.