Risso’s Dolphins (Gampus griseus): impact of the Sri Lankan tuna gillnet fishery

Cetaceans were observed off the south coast of Sri Lanka in the month of April, every year over a seven year period, 2007-2013. During 48 days at sea a total of 290 cetacean sightings were recorded. Risso’s dolphins (Grampus griseus) were only seen once, despite being reported as common around Sri Lanka in the early 1980s. Reviews of published records of cetacean sightings and bycatch landings around Sri Lanka both confirm declines in relative abundance of Risso’s dolphins. They have been taken in large numbers by Sri Lankan fisheries, particularly tuna gillnet fisheries, and appear to have been almost extirpated locally.