A fisherman looks at shark tail fins in the freezer hold of Taiwanese longliner, Sing Man Yi 6, in the Pacific Ocean. The vessel's catch log lists blue sharks as the only shark species retained on board, however identification on the basis of detached fins is extremely difficult. Greenpeace travels into the Pacific to expose out of control tuna fisheries. Tuna fishing has been linked to shark finning, overfishing and human rights abuses.