Tuna species are found throughout the world's oceans and range from large bluefins found in temperate waters and prized on the sushi market to small, tropical skipjacks, which are destined for canning. As a group, the major tuna species are caught, traded, and consumed worldwide at a pace of about 4 million tons a year.
Some populations of yellowfin, bigeye, and albacore tuna are overexploited, and all three bluefin species are overfished—some populations severely so. Pew sponsors biological and economic research that informs the management of these important and wide-ranging fish.