Three species of bluefin tuna are found around the world—Northern (or Atlantic) bluefin tuna (Thunnus thynnus), Southern bluefin tuna (Thunnus maccoyh) and Pacific bluefin tuna (Thunnus orientalis). Pacific bluefin tuna is managed as a single stock and is primarily found in the North Pacific Ocean, ranging from East Asia to the North American West Coast.
The Pacific bluefin tuna has a streamlined body and a high powered muscle system which makes it one of the fastest fish in the Pacific Ocean. Bluefin tunas are warm blooded, and unlike cold blooded fish, they can keep their body temperature higher than the surrounding water. This allows them to achieve great power and speeds, sometimes reaching sprint speeds of up to 60 miles per hour. Being warm blooded also means that their range is less limited by water temperatures and climate variability.
Commercial and recreational fisheries for Pacific bluefin tuna have existed for thousands of years. As sushi and sashimi markets developed in the 1970s and 1980s, the demand and prices for bluefin tuna soared.
Today, tuna remain a commercially important species around the world. As fisheries expanded, fishing pressure increased dramatically, and many bluefin tuna populations are currently overfished. Since bluefin tuna are late to mature, slow-growing, and long lived, they are especially vulnerable to fishing pressure compared to faster growing, more productive species. Many nations harvest bluefin tuna and effective conservation and management of this resource and its fisheries requires strong international cooperation. In 2013, the Inter-American Tropical Tuna Commission (IATTC) developed conservation and management measures for bluefin tuna, including international catch limits. Other management organizations, like the Western Central Pacific Fisheries Commission (WCPFC) have also adopted conservation and management measures. U.S. fisheries generally harvest a small fraction of the total Pacific-wide bluefin harvest, and represent only two percent of the average annual landings from all fleets fishing in the Eastern Pacific Ocean.