tuna

Tuna is a collective term for several species of large, migratory, pelagic fish in the tribe Thunnini of the mackerel family Scombridae. True tunas are mainly in the genus Thunnus, including Atlantic bluefin (Thunnus thynnus), Pacific bluefin (Thunnus orientalis), yellowfin (Thunnus albacares), bigeye (Thunnus obesus), and albacore (Thunnus alalunga). Skipjack tuna is Katsuwonus pelamis and is widely sold as canned tuna. Tunas inhabit warm and temperate oceans worldwide and are highly migratory.

Biology: They are fast, streamlined predators with a crescent tail and finlets. Many species are endothermic to some degree, enabling retention of body heat. Diet consists mainly of fish and squid. They reach maturity after several years; some species live for decades. Spawning occurs in warm offshore waters and often involves large numbers in restricted areas.

Fisheries and management: Tuna support major global fisheries. Common capture methods include purse seines, longlines, and pole-and-line. Bycatch and ecosystem effects drive management actions by regional bodies such as ICCAT (Atlantic and Mediterranean stocks) and IATTC (eastern Pacific). Quotas, size limits, and seasonal closures aim to prevent overfishing, though bluefin stocks have faced historical declines.

Uses and nutrition: Tuna is consumed fresh as steaks, canned, or as sushi-grade products. It provides high-quality protein and omega-3 fatty acids, with mercury exposure varying by species and size. Sustainability considerations, including certifications and source tracking, influence consumer choices. Aquaculture and farming of certain tuna species supplement supply, though these operations raise environmental and feed-use concerns.