Tonfisk

Tonfisk is the common name used in several Nordic languages for tuna, a group of large, migratory predatory fish belonging to the family Scombridae. The most important tunas belong to the genus Thunnus, including albacore, yellowfin, bigeye and bluefin, while other tuna-like species such as skipjack (Katsuwonus pelamis) are also associated with the term. Tonfisk are found in warm and temperate oceans worldwide and undertake long-distance migrations between feeding and spawning grounds. They have streamlined bodies, strong caudal fins, and in some species specialized heat-retaining tissues that help maintain body temperature above the surrounding water.

In fisheries, tonfisk is primarily harvested for canned tuna, which is produced from several species. Light canned tuna typically uses skipjack, while white canned tuna commonly uses albacore. Fresh tonfisk fillets are sold for grilling, searing or used in sushi and sashimi. Nutrition-wise, tuna is a high-protein source of omega-3 fatty acids but can contain notable mercury levels, with larger species posing greater risk; consumption guidelines vary by age and pregnancy.

Sustainability concerns have led to international stock assessments and management measures by organizations such as ICCAT. Some markets emphasize certified sustainable products or line-caught methods to reduce bycatch and environmental impact.