Tuna Welfare in Industrial Fisheries

Tuna are large, fast, highly migratory fish whose capacity for suffering is increasingly recognised, raising welfare questions about industrial fishing methods including purse seining, longlines, and live fish aggregating devices.

Key Facts

Global tuna catches exceed 7 million tonnes annually, making tuna among the most commercially important fish groups
Atlantic bluefin tuna can reach 3 metres in length, weigh 700 kg, and live for 40 years
Purse seine nets around fish aggregating devices can catch and kill non-target species including sharks, turtles, and juvenile tuna at high rates
Longline fishing for tuna catches an estimated 145 million additional animals annually as bycatch, including seabirds and sea turtles
Tuna are endothermic, maintaining body temperatures above ambient water, suggesting more complex physiology than many fish

Welfare Considerations

Tuna welfare during capture involves significant suffering. Purse seine capture concentrates thousands of fish in shrinking net volumes, causing collision injuries, scale loss, and extreme physical stress before hauling. Longline-caught fish may remain on hooks in the water for hours to days before retrieval. The physiological complexity of tuna, including partial warm-bloodedness and sophisticated sensory systems, supports the likelihood that they experience meaningful welfare states. Mass mortality events in net holds from oxygen depletion and crowding represent large-scale welfare failures.

What You Can Do

Choose pole-and-line caught tuna products which have significantly lower bycatch and per-fish welfare costs
Support International Seafood Sustainability Foundation programmes that improve tuna fishery practices
Advocate for fish welfare to be included in fisheries management and certification standards
Reduce tuna consumption frequency and opt for smaller-volume canned products from certified sources