Bluefin Tuna Aquaculture Welfare and Expansion

Atlantic and Pacific bluefin tuna are increasingly farmed in sea cages - welfare science for these highly migratory open-ocean fish is at an early stage but critical given expansion.

Key Facts

Bluefin tuna aquaculture involves catching juvenile wild fish and fattening them in sea cages
True closed-cycle aquaculture (captive breeding) for Atlantic bluefin is technically achieved but not commercially scaled
Bluefin tuna can swim at over 70km/h and cover thousands of kilometres in the wild
Net pen confinement severely restricts movement; injury from net collisions is common
Slaughter methods for tuna aquaculture vary from ike jime (brain spike - most humane) to ice water asphyxiation
Welfare research on tuna is limited due to difficulty in studying high-speed open-ocean fish

Welfare Considerations

Bluefin tuna welfare in aquaculture presents profound challenges. These are large, fast, highly migratory open-ocean fish with space requirements that cannot be met in any practical farming system. The mismatch between natural history and farm conditions is extreme. The most immediate welfare priority is improving slaughter methods - ike jime (immediate brain destruction) is the fastest and least aversive method but requires skilled application. Consumer demand for sushi and sashimi drives aquaculture expansion; increasing demand from high-welfare, certified sources can incentivise better practices.

What You Can Do

Choose sushi and sashimi from restaurants that can provide supply chain information about their tuna
Support campaigns for mandatory humane slaughter standards in tuna aquaculture
Reduce bluefin tuna consumption given both welfare and conservation concerns
Engage with ASC and other certification bodies about developing tuna welfare standards
Follow fish welfare organisations publishing research on tuna welfare and slaughter
Advocate for investment in alternative, less welfare-compromising protein sources