Bluefin Tuna Ranching Welfare | Animal Welfare Hub

Bluefin tuna ranching — catching juvenile wild fish and growing them to market size in sea cages — raises serious welfare concerns for one of the ocean's most powerful predators.

Key Facts

Atlantic and Pacific bluefin tuna are ranched in Mediterranean and Pacific cage systems
Wild juveniles are captured by purse seine and transferred to grow-out cages
Bluefin tuna are highly migratory and active — cages represent extreme confinement
Stressed tuna are prone to ramming cage walls and internal injuries
Ranching pressure on wild juvenile stocks has conservation implications

Welfare Considerations

Bluefin tuna welfare in ranching systems is profoundly compromised — these are among the largest, fastest and most wide-ranging fish in the ocean, capable of swimming thousands of miles. Confinement in sea cages causes stereotypic circular swimming, wall-striking, fin damage and severe stress. Capture and transfer from wild to cages involves intense handling stress. There is a strong argument that bluefin tuna cannot be held in cages with acceptable welfare, regardless of production economics.

What You Can Do

Avoid consuming bluefin tuna from ranching operations given severe welfare concerns
Advocate for welfare assessment as a prerequisite for aquaculture licensing of highly migratory species
Support research into welfare-compatible aquaculture for large active marine species
Engage with certification bodies on excluding ranched bluefin tuna from sustainability schemes
Raise awareness of bluefin tuna welfare issues alongside the conservation concerns about ranching