Farmed Halibut Welfare: Aquaculture of a Flatfish Giant

Atlantic halibut is the largest flatfish and one of the most challenging species to farm, with welfare considerations around aggressive behaviour, eye migration, and the long production cycles needed before market size.

Key Facts

Atlantic halibut take 3-5 years to reach market size in aquaculture - one of the longest of any farmed fish
They are the largest flatfish, reaching weights of over 300kg in the wild
Juvenile halibut undergo metamorphosis including eye migration from a bilateral to a flatfish body plan
Cannibalism in juveniles is a major challenge requiring careful density and feeding management
Welfare standards for halibut are essentially absent; the species is a niche but growing aquaculture target

Welfare Considerations

Halibut aquaculture presents welfare challenges at multiple life stages. Juveniles undergoing metamorphosis are physiologically vulnerable. Cannibalism in crowded juvenile tanks causes injury and death. The long production cycle exposes fish to extended periods in captive conditions. Aggressive feeding behaviour at stocking densities creates competitive stress and injury. As halibut farming expands from its current small scale, establishing welfare standards and practices before scaling is the welfare-responsible approach that avoids the mistakes of salmon aquaculture.

What You Can Do

Ask retailers about welfare and production standards in their halibut supply chains
Support development of welfare standards for halibut by aquaculture certification bodies
Choose wild-caught halibut from certified sustainable fisheries where welfare concerns about farming are a priority
Advocate for inclusion of halibut in expanded aquaculture welfare certification
Support research into halibut behaviour and welfare needs in culture conditions