Marine fish farming is growing rapidly to meet seafood demand. Welfare challenges in marine aquaculture include crowding, sea lice, escape risk, and slaughter methods.
Marine fish aquaculture is one of the fastest-growing food production sectors globally, and its welfare challenges are significant. Atlantic salmon in sea cages routinely experience sea lice infestations that cause painful skin damage. Crowding induces chronic stress reflected in elevated cortisol and reduced immune function. Slaughter without stunning — fish are often killed by asphyxiation in ice slurry or by gutting while conscious — causes prolonged suffering. The development of marine aquaculture welfare standards lags far behind terrestrial livestock welfare, and there is an urgent need for welfare-aware production standards, mandatory stunning requirements, and sea lice management protocols that prioritize fish health alongside pest control.