Sea Trout Welfare: Overlap with Salmon Aquaculture Challenges

Sea trout face welfare threats from sea lice produced by salmon farms, with parasitic infestation causing skin damage and mortality in wild migratory fish.

Key Facts

Sea trout and Atlantic salmon both use coastal waters adjacent to salmon farm sites
Salmon farm sea lice infestations can reach levels that pose serious welfare risks to wild sea trout
Sea lice cause severe skin and gill damage, secondary infections, and mortality in heavy infestations
The link between salmon farm lice burdens and wild salmonid welfare is scientifically well-established
Integrated pest management in salmon farming, including cleaner fish and treatment protocols, partly addresses the problem

Welfare Considerations

Wild sea trout passing through areas with high salmon farm lice densities can acquire lethal parasite burdens within days. The welfare impact on heavily infested fish is severe: lice feeding on skin and mucus cause open wounds, secondary bacterial and fungal infections, and osmotic imbalance. Heavily infested fish show behavioural abnormalities and reduced feeding before dying. The welfare of wild fish is routinely overlooked in regulatory frameworks that focus primarily on farmed fish welfare and salmon farm production losses. Reducing sea lice on salmon farms has direct welfare benefits for wild sea trout and salmon populations.

What You Can Do

Support salmon aquaculture regulatory reform requiring lower sea lice thresholds
Back organisations advocating for wild fish welfare alongside farmed fish welfare
Choose salmon from farms with documented low sea lice levels and good integrated pest management
Stay informed about the interaction between salmon aquaculture and wild salmonid welfare