Aquatic Animals

Sea Lice and Salmon Welfare in Aquaculture

Sea lice infestations cause significant suffering in farmed salmon; treatments can also have welfare and environmental costs.

Key Facts

Sea lice eat skin, mucus, and flesh, causing open sores
Severe infestations cause osmoregulatory failure and death
Chemical and thermal treatments for sea lice cause additional stress
Wild salmon populations are impacted by sea lice from farms

Welfare Considerations

Sea lice cause chronic pain, tissue damage, and immune stress in farmed Atlantic salmon. Treatment methods including hydrogen peroxide baths and thermal delicing have their own welfare costs. High stocking densities promote rapid parasite spread. Welfare-positive solutions include enclosed containment systems and biological controls.

What You Can Do

Choose salmon certified under the ASC or equivalent standards
Support aquaculture research into biological sea lice control
Advocate for enclosed aquaculture systems that prevent sea lice
Reduce farmed salmon consumption given unresolved welfare issues