Sea lice infestations are a major welfare problem in farmed Atlantic salmon. Treatment methods themselves cause significant stress, and prevention through better farming practices is the priority.
Sea lice represent a chronic welfare challenge in open-net salmon farming. The lice cause physical damage and stress, and the treatments — chemical, mechanical, or biological — all impose additional welfare costs. The industry's inability to sustainably control lice without harming fish is a strong argument for transitioning to closed containment systems where infestations cannot occur.