Salmon is the most valuable finfish in global aquaculture, but welfare standards have lagged behind the sector's rapid growth.
Salmon welfare in aquaculture is a rapidly developing field because both industry economics and consumer expectations are driving change. Lice infestations cause painful skin lesions and behavioral changes that indicate significant suffering. Crowding at harvest causes cortisol levels comparable to severe pain in humans. The development of objective welfare indicators for salmon — including operant self-administration of analgesics and cognitive bias tests — has provided scientific tools that are beginning to influence regulatory standards.