Rainbow trout are among the most widely farmed fish in the world. Scientific evidence supports their capacity for pain and suffering, warranting improved welfare standards.
Farmed rainbow trout are sentient animals whose welfare in conventional aquaculture is frequently poor. High stocking densities prevent natural territorial and shoaling behaviors. Sea lice — external parasites — cause painful skin lesions and physiological stress. Crowding during harvest and death by asphyxiation cause suffering that could be avoided using electrical or percussion stunning. The UK and other progressive jurisdictions now require pre-slaughter stunning for farmed trout, demonstrating that humane methods are commercially viable.