Rainbow trout is the most farmed fish in the UK, and significant progress has been made on welfare standards in recent years, though gaps remain between best and average practice.
UK rainbow trout aquaculture has made genuine welfare progress through RSPCA Assured certification requirements for electrical stunning and water quality standards. However, significant variation exists between farms with cataracts, crowding-related injury, and disease pressure still common in non-certified systems. The distance between best practice farms and average farms represents a substantial welfare gap that policy and consumer pressure can narrow.