Rainbow trout are among the most widely farmed fish in Europe. Their welfare in aquaculture is affected by stocking density, disease, and slaughter method.
Rainbow trout welfare in aquaculture is better addressed than most farmed fish species, partly due to RSPCA Assured certification covering this species. However, significant gaps remain. High stocking densities allowed under even higher-welfare standards still cause measurable stress compared to lower density controls. Disease management frequently involves antibiotic treatment rather than prevention through biosecurity and vaccination. Slaughter welfare depends critically on stunner calibration and maintenance - unstunned or poorly stunned fish experience conscious slaughter. Regular stunner testing and certification is a basic welfare requirement that is not universally enforced.