Rainbow trout are one of the most extensively farmed fish species worldwide. Growing evidence for trout sentience and the welfare science of salmonid farming informs meaningful improvements in practice.
The welfare of farmed trout has long been dismissed on the grounds that fish do not suffer meaningfully. Accumulating scientific evidence challenges this position: trout respond to noxious stimuli in ways consistent with pain experience, show learned avoidance, and alter normal behavior when exposed to analgesics — suggesting they seek relief from aversive states. Welfare challenges on trout farms are numerous: crowding, chronic disease, handling stress, net changes, and slaughter without effective stunning. The gap between what is possible and what is standard in trout aquaculture represents an enormous quantity of preventable suffering that welfare science is beginning to address through industry engagement and regulatory reform.