Rainbow trout are among the most widely farmed fish globally, yet their welfare in intensive aquaculture systems is frequently compromised by crowding, handling, and slaughter practices.
Trout welfare in aquaculture is shaped by the same fundamental tension facing all intensive fish farming: economic pressure toward maximum density and minimum cost directly conflicts with fish welfare requirements for space, water quality, and low-stress conditions. Trout are particularly responsive to stocking density as a welfare stressor — at high densities, subordinate fish experience chronic stress and reduced food access that compounds over the production cycle. The improvement of trout welfare requires both technical interventions (better water quality management, humane slaughter) and structural changes (reduced stocking densities, welfare monitoring requirements) that the aquaculture industry has been slow to adopt.