The stocking of rivers and lakes with hatchery-raised fish for sport fishing raises welfare concerns about hatchery conditions, release stress and the welfare of caught and returned fish.
Sport fishing stocking raises welfare questions at multiple stages. Hatchery fish are raised in high densities, leading to fin erosion, aggression injuries and behavioral abnormalities from barren environments. Release into rivers is stressful and mortality rates can be high. Even successfully established fish that are then caught face the physiological stress of capture, air exposure and handling. Catch-and-release, while preferred from a conservation perspective, still imposes welfare costs on individual fish. Best-practice handling guidelines — quick release, wet hands, no air exposure, cool water — reduce but do not eliminate these harms.