A survey of wildlife depredation and control techniques at fish- rearing facilities

Surveyed 336 fish hatchery managers predominantly from the E USA, of which 85% responded, to assess aspects of hatchery depredation. Most facilities (63%) experienced losses to predators and managers identified 4 species of insects, 13 species of herpetofauna, 18 species of mammals, and 43 species of birds as predators. Control devices were used by 85% of the managers to limit depredation losses; top screens, enclosures, and shooting were rated as most effective in deterring predators and visual scare devices as least effective. Most managers (73%) could not place an economic value on their losses. -from Authors