Hatcheries’ metal can disrupt steelhead magnetic sense

Young trout raised in distorted field flunk first test of which direction to swim

DISORIENTED  In a hatchery, young steelhead trout, each about 20 centimeters long, may experience such odd magnetic fields that they fail to properly calibrate their inherited magnetic sense. 

Emily Putman

Young steelhead trout don’t get off to a good start as navigators if they’re reared in hatchery tanks where iron pipes cause weirdness in magnetic fields.