Some current research being conducted on salmonid fishes at the Hanford nuclear complex on the Columbia River is discussed. Studies of thermal effects on reproduction and behavior include a 20-year annual census of spawning chinook salmon near reactor discharges, laboratory experiments on incubation and rearing success at elevated temperatures, studies of equilibrium loss prior to thermal death at lethal temperatures, tests of relative predation rates upon thermally shocked and normal young salmonids, and tracking sonic tagged adults to determine migration behavior near thermal outfalls.