Adults return to natal streams from the sea to spawn (Ref. 27547). Fry may migrate to the sea after only 3 months in fresh water, some may stay for as long as 3 years, but generally most stay a year in the stream before migrating (Ref. 27547). Some individuals remain close inshore throughout their lives, but some make extensive migrations (Ref. 27547, 44894). Also found in lakes (Ref. 1998). Possibly up to 375 m depth (Ref. 6793). Epipelagic (Ref. 58426). Food in streams is mainly terrestrial insects and small crustaceans; in the sea, major food items include fishes, crustaceans, crabs and other invertebrates (Ref. 9137, 27547). Young are preyed upon by fishes and birds (such as mergansers and kingfishers); adults are prey of large mammals and large birds (Ref. 1998).