The coho salmon was introduced from Pacific waters into the Great Lakes and is now abundant there. Silver salmon, hook nose salmon, blueback salmon, jack salmon, salmon trout, siverside salmon and white salmon. Spawning occurs from November to January, with the eggs hatching the following spring.
Coho fry remain in streams for over a year.
Moving seaward the following spring, most cohos return to spawn when they are three years old. Coho salmon utilize freshwater, nearshore and offshore environments during its lifecycles. Most coho fry stay in the stream for over a year feeding on aquatic insects, zooplankton and small fish. Adequate stream cover is important to fry survival, as is high dissolved oxygen levels. Mortality is especially high during freshwater lifestages, often a result of poor forest and agricultural management practices that lead to siltation, which may ruin spawning beds or smother the eggs.