Details
Oncorhynchus nerka
The sockeye salmon is a seasonal salmonid linking North Pacific seas with Nearctic freshwater. It grows at sea and returns in groups to natal waters.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
It uses cold lakes, rivers, estuaries, and the North Pacific Ocean. Many hatch in freshwater, rear there for a time, and later migrate to sea.
Length is about 60-84 cm and weight about 2-7 kg. Fish are silver at sea, but spawning adults turn red-bodied with green heads.
Its life is strongly seasonal, with groups moving downstream and later migrating upstream. On spawning grounds adults become territorial around nests.
It is carnivorous, feeding at sea on zooplankton, small crustaceans, and small fish. Juveniles in freshwater take tiny aquatic animals.
Adults return to natal rivers or lakes, where females dig redds in gravel. After spawning, most adults die and return nutrients to streams and forests.
Its status is listed as Least Concern. Local runs depend heavily on river connectivity, water temperature, and food conditions at sea.
