Talk:Oncorhynchus nerka
Oncorhynchus nerka the sockeye salmon is also known by the common names blueback and red salmon. Sockeye salmon is one of the Pacific salmon species. All Pacific salmon species including sockeye are anadromous, being born in freshwater, emigrating to salt water within weeks to two or (rarely) three years years of hatching, depending on the species. As is also the case with all Pacific salmon species, sockeye salmon all die after spawning for the first time (semilparous) typically at the age of five years. Adults deposit eggs in the late summer and early fall, the entire life cycle usually encompassing two winters in freshwater and three in saltwater. Sockeye salmon typically deposit eggs in nests (redds) constructed in the gravel of tributaries or outlets of lakes, and the young enter the lake after hatching to rear for one or two summers before emigrating to the sea. Some lake-rearing sockeye deposit eggs on the lake bottom in areas where there is flow from groundwater (upwelling). Some sockeye populations are not lake-rearing. Non-lake rearing sockeye spawn on gravel bars of large rivers (Kanektok River, Alaska, USA, south of Bethel, 60.792 -161.756) or in freshwater springs with marine connections (Dry Bay, Alaska, USA, near Yakutat, 59.547 -139.727) and the young move into saltwater sometime during the first summer of life.
The presence of land locked (solely freshwater) populations demonstrates that sockeye salmon can successfully complete the life cycle without being anadromous. Nonanadromous sockeye salmon are commonly called kokanee. World famous kokanee populations are found in Lake Okanagon, British Columbia, Canada and Red Lake, Idaho, United States.
Sockeye salmon are usually found in watersheds north of latitude 44.000 that contain lakes connected to the Pacific Ocean by rivers that are navigable by adult salmon. The Fraser River that flows through Vancouver, British Columbia, Canada (49.250 -123.133) is one of the world's best known sockeye salmon producing watersheds, and the tributaries of Bristol Bay, Alaska, United States (59.040 -158.458) produced the world's largest recorded annual return of adult sockeye salmon of approximately 63 million in 1980.