An Introduction to the Ecology of Juvenile Salmon in the Northeast Pacific Ocean: Regional Comparisons
Churchill B. Grimes, Richard D. Brodeur, Stewart M. McKinnell, and Lewis J. Haldorson
Pacific salmon Oncorhynchus spp. is a group of species that have achieved iconic status among human societies in the northeast Pacific (NRC 1996). Their geographical range along the North American coast extends from Southern California to the Arctic Ocean (Groot and Margolis 1991). Their abundance, nutritional value, and accessibility have combined to provide food security for indigenous peoples for millennia and served as the underpinning of the industrial salmon fisheries of the late 19th and 20th centuries. The genus members with piscivorous tendencies include the coho salmon O. kisutch, Chinook salmon O. tshawytscha, and steelhead O. mykiss. In the eastern Pacific Ocean, these taxa predominate at southern latitudes of the range of the genus. The largely planktivorous species, sockeye salmon O. nerka, pink salmon O. gorbuscha, and chum salmon O. keta, are dominant in the northern northeast Pacific. Overall, the greatest diversity of species occurs in British Columbia because of its location in the transition between two major oceanographic features of the North American west coast. The ecological importance of salmon extends to the freshwater and terrestrial ecosystems where they become prey for upper trophic level predators and, following spawning migrations and death, contribute nitrogen, phosphorous, carbon, various trace elements, and organic matter. Their decaying carcasses directly sustain many resident organisms of their natal river basins, including bacteria, insects, jays, eagles, otters, mink, and bears (Augerot 2005).