Surf and turf

Natural History, June, 2003 by Kenneth I. Ashley

I read with great interest Robert S. Semeniuk's article "How Bears Feed Salmon to the Forest" [4/03], on the work of Thomas E. Reimchen in investigating marine-derived nutrients in forest ecosystems. Fisheries biologists have long regarded Pacific salmon as "keystone species" because of their ability to transport vast amounts of oceanic nutrients far inland during spawning migrations. Reimchen's research adds complexity to the existing paradigm by delineating the second stage of the "nutrient pump": large carnivores transporting huge numbers of salmon carcasses into the terrestrial environment. Marine-derived nutrients thus get distributed over a far greater area than they would be otherwise. Hence bears, being an integral part of the nutrient pump, are critical to the health of the Pacific Northwest's coastal ecosystems.

Kenneth I. Ashley

University of British Columbia

Vancouver, British Columbia