Skip to main content
U.S. flag

An official website of the United States government

Sequential megafaunal collapse in the North Pacific Ocean: An ongoing legacy of industrial whaling?

January 1, 2003

Populations of seals, sea lions, and sea otters have sequentially collapsed over large areas of the northern North Pacific Ocean and southern Bering Sea during the last several decades. A bottom-up nutritional limitation mechanism induced by physical oceanographic change or competition with fisheries was long thought to be largely responsible for these declines. The current weight of evidence is more consistent with top-down forcing. Increased predation by killer whales probably drove the sea otter collapse and may have been responsible for the earlier pinniped declines as well. We propose that decimation of the great whales by post-World War II industrial whaling caused the great whales' foremost natural predators, killer whales, to begin feeding more intensively on the smaller marine mammals, thus "fishing-down" this element of the marine food web. The timing of these events, information on the abundance, diet, and foraging behavior of both predators and prey, and feasibility analyses based on demographic and energetic modeling are all consistent with this hypothesis.

Citation Information

Publication Year 2003
Title Sequential megafaunal collapse in the North Pacific Ocean: An ongoing legacy of industrial whaling?
DOI 10.1073/pnas.1635156100
Authors A.M. Springer, J. A. Estes, Gus B. Van Vliet, T. M. Williams, D.F. Doak, E.M. Danner, K.A. Forney, B. Pfister
Publication Type Article
Publication Subtype Journal Article
Series Title Proceedings of the National Academy of Sciences of the United States of America
Index ID 70025539
Record Source USGS Publications Warehouse