Archived Blog Post: September 23, 2003

Collapse of seals, sea lions & sea otters in North Pacific triggered by overfishing of great whales: "To see if it was possible for a change in killer whale feeding behavior to have a significant impact on seals and sea lions, co-authors Dan Doak and Terrie Williams modeled the nutritional requirements of killer whales, the nutritional value of sea lions and otters, and the number of deaths necessary to explain the documented declines of marine mammals in the Aleutian Islands. They found that a dietary shift by less than 1% of the estimated 3,888 killer whales across the region would have been enough to drive the observed declines. The inability of sea otters, seals and sea lions to sustain increased mortality from redirected killer whale predation makes sense based on their much smaller aggregate biomass compared with the great whales."

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