Trend data do support the sequential nature of pinniped and sea otter declines in the North Pacific Ocean, but does it really matter?

Abstract

TheSequentialMegafaunalCollapseHypothesis(SMCH)positsthatdecimationofgreat whales in the North Pacific Ocean in the 1950s and 1960s, by Russia and Japanfollowing the end of World War II, removed an important source of prey for marinemammal eating killer whales in southwest Alaska (the Aleutian Islands, southernBering Sea, and western and central Gulf of Alaska). The killer whales subsequentlybroadened their diets to include a larger proportion of other, much smaller species—harbor seals, Steller sea lions, fur seals, and sea otters—driving them into steepdecline. In the preceding letter, Wade, Ver Hoef, and DeMaster present informationand analyses that purportedly refute the SMCH. But, as explained below, we takeexception to their analytical procedures, use of data, and the strong claims they haveemployed in their continuing attempts to discredit the hypothesis.