19. Whales And Whaling In The North Pacific Ocean And Bering Sea Oceanographic Insights And Ecosystem Impacts

Abstract

Hideo Omura's concern over the killing of fin whales in the early 1950s, just a few years after the resumption of whaling following World War II, foreshadowed the demise of most of the remaining great whales in the following two decades as the slaughter expanded across the North Pacific (Springer et al. 2003). His concern was warranted because of the development of an unprecedented human capability for large-scale harvests of even the fastest whales using high-speed catcher boats and mechanized factory ships designed specifically for this purpose. In 1955, the nominal harvest of fin whales was about 2,100, and it doubled over the next 10 years to a peak of some 4,000 in 1965 before declining through 1975 when the harvest was ended. Other species were similarly exploited and depleted until pelagic hunting was successively halted for humpback and blue whales in 1965, for sei whales in 1975, and for sperm and Bryde's whales in 1979. Populations of most species were severely depleted by the mid-1980s (Stewart et al. 1987; Rice and Wolman 1982). Exceptions were humpback whales in the northeastern Pacific, which had begun to recover slowly after protection was enacted in 1965 (Calambokidis et al. 2001), and bowhead whales and gray whales that had been ravaged 100 years earlier (Raferty et al. 1995; Rugh et al. 1999). Reports of larger numbers of some species in the southeastern Bering Sea in the late 1980s in comparison with the midto late 1970s (Baretta and Hunt 1994) are difficult to interpret because changes in distribution rather than abundance could explain the difference in 'numbers between decades (Tynan 2004). Fin whales were possibly showing signs of slow recovery by the late 1990s in the northern Gulf of Alaska and Bering Sea, although sperm whales remained scarce (Moore et al. 2000; Tynan 2004).