Interactions of Northern Fur Seals and Commercial Fisheries

Under international agreement, the northern fur seal (Callorhinus ursinus) is managed with the objective of obtaining a maximum sustainable yield. Currently the harvest is restricted to subadult males; however, between 1956 and 1968 the fur seal population of the Pribilof Islands was subjected to a harvest of females. This harvest was justified, in part, as an attempt to stimulate the production of greater quantities of harvestable animals (Chapman 1981). A reduction in the population occurred during this period as can be seen in Figure 1. As described in York and Hartley (1981), the female harvest itself provides an explanation for part of this reduction, but cannot account for more than about 70 percent of the decline in the numbers of pups born. It was expected that the population would increase following the termination of the harvest of females in 1968, yet no increase occurred