Harvesting Young-of-the-Year from Large Mammal Populations: An Application of Systemic Management

摘要

We evaluate the current commercial harvest of harp seal (Pagophilus groenlandicus) and proposed subsistence harvests of northern fur seal (Callorhinus ursinus) pups based on intraspecific comparisons. These comparisons utilize a pattern derived from 167 cases of estimated consumption rates by large mammals. In all cases, the predation rates involve large mammal prey less than 1 year of age. Recent harvests of harp seal pups are exceeded by 20 (about 12%) of the estimated consumption rates among the nonhuman species. Although this is not statistically significant, further analysis may find this harvest to be unsustainable when we account for other factors such as the number of other predators, the number of prey each predator consumes, trophic level, the biodiversity of the system, and differences involving terrestrial predators preying on marine prey. Initially, there is no scientific basis for rejecting a proposed subsistence harvest of 150 northern fur seal pups on St. George Island, Alaska, or a comparable harvest of 1,125 pups on St. Paul Island.