Developing Classification Criteria under the U.S. Endangered Species Act: Bowhead Whales as a Case Study

Abstract: Under the U.S. Endangered Species Act, a species is classified as endangered, threatened, or recovered based on the extent to which its survival is affected by one or more of five subjective factors. A key criticism of the act is that it makes no reference to quantitative or even qualitative parameters of what constitutes "danger of extinction." Without objective standards to guide decisionmakers, classification decisions fall prey to political and social influences. We recommend the development of species-specific, status-determining criteria as a means to rationalize and expedite the listing process and reclassification decisions, independent of the requirement for delisting criteria in recovery plans. Such criteria should (1) clearly define levels of vulnerability, (2) identify gaps in information on life-history parameters, and (3) address uncertainty in existing data. As a case study, we developed preliminary criteria for bowhead whales (    Balaena mysticetus ). Thresholds for endangered and threatened status were based on World Conservation Union ( IUCN) Red List criteria and population viability analyses. Our analysis indicates that particular attention must be focused on population structure within the species to appropriately classify the degree to which one or more components of a species are vulnerable to extinction. A similar approach could be used in the classification of other species. According to our application of the IUCN criteria and those developed for similar species by Gerber and DeMaster (1999) , the Bering Sea population of bowhead whales should be delisted, whereas the other four populations of bowheads should continue to be considered endangered.