Optimizing the Cosewic Criterion of Location: Freshwater Fishes As a Case Study

Location is an indicator often used in the conservation assessments of species by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). According to COSEWIC, location is defined as a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the taxon present. The guidelines on the definition and calculation of location have received criticism for their ambiguity, which could result in subjective calculations and improper assessments of conservation status. To examine the application of location, we summarized the use of locations in COSEWIC assessment reports for 131 Canadian freshwater taxa. We propose an alternative method for calculating location using a standardized geographic buffer. Simulations to test the applicability of the buffer were conducted in ArcGIS using distribution data, scale of the primary threat, and minimum area for viable population for 20 imperiled freshwater fish species of southwestern Ontario. The shape of the buffer is dependent on the species habitat and the primary threat to the species. An objective method of calculating location will contribute to more accurate conservation assessments of species, and subsequent development and implementation of conservation strategies.