Patterns of threats for aquatic species listed under Canada’s Species at Risk Act

Session: Imperiled Species in the Great Lakes Basin: Identifying Threats and Restoring Populations (1)

Jacob Ziegler, Fisheries and Oceans Canada, [email protected]
Samuel McIntosh, University of Ottawa, [email protected]
Marten Koops, Fisheries & Oceans Canada, [email protected]
Andrew Drake, Fisheries and Oceans Canada, [email protected]

Abstract

Species listed under Canada’s Species at Risk Act face multiple threats, which can affect populations directly (e.g., fishing mortality) or indirectly through habitat-related effects.  To date, there is no general theory that describes the incidence or effect of multiple threats on species at risk (SAR) or their habitat. We summarize known threats for all aquatic SAR in Canada and test the ability of several metrics, originally developed for measuring biodiversity, to describe the incidence of multiple threats to SAR, including their ability to predict species listing status and the incidence of known habitat stressors. Threat diversity was the only significant predictor of SAR listing severity. While all threat metrics significantly predicted the number of habitat stressors SAR experienced, threat richness was the best predictor, explaining 53% of the variation. Approximately 75% of SAR threats did not differ from random co-occurrence patterns with other threats, indicating that threat aggregations are inconsistent among SAR. Therefore, understanding the influence of multiple threats will require context-dependent investigation of how particular threats interact to influence species and their habitat.

Twitter handle of presenter
@JP_Ziegler