Identification of Critical Habitat for Endangered Fishes in Southern Ontario

The identification of critical habitat for at risk fishes is a key priority for recovery programs in the lower Great Lakes region of southern Ontario.  For species listed as Endangered, such as Lake Chubsucker (Erimyzon sucetta), Pugnose Shiner (Notropis anogenus) and Northern Madtom (Noturus stigmosus), the identification of critical habitat is a requirement of Canada’s Species at Risk Act (SARA); once identified, SARA includes provisions to prevent the destruction of critical habitat.  One of the key challenges encountered in protecting habitat for these fishes is the limited amount of information regarding their distribution and habitat requirements as well as the absence of detailed habitat mapping for waterbodies where they occur.  As a result, an area of occupancy approach (combined with a functional habitat approach) was taken to identify critical habitat for fishes in both riverine and wetland habitats.  Where possible, available habitat information (e.g. bathymetry, ecological classification, habitat surveys) was used to help delineate geospatial boundaries.  The application of Minimum Viable Population (MVP) size was used in an analysis of population viability for individual populations.  Challenges and lessons learned from the various approaches will be discussed as well as implications for the conservation and management of the species.