Research Document 2019/033

Information in support of a Recovery Potential Assessment of Redside Dace (Clinostomus elongatus) in Canada

By Lebrun, D.E., Bouvier, L.D., Choy, M., Andrews, D.W., and Drake, D. Andrew R

Abstract

In April 1987, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed Redside Dace (Clinostomus elongatus) as Special Concern, and this status was re-examined and assessed as Endangered in April 2007. A re-assessment by COSEWIC in November 2017 kept the species designation as Endangered. The reason given for this designation was “this small, colourful minnow is highly susceptible to changes in stream flow and declines in water quality, such as those that occur in urban and agricultural watersheds. The Canadian range of this species largely overlaps with the Greater Toronto Area (GTA), where urban land use is widespread and projected to increase in the future. The continued expansion of the GTA has led to ongoing habitat degradation, causing serious declines in range and number of individuals and populations” (COSEWIC 2017). Redside Dace has been lost from nine of its 25 historical locations, and may now be gone from an additional three; as well, a continued decline is evident in 10 of the 13 remaining historical locations. More than 80% of the Canadian distribution occurs in the ‘Golden Horseshoe Region’ of southwestern Ontario where urban development poses the most immediate threat to the continued existence of this species in Canada. In May 2017, Redside Dace was listed as Endangered under the federal Species at Risk Act (SARA). The Recovery Potential Assessment (RPA) provides background information and scientific advice needed to fulfill various requirements of SARA. This research document provides the current state of knowledge of the species including its biology, distribution, population trends, habitat requirements, and threats, which will be used to inform recovery plans. Mitigation measures and alternative activities related to the identified threats, that can be used to protect the species, are also presented. This information may be used to inform the issuing of SARA Section 73 permits.

Research Document 2019/033 (PDF, 3,105 KB)