Renseignements à l'appui d'une mise à jour de l'évaluation sur le potentiel de rétablissement du sucet de lac (Erimyzon sucetta) au Canada, 2011- 2020

Abstract

The Lake Chubsucker (Erimyzon sucetta) is a small member of the Catostomidae family requiring clear, still, well-vegetated waters. In Canada, it is found in watersheds of southern Lake Huron through Lake Erie. The species was first assessed as Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) in 1994, reassessed as Threatened in 2001, and was listed as Threatened under Schedule 1 of the Species at Risk Act (SARA) in June 2003. Lake Chubsucker was subsequently re-assessed by COSEWIC in 2008 (and again most recently in May 2021) as Endangered and is listed as Endangered under SARA owing to a decline in suitable habitat and extant locations, and multiple habitat-related threats. 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, with updated information from 2011 through 2020. Limited information exists to adequately assess the status of most populations, as records generally represent few individuals caught over a limited number of sampling events using varied sampling protocols. A threat assessment identified the greatest threats to Lake Chubsucker in Ontario as aquatic invasive species, natural system modifications, pollution, and climate change; however, the impacts of these threats are not well understood. Mitigation measures and alternative activities related to the identified threats are presented. Important knowledge gaps remain regarding population trends, physiological tolerances to environmental conditions and pollutants, and habitat requirements by life stage.