Research Document - 2010/081
Information Relevant to a Recovery Potential Assessment of Lake Sturgeon: Saskatchewan River Populations (DU2)
By H. Cleator, K.A. Martin, T.C. Pratt, R. Campbell, M. Pollock, and D. Watters
Abstract
The Lake Sturgeon (Acipenser fulvescens) was common in nearshore waters across much of Canada in the nineteenth century, but intensive fishing, habitat loss and degraded water quality caused severe reductions in population size or extirpation across their range. Today they remain extant from the North Saskatchewan River in Alberta, to Hudson Bay in the north, and eastward to the St. Lawrence River estuary. In November 2006, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed Lake Sturgeon in Canada. Designatable Unit (DU) 2, the Saskatchewan River populations, includes Lake Sturgeon in the Saskatchewan River upstream of the Grand Rapids Generating Station at Lake Winnipeg and all drainages west to east-central Alberta. COSEWIC assessed and designated DU2 as Endangered. Commercial over-exploitation and the detrimental impacts associated with dams/impoundments and other barriers contributed to the declines in Lake Sturgeon abundance in DU2. Negative impacts associated with fishing and habitat degradation or loss and population fragmentation, resulting from dams/impoundments and other barriers, are ongoing. These, combined with new threats from agriculture, urban development and forestry, currently pose the greatest threats to the survival and recovery of Lake Sturgeon in DU2, although the importance of individual threats vary by Management Unit (MU).
DU2 Lake Sturgeon is being considered for legal listing under the Species at Risk Act (SARA). In advance of making a listing decision, Fisheries and Oceans Canada (DFO) has been asked to undertake a Recovery Potential Assessment (RPA). This RPA summarizes the current understanding of the distribution, abundance and population trends of Lake Sturgeon in DU2, along with recovery targets and times. The current state of knowledge about habitat requirements, threats to both habitat and Lake Sturgeon, and measures to mitigate these impacts for DU2 are also included. This information may be used to inform both scientific and socio-economic elements of the listing decision, development of a recovery strategy and action plan, and to support decision-making with regards to the issuance of permits, agreements and related conditions, as per sections 73, 74, 75, 77 and 78 of SARA.
Six Lake Sturgeon MUs have been identified for DU2. Available data and expert opinion indicate that the current status and population trajectory of MUs 1, 2 and 4 is cautious and stable or increasing, respectively. Abundance in MUs 1 and 4 is probably low to moderate while MU2 appears to be somewhat higher. MU5 is thought to be cautious though its trajectory is unknown. The status of MUs 3 and 6 is deemed to be critical with a stable trajectory in MU6 and unknown trajectory in MU3. Available data and expert opinion suggest that Lake Sturgeon abundance in DU2 ranges from very low to moderate. The long-term recovery goal for DU2 is to protect and maintain healthy, viable populations of Lake Sturgeon in all MUs.
Accessibility Notice
This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.
- Date modified: