Terms of Reference

Recovery Potential Assessment – Westslope Cutthroat Trout, Oncorhynchus clarkia lewisi, Saskatchewan-Nelson River Populations (DU1)

Regional Peer Review Meeting – Central and Arctic Region

December 17, 2019
Teleconference/WebEx

Chairperson: Joclyn Paulic

Context

After the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses an aquatic species as Threatened, Endangered or Extirpated, Fisheries and Oceans Canada (DFO) undertakes a number of actions required to support implementation of the Species at Risk Act (SARA). Many of these actions require scientific information on the current status of the wildlife species, threats to its survival and recovery, and the feasibility of recovery. Formulation of this scientific advice has typically been developed through a Recovery Potential Assessment (RPA) that is conducted shortly after the COSEWIC assessment. This timing allows for consideration of peer-reviewed scientific analyses into SARA processes including recovery planning.

COSEWIC met in November 2016 and recommended that Westslope Cutthroat Trout (Oncorhynchus clarkia lewisi) in designatable unit (DU) 1 (Saskatchewan-Nelson River populations) be designated Threatened and in DU2 (Pacific populations) Special Concern. Westslope Cutthroat Trout was previously assessed by COSEWIC in May 2005 and November 2006. The recommended designations for both of these assessments were Threatened and Special Concern for DUs 1 and 2, respectively. A Recovery Potential Assessment was conducted in 2009 and the documents resulting from that meeting are available on the Canadian Science Advisory Secretariat website. The Saskatchewan-Nelson River populations of Westslope Cutthroat Trout are currently listed as Threatened on Schedule 1 of the SARA and a proposed Recovery Strategy and Action Plan has been developed (DFO 2019).

In light of the November 2016 assessment by COSEWIC, DFO Science has been asked to undertake a partial RPA, based on the national RPA Guidance. The Species at Risk Program has requested science advice on life history parameters, recovery targets, and allowable harm. The advice in the RPA may be used to update the existing recovery strategy and action plan, and to support decision making with regards to the issuance of permits or agreements, and the formulation of exemptions and related conditions, as per sections 73, 74, 75, 77, 78 and 83(4) of SARA. The advice in the RPA may also be used to prepare for the reporting requirements of SARA s.55. The advice generated via this process will update and/or consolidate any existing advice regarding Westslope Cutthroat Trout (Saskatchewan-Nelson River populations).

Objective

To provide up-to-date information, and associated uncertainties, to address the following elements:

Life History Parameters

Element 1: Estimate the current or recent life-history parameters for Westslope Cutthroat Trout.

Recovery Targets

Element 2: Propose candidate abundance and distribution target(s) for recovery.

Element 3: Project expected population trajectories over a scientifically reasonable time frame (minimum of 10 years), and trajectories over time to the potential recovery target(s), given current Westslope Cutthroat Trout population dynamics parameters.

Habitat and Residence Requirements

Element 4: Provide advice on the degree to which supply of suitable habitat meets the demands of the species both at present and when the species reaches the potential recovery target(s) identified in Element 2.

Element 5: Assess the probability that the potential recovery target(s) can be achieved under current rates of population dynamics parameters, and how that probability would vary with different mortality (especially lower) and productivity (especially higher) parameters.

Allowable Harm Assessment

Element 6: Evaluate maximum human-induced mortality and habitat destruction that the species can sustain without jeopardizing its survival or recovery.

Expected Publications

• Proceedings
• Research Document
• Science Advisory Report

Expected Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, Ecosystem Management, and Strategic Policy)
• Government of Alberta, Alberta Environment and Parks

References

COSEWIC. 2006. COSEWIC assessment and update status report on the westslope cutthroat trout Oncorhynchus clarkii lewisi (British Columbia population and Alberta population) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 67 p.

COSEWIC. 2016. COSEWIC assessment and status report on the Westslope Cutthroat Trout Oncorhynchus clarkii lewisi, Saskatchewan-Nelson River populations and Pacific populations, in Canada. Ottawa. xvi + 83 p.

DFO. 2019. Recovery Strategy and Action Plan for the Alberta populations of Westslope Cutthroat Trout (Oncorhynchus clarkii lewisi) in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Fisheries and Oceans Canada, Ottawa. vii + 60 pp + Part 2