Terms of Reference

Assessment of Dolly Varden, Salvelinus malma malma, from the Rat River, Northwest Territories

Regional Peer Review – Central and Arctic Region

February 10-11, 2015
Winnipeg, Manitoba

Chairperson: Margaret Treble

Context

Situated in the Gwich’in settlement Area (GSA), the Rat River is inhabited by anadromous Dolly Varden that are harvested by both Gwich’in and Inuvialuit beneficiaries. The harvest of Dolly Varden from the Rat River occurs during the summer at feeding areas along the coast (by the Inuvialuit) and also during the upstream migration in the Mackenzie Delta (by both the Gwich’in and Inuvialuit). Dolly Varden are co-managed under an Integrated Fisheries Management Plan (IFMP) whose signatories include Fisheries and Oceans Canada (DFO), Gwich'in Renewable Resources Board, Fisheries Joint Management Committee, and Parks Canada Agency. The Rat River Working Group, the co-management body that makes recommendations for voluntary harvest levels for Dolly Varden stocks in the GSA, has supported research activities that facilitate implementation of the IFMP, including studies to monitor harvest levels and assess the population status.

Dolly Varden from the Rat River were last assessed in 2008. Fisheries Management has requested an updated assessment and evaluation of population status for the Rat River stock.

Objectives

Fisheries Management requests Science advice on stock status, abundance estimates and sustainable harvest levels for the Rat River stock based on the following:

1. Comparison of current and past population estimates (based on mark recapture methods);
2. Estimates of effective population size (using genetic methods) and how it relates to the mark-recapture estimates of population size;
3. Comparison of current biological information (length, weight, age, sex, maturity, and growth) (2009-2014) with past data (1995-2008) collected through the Rat River Harvest Monitoring Program and the seining program at the spawning/ overwintering area;
4. Population dynamics modelling using total harvest, catch-effort, biological, and abiotic (water levels and debris) information; standardize catch per unit effort related to fishery-dependent monitoring of stock status; and generate biological reference points;
5. Evaluation of the contribution of Dolly Varden from the Rat River to the mixed-stock-fishery at Shingle Point, Herschel Island, and Ptarmigan Bay using genetic mixed stock fishery analysis (2011-2014);
6. Compilation of annual harvest information for Dolly Varden captured along the Beaufort Sea coast and in the Mackenzie Delta (2009-2014); and

Estimation of sustainable harvest levels and the associated risks for the stocks.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document(s)

Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, and Ecosystems and Fisheries Management sectors)
• Gwich’in Renewable Resource Board
• Fisheries Joint Management Committee
• Academics
• Other invited experts