Terms of Reference

Walleye Pollock (Theragra chalcogramma) stock assessment for British Columbia in 2016

Regional Peer Review Process – Pacific Region

November 14-15, 2017
Nanaimo, BC

Chairperson: To be determined

Context

The last assessment of Walleye Pollock, conducted in 1997, did not estimate stock status relative to reference points that are consistent with Fisheries and Oceans Canada (DFO)’s Fishery Decision-Making Framework Incorporating the Precautionary Approach (DFO Precautionary Approach) (DFO 2009). Harvest advice is required for this species to determine if current harvest levels are sustainable and are compliant with the DFO Precautionary Approach. A 2013 request to reassess Walleye Pollock was considered unachievable at the time due to data limitations. 

The Walleye Pollock fishery in Alaska is substantially larger than the Walleye Pollock fishery in BC, and supports the largest landings of any single species in the USA. The highest concentrations of Walleye Pollock occur in the Eastern Bering Sea (annual catches > 1 million tonnes), with lesser amounts caught in the Gulf of Alaska (annual catches > 100,000 tonnes). These Alaskan fisheries are supported by complex, age-structured models; with a strong investment in acoustic and trawl surveys, as well as catch sampling and an intensive ageing program. Data available from the Alaskan fisheries can be utilized for the BC Walleye Pollock assessment (Dorn et al. 2012, Dorn et al. 2015, Ianelli et al. 2015).

DFO Fisheries Management has requested DFO Science provide advice regarding the assessment of the coastwide Walleye Pollock stock relative to reference points that are consistent with the DFO’s Precautionary Approach, and implications of varying harvest rates on expected stock status. The advice arising from this Canadian Science Advisory Secretariat (CSAS) Regional Peer Review (RPR) will be used to inform fisheries management decisions.  This work may also inform and supplement decisions external to DFO; including those on Marine Stewardship Council (MSC) certification and trans-boundary fisheries management.

Objective

The following working paper will be reviewed and provide the basis for discussion and advice on the specific objectives outlined below.

Starr, P.J., Haigh, R.  Stock assessment for Walleye Pollock (Theragra chalcogramma) in British Columbia in 2016. CSAP Working Paper 2013GRF03.

Guided by the DFO Sustainable Fisheries Framework, the following objectives for this assessment have been established:

1. assess the current biomass and status of Walleye Pollock (Theragra chalcogramma) for BC waters (the number of stock assessments will depend on the stock structure determination and the availability/suitability of data);
2. suggest candidate reference points (either biomass-based or fishing mortality-based) consistent with the DFO Precautionary Approach, including alternatives to model-based reference points;
3. provide the rationale used to select recommended candidate reference points, including reasons if the candidate points differ from the PA framework default reference points;
4. provide decision tables forecasting the predicted status of Walleye Pollock relative to reference points across a range of management actions;
5. identify additional information needed to enhance appropriate stock assessment advice consistent with goal of implementing ecosystem-based fisheries management, as articulated in the Sustainable Fisheries Framework;
6. if possible, propose an appropriate time interval between assessments, and a trigger mechanism that may affect the assessment schedule; or, provide rationale why this is not possible.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document

Expected Participation

• Fisheries and Oceans Canada (DFO) (Science and Groundfish Fisheries Management)
• Commercial and Recreational Fishing Representatives
• Environmental Non-government Organizations
• Academia

References

DFO 2009. A Fishery Decision-Making Framework Incorporating the Precautionary Approach. (Accessed March 31, 2017)

Dorn, M., K. Aydin, S. Barbeaux, D. Jones, A. McCarthy, K. Spalinger and W. Palsson.  2012.  Assessment of the Walleye Pollock stock in the Gulf of Alaska.  In Stock Assessment and Fishery Evaluation Report for Groundfish Resources of the Gulf of Alaska. Prepared by the Gulf of Alaska Groundfish Plan Team, North Pacific Fishery Management Council, P.O. Box 103136, Anchorage, AK 99510. North Pacific Fisheries Management Council, Anchorage, AK. 95 p. + 5 Appendices.

Dorn, M., K. Aydin, D. Jones, A. McCarthy, W. Palsson, and K. Spalinger.  2015.  Assessment of the Walleye Pollock stock in the Gulf of Alaska.  In Stock Assessment and Fishery Evaluation Report for Groundfish Resources of the Gulf of Alaska. Prepared by the Gulf of Alaska Groundfish Plan Team, North Pacific Fishery Management Council, P.O. Box 103136, Anchorage, AK 99510. North Pacific Fisheries Management Council, Anchorage, AK.  158 p. + 4 Appendices.

Ianelli, J.N., Honkalehto, T., Barbeaux, S., and Kotwicki, S. 2015. Chapter 1. Assessment of the Walleye Pollock Stock. In the Eastern Bering Sea NPFMC Bering Sea and Aleutian Islands SAFE, North Pacific Fisheries Management Council, 53-152.