Terms of Reference

Stock status and fishery advice for May 2022 to May 2027 for Witch Flounder (Glyptocephalus cynoglossus) from NAFO Division 4RST, Gulf of St. Lawrence

Regional Advisory Meeting – Gulf Region

March 1-2, 2022
Virtual Meeting

Chairpersons: Elizabeth Thompson and Stephanie Boudreau

Context

The Witch Flounder (Glyptocephalus cynoglossus) fishery in the Gulf of St. Lawrence (NAFO Divs. 4RST) is managed using a five-year management plan that includes an annual total allowable catch (TAC) set at 500 t, for the fishing years May 15, 2017 to May 14, 2022. The last stock assessment was completed in February 2017 for the fishery years May 2017 to May 2022 (DFO 2017; Ricard and Swain 2018). In this last assessment, the estimate of the spawning stock biomass in 2016 was at about the limit reference point (LRP) and the estimated exploitation rate in 2016 of 0.04 was below the maximum removal rate in the healthy zone of 0.07. The biomass was expected to increase with annual catches of 500 t however, even with no catch, there was a 23% probability that the spawning stock biomass would remain below the LRP in five years. The annual indicator of abundance, combined research vessel index from NAFO Divs. 4RST, showed continuous improvement in biomass since the last assessment due to the recruitment of a strong-year class to commercial sizes, however, the indices for this stock showed high inter-annual variability (DFO 2020).

In support of DFO Ecosystems and Fisheries Management multi-year management approach and request for advice for a TAC decision for May 2022 to May 2027, DFO Science Branch Gulf Region will undertake a peer review of the stock status and develop management advice for the fishery on Witch Flounder from NAFO Divs. 4RST.

Objectives

To develop science advice in support of the multi-year TAC decision (May 2022 to May 2027) for Witch Flounder (NAFO Divs. 4RST) the following items will be considered.

• Amounts, age, and size structure of the catch of Witch Flounder from the Gulf of St. Lawrence fisheries to 2021.
• Indices of abundance of Witch Flounder from the research vessel and sentinel fishery surveys.
• Best estimates from a population model of the spawning stock biomass, recruitment, recruitment rates, and mortality rates (fishing, natural) to 2021.
• Definition or revision if warranted of reference points for the Witch Flounder stock of the Gulf of St. Lawrence.
• Status of the stock relative to defined biological reference points.
• Population trajectories under current productivity (growth, recruitment, natural mortality) rates and assuming an annual total allowable catch of Witch Flounder of 500 t to 2000 t, and probabilities of the spawning stock biomass being in the critical zone, the cautious zone, or the healthy zone of the Precautionary Approach framework for 2022 to 2027.
• As per DFO (2016), identify indicators which would be used to characterize stock status in the intervening years of the five-year assessment and management cycle, the changes in the indicators which would suggest that a full stock re-assessment may be warranted earlier than the scheduled five-year stock assessment cycle, and propose the frequency and timing of interim-year updates to be provided between full peer-reviewed stock assessments as well as the information to be included within the updates.
• Identification of uncertainties and knowledge gaps.

Expected Publications

• Research Document
• Science Advisory Report

Expected Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, and Ecosystems and Fisheries Management)
• Fishing industry
• Aboriginal organizations
• Provinces
• External experts

References

• DFO. 2016.Guidelines for providing interim-year updates and science advice for multi-year assessments. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2016/020.
• DFO. 2017. Stock assessment of Witch Flounder (Glyptocephalus cynoglossus) in the Gulf of St. Lawrence (NAFO Divs. 4RST) to 2016. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2017/036. (Erratum: February 2020)
• DFO. 2020.Updated indices of abundance to 2019 for Winter Flounder from NAFO Div. 4T, Witch Flounder from NAFO Divs. 4RST and White Hake from NAFO Div. 4T. DFO Can. Sci. Advis. Sec. Sci. Resp. 2020/008.
• Ricard, D., and Swain, D.P. 2018.Assessment of Witch Flounder (Glyptocephalus cynoglossus) in the Gulf of St. Lawrence (NAFO Divisions 4RST), February 2017. DFO Can. Sci. Advis. Sec. Res. Doc. 2018/023. xi + 78 p.