Terms of Reference

Stock status and fishery advice for May 2017 to May 2022 for Witch Flounder (Glyptocephalus cynoglossus) from NAFO Divisions 4RST, Gulf of St. Lawrence

Regional Peer Review – Gulf Region

March 2, 2017
Moncton, NB

Chairperson: Hugues Benoît

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 300 t, for the fishing years May 15, 2012 to May 14, 2017. The last stock assessment was completed in February 2012 for the fishery years May 2012 to May 2017 (DFO 2012; Swain et al. 2012). In this last assessment, the estimate of the spawning stock biomass in 2011 was at about half the limit reference point (LRP) and the estimated exploitation rate in 2011 of 0.09 was above the maximum removal rate in the healthy zone of 0.07. The biomass was expected to increase with annual catches of 300 t however, even with no catch, there was a 62% 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 some 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 2016a).

In support of DFO Ecosystems and Fisheries Management multi-year management approach and request for advice for a TAC decision for May 2017 to May 2022, 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 2017 to May 2022) 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 2016.
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 2016.
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 100 t to 500 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 2017 to 2022.
As per DFO (2016b), 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

CSAS Science Advisory Report
CSAS Proceedings
CSAS Research Document

Participation

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