Terms of Reference

Stock assessment of Yellowtail Flounder (Limanda ferruginea) of the southern Gulf of St. Lawrence (NAFO Div. 4T)

Regional Peer Review – Gulf Region

February 29 and March 1, 2016
Moncton, NB

Chairperson: Gérald Chaput

Context

The last full assessment of the Yellowtail Flounder (Limanda ferruginea) stock in the southern Gulf of St. Lawrence (NAFO Div. 4T) was completed in 2002 (DFO 2002; Poirier and Morin 2002). It was suggested that the stock appears able to support harvest levels closer to 300 t. a review of size at maturity and size characteristics of the catches in the fishery in the Magdalen Islands was conducted in 2010 (DFO 2010). An update of status was provided in 2005 (DFO 2005b) and indicators of abundance were updated in 2013 and 2014 (DFO 2014; DFO 2015). Indices of commercial biomass have declined greatly since the last assessment in 2002. These declines have occurred despite relatively high biomass at pre-commercial sizes, suggesting that mortality at commercial sizes must be very high. The decline in commercial biomass was particularly severe in the strata surrounding the Magdalen Islands, where the main fishery for this stock occurs. In this area, the index dropped suddenly to the lowest level on record in 2007 and has remained at that very low level since then (DFO 2015).

There is an annual total allowable catch (TAC) of 300 t for the fishery on this species. The main fishery for yellowtail flounder occurs in the waters off the Magdalen Islands. In support of DFO Ecosystems and Fisheries Management multi-year management approach and request for advice for a TAC decision for May 2016 to May 2021 for the southern Gulf of St. Lawrence Yellowtail Flounder, DFO Science Branch Gulf Region will undertake a peer review of the stock status of Yellowtail Flounder and develop management advice for the fishery on this stock.

Objectives

To develop science advice in support of the multi-year TAC decision (May 2016 to May 2021) for Yellowtail Flounder (NAFO Div. 4T) the following items will be considered.

• Amounts, age, and size structure of the catch of Yellowtail Flounder from the southern Gulf of St. Lawrence fisheries to 2015.
• Indices of abundance of Yellowtail Flounder from the research vessel and sentinel surveys.
• Best estimates of the spawning stock biomass, recruitment, recruitment rates, and fishing mortality rates to 2015 using a population model or from survey-based estimates.
• Definition of reference points for the Yellowtail Flounder stock of the southern 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 a maximum annual total allowable catch of Yellowtail Flounder of 100 t or 300 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 2016 to 2021.
• Identify indicators which would be used to characterize stock status in the intervening years of the five-year assessment and management cycle and the changes in the indicators or in the characteristics of the fisheries that catch Yellowtail Flounder incidentally which would trigger a re-assessment earlier than the scheduled five-year assessment cycle.
• 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

References

DFO. 2002. Yellowtail Flounder in the southern Gulf of St. Lawrence. DFO Science Stock Status Report A3-16 (2002).

DFO. 2005. Yellowtail Flounder in the southern Gulf of St. Lawrence. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2005/010.

DFO. 2010. Size at sexual maturity and catch characteristics of the yellowtail and winter flounder fishery in the Magdalen Islands. DFO Can. Sci. Advis. Sec. Sci. Resp. 2009/020.

DFO. 2014. Updated indices of abundance to 2013 for stocks of six groundfish species assessed by DFO Gulf Region. DFO Can. Sci. Advis. Sec. Sci. Resp. 2014/028.

DFO. 2015. Updated indices of abundance to 2014 for stocks of six groundfish species assessed by DFO Gulf Region. DFO Can. Sci. Advis. Sec. Sci. Resp. 2015/015.

Poirier, G., and Morin, R. 2002. The status of yellowtail flounder in NAFO Division 4T in 2001. DFO Can. Sci. Advis. Sec. Res. Doc. 2002/034. 40 p.