Terms of Reference

Development of an assessment model for northern shrimp stocks in the Estuary and Gulf of St. Lawrence

Regional Peer Review - Quebec Region

June 28, 2023
Mont-Joli, QC

Chairperson: Stéphane Plourde

Context

The first precautionary approach for the four Estuary and Gulf of St. Lawrence northern shrimp stocks was adopted in 2012 (DFO 2011). However, during the last stock assessment in winter 2022 (DFO 2022), it was concluded that the precautionary approach should be reviewed before the next assessment. This review is justified since ecosystem conditions have changed since the precautionary approach was developed in the early 2010s, and since a bias has been observed in the main stock status indicator. The new precautionary approach will be developed on the basis of a new assessment model that should make it possible to:

1. estimate the population biomass,
2. establish reference points consistent with the precautionary approach,
3. estimate the exploitation rate,
4. consider the changing environment, and
5. provide the opportunity to make projections.

In addition, at this meeting, the geographic boundaries delineating shrimp stocks will be reviewed using information on the spatial distribution of northern shrimp, information on seabed topography, and population genomics studies.

Objectives

Evaluate an assessment model that could be used as a basis for providing science advice on the northern shrimp stocks in the Estuary and Gulf of St. Lawrence. If a model is deemed appropriate for the assessment, it will be used in the review of the precautionary approach and in the next stock assessment. Specifically, the meeting will address the following:

1. Review the geographic boundaries of shrimp stocks in the Estuary and Gulf of St. Lawrence, in particular the boundary between the Sept-Îles and Anticosti areas south of Anticosti Island
• Estimating historical landings in the new assessment areas
• Estimating biomass indices in new assessment areas
2. Review a surplus production stock assessment model
• Model fitting using landings data and biomass indices
• Studying the sensitivity of different model input parameters
3. Provide direction on projection methods for future catch options
4. Provide direction for an approach to estimating reference points for these stocks
5. Identify uncertainties and knowledge gaps
6. Identify priority short- and medium-term research recommendations to improve data sources, assessment model formulation and estimation, and projection methods

Expected Publications

• Research Document

Expected Participation

• Fisheries and Oceans Canada (DFO) (Science and Ecosystems and Fisheries Management)
• Fishing industry
• Provincial representatives
• Indigenous communities/organizations

References

• DFO. 2011. Reference points consistent with the precautionary approach for northern shrimp in the Estuary and Gulf of St. Lawrence. DFO Can. Sci. Advis. Sec., Sci. Advis. Rep. 2011/062. 
• DFO. 2022. Assessment of Northern Shrimp stocks in the Estuary and Gulf of St. Lawrence in 2021. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2022/006.