Terms of Reference

Assessment of stock status of Atlantic herring (Clupea harengus) from the southern Gulf of St. Lawrence (NAFO Div. 4T-4Vn) to 2019 and advice for the 2020 and 2021 fisheries

Regional Science Peer Review – Gulf Region

March 12-13, 2020
Moncton, NB

Chairperson: Matthew Hardy

Context

The assessment of Atlantic herring (Clupea harengus) in the southern Gulf of St. Lawrence (sGSL; NAFO Div. 4T) is conducted on a two-year cycle. The most recent peer review meeting of the assessment of Atlantic herring in the southern Gulf of St. Lawrence was conducted in March 2018 to provide advice for the 2018 and 2019 fisheries (DFO 2018; McDermid et al. 2018).

In support of a request for science advice from DFO Resource Management, DFO Gulf Science Branch will review the status to 2019 of the spring spawning and fall spawning components of the Atlantic herring stock of the of the southern Gulf of St. Lawrence, NAFO Division 4T and provide advice for the 2020 and 2021 fisheries years.

Objectives

Assessment of the status of the spring and fall spawning components of Atlantic herring of the southern Gulf of St. Lawrence (NAFO Div. 4T) including:

• Information on catches to the end of 2019, including best estimates of total removals by all fisheries;
• Key indicators of stock status and trends (commercial catch rates, survey indices, size and/or age composition, etc.);
• Evaluation of the appropriateness and results of the population model(s) for spring and fall spawning components including models that provide estimates of abundance of fall spawners for three geographic areas (north, central, south) of the southern Gulf of St. Lawrence;
• Considering variations in natural mortality and timing of the fisheries, review the most appropriate date for evaluating status relative to reference points and catch options;
• If required, review reference points in the context of revised population models for both spring and fall spawner components;
• For spring spawning herring, a quantitative risk analysis of annual catch options for 2020 and 2021 relative to the following objectives:
  • A 75% or greater probability of the SSB being out of the critical zone within six years;
• For an annual catch of 500 t, how many years are required for the SSB to exceed the upper stock reference point (i.e. in the healthy zone of the PA) with a 50% or greater probability.
• For fall spawning herring, a quantitative risk analysis of annual catch options for 2020 and 2021 relative to the following objectives:
• For fixed annual catch levels, probabilities of 60%, 75%, 95% of the SSB being in the healthy zone within six years;
• For fixed annual catch levels, probabilities of SSB in 2021 and 2022 (post-fishery 2020 and 2021) being equal to or above the USR;
• For fixed annual catch levels, probabilities of an increase in spawning stock biomass (SSB) from 2019;
• For fixed annual catch levels, probabilities of exceeding the F0.1 reference level, if the projected SSB is in the healthy zone.
• Ecosystem considerations including variations in life history parameters, species interactions (e.g. predators, prey) and environmental conditions that affect growth, survival, recruitment, and recruitment rates of herring in the southern Gulf of St. Lawrence.

Expected Publications

• Science Advisory Report
• Research Document(s)

Expected Participation

• Fisheries and Oceans Canada (DFO) (Science Branch and Ecosystems and Fisheries Management)
• Indigenous organizations
• Fishing industry
• Invited external experts
• Provincial governments

References

DFO. 2018. Assessment of the southern Gulf of St. Lawrence (NAFO Div. 4T) spring and fall spawner components of Atlantic herring (Clupea harengus) with advice for the 2018 and 2019 fisheries. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2018/029.

McDermid, J.L., Swain, D.P., Turcotte, F., Robichaud, S.A., and Surette, T. 2018. Assessment of the NAFO Division 4T southern Gulf of St. Lawrence Atlantic herring (Clupea harengus) in 2016 and 2017. DFO Can. Sci. Advis. Sec. Res. Doc. 2018/052. xiv + 122 p.