Terms of Reference

Identification of a Limit Reference Point for Southwest Nova Scotia/Bay of Fundy Atlantic Herring (Clupea harengus)

Regional Advisory Meeting – Maritimes Region

November 12-13, 2020
Virtual meeting

Chairperson: Kent Smedbol

Context

Fisheries and Oceans Canada (DFO) is currently developing an “assessment” framework using management strategy evaluation (MSE) for the southwest Nova Scotia/Bay of Fundy Atlantic herring stock (SWNS/BoF herring). Qualitative objectives have been defined for the fishery and key uncertainties in fishery dynamics have been captured in a reference set of operating models (OMs). Twenty-four OMs have been defined based on a cross of all levels of four axes of uncertainty (natural mortality, future growth, resilience, and inclusion of the southwest New Brunswick weir fishery catch and composition data). The OMs have been conditioned to fishery catch and composition data (1978-2018), an acoustic survey of spawning stock biomass (1999-2018), and a larval survey as an index of spawning stock abundance (1972-1998, 2009) using a multi-fleet stock reduction analysis modelling approach (Carruthers et al. 2020). DFO and stakeholders are currently in the process of defining performance metrics for evaluating candidate management procedures in the MSE.

DFO’s fishery decision making framework incorporating the precautionary approach (DFO 2009) applies to key harvested stocks managed by DFO, including SWNS/BoF herring. One component of the framework, herein referred to as the PA framework, is to define reference points while taking into account uncertainty and risk. The PA framework includes general guidance for defining limit reference points (LRPs) as well as a set of provisional reference points based on fixed proportions of biomass at maximum sustainable yield.

During discussions of performance thresholds for evaluating the performance of candidate management procedures in the MSE, the need to conduct a peer-reviewed evaluation of LRPs was identified to ensure that the selection of a management procedure in the MSE is compliant with the PA framework and its objectives.

Objectives

The objectives of this meeting are to:

• review the definition of an LRP in consideration of the PA framework;
• evaluate the suitability of candidate LRPs and identify the most appropriate LRP to meet the objectives of the PA framework for the reference set of 24 OMs; and
• review the role of the LRP in the MSE in relation to defining performance limits and determining stock status.

Expected Publications

• Proceedings
• Research Document

Expected Participation

• DFO Science
• DFO Resource Management
• DFO Ecosystem Management
• Industry stakeholders
• Provincial government
• Non-government Organizations
• Indigenous groups

References

Carruthers, T.R., Hordyk, A.R., Huynh, Q.C., Singh, R., and Barrett, T.J. 2020. A framework for conditioning operating models for the southwest Nova Scotia/Bay of Fundy spawning component of 4VWX herring. DFO Can. Sci. Advis. Sec. Res. Doc. Unpublished Report.

Fisheries and Oceans Canada (DFO). 2009. A fishery decision-making framework incorporating the precautionary approach.