Terms of Reference

Framework Review for 4X5Y Haddock: Projections, Simulation Approach, and Reference Points

Regional Peer Review - Maritimes Region

November 25-26, 2024

St. Andrews, NB

Chairperson: Tara McIntyre

Context

Haddock (Melanogrammus aeglefinus) are caught as part of a multi-species groundfish fishery concentrated on the western Scotian Shelf (SS) and in the Bay of Fundy (BoF) in the Northwest Atlantic Fisheries Organization (NAFO) Divisions 4X5Y. In 2017, a virtual population analysis (VPA) model with fixed natural mortality time blocks on older fish, was chosen to provide catch advice (Wang et al. 2017). In 2018, projections from the VPA model showed large retrospective patterns and there was a mismatch between the model predicted biomass and the survey biomass (Finley et al. 2018). The VPA model has therefore not been used to provide catch advice or estimate stock status since 2018, and stock status updates have been provided qualitatively by comparing the survey biomass index to 40% and 80% of the 1985-2020 time series median.

The intent of this framework review, initiated by DFO Maritimes Science, is to develop an analytical modeling framework that can be used to evaluate the performance of management procedures for the 4X5Y Haddock fishery. The first and second peer review meetings for this framework were a review of the data inputs (October 2023; Barrett and Barrett In Prep¹ and a review of the modeling approach (March 2024; Barrett and Barrett In Prep². The objective of this third meeting will be to review the projection scenarios and simulation approach using the set of models that were chosen to capture uncertainty in the historical fishery dynamics at the second peer review meeting. These models and projection scenarios will be used to define operating models (OMs) to be used in the evaluation of the performance of management procedures for the 4X5Y Haddock fishery. Reference points will also be defined to inform on stock status and to be used in performance metrics in the management procedure evaluation.

Objectives

The specific objectives of this third peer review meeting are to review the following Science components of the management procedure evaluation framework:

• The set of OMs that capture uncertainty in the historical and future stock dynamics, where uncertainty in the historical dynamics is captured by the models from the March 2024 peer-review meeting, and uncertainty in the future dynamics will be captured by defining projection scenarios.
• The projection scenarios for weight-at-age, maturity-at-age, selectivity, natural mortality rate, and recruitment for each OM.
• A biomass limit reference point and fishing mortality limit reference point (Fref) and one or more candidate biomass upper stock reference point(s) for each OM.
• An approach to estimate overall stock status from the set of OMs.
• The simulation approach to test management procedures:
• Observation model assumptions
• Weighting of OMs
• Exceptional circumstances that would indicate assumptions of the OMs are no longer valid.
• The proposed frequency and timing of interim-year updates to be provided between full peer-reviewed frameworks, and the recommended timing of the next framework.

Expected Publications

• Research Document

Expected Participation

• DFO Science
• DFO Resource Management
• Provinces of Nova Scotia and New Brunswick
• Academics
• Indigenous communities/organizations
• Fishing industry
• Environmental non-government organizations
• US National Marine Fisheries Service

References

• Barrett, T.J., and Barrett M.A. In Prep¹. 2024 4X5Y Haddock Framework: Data Inputs. DFO Can. Sci. Advis. Sec. Res. Doc.
• Barrett, T.J., and Barrett M.A. In Prep². 2024 4X5Y Haddock Framework: Modeling Approach. DFO Can. Sci. Advis. Sec. Res. Doc.
• Finley, M., Wang, Y., and Stone, H.H. 2018. Assessment of 4X5Y Haddock (Melanogrammus aeglefinus) in 2016. DFO Can. Sci. Advis. Sec. Res. Doc. 2018/041. iv + 54 p.
• Wang, Y., Stone, H. H., and Finley, M. 2017. 4X5Y Haddock 2016 Framework Assessment: Modelling and Reference Points. DFO Can. Sci. Advis. Sec. Res. Doc. 2017/026.