Terms of Reference

Application of the Herring Operating Model for the Strait of Georgia

Regional Peer Review - Pacific Region]

September 23, 2024

Virtual Meeting

Chairperson: Chris Rooper

Context

Fisheries and Oceans Canada (DFO) initiated a Management Strategy Evaluation (MSE) process in 2018 to update the harvest strategies for Pacific Herring in BC (DFO 2019). Herring MSE is guided by the Sustainable Fisheries Framework (DFO 2009), and includes engagement with coastal First Nations and the Herring Industry Advisory Board (HIAB).

Performance of harvest strategies within MSE is determined by simulation testing management procedures (MPs) against operating models (OM) that represent a range of hypotheses about uncertain Herring stock and fishery dynamics. The performance of MPs is measured against conservation and socio-economic objectives for the stock and fishery. The first set of operating models for Pacific Herring were developed in 2015 to examine the utility of a range of conservation objectives (candidate limit reference points) (Cox et al. 2019). The OMs were subsequently modified for implementation in the first MSE cycle in all 5 major stock areas (DFO 2019, DFO 2020, Benson et al. 2023).

Feedback from scientific peer review and consultation with First Nations and the fishing industry indicated the functionality of the OMs should expand to better represent ecosystem effects on the Herring populations, and to account for ongoing analytical issues. In June 2023, a new modelling framework was developed for this purpose. The new modeling framework is a spatially integrated statistical catch-at-age herring model (SISCAH) which includes flexibility for: (i) modelling natural mortality as a density-dependent process to represent potential ecosystem impacts (e.g., depensatory predation) on Herring; (ii) a method for integrating data from surface and dive surveys in estimation of the survey index; (iii) representation of timing of all fisheries throughout the year; (iv) inclusion of spawn-on-kelp fisheries; and (v) an age-composition likelihood function that captures correlation among ages. The SISCAH modelling framework was reviewed through the Canadian Science Advisory Secretariat (CSAS) process (DFO 2023b; Johnson et al. 2024^{Footnote 1}), and approved for use as both a stock assessment and an MSE operating model for the 5 major Pacific Herring stocks.

In addition to endorsing adoption of SISCAH as the modelling framework, the CSAS review recommended that the Pacific Herring MSE process (i) use a minimum 3-year cycle for OM update and MP evaluation, unless new evidence reveals exceptional circumstances; and (ii) that implementation of SISCAH should be done in phases for each major stock area in consultation with managers, First Nations and stakeholders. Highest priority is given to Herring stocks with active fisheries.

Given these recommendations, the DFO Fisheries Management Branch requested that Science Branch begin with the Strait of Georgia herring stock, and update SISCAH with the most recent data to undertake simulation-evaluation of MPs for identifying harvest strategies. The advice arising from this CSAS Science Response process will provide fishery managers with MP(s) that meet the established conservation objective (DFO 2023a) and are compliant with both the “DFO Sustainable Fisheries Framework” policy and “A fishery decision-making framework incorporating the Precautionary Approach” policy (DFO 2009). This work will support development of the 2024/2025 Integrated Fisheries Management Plan.

Objectives

The specific objectives of this Science Response are to:

1. Provide the results of fitting (conditioning) a SISCAH operating model to updated stock monitoring and fishery data for Strait of Georgia Herring.
2. Characterize stock status relative to reference points and for the operating model configuration.
3. Present MP(s) which meet the established conservation objective and are compliant with the DFO Precautionary Approach Policy.
4. Apply MP(s) for 2024/25.

Expected Publications

• Science Response

Expected Participation

• DFO Science and Fisheries Management

References

• Benson, A.J., Cleary, J.S., Cox, S.P., Johnson, S.D.N., and Grinnell, M. 2022. Performance of management procedures for British Columbia Pacific Herring (Clupea pallasii) in the presence of model uncertainty: closing the gap between precautionary fisheries theory and practice. DFO Can. Sci. Advis. Sec. Res. Doc. 2022/048.
• Cox, S.P., Benson, A.J., Cleary, J.S, and Taylor, N.G. 2019. Candidate Limit Reference Points as a Basis for Choosing Among Alternative Harvest Control Rules for Pacific Herring (Clupea pallasii) in British Columbia. DFO Can. Sci. Advis. Sec. Res. Doc. 2019/050. viii + 47 p.
• DFO. 2009. A fishery decision-making framework incorporating the Precautionary Approach.
• DFO 2018. Stock Assessment and Management Advice for BC Pacific Herring: 2017 Status and 2018 Forecast. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2018/002.
• DFO. 2019. Evaluation of Management Procedures for Pacific Herring (Clupea pallasii) in the Strait of Georgia and the West Coast of Vancouver Island Management Areas of British Columbia. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2019/001.
• DFO. 2020. Evaluation of Management Procedures for Pacific Herring (Clupea pallasii) in Haida Gwaii, Prince Rupert District, and the Central Coast Management Areas of British Columbia. DFO Can. Sci. Advis. Sec. Sci. Resp. 2020/003.
• DFO. 2022. Stock status update with application of management procedures for Pacific Herring (Clupea pallasii) in British Columbia: Status in 2022 and forecast for 2023. DFO Can. Sci. Advis. Sec. Sci. Resp. 2022/046.
• DFO. 2023a. Management Strategy Evaluation Update and Evaluation of Upper Stock Reference Point Options for Pacific Herring (Clupea pallasii) in British Columbia, Canada. DFO Can. Sci. Advis. Sec. Sci. Resp. 2023/002.
• DFO. 2023b. Application of a new modelling framework for the assessment of Pacific Herring (Clupea pallasii) major stocks and implementation in the management strategy evaluation process. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2023/040.
• DFO. 2024. Stock Status Update with Application of Management Procedures for Pacific Herring (Clupea pallasii) in British Columbia: Status in 2023 and Forecast for 2024. DFO Can. Sci. Advis. Sec. Sci. Resp. 2024/001.
• Kronlund, A.R., Forrest, R.E., Cleary, J.S., and Grinnell, M.H. 2018. The selection and role of limit reference points for Pacific Herring (Clupea pallasii) in British Columbia, Canada. DFO Can. Sci. Advis. Sec. Res. Doc. 2018/009. ix + 125 p.