Terms of Reference

An evaluation of the performance of alternative Management Procedures for the Sablefish fishery in British Columbia, Canada

Regional Science Response Process – Pacific Region

September 23, 2019
Nanaimo, BC

Chairperson: Brendan Connors

Context

Guided by the Sustainable Fisheries Framework (DFO 2009), Fisheries and Oceans Canada (DFO) has collaborated with the British Columbia (BC) Sablefish fishing industry on a Management Strategy Evaluation (MSE) process intended to develop and implement a transparent and sustainable harvest strategy for Sablefish in BC. As part of the MSE, the performance of alternative harvest strategies is determined by simulation testing alternative Management Procedures (MPs) against operating models that represent a range of hypotheses about uncertain Sablefish stock dynamics. The performance of MPs is measured against conservation and socio-economic objectives for the stock and fishery (DFO 2017). 

The Sablefish MSE process, and underlying operating model, have been reviewed through various Canadian Science Advisory Secretariat (CSAS) processes (Cox et al. 2011; DFO 2014, DFO 2016, DFO 2017). The Sablefish MSE aims to follow a 3-year cycle in which the current operating model (DFO 2017) is updated to be consistent with most recent data and hypotheses for Sablefish stock dynamics and fishing effects. 

Sablefish begin to appear in commercial fisheries at 2-3 years of age, but regulations require release of fish measuring less than 55 cm fork length, considered to be sub-legal in size. Past Sablefish MSEs have identified a need to limit recruitment and growth overfishing caused by at-sea release mortality of these sub-legal Sablefish because they affect the rate of stock rebuilding and medium- to long-term fishery yield. While some management tactics aimed at reducing sub-legal mortality have been identified and implemented, to date management tactics aimed at reducing sub-legal mortality have not been formally evaluated through the Sablefish MSE process.

The DFO Fisheries Management Branch has requested that the Science Branch update the Sablefish operating model with the most recent data and provide advice about the performance of the current MP, as well as possible alternatives including measures aimed at reducing sub-legal mortality. The advice arising from this CSAS Science Response process will be used to update the current Sablefish MSE, and to inform fishery managers of the sustainability of alternative harvest strategies. It is expected that the advice will be compliant with the “DFO Sustainable Fisheries Framework” policy and “A fishery decision-making framework incorporating the Precautionary Approach” policy (DFO 2009).

Objective

The specific objectives of this Science Response are to:

1. Provide the results of fitting (conditioning) a range of operating model configurations that represent hypotheses about uncertain Sablefish dynamics to updated stock monitoring and fishery data.
2. Characterize Sablefish stock status for each operating model configuration.
3. Quantify and rank the relative performance of alternative MPs against updated Sablefish MSE Objectives. Procedures may include:
   1. The current procedure (DFO 2017)
   2. Procedures based on alternative stock assessment methods (e.g., delay difference model structure)
   3. Procedures with alternative harvest rate ceilings in the harvest control rule (e.g., tuned to ensure all biological Objectives are met with high a high degree of certainty)
   4. Procedures that incorporate measures aimed at reducing sub-legal mortality (e.g., sub-legal caps with ability to carry forward total allowable catch overages to subsequent years)

Expected Publication

• Science Response

Expected Participation

• Fisheries and Oceans Canada (Ecosystems and Oceans Science, Fisheries Management)
• Commercial Sablefish Industry

References

Cox, S.P., Kronlund, A.R., Lacko, L. 2011. Management procedures for the multi-gear Sablefish (Anoplopoma fimbria) fishery in British Columbia, Canada. DFO Can. Sci. Advis. Sec. Res. Doc. 2011/063. viii + 45 p.

DFO. 2009. A Fishery Decision-making Framework Incorporating the Precautionary Approach.

DFO. 2014. Performance of a revised management procedure for Sablefish in British ColumbiaDFO Can. Sci. Advis. Sec. Sci. Resp. 2014/025.

DFO. 2016. A revised operating model for Sablefish (Anoplopoma fimbria) in British Columbia, Canada. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2016/015.

DFO. 2017. Evaluating the robustness of management procedures for the Sablefish (Anoplopoma fimbria) fishery in British Columbia, Canada for 2017-18. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2017/017.