Proceedings 2021/044
Proceedings of the Pacific regional peer review on the selection and role of limit reference points for Pacific Herring (Clupea pallasii) in British Columbia, Canada; February 7-8, 2017
Chairperson: Linnea Flostrand
Editor: Julia Bradshaw
Summary
These proceedings summarize the discussions and key conclusions that resulted from a Fisheries and Oceans Canada (DFO) Canadian Science Advisory Secretariat (CSAS) Regional Peer Review meeting of February 7-8, 2017 held in Nanaimo, British Columbia (BC) to review the Working Paper titled “The selection and role of limit reference points for Pacific Herring (Clupea pallasii) in British Columbia, Canada”.
In-person and web-based participation included individuals from Fisheries and Oceans Canada (DFO) Science Branch (current and retired employees) and Fisheries Management Branch; individuals representing: First Nations, the Alaska Department of Fish and Game, the commercial fishing sector, academia, and consultants.
The Working Paper presented information pertaining to requirements under the DFO Decision-Making Framework Incorporating the Precautionary Approach (DFO 2009) as part of the commitment to renewal of the Pacific Herring management system. Surplus production relationships for the five major stocks of Pacific Herring in relation to spawning stock biomass were evaluated to determine whether there is evidence for stock states that show signs of persistent low production and low biomass that are consistent with signs of possible serious harm. Additionally, a range of theoretical equilibrium reference fishing mortality rates related to the concept of the replacement fishing mortality was investigated along with associated proxies based on maximum sustainable yield, spawning potential ratio and yield-per-recruit. Persistent low production and low biomass states were diagnosed for stocks in the Central Coast (CC), Haida Gwaii (HG), and West Coast (WCVI) major management areas; similar states were not diagnosed for stocks in the Prince Rupert District (PRD) and Strait of Georgia (SOG) management areas. A limit reference point of 0.3 of the unfished spawning biomass (0.3B0) was recommended for stocks in all major management areas based on the upper spawning biomass frontier of the low production, low biomass states for stocks in the CC, HG, and WCVI management areas. This recommendation is conditioned on the assumptions, data, and outputs from current stock assessment models (DFO 2016) and is based on the analysis of production relationships and the policy requirement to position biomass-based limit reference points above states of possible slowly reversible or irreversible serious harm. Limit equilibrium fishing mortality rates based on the concept of replacement fishing mortality could not be recommended because of implausible estimates that were attributed to non-stationarity in natural mortality, changes in observed weight at age, and the relative positions of maturity at age and commercial gear selectivity.
The conclusions and advice resulting from this review will be provided in the form of a Science Advisory Report (SAR), and will be used to inform the ongoing renewal of the management framework for BC Pacific Herring. The Science Advisory Report and supporting Research Document will be made publicly available on the Canadian Science Advisory Secretariat (CSAS) website.
Accessibility Notice
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