Terms of Reference

The identification of candidate reference points and harvest rate options for the commercial Red Sea Urchin (Mesocentrotus franciscanus) fishery in British Columbia

Regional Peer Review Process – Pacific Region

February 13, 2019
Nanaimo, British Columbia

Chairperson: Lyanne Curtis

Context

The Red Sea Urchin fishery in British Columbia (BC) is managed using an annual harvest rate of 2% (Leus et al. 2014). This harvest rate was derived using a modified Gulland surplus production model; a model used when a stock is data limited and in the early stages of exploitation. The model is simple and precautionary, however it carries an inherent uncertainty because it multiplies the estimated instantaneous natural mortality rate by an arbitrary correction factor of 0.2. The Red Sea Urchin fishery is not in the early stages of exploitation, rather commercial harvesting has been occurring for over 40 years and there has been almost 25 years of density and size data gathered on fishery independent surveys. Data from these surveys have been used to estimate growth and mortality rates for Red Sea Urchins in BC (Zhang et al. 2008, Zhang et al. 2011).  The availability of a substantial amount of biological information warrants a re-evaluation of the 2% harvest rate derived from the modified Gulland model.

The existing Red Sea Urchin harvest strategy lacks a clearly defined set of biological reference points that reflect conservation thresholds under DFO's Sustainable Fisheries Framework (DFO 2009). Biological reference points are used in harvest strategies as quantitative conservation benchmarks from which management actions can be taken.

Fisheries and Oceans Canada (DFO) Fisheries Management requested DFO Science Branch to provide advice on the application of a range of harvest rates for the Red Sea Urchin commercial fishery.  This Canadian Science Advisory Secretariat (CSAS) Regional Peer Review (RPR) will develop a new model that will simulate the response of Red Sea Urchin populations to a range of harvest rates for the following regions of the coast: the Inside Waters between Vancouver Island and the Mainland, Mainland North Coast and Haida Gwaii. 

In addition, to assess whether harvest rates are sustainable and compliant with the DFO Precautionary Approach the concept of serious harm will be considered in identifying a Limit Reference Point (LRP) and an Upper Stock Reference (USR) for the Red Sea Urchin fishery.  Density-based reference points will be recommended and the rationale for this approach will be reviewed.

The assessment and advice arising from this Canadian Science Advisory Secretariat (CSAS) Regional Peer Review (RPR) will be used to update the British Columbia Red Sea Urchin fishery management framework. More specifically, advice will be used to establish reference points and update the Red Sea Urchin harvest rates implemented in British Columbia.

Objective

The following working paper will be reviewed and provide the basis for discussion and advice on the specific objectives outlined below.

Lochead, J, Zhang, Z., and D. Leus. The identification of candidate reference points and harvest rate options for the commercial Red Sea Urchin (Mesocentrotus franciscanus) fishery in British Columbia. CSAP Working Paper. 2016INV02

Guided by the DFO Sustainable Fisheries Framework, the following objectives for this assessment have been established:

1. Develop a new model that will simulate the response of British Columbia Red Sea Urchin populations to a range of harvest rates for the following regions of the coast: the Inside Waters between Vancouver Island and the Mainland, Mainland North Coast and Haida Gwaii.
2. Recommend a candidate Limit Reference Point and Upper Stock Reference consistent with the DFO Precautionary Approach for the Red Sea Urchin fishery.
3. Provide decision tables specifying the estimated probability of breaching the LRP and USR across a range of harvest rates, for the following regions of the coast: the Inside Waters between Vancouver Island and the Mainland, Mainland North Coast and Haida Gwaii.
4. Where possible, assess the current status of Red Sea Urchin populations relative to the candidate reference points for the following regions of the coast: the Inside Waters between Vancouver Island and the Mainland, Mainland North Coast and Haida Gwaii.
5. Examine and identify uncertainties in the data and methods.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document

Expected Participation

• Fisheries and Oceans Canada (DFO) (Ecosystems and Oceans Science, and Ecosystems and Fisheries Management sectors)
• First Nations
• Pacific Urchin Harvesters Association

References

DFO 2009. A Fishery Decision-Making Framework Incorporating the Precautionary Approach. (Accessed December 19, 2018)

Leus, D., Campbell, A., Merner, E., Hajas, W.C., and L.L. Barton. 2014. Framework for estimating quota options for the Red Sea Urchin (Strongylocentrotus franciscanus) fishery in British Columbia using shoreline length and linear density estimates. DFO Can. Sci. Advis. Sec. Res. Doc. 2013/094. vi + 68 p.

Zhang, Z., Campbell A. and D. Bureau. 2008. Growth and nautral mortality rates of Red Sea Urchin (Strongylocentrotus Franciscanus) in British Columbia. Journal of Shellfish Research 27(5): 1291-1299.

Zhang, Z., Campbell, A., Leus, D. and D. Bureau. 2011. Recruitment patterns and juvenile–adult associations of red sea urchins in three areas of British Columbia. Fisheries Research 109: 276–284.