Terms of Reference

Development of biological reference points and retrospective evaluation of abundance trends in Fraser River Dungeness Crab (Management Areas I and J)

Regional Peer Review – Pacific Region

February 28 – March 1, 2022
Virtual Meeting

Chairperson: John Candy

Context

Fisheries and Oceans Canada (DFO) manages the Dungeness Crab fishery, which consists of seven Crab Management Areas (CMAs; A, B, E, G, H, I, and J) in the Fraser River Delta, British Columbia (BC). Although some differences exist between the CMAs (Harbo and Wylie, 2006), within Canada, Dungeness Crab fisheries are primarily managed based on a ‘3 S’ (size, sex, and season) management strategy. This management strategy is designed to allow sexually mature sublegal male crabs one to two breeding seasons prior to recruiting into the fishery, to protect female crabs, and to protect crabs during vulnerable softshell periods.

As is typical of the Dungeness Crab fisheries along the Pacific coast of North America, catch has fluctuated between and within CMAs on both annual and decadal scales. Although a similar management strategy has been in place since the early 1900s, recent declines in commercial catch for CMAs I and J, along with heightened awareness of the effects of changing environmental conditions, have elevated concerns regarding the long term sustainability of the fishery. In response to these concerns, as well as the need to be compliant with the fish stock provisions of the Fisheries Act, and DFO’s Precautionary Approach (DFO 2009), DFO is taking the necessary steps to promote the sustainability of the stock.

Fisheries and Oceans Canada (DFO) Fisheries Management Branch has requested that DFO Science Branch develop biological reference points to help determine the stock status of the Fraser River Dungeness Crab Management Areas (I & J), relative to abundance trends.

The advice arising from this Canadian Science Advisory Secretariat (CSAS) Regional Peer Review (RPR) process will be used to inform resource managers on stock status, including the need for evaluating alternative harvest strategies. The advice may also provide a framework for developing biological reference points and a method for assessing abundance trends in other CMAs. Crab Management Areas I and J currently have the most comprehensive DFO fishery independent survey data, making them a logical starting point for developing reference points coast-wide.

Objectives

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

Aulthouse B., Araujo, H. A., Obradovich, S., Burton M.,  Zhang, Z., Fong, K. and Curtis, D. Development of biological reference points and retrospective evaluation of abundance trends in Crab Management Areas I and J. 2022. CSAP Working Paper 2016INV01.

The specific objectives of this review are to:

1. Develop a biological limit reference point and recommend an upper stock reference for DFO Crab Management Areas I and J.
2. Compare long-term trends in abundance indices for (a) legal male, (b) female, and (c) sub-legal male Dungeness Crab in CMAs I and J, and where appropriate, compare these indices to the reference points in (1) to determine stock status.
3. Discuss sources of uncertainty, including the applicability of these methods to determine reference points in other CMAs.

Expected Publications

• Science Advisory Report
• Proceedings
• Research Document

Expected Participation

• Fisheries and Oceans Canada (Science, and Fisheries Management sectors)
• Academia (e.g. University of British Columbia)
• First Nations (e.g. Cowichan, Musqueam, Semiahmoo, Squamish, Tsawwassen and Tseil-Waututh)
• Commercial Industry
• Sport Fishing Advisory Board

References

• DFO. 2009. A Fishery Decision-Making Framework Incorporating the Precautionary Approach. Fisheries and Oceans Canada.
• Harbo, R.M. and Wylie, E.S. (eds.) 2006. Pacific commercial fishery updates for invertebrate resources (2000). Can. Manuscr. Rep. Fish. Aquat. Sci. 2735: viii + 304 p.