Terms of Reference

Review of the Current Shrimp Trawl Biomass Survey Assessment Methodology for the BC Shrimp Trawl Fishery

Regional Peer Review - Pacific Region

April 1-3, 2025

Nanaimo, BC

Chairperson: Mary Thiess

Context

Commercial trawl fisheries for Northern/Spiny Pink Shrimp (Pandalus borealis), Smooth Pink Shrimp (P. jordani), and Sidestripe Shrimp (Pandalopsis dispar) have been active in British Columbia since the 1930s (DFO 2024). In response to rapid fishery expansion in the mid-1990s, Fisheries and Oceans Canada (DFO) implemented key management changes in 1997, including the establishment of Shrimp Management Areas (SMAs) with annual total allowable catches (TACs), seasonal openings for offshore pink shrimp, and industry-funded programs for catch monitoring and stock assessment.

DFO currently conducts standardized surveys in 10 of 36 SMAs, aiming to maintain a fixed-station design over known fishing grounds to generate an abundance index. Shrimp trawl survey protocols in BC follow document CSAS 99/124 (Boutillier et al. 1999), developed with industry input. In the management context, the current survey index is assumed to represent absolute biomass, which is used to set quotas. Although the framework has been designed to align with the Precautionary Approach (DFO 2009), the shrimp population structure in BC remains poorly understood. It is unclear whether the fixed-station survey design sufficiently accounts for interannual changes in shrimp distribution and abundance or if the SMAs accurately represent the stock’s spatial structure.

Defining stock structure is essential for aligning shrimp management with the Fish Stocks Provisions of the amended Fisheries Act (2019) (DFO 2023a). Further, mismatches between the spatial scales at which biological processes, management and assessment activities occur may compromise the efficacy of stock assessment and management systems aiming to avoid serious harm to stocks (DFO 2023b). Thus, work to determine meaningful spatial units will aid in stock assessment, enhance the current survey design, and improve the accuracy of biomass index estimation.

Note that the current peer review process focuses on evaluation of survey design using a simulation framework. As such, aspects of survey design outside the simulation framework, such as number of animals sampled, different gear configurations, and tow length, are beyond the scope of the current process. Outcomes from this process are expected to provide the basis for future assessments of stock status and reference points, and potentially alternative stock assessment methods for the fishery.

Objectives

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

Araujo, H. A., Mazur, M., Burton M., Cao, J., Noble V., Aulthouse B. Obradovich, S., Anderson S. CSAP Working Paper 2020INV02-2022INV03.

Given available information and data, there are four main objectives for this project:

1. Evaluate spatial stock definitions for Smooth pink, Spiny pink, and Sidestripe shrimp in BC, consistent with the DFO Fish Stocks Provisions;
2. Recommend survey areas based on the presence and absence of Smooth Pink, Spiny Pink, and Sidestripe Shrimp;
3. Evaluate the accuracy and precision of candidate survey designs and index estimation methods for monitoring Smooth Pink, Spiny Pink, and Sidestripe Shrimp stocks in BC, along with recommendations on the optimal survey design and index estimation method; and
4. Describe sources of uncertainty related to stock definition, selected survey design, and index estimation method.

Expected Publications

• Science Advisory Report
• Research Document

Expected Participation

• Fisheries and Oceans Canada
• Academia
• Indigenous communities/organizations
• Fishing Industry
• Other Organizations

References

• Boutillier, J.A., J. A Bond, and H. Nguyen. 1999. Evaluation of a New Assessment and Management Framework for Shrimp Stocks in British Columbia. Canadian Stock Assessment Secretariat Research Document 99/124.
• DFO. 2009. A Fishery Decision-Making Framework Incorporating the Precautionary Approach. Fisheries and Oceans Canada.
• DFO. 2023a. Guidelines for Implementing the Fish Stocks Provisions in the Fisheries Act. Fisheries and Oceans Canada.
• DFO. 2023b. Science Advice on Guidance for Limit Reference Points under the Fish Stocks Provisions. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2023/009.
• DFO. 2024. Shrimp by Trawl Fisheries Management Plan 2024/25. 23-2293: 182 p.