Terms of Reference

Stock Assessment Update of British Columbia Pacific Cod for Areas 3CD, and 5ABCD in 2020

Regional Science Response Process – Pacific Region

October 2020
Virtual Meeting

Chairperson: Robyn Forrest

Context

Pacific Cod (Gadus macrocephalus) is a commercially important species of cod that occurs along the entire coast of British Columbia (BC), Canada, and is considered to be a short lived species (10-11 years). The majority of catches are taken in Hecate Strait and Queen Charlotte Sound, where abundance is highest, although large catches have also been taken off the West Coast of Vancouver Island.  Pacific Cod are caught by the groundfish trawl fishery and occasionally by hook and line fisheries. Four stocks of Pacific Cod are defined for management purposes in BC: Strait of Georgia (4B); West Coast Vancouver Island (3CD); Queen Charlotte Sound (5AB); and Hecate Strait (5CD). This request is for Areas 3CD, 5AB, and 5CD only.

The last assessment for Pacific Cod was conducted in 2018 for Areas 5ABCD and Area 3CD (DFO 2019). The 2018 assessment recommended updating stock advice on a biennial cycle. Furthermore, the 2018 survey index in Area 3CD showed a notable reduction in the abundance index for Pacific Cod. However, due to COVID-19, the scheduled 2020 synoptic trawl survey in Area 3CD did not occur, meaning that there will be no update to the survey index until at least 2021.

The Fishery Decision-Making Framework Incorporating the Precautionary Approach (DFO 2009) policy recommends stock status be estimated relative to reference points. These reference points can include Limit Reference Points, Upper Stock Reference Points, and Target Reference Points. In 2018, reference points, based on estimated historical biomass, were calculated for both stocks (DFO 2019).

Fisheries and Oceans Canada (DFO) Fisheries Management has requested that DFO Science provide updated stock assessment advice based on the 2018 modelling (Forrest et al 2020) for Pacific Cod in Areas 3CD and 5ABCD (using data through to 2020), and present the implications of varying catches on expected stock status relative to reference points that are consistent with the DFO’s Precautionary Approach (DFO 2009).

The advice arising from this Canadian Science Advisory Secretariat (CSAS) Science Response (SR) process will be used to inform fisheries management decisions to define catch levels for the 2021/22 Integrated Fisheries Management Plan.

Objectives

The specific objectives of this Science Response are to:

1. Assess the current status of Pacific Cod for Areas 3CD, and 5ABCD, relative to established reference points.
2. Using probabilistic decision tables, evaluate the consequences of a range of constant catch harvest policies to projected biomass relative to the reference points and additional stock metrics including projected biomass relative to current biomass.
3. Describe the sources of uncertainty related to the model (e.g. model parameter estimates, assumptions regarding catch, productivity, and population status);
4. Recommend an appropriate interval between formal stock assessments, indicators used to characterize stock status in the intervening years, and/or triggers of an earlier than scheduled assessment.  Provide a rationale if indicators and triggers cannot be identified.

Expected Publications

• Science Response

Expected Participation

• Fisheries and Oceans Canada (DFO) (Science and Fisheries Management sectors)

References

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

DFO 2019. Assessment of British Columbia Pacific Cod for Areas 3CD, and 5ABCD in 2018. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2019/008.

Forrest, R.E., Anderson, S.C., Grandin, C.J., and Starr, P.J. 2020. Assessment of Pacifc Cod (Gadus macrocephalus) for Hecate Strait and Queen Charlotte Sound (Area 5ABCD), and West Coast Vancouver Island (Area 3CD) in 2018. DFO Can. Sci. Advis. Sec. Res. Doc. 2020/70. v + 215 p.