Évaluation de l’état du stock de morue (Gadus morhua) de la sous-division 3Ps de l’OPANO en 2020

Abstract

The status of the cod stock in the Northwest Atlantic Fisheries Organization (NAFO) Subdivision (Subdiv.) 3Ps was assessed during a Fisheries and Oceans Canada (DFO) Regional Peer Review Process meeting held November 2–7, 2020. Total landings for the 2019–20 management year (April 1–March 31) were 3,499 t, or 59% of the Total Allowable Catch (TAC). This marks the tenth consecutive season that the entire TAC has not been taken. There was no DFO research vessel (RV) survey during spring 2020 due to the pandemic. Sentinel gillnet catch rates have been very low and stable since 1999. Sentinel line trawl catch rates were below average over 2011–18, but the 2019 catch rates were relatively high. An integrated state space model resulting from the 2019 3Ps Cod Framework meeting was used to assess the status of the stock and estimate fishing mortality. The Limit Reference Point (LRP) is 66,000 t of Spawning Stock Biomass (SSB). SSB at January 1, 2021, is estimated to be 25 kt (18 kt–35 kt). The stock is in the Critical Zone (38% of Blim [27–53%]) as defined by the DFO Precautionary Approach (PA) Framework. The probability of being below Blim is >99.9%. The estimated fishing mortality rate (ages 5–8) has generally declined, from 0.16 in 2015 to 0.11 in 2019. With an assumed catch of 2,702 t in 2020, fishing mortality (F) is projected to be 0.07 (0.05–0.09) in 2020. Natural mortality (ages 5–8) was estimated to be 0.43 (0.35–0.52) in 2019. Values of natural mortality (M) during the last four years are the among the highest in the time series. Recruitment (age 2) estimates have been below the long term average since the mid-1990s. Projection of the stock to 2023 was conducted assuming: 1. fishery removals to be within ±60% of current values, 2. a catch of 2,702 t for 2020, and 3. no catch in 2021 and 2022. Under these scenarios, there was a >99% probability that the stock will remain below Blim between 2021 and the beginning of 2023. The probability of stock growth to 2023 ranged between 39% and 78% across catch scenarios (+/-60% of current levels) and was 88% when there are no removals. Natural mortality plays an important role in projections for this stock. If natural mortality rates are appreciably different from those used, outcomes will differ from those projected above. Bottom temperatures in Subdiv. 3Ps remained above normal between 2009–19, but no data were available for 2020. No zooplankton data were available for 2019 and 2020. Satellite imagery indicates that the timing and magnitude of the spring phytoplankton bloom were normal in 2020, after two consecutive years of early onset and above-normal production. Ongoing warming trends, together with an increased dominance of warm water fishes, indicate that this ecosystem continues to experience structural changes. Reduced condition is indicative of diminished productivity in 3Ps cod.