Assessment of snow crab (Chionoecetes opilio) in the southern Gulf of St. Lawrence (areas 12, 12E, 12F and 19) to 2021 and advice for the 2022 fishery

Abstract

Snow crab in the southern Gulf of St. Lawrence (sGSL) is considered as a single stock unit for assessment purposes. Issues with survey catchability led to concerns of over-estimation in recent stock indices. As a precaution, the estimate for the commercial biomass was reduced by 15% before establishing the catch option for 2021, as agreed to during an Advisory Committee meeting on February 24th, 2021. Landings of sGSL snow crab in 2021 were 24,479 tonnes (t), comprised of 21,423 t in Area 12, 223 t in Area 12E, 592 t in Area 12F, and 2,241 t in Area 19. Following slight adjustments in the survey protocol, the 2021 estimates are considered to provide better population indices compared to previous year’s estimates. Commercial stock biomass from the post-fishery survey is estimated at 80,950 t, composed of 77% new recruitment and 23% of residual biomass. Based on the harvest control rule, the commercial stock biomass index corresponds to a target exploitation rate of 40.96% resulting in a Total Allowable Catch (TAC) of 33,163 t for the 2022 fishery. A risk analysis indicates that a catch option of 33,163 t in 2022 would result in a very low likelihood that the residual stock biomass would be below the limit reference point (Blim) and a very high likelihood that the 2022 commercial stock biomass would be above the upper stock reference point (Busr), as defined by the Precautionary Approach (PA). The stock is considered to be in the healthy zone of the PA. Spawning stock abundance and recruitment indices are high. There is continued evidence of warming conditions in the sGSL and the extent to which it could impact snow crab population dynamics and distribution is not well understood.