Évaluation du crabe des neiges de Terre-Neuve-et-Labrador (divisions 2HJ3KLNOP4R)

Abstract

Overall – Divisions 2HJ3KLNOP4R. The overall exploitable biomass increased from historic lows in both trawl and trap surveys over the past four years; however, this increase was not seen in Assessment Division (AD) 2HJ. Fishery Exploitation Rate Indices (ERIs) were near time-series lows in all ADs in 2021 except 2HJ and 4R3Pn, where exploitation was over 50%. Status quo removals would further reduce the exploitation rate in all ADs in 2022, except 2HJ, where it would remain over 60% of the exploitable biomass index. With status quo removals in 2022, all ADs are projected to be in the Healthy Zone of the provisional Precautionary Approach Framework (PAF), except 2HJ, which is projected to be in the Cautious Zone. Recent and ongoing data deficiencies result in the exclusion of 4R3Pn in the provisional PAF. Pre-recruit abundance indices remain generally favourable for the fishery in the next two to four years, but there are indications that these indices may have peaked. In 2021, there was reduced Fisheries and Oceans Canada (DFO) trawl survey coverage in ADs 2HJ and 3K. This may have resulted in overestimation of the exploitable biomass index, particularly in 2HJ. The DFO trawl survey was not conducted in AD 3LNO in 2021. The Collaborative Post-Season (CPS) survey was used as an exploitable biomass index. This approach was supported by comparative model analyses. There is particular concern about the stock in AD 2HJ. Exploitation rates have been persistently high and the residual biomass is very low. Total mortality in males is high with large declines in male size-at-maturity. There have been declines in mature female abundance and short-term recruitment prospects are poor. Environment and Ecosystem The Newfoundland and Labrador (NL) Climate Index indicated that 2021 was one of the warmest years on record, continuing the ongoing warming trend since 2018. The spring phytoplankton bloom was earlier than average in 2021 on the NL Shelf (North Atlantic Fisheries Organization [NAFO] Divisions 2GHJ3K) and in the Gulf on St. Lawrence (3Pn4R), and mostly near normal on the Grand Banks (3LNOPs). Since the mid-2010s, the zooplankton community has been transitioning to a state with a higher proportion of larger copepod species (Calanus finmarchicus) with a positive impact on overall zooplankton biomass and, potentially, energy transfer to upper trophic levels. The ecosystems in the NL bioregion continues to experience overall low productivity conditions, with total biomass well below pre-collapse levels. While the fish community has returned to a finfish-dominated structure, groundfish rebuilding stalled in the mid-2010s, where biomass declines were observed. However, ecosystem indicators (e.g., biomass trends, stomach content weights) in recent years appear to be improving. Predation mortality of Snow Crab declined across ecosystem units from the peak values observed in the mid-late 2010s. The current predation rate index was highest in 2J3K and lowest in 3LNO, with intermediate values in 3Ps.