L'état du stock de morue franche (Gadus morhua) du nord du golfe du Saint-Laurent (3Pn, 4RS) en 2022

Abstract

The Atlantic cod stock in the northern Gulf of St. Lawrence (NAFO Subdivision 3Pn and Divisions 4R and 4S) has been fished for centuries, and has been managed using a total allowable catch since 1977. Following a sharp increase in fishing mortality beginning in the late 1980s, accompanied by an increase in natural mortality, the stock collapsed and was placed under moratorium from 1994-1996. Although some recovery occurred during this period, the stock has fluctuated at a low level of abundance since then, despite relatively low fishing mortality, including a moratorium in 2003 and a closure of the directed commercial fishery for the 2022-2023 season. A new model developed during the review of the northern Gulf of St. Lawrence cod assessment framework that took place in 2021 and 2022 was used for the first time for this assessment. This document describes the data and methods employed to assess a number of indicators later used in the assessment model as inputs. Fishing mortality, for which the estimate is based on reported or inferred catches, was low in 2021 and even lower in 2022, specifically at the lowest level since the 2003 moratorium. However, natural mortality has been at high levels for at least a decade and it is likely that part of this natural mortality is in fact made up of unaccounted fishing mortality. In 2022, cod condition was particularly poor, especially in Division 4S, and at levels where increased natural mortality has been observed in the past. The cohort born in 2018, which has been observed annually in the Fisheries and Oceans Canada annual survey since 2019, appears to be the most abundant since the early 1990s. The prospects for this cohort will depend on the mortality it experiences in the coming years. A precautionary approach limit reference point (LRP), based on long-term stock trends in stock spawning biomass (SSB), was adopted at a value of 71,970 t. Other reference points using the same framework as the LRP were proposed, including the upper stock reference point (USR, 143,939 t) and the target reference point (TRP, 179,924 t). The stock has been in the critical zone since 1991, and the SSB estimate for 2022 (42,906 t) corresponded to 60% of the LRP. An examination of stock productivity revealed that the stock had surplus production for the majority of years since 1995 and would likely have grown in the absence of commercial and recreational fisheries. A brief review of other factors that may have affected the productivity of this stock identified some that may have been relevant, to a degree and in some years, but did not conclusively identify the principal drivers of the high natural mortality that is largely preventing recovery.