Évaluation du capelan dans les divisions 2J, 3K et 3L jusqu'en 2023

Abstract

The Newfoundland and Labrador (NL) ocean climate fluctuates on decadal timescales with known impacts on ecosystem productivity. The poor productivity of lower trophic levels in the mid-2010s has been associated with a cooler climate phase. Since 2018, a warmer and potentially more productive ocean phase has been emerging. The current phase is characterized by earlier phytoplankton blooms and higher abundance of Calanus finmarchicus, a key zooplankton species for the ecosystem. The NL bioregion continues to experience overall low productivity conditions, with total biomass measured in the DFO research vessel survey well below pre-collapse levels. The marine community has returned to a finfish dominated structure. Ecosystem indicators in 2019–23 (e.g., biomass trends, stomach content weights) show improvements from the lows in the late-2010s, but overall biomass has not returned to the early-2010s level. This stock continues to have a truncated age structure due to the high proportion of fish that are maturing at younger ages relative to the pre-collapse period, which reduces the reproductive potential of the stock. The 2023 larval abundance index suggests an average year-class relative to the post collapse period. The Capelin forecast model predicts that the 2024 Capelin acoustic biomass index will be similar to or slightly lower than 2023. The 2J3KL Atlantic Cod Limit Reference Point (LRP) was changed in 2023, which required an update of the Capelin LRP. The revised value of the Capelin LRP is 155 kt for the spring acoustic biomass index. The 2023 acoustic biomass index (333 kt, 90% confidence interval (CI): 235–568 kt) was above the LRP. The stock has been mostly above this updated LRP since 2007, except for 2010 and 2017, and is projected to remain so in 2024, with a 10–17% probability of being in the critical zone. The cautious and healthy zones have not been defined for this stock. This stock is currently facing challenges related to delayed spawning, early maturation, and an age-truncated population structure. Furthermore, the acoustic biomass index remains well below the 1985–90 period. These factors indicate reduced stock productivity. A cautious management approach is recommended.