The Status of Northern Gulf of St. Lawrence (3Pn, 4RS) Atlantic cod (Gadus morhua) Stock in 2024
Notice bibliographique
Résumé
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.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,001 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».