Assessment of Scotian Shelf Snow Crab
Notice bibliographique
Résumé
Snow Crab landings from the Scotian Shelf in 2023 were 972 t in north-eastern Nova Scotia (N-ENS); 7,342 t in south-eastern Nova Scotia (S-ENS); and 7 t in crab fishing area (CFA) 4X (season was ongoing at the time of assessment), representing a decrease of 0.3%, an increase of 0.3% and a decrease of 84.2%, respectively, relative to 2022. Total allowable catches (TACs) for 2023 were 979 t, 7,345 t, and 55 t in N-ENS, S-ENS, and 4X, respectively. Bycatch of non-target species is low (<<1% of total catch) in all Snow Crab fishing areas; however, as sampling targets for at-sea observer coverage have not been met in recent years, there is uncertainty in the representativity of the data. In N-ENS, the modelled biomass (pre-fishery) of Snow Crab in 2023 was 3.27 kt, a decline of 10.9% relative to 3.67 kt in 2022. In S-ENS, the modelled biomass (pre-fishery) was 37.91 kt, a decline of 10.6% relative to 42.42 kt in 2022. In 4X, the 2023–2024 season’s modelled biomass (pre-fishery) was 0.08 kt, a decline of 46.7% relative to 0.15 t in the 2022–2023 season. Egg and larval production is expected to be high in 2024 in S-ENS and 4X. Based on length frequency data, little to no recruitment is expected for the next 1–3 years in N-ENS. Continued recruitment is expected for the upcoming years in S-ENS. Low levels of recruitment are expected in 4X; high mortality of adolescent crab makes recruitment into the fishable component uncertain. In 2023, bottom temperatures from the Snow Crab survey have returned to the historical mean in all three CFAs; however, a general warming trend has been observed in the Snow Crab survey since the early 1990s. The amount of viable Snow Crab habitat has consistently declined in all three areas since 2010, and does not show any strong evidence of increase. In 2023, the N-ENS mean estimated fishable biomass was above the upper stock reference (USR), placing the stock in the healthy zone; however, there is considerable model uncertainty around both the estimate and the reference point. In 2023, the harvest rate was 30.17%, slightly above the harvest control rule of 10–30%. A more conservative harvest strategy may support the stock in bridging the expected gap in recruitment. In 2023, the S-ENS mean estimated fishable biomass was above the USR, placing it in the healthy zone; however, there is considerable model uncertainty around both the estimate and the reference point. Harvest rates derived from the fishery model were 19.7% in 2023, and have remained between 10–20% since 2020. The stock status in S-ENS suggests that the current harvest strategy has not been detrimental to the stock. In 2023, the 4X mean estimated fishable biomass was below the limit reference point (LRP), placing the stock in the critical zone. The area is in the southernmost extent of Snow Crab distribution in the North Atlantic and experienced an extended period of unfavorable conditions for Snow Crab in the region.
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 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,000 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 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 ».