Shrimp fishing areas (SFA) 4-6 Northern Shrimp (Pandalus borealis) stock assessment in 2023
Notice bibliographique
Résumé
Status SFA 4: The 2023 spawning stock biomass (SSB) index is above the Upper Stock Reference point (USR) with a 68% probability, with the stock remaining in the Healthy Zone. SFA 5: The 2023 SSB index is above the Limit Reference Point (LRP, with a 99% probability), but below the USR (with a 60% probability), moving the stock from the Healthy Zone to the Cautious Zone. SFA 6: The 2023 SSB index is below the LRP with a greater than 99% probability, with the stock remaining in the Critical Zone. Trends SFA 4: There have been general increases in biomass indices from time-series (2005–23) lows in 2018. Fishable biomass (FB) and SSB indices increased by 2% and 13% respectively from 2022 to 2023. SFA 5: There have been general decreases in biomass indices and they are currently amongst the lowest values in the time series (1996–2023). FB and SSB indices decreased by 17% and 8% respectively from 2021 to 2023. SFA 6: FB and SSB indices have remained at or near time-series (1996–2023) lows without trends since 2016. The FB index did not change from 2021 to 2023, and the SSB index decreased by 13% from 2021 to 2023. Ecosystem and Climate Change Considerations The Newfoundland and Labrador (NL) ocean climate varies on near-decadal timescales with cooling and warming phases known to impact ecosystem productivity. The current warming phase of the climate has been ongoing since about 2018 and has likely contributed to the improved conditions that have been observed at the lower trophic levels (i.e., phytoplankton, zooplankton). The NL bioregion continues to experience overall low productivity conditions, with total biomass well below pre-collapse levels (late-1980s), and has returned to a finfish dominated structure. Due to lack of data, conditions in 2G (SFA 4) are unknown. Under current ecosystem conditions, fishing and predation have been potential drivers of the stock in 2H (~SFA 5), while predation has been the stronger potential driver in 2J3KL (~SFA 6–7). Per capita net production of shrimp in 2J3KL remains lower in recent years than in the late-2000s. This trend is likely associated with impacts from predation, fishing, and ocean climate. No major changes in per capita net production of shrimp would be expected within the next 1–3 years based on these associations. Stock Advice The application of conversion factors to account for new survey vessels resulted in a revision of the biomass and exploitation rate indices (ERIs) in SFA 5 and 6 (1996–2021), and recalculation of the LRPs and USRs. The new vessels generally catch more shrimp than the CCG Needler and fewer shrimp than the CCG Teleost. These differences in catchability impact biomass indices and therefore the interpretation of past ERIs and calculations of current ERIs. The impact of this change represents annual changes of past FB indices’ values (1996–2021) ranging from -7.4– 18.9% for SFA 5 (median of -7.1%), and ranging from -6.6–21.7% for SFA 6 (median of - 1.0%). SFA 4: The ERI ranged between 6.8% and 36.7% from 2005/06 to 2022/23 and the preliminary ERI was 10.8% in 2023/24. If the Total Allowable Catch (TAC) is taken in 2023/24, the ERI would be 18.4%. SFA 5: The ERI ranged between 6.6% and 31.5% from 1997 to 2022/23 and could not be calculated for 2023/24 due to no survey occurring in 2022. If the 2023/24 TAC is maintained and taken in 2024/25, the ERI would be 25.9%. SFA 6: The 2018 rebuilding plan states a maximum ERI of 10% while the stock is in the Critical Zone. If the 2023/24 TAC is maintained and taken in 2024/25, the ERI would be 10.7%.
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) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,001 |
| Bibliométrie | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,001 |
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 ».