Notice bibliographique
Résumé
In the midst of several management failures, marine reserves are seen as a potential management tool to control overexploitation. In the literature, both modelling and empirical work have demonstrated that closing an area to fishing would lead to an increase in biomass and mean body size within the reserve. Benefits, in the form of increased catch, outside the reserves are sometimes shown using modelling, but the assessment of such benefits in nature is more difficult. Home range and migration rate of the targeted species are important factors to consider in the establishment of a reserve. A few cases convincingly point at the importance of the source of larvae and the direction and rate of dispersal. Reserves could also be used as a hedge against uncertainty and management mistakes by limiting fishing mortality. This study is intended to evaluate the possibility of using marine reserves to control fishing mortality for northern cod, a migrating fish. A simple dynamic pool model emphasized the importance of including stock recruitment relationship to properly assess reserves benefits. By protecting a part of the spawners, the system containing a reserve was more resilient than the control (no-reserve). However, these results were probably overly optimistic because the proportion of fish staying within the reserve was overestimated. An age- and spatially-structured model was then built to mimic the historical evolution of fishing and stock collapse of the northern cod, offshore Newfoundland. The model included four stocks, migrations, and range dynamics. Fishers were assumed to show hunting behaviour to various degree depending on the gear used. In the first version of the model had to increase catchability as cod biomass decreased. The second model used effort profiles based on documented qualitative and quantitative changes in fishing capacity and effort. In both cases, results showed that very large marine reserves (80%) by themselves could have hedge against mismanagement, while a 50% reserve would have only slowed the decrease of the cod population. The results also suggest that adding seasonal closures could help control fishing mortality although possible temporal effort displacement was not investigated. The principal benefits of seasonal closures would be to protect the spawning aggregations rather than controlling fishing mortality. Every management scenario that was efficient at controlling fishing mortality implied decreasing the catch before the stock started rebuilding. Marine reserves could be used as an additional management tool along with other measures limiting the range of action of the fishery. For example, banishment or severe restrictions on gears allowed in the fishery could limit the geographical range of the fishery and help control fishing mortality.
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 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) | 0,008 | 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 ».