Monitoring effectiveness of emamectin benzoate for the treatment of sea lice (Lepeophtheirus salmonis) on farmed Atlantic salmon (Salmo salar)
Notice bibliographique
Résumé
Resistance development to parasiticides has been a problem in both terrestrial and aquatic environments. A major challenge exists in early detection of resistance emergence due to the low frequency at which resistant organisms can occur initially within a population and the difficulty in detecting these organisms. Emamectin benzoate is an avermectin compound which has been used effectively in the treatment of sea lice on farmed salmonids around the world. The main purpose of this thesis was to examine field collected sea lice abundance data and treatment records to estimate changes in the effectiveness of emamectin benzoate for treatment of sea lice (Lepeophtheirus salmonis) infestations on farmed Atlantic salmon (Salmo salar).\nThe objectives of this thesis were: (1) to review and describe methods for the evaluation of sea lice treatment effectiveness, (2) to evaluate and establish if changes in effectiveness of emamectin benzoate for the treatment of sea lice (L. salmonis) on farmed Atlantic salmon in New Brunswick, Canada, had occurred from 2004 to 2008, and (3) to determine if there was evidence of differences in the temporal development of resistance to emamectin benzoate across L. salmonis life stages using data collected in both Canada and Scotland.\nField collected data from New Brunswick salmon farms (2004 to 2008) were examined for temporal and spatial changes in treatment effectiveness in populations of L. salmonis. Data analysis was carried out in two parts: examination of trends in treatment effectiveness and L. salmonis abundance and an examination of multiple factors influencing post-treatment L. salmonis abundance and treatment outcome through the use of statistical models (linear and logistic regression). A reduction in treatment effectiveness was found from 2004 to 2008 and treatment effectiveness was found to vary by location.\nFurther analysis was carried out to examine for possible differences in treatment effectiveness between different sea lice life stages. Life stages were categorized into two groups: adult females (gravid and non-gravid) and other mobile stages (pre-adult female, pre-adult male, and adult male). Sea lice abundance records following emamectin benzoate treatments from the west coast of Scotland (2002 to 2006) and from New Brunswick, Canada (2004 to 2008) were examined. Differences in treatment effectiveness were found between the two groups by year and location. Changes in sea lice sensitivity to emamectin benzoate were not synchronized in all life stages. A difference in the rates of resistance development between locations was noted, with resistance developing more rapidly in New Brunswick than in Scotland.\nIn summary, this research examined methods for the evaluation of emamectin benzoate effectiveness for the control of sea lice. A reduction in emamectin benzoate effectiveness occurred over time and varied by location. In addition, resistance development was not synchronized in all sea lice life stages. These methods could help aid in the detection of resistance development in parasites. However, no single method is likely to suffice for monitoring changes in sea lice sensitivity. In future, coordinated analyses from both laboratory and field studies will likely yield the best results.
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 | 0,000 | 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) | 0,000 | 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 ».