Monitoring effectiveness of emamectin benzoate for the treatment of sea lice (Lepeophtheirus salmonis) on farmed Atlantic salmon (Salmo salar)
Bibliographic record
Abstract
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.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".