Detection of emamectin benzoate tolerance emergence in different life stages of sea lice, Lepeophtheirus salmonis, on farmed Atlantic salmon, Salmo salar L

• Published in: Journal of Fish Diseases
• Main Authors: Jones, P G, Hammell, K L, Gettinby, G, Revie, C W
• Other Authors: Atlantic Innovation Fund, Prince Edward Island Department of Fisheries, Aquaculture and Rural Development, Prince Edward Island Department of Innovation, Advanced Learning for providing, provincial government partners, Nova Scotia Department of Fisheries and Aquaculture, Newfoundland and Labrador Department of Fisheries and Aquaculture, New Brunswick Department of Agriculture, Aquaculture, and Fisheries
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2013
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/jfd.12022; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fjfd.12022; https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfd.12022

Abstract Emamectin benzoate has been used to treat sea lice, L epeophtheirus salmonis , infestations on farmed A tlantic salmon, S almo salar . Recent evidence suggests a reduction in effectiveness in some locations. A major challenge in the detection of tolerance emergence can be the typically low proportion of resistant individuals in a population during the early phases. The objectives of this study were to develop a method for determining differences in temporal development of tolerance between sea lice life stages and to explore how these differences might be used to improve the monitoring of treatment effectiveness in a clinical setting. This study examined two data sets based on records of sea lice abundance following emamectin benzoate treatments from the west coast of S cotland (2002–2006) and from N ew B runswick, C anada (2004–2008). Life stages were categorized into two groups (adult females and the remaining mobile stages) to examine the trends in mean abundance and treatment effectiveness. Differences in emamectin benzoate effectiveness were found between the two groups by year and location, suggesting that an important part of monitoring drug resistance development in aquatic ectoparasites may be the need to focus on key life stages.