Multivariate evaluation of the effectiveness of treatment efficacy of cypermethrin against sea lice (Lepeophtheirus salmonis) in Atlantic salmon (Salmo salar)

摘要

The sea louse Lepeophtheirus salmonis is the most important ectoparasite of farmed Atlanticsalmon (Salmo salar) in Norwegian aquaculture. Control of sea lice is primarily dependent onthe use of delousing chemotherapeutants, which are both expensive and toxic to otherwildlife. The method most commonly used for monitoring treatment effectiveness relies onmeasuring the percentage reduction in the mobile stages of Lepeophtheirus salmonis only.However, this does not account for changes in the other sea lice stages and may result inmisleading or incomplete interpretation regarding the effectiveness of treatment. With theaim of improving the evaluation of delousing treatments, we explored multivariate analysesof bath treatments using the topical pyrethroid, cypermethrin, in salmon pens at fiveNorwegian production sites.