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

BMC Veterinary Research

George Gettinby²  Peder A Jansen³  Simon P Hardy³  Crawford W Revie¹  Daniel F Jimenez³ 

[1] Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada;University of Strathclyde, Glasgow, Scotland, UK;Norwegian Veterinary Institute, PO Box 50 Sentrum, 0106 Oslo, Norway

关键词: Multivariate analysis;    Treatment effectiveness;    Atlantic salmon;    Lepeophtheirus salmonis;   

Others  :  1119380
DOI  :  10.1186/1746-6148-9-258

 received in 2013-04-01, accepted in 2013-12-16,  发布年份 2013

【 摘 要 】

Background

The sea louse Lepeophtheirus salmonis is the most important ectoparasite of farmed Atlantic salmon (Salmo salar) in Norwegian aquaculture. Control of sea lice is primarily dependent on the use of delousing chemotherapeutants, which are both expensive and toxic to other wildlife. The method most commonly used for monitoring treatment effectiveness relies on measuring 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 in misleading or incomplete interpretation regarding the effectiveness of treatment. With the aim of improving the evaluation of delousing treatments, we explored multivariate analyses of bath treatments using the topical pyrethroid, cypermethrin, in salmon pens at five Norwegian production sites.

Results

Conventional univariate analysis indicated reductions of over 90% in mobile stages at all sites. In contrast, multivariate analyses indicated differing treatment effectiveness between sites (p-value < 0.01) based on changes in the proportion and abundance of the chalimus and PAAM (pre-adult and adult males) stages. Low water temperatures and shortened intervals between sampling after treatment may account for the differences in the composition of chalimus and PAAM stage groups following treatment. Using multivariate analysis, such factors could be separated from those which were attributable to inadequate treatment or chemotherapeutant failure.

Conclusions

Multivariate analyses for evaluation of treatment effectiveness against multiple life cycle stages of L. salmonis yield additional information beyond that derivable from univariate methods. This can aid in the identification of causes of apparent treatment failure in salmon aquaculture.

【 授权许可】

   
2013 Jimenez et al.; licensee BioMed Central Ltd.

【 图 表 】

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