Analysis and management of resistance to chemotherapeutants in salmon lice, <i>Lepeophtheirus salmonis</i> (Copepoda: Caligidae)

Denholm, I.; Devine, Gregor J.; Horsberg, Tor Einar; Sevatdal, Sigmund; Fallang, Anders; Nolan, D.T.; Powell, Richard

doi:10.1002/ps.482

Cited by 169 publications

(175 citation statements)

References 47 publications

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“…selection of resistant sea lice) in comparison with other areas. Increased frequency of pesticide application is one of the factors associated with development of parasiticide resistance (Denholm et al 2002).…”

Section: Discussionmentioning

confidence: 99%

Effectiveness of emamectin benzoate for treatment of Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, Canada

Jones¹,

Hammell²,

Dohoo³

et al. 2012

Dis. Aquat. Org.

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Emamectin benzoate (an avermectin chemotherapeutant administered to fish as an in-feed treatment) has been used to treat infestations of sea lice Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, New Brunswick, Canada, since 1999. This retrospective study examined the effectiveness of 114 emamectin benzoate treatment episodes from 2004 to 2008 across 54 farms. Study objectives were to establish whether changes in the effectiveness of emamectin benzoate were present for this period, examine factors associated with treatment outcome, and determine variables that influenced differences in L. salmonis abundance after treatment. The analysis was carried out in 2 parts: first, trends in treatment effectiveness and L. salmonis abundance were explored, and second, statistical modelling (linear and logistic regression) was used to examine the effects of multiple variables on post-treatment abundance and treatment outcome. Post-treatment sea lice abundance increased in the later years examined. Mean abundance differed between locations in the Bay of Fundy, and higher numbers were found at farms closer to the mainland and lower levels were found in the areas around Grand Manan Island. Treatment effectiveness varied by geographical region and decreased over time. There was an increased risk for unsuccessful treatments in 2008, and treatments applied during autumn months were more likely to be ineffective than those applied during summer months.

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Section: Discussionmentioning

confidence: 99%

Effectiveness of emamectin benzoate for treatment of Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, Canada

Jones¹,

Hammell²,

Dohoo³

et al. 2012

Dis. Aquat. Org.

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“…HIV, leprosy, malaria and tuberculosis, reviewed in [4]) and terrestrial agricultural pests (reviewed in [5]). Currently, combination treatment strategies are not in wide use on salmon farms and many farms use some form of the responsive alternation strategy, applying a single chemical until it is no longer efficacious [7,10]. The salmon farming industry is now discussing combination strategies more extensively.…”

Section: Broader Implicationsmentioning

confidence: 99%

Managing aquatic parasites for reduced drug resistance: lessons from the land

McEwan

Groner²,

Burnett

et al. 2016

J. R. Soc. Interface.

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Atlantic salmon farming is one of the largest aquaculture industries in the world. A major problem in salmon farms is the sea louse ectoparasite Lepeophtheirus salmonis, which can cause stress, secondary infection and sometimes mortality in the salmon host. Sea lice have substantial impacts on farm economics and potentially nearby wild salmonid populations. The most common method of controlling sea louse infestations is application of chemicals. However, most farming regions worldwide have observed resistance to the small set of treatment chemicals that are available. Despite this, there has been little investigation of treatment strategies for managing resistance in aquaculture. In this article, we compare four archetypical treatment strategies inspired by agriculture, where the topic has a rich history of study, and add a fifth strategy common in aquaculture. We use an agentbased model (ABM) to simulate these strategies and their varying applications of chemicals over time and space. We analyse the ABM output to compare how the strategies perform in controlling louse abundance, number of treatments required and levels of resistance in the sea louse population. Our results indicated that among the approaches considered applying chemicals in combination was the most effective over the long term.

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“…El mal uso de estos productos puede provocar problemas en el ambiente acuático y en los organismos vivos que habitan en las zonas circundantes si no son usados apropiadamente (Ait et al, 2011;Kumar et al, 2011;Wang et al, 2011;Shen et al, 2012). Sin embargo, uno de los grandes problemas que se han evidenciado en Chile y en otros países, es la pérdida de sensibilidad del piojo de mar frente al uso repetitivo de un mismo fármaco (Jones et al, 1992;Denholm et al, 2002;Sevatdal & Horsberg, 2003;Sevatdal et al, 2005;Bravo et al, 2008b;Helgesen et al, 2014).…”

Section: Caligus Rogercresseyiunclassified

Evaluacion de la efectividad del tratamiento con agua dulce para el control del piojo de mar Caligus rogercresseyi Boxshall y Bravo, 2000

Bravo

Pozo

Silva

2015

lajar

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RESUMEN. Para evaluar la tolerancia de Caligus rogercresseyi al tratamiento con agua dulce, se recolectaron parásitos desde dos centros de cultivos localizados en el área de Calbuco, sur de Chile. El primer estudio se realizó en diciembre 2012 en un centro de cultivos ubicado en el Canal Huito, cuya salinidad fue de 26 y el segundo estudio se realizó en abril 2013 en un centro de cultivos en el Canal Chidhuapi, donde la salinidad fue de 32. En el primer estudio se evaluó la tolerancia de hembras y machos adultos de C. rogercresseyi al agua dulce y también la tolerancia de esta especie en truchas bañadas con agua dulce por 30 min de exposición. En el segundo estudio se evaluó la tolerancia de machos y hembras adultas a diferentes gradientes de salinidad, y también la tolerancia de copepoditos a la baja salinidad. En el primer estudio el 100% de los machos y hembras estuvieron inconscientes después de 30 min de exposición. Sin embargo, una vez que los parásitos inconscientes fueron retornados a agua de mar se registró una supervivencia de 93% en machos, 73% en hembras ovígeras y 100% en hembras sin sacos. En el segundo estudio se registró una supervivencia de 45% en hembras y 20% en machos sometidos a salinidad de 15 por 24 h. Los copepoditos no sobrevivieron a salinidad de 25. La eficacia registrada en el desprendimiento de C. rogercresseyi en las truchas tratadas con agua dulce fue de 57%, con una mayor tolerancia de las hembras en comparación con los machos. Los parásitos colectados desde el sector con 26 de salinidad, mostraron mayor tolerancia al agua dulce en comparación con los parásitos colectados del sitio con 32 de salinidad. Palabras clave: Caligus rogercresseyi, piojo de mar, salmónidos, salinidad, tolerancia agua dulce, sur de Chile. Assessment of the freshwater treatment to control the sea lice Caligus rogercresseyiBoxshall & Bravo, 2000ABSTRACT. Sea lice were collected from two salmon farms located in Calbuco, southern Chile to assess the tolerance of Caligus rogercresseyi to freshwater treatment. The first study was carried out in December 2012 in Huito Channel, where salinity reached 26. The second study was carried out in April 2013 in Chidhuapi Channel, where salinity reached 32. In the first study the tolerance of males and females exposed directly to freshwater was assessed, and also the tolerance of C. rogercresseyi infesting rainbow trout (Oncohrynchus kisutch) exposed to bath treatment with freshwater for 30 min. In the second study the tolerance of males and females to a different gradient of salinity was assessed, and also the tolerance of copepodids to reduced salinity. In the first study 100% of males and females were unconscious after 30 min of exposure. However, once they were returned to seawater the survival in males was 93%, 73% in gravid females and 100% in females without egg strings. In the second study a survival of 45% females was recorded and 20% males kept at salinity of 15 for 24 h. However, copepodids were not able to survive at a salinity of 25. The efficacy recorded in t...

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Analysis and management of resistance to chemotherapeutants in salmon lice, Lepeophtheirus salmonis (Copepoda: Caligidae)

Cited by 169 publications

References 47 publications

Effectiveness of emamectin benzoate for treatment of Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, Canada

Effectiveness of emamectin benzoate for treatment of Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, Canada

Managing aquatic parasites for reduced drug resistance: lessons from the land

Evaluacion de la efectividad del tratamiento con agua dulce para el control del piojo de mar Caligus rogercresseyi Boxshall y Bravo, 2000

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