title: Increased frequency and changed methods in the treatment of sea lice (Lepeophtheirus salmonis) in Scottish salmon farms 2005-2011.
abstract: BACKGROUND
  The sea louse is the most economically and environmentally serious ectoparasite of marine salmonids. Sea lice have been largely controlled by treatment with a variety of medicines. In order to understand the sustainability of medicine usage, an analysis of sea louse treatment data has been carried out for all Scottish salmon farms from 2005 to 2011.
  
  
  RESULTS
  Overall, there was an increase from 0.156 to 0.282 treatments month(-1) ; treatments could involve one or multiple agents. This increase was mostly in bath treatments (cypermethrin in 2007, largely replaced by deltamethrin and azamethiphos in 2008). Treatments using in-feed treatments (emamectin benzoate and teflubenzuron) increased only slowly. Treatments involving more than one medicine in a single month also increased, as did the probability of follow-up treatments. Treatments were seasonal, with peaks of in-feed treatments in March and August and bath treatments more frequent between August and December.
  
  
  CONCLUSIONS
  Frequency of sea louse treatment increased substantially, with an increase in multiagent and follow-up treatments. This increase in treatment activity is expensive to the industry and increases exposure of the neighbouring environment. This indicates that earlier louse control practices were not sustainable and so adapted.
authors.affiliation: Marine Scotland Science, Aberdeen, UK.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Murray
mesh_terms: D000818:Animals; D000977:Antiparasitic Agents / Q000627:therapeutic use*; D017756:Aquaculture; D001549:Benzamides / Q000627:therapeutic use; D033342:Copepoda / Q000187:drug effects*; D005393:Fish Diseases / Q000188:drug therapy* / Q000469:parasitology; D007559:Ivermectin / Q000031:analogs & derivatives / Q000627:therapeutic use; D009570:Nitriles / Q000627:therapeutic use; D011722:Pyrethrins / Q000627:therapeutic use; D012474:Salmon / Q000469:parasitology*; D012621:Seasons
chemical_list: D000977:Antiparasitic Agents; D001549:Benzamides; D009570:Nitriles; D011722:Pyrethrins; C017160:cypermethrin; C017180:decamethrin; D007559:Ivermectin; C052595:teflubenzuron; C108024:emamectin benzoate
keywords: Lepeophtheirus salmonis; Salmo salar; aquaculture; treatment