Salmon lice--impact on wild salmonids and salmon aquaculture.
Bottom Line: Intensive salmon farming provides better conditions for parasite growth and transmission compared with natural conditions, creating problems for both the salmon farming industry and, under certain conditions, wild salmonids.This is considered to have a moderate population regulatory effect.Several large initiatives have been taken to encourage the development of new strategies, such as vaccines and novel drugs, for the treatment or removal of salmon lice from farmed fish.
Affiliation: Institute of Marine Research, Nordnes, Bergen, Norway. firstname.lastname@example.orgShow MeSH
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Mentions: Lice levels on farmed fish have been monitored in Ireland since 1991, and a comprehensive monitoring programme has been in place since 1993 (O'Donohoe et al. 2011). Lice levels on farmed salmon increase with time at sea (Jackson et al. 2000) with two sea-winter fish carrying the heaviest burden. Fallowing and separation of generations of farmed fish reduce the effect of sea age on the lice burden (Jackson et al. 1997; O'Donohoe et al. 2011) of farmed fish. Studies of wild salmon at sea reveal a similar increased abundance of lice with sea age in salmon obtained from north of the Faroe Islands (Jacobsen & Gaard 1997). Salmon lice monitoring and control measures were modified in 2000 and formed the basis of an integrated management protocol for salmon lice in farmed salmon in Ireland (Jackson, Hassett & Copley 2002). Crucial elements of this strategy were identified as separation of generations, annual fallowing of sites and strategic applications of treatments, good fish health management and close cooperation between farms. The monitoring and inspection programme results revealed the benefits of this approach on levels of control achieved from 2000 through 2004 (Fig. 3). From 2005 to 2007, there was a progressive increase in the mean levels of infestation of farmed fish. The increased infestation was identified as resulting from a range of factors, including changes in production practices (Jackson 2011). To address these issues, the Irish authorities issued new guidelines as a Strategy for Improved Pest Control on Irish Salmon Farms in 2008. These guidelines were implemented over the succeeding 2 years and have led to a progressive reduction in the mean levels of infestation (Fig. 3).
Affiliation: Institute of Marine Research, Nordnes, Bergen, Norway. email@example.com