Lice pressure from salmon farms on wild sea trout (Salmo trutta) in a Norwegian fjord

Frontiers in Marine Science

Pal Arne Bjorn¹  Marius Berg²  Pablo Arechavala-Lopez³ 

[1] Institute of Marine Research;Norwegian Institute for Nature Research;University of Alicante;

关键词: Aquaculture;    Norway;    parasite;    salmonids;    sea lice;    Environmental effects;   

DOI  :  10.3389/conf.fmars.2015.03.00111

来源: DOAJ

【 摘 要 】

Salmon lice Lepeophtheirus salmonis are external parasites on salmonids in the marine environment. However, during recent years, salmon lice abundance has increased due to the presence of salmon farming. Scientific studies shows that salmon farming increases the abundance of lice in the marine habitat and that salmon lice in the most intensively farmed areas have negatively affected wild fish populations. The present study assesses the spatiotemporal distribution of salmon lice infestations on wild sea trout population in the Romsdalsfjord region (Norway), and the potential relationship with fish-farming activity and environmental parameters in this area. Salmon lice at farms varied among localities or farming areas, although infestation levels were under the safety established thresholds (max: 0.5 adult females per fish) in most of the cases. However, salmon farms with these levels might produce and release millions of copepods, potentially infecting wild salmonids. In accordance, low lice loads were recorded on wild sea trout captured in areas with low farming activity, while higher mean loads were recorded in areas with higher farming activity. A clear seasonal pattern and a positive correlation between lice on sea trout and sea water temperature were observed throughout the study period. The estimated production of copepods at farms and the mobile lice counted on wild sea trout one month later were correlated, suggesting the potential use of lice monitoring on sea trout as a proxy indicator of salmon lice infestation risks.

【 授权许可】

Unknown