Salmon lice project in the Hardangerfjord, 2004 - 2007

Research carried out during the late 1990's and later suggests that salmon lice at present must be regarded a major population regulating factor in many Norwegian salmon stocks. The actual impact in terms of absolute reduction in the size of the total sal mon run is, however, uncertain due to lack of systematic investigations. Methods to asssess salmon lice infection in seaward migration postsmolt salmon have been successfully developed. The fish farming industry has introduced measures to reduce the infec tion levels and consequently the potential numbers of salmon lice larvae in may areas. The effects of these reductions are most probably positive to the wild salmon stocks. In this project we propose a three-year research effort focusing on the interactions of salmon lice beetween farmed and wild salmonids in the Hardangerfjord. This system is an ideal study area because it is mainly affected by inner fjord dynamics, has im portant wild salmon and sea trout stock affected by salmon lice, and many salmon farms cooperating through a fish health network. The project consists of several work packages including registration of salmon lice abundance on wild and escaped salmonids, optimised salmon lice monitoring and control strategies i n farms, quality of farmed and wild smolts, migration speeds and routes of Atlantic salmon smolts, spread of salmon lice larvae, and physical occeanographical factors on salmon lice distribution in the Hardangerfjord. The present project will be closely c oordinated with another ongoing project in the Hardangerfjrod (Institue of Marine Research) thus giving maximal advantage for both projects. Through broad cooperation between the leading Norwegian research institutes, industry and management and experienc es from adjoining projects we aim to develop a know ledge base for the Hardangerfjord system which can be used in furhter management of decreasing the effects of salmon lice and wild salmonids.