Activiteit: Gesprek of presentatie › Lezing en mondelinge bijdrage
Ectoparasitic sea lice are the most important parasite problem to date for the salmon farming industry in the northern and southern hemispheres. • Because the sea lice feeds on mucus, skin and blood of the host, it causes chronic stress, resulting in decreased immune responses and increase susceptibility to other diseases and also in reduction in growth and performance. • But there is also the direct costs of purchasing and administering the delousing agents. • Although still uncertain, sea lice could also be a carrier of other pathogens • Last and certainly not the least is the fact that sea lice in salmon farms increases the infestation pressure on wild salmon. Out-migrating juvenile wild smolt passes on their way salmon farming sites, which are infected with sea lice, which increases the infestation pressure. In 1990 220 million farmed salmon were estimated to have produced 145 billion eggs during the 2-month spring migration of wild salmon (Heuch and Mo 2001); 30-50% of all sea trout and 48-86% of salmon smolts leaving Norway’s rivers were killed by farm-source lice.) The total economic cost is estimated at $300 million per year. The salmon industry is therefore under heavy public pressure to solve the sea lice problem.