Fisheries Ecology and Aquaculture

Kåre Andreas Thorsen

Wash away or chase away – the effect of mucus cells and larger salmon lice to control new chalimus infection

Hello, my name is Kåre Andreas and I am a master’s student in aquaculture at the University of Bergen. The mucosal layer of a fish represents a physical and biochemical barrier that stretches along the outside of the majority of surfaces exposed to water, such as the gastrointestinal tract, the gills and the skin. My project will look at the changes in the mucosal layer in the skin of Atlantic salmon, Salmo salar, as a result of a controlled infection with a known density of the sea lice, Lepeophtheirus salmonis, in the chalimus stage. Changes in the mucosal layer will be linked to the innate immune system of the fish and rates of lice infection. My supervisor is Prof. Karin Pittman from the University of Bergen. The experimental phase was conducted at BIO wetlabs facilities and contained three separate groups of fish, with two duplicates of each group in separate tanks. One of those groups was infected twice, with the lice being cleared before the next infection. Parameters like infection rate, size, sex, lice count/placement and no. of infections were measured. With the sea lice being such a large problem, I believe that a further understanding in its dynamics in relation to fish is an important step towards establishing a healthier and more productive salmonid aquaculture.