Modelled distribution of salmon lice in a Norwegian fjord
Abstract
Salmon lice is a huge problem for both wild and farmed salmonid fish in fjords. An
assessment of salmon lice in a fjord system will bring forward the knowledge of wild
salmonid fish stocks and help manage salmonid fish farming. Numerical models have been
used to produce time series of salmon lice distribution in the Norwegian fjord Sognefjorden.
Currents and hydrography were calculated from a high resolution, three-dimensional ocean
model. Inside the fjords, detailed wind forcing was necessary, and these winds were
produced by a meso-scale atmospheric model. The distribution of salmon lice was calculated
by a three-dimensional particle advection model including temperature dependent growth.
The model results show that the variability in salmon lice distribution is huge for the
Norwegian fjord areas, with spreading of lice with the currents ranging from 0 to 100 km
within only a few days. We will show the simulated encounter rate of salmon smolt on its
way to the ocean and salmon lice, and show how different locations of fish farms affect this.
Publisher
ICESSeries
ICES CM documents2004/P:11