Simulating the spread and fate of sea lice larvae from an infested Atlantic salmon farm on the west coast of Ireland

This study investigates the spread and fate of sea lice larvae from salmon farming activities in Wary Harbour, Co. Galway. Numerical modelling is used to simulate the transport dispersion and fate of sea lice larvae from the farm cages. Model simulations are run to quantify the risk of infestation of wild sea trout stocks from the salmon farms. A quasi 3-dimensional hydrodynamic model is developed to simulate the tide, river and wind induced currents within the Harbour. The dispersion of sea lice larvae is modelled using a Legrangian random walk particle tracking technique. The particle tracking technique was chosen in preference to the conventional Eulerian dispersion techniques as it eliminates numerical dispersion and allows various behavioural characteristics of the free swimming lice larvae to be incorporated.