Modelling of surface and 3D pellet distribution in Atlantic salmon (Salmo salar L.) cages

•We model 3D pellet distribution in salmon cages.•Surface spreader patterns are modelled based on measured data.•Low level validation of turbulent pellet diffusion is done.•The model shows good agreement with measured feed waste pattern.

Feed represents the greatest single cost factor in the production of Atlantic salmon (Salmo salar L.). Focusing on the problem of maximising the available feed for the fish while minimising the feed waste, a mathematical model of the feeding process has been developed. The model covers the feed spreader delivering the feed, water currents, pellet sinking speed and turbulent diffusion, fish appetite as a function of temperature, gut fullness and population structure, and is intended as a tool both for optimising general feeding strategies, and to support the daily handling of the feeding process. The process of horizontal and vertical diffusion of feed pellets in the model has been parametrised and validated through two low level validation experiments. Furthermore, global distribution patterns simulated by the model were verified by comparisons with experimental data from the literature.