Every year large amounts of sand are extracted from the North Sea to meet the demand for construction and nourishment activities. Potential ecological effects of these activities have to be examined and reported in Environmental Impact Assessments (EIAs). Sand mining cause an increase in fine sediment concentrations. Increased concentrations of fines can increase turbidity, change the relative composition of organic and inorganic particulate matter in the water column and limit the light penetration, thus affecting water quality and reducing primary production. Most of the bivalves are filter feeders and extensive knowledge of how increased sediment concentrations influence their physiological organisation is essential if an impact assessment is to be made. In order to understand the effect of suspended sediment concentrations on the activity of filter-feeding bivalves, deterministic model is presented using the model species, the blue mussel Mytilus edulis.