Applying a combined geospatial and farm scale model to identify suitable locations for mussel farming

Mussel farming has increasingly come into focus as a potential mitigation measure for fish farms and eutrophication, in addition to being a food source. This study presents a GIS-based suitability analysis combined with a farm scale model to identify appropriate mussel farming sites. The sites are investigated in terms of potential mussel harvest, nutrient removal, and effects on water transparency. The model is applied to the south-western Baltic Sea. The identified suitable area is about 5-8% of the case study extent. The model shows that elevated chlorophyll levels stimulate mussel growth and that upon mussel harvest, nutrients can be removed. A single mussel farm cannot compensate for all nutrients emitted by a fish farm, but it can increase water transparency up to at least 200 m from the farm. Potential nutrient removal and water transparency increases are essential criteria for site selection in eutrophic seas, such as the Baltic Sea.