Ecosystem services by blue mussels in a coastal area; a study with commercial fish farming and blue mussels in the Faroe Islands

The aim of this study was to evaluate how many nutrients can be harvested in blue mussel biomass in Faroese conditions, compared to what is emitted from a commercial Atlantic salmon farm. A mussel growth experiment in Sørvágsfjørður, Faroe Islands and production data from a commercial salmon farm were used for this. The study showed that the salmon farm released 40 ton of dissolved inorganic nitrogen during summer, which could possibly increase phytoplankton biomass. Harvesting mussels containing 40 of nitrogen would require a biomass harvest of 2920 ton of mussels. The area needed to grow this biomass depends highly on the blue mussel density on the lines and the blue mussel farming strategy. Mussel spat settlement, density and growth varies greatly in different countries and regions, which is important for the nutrient harvest potential of an area.