The Baltic Sea Action Plan (HELCOM, 2007) has identified country specific targets for nutrient reduction. Consequently, the countries have been devising and implementing plans to comply with these targets. So far, the main focus has been on terrestrial reduction measures. However, none of them so far has been sufficient to reduce nutrient loading and eutrophication (Petersen et al., 2012) and it has been argued that costs of further possible mitigation measures if they approach their technological limits might exceed those of mussel farming (Rose et al., 2012). Furthermore, it has been stressed that mussel farms can be very effective at mitigation on a local scale since the mussel effect is immediate in contrary to land based measures where effects often have large time lags. On the other hand, there has been expressed concern that sedimentation of organic material can lead to enhanced oxygen consumption below mussel farm resulting in hypoxic or even anoxic conditions that will negatively alter nutrient release from sediments (Stadmark and Conley 2011) so arguing that nutrient removal by this method is substantially offset by altered environmental conditions. However, it should be stressed that effect of enhanced biodeposition under mussel farms is local and highly site specific from limited impact of farm on benthic environment in sheltered already hypoxic area (Holmer et al., 2015) to increase in biomass and species richness (e.g., Kraufvelin and Diaz 2015; Ysebaert et al., 2009) in well oxygenated coastal areas. There have been few cases when negative impact of mussel farms on benthic communities was demonstrated (e.g., Christensen et al., 2003), however, none of them was in the Baltic Sea.