This study investigated a new material – activated limestone – that was added to nutrient rich Baltic Sea bottom sediment with the ambition to stop nutrient release and thereby reduce eutrophication.

Our results show that the activated limestone was very efficient in stopping leakage of phosphorus from eutrophic sediments collected at a fish farm on Åland from which fish faeces have contributed to the nutrient load and accumulation in its surrounding waters. The phosphate release from the sediment was completely stopped by addition of 600 g/m2 activated limestone. In addition, the risk of potential side effects, such as greenhouse gas emissions, was measured and found to be low after addition of the activated limestone.