New scientific article: Capturing past eutrophication in coastal sediments – Towards water-quality goals

Author: BalticSea2020
Year published: 2019

The scientific journal Estuarine, Coastal and Shelf Science have published an article from the project Living coast.

The article, written by the scientists and project managers Linda Kumblad and Emil Rydin, is named Capturing past eutrophication in coastal sediments – Towards water-quality goals and describes the implementation and results if the method used in Björnöfjärden in order to eradicate previous years' release of the nutrient phosphorus. This is the first time someone has quantified and shown how phosphorus is bound in the upper parts of the sediment.

Björnöfjärden is a semi-enclosed brackish bay located in the Stockholm archipelago. Over the past century, the phosphorus load from the catchment area has been greater than what the bottom sediment of the bay can naturally bind. At the same time, eutrophication has caused anoxic bottoms, which reduces the ability of the natural binders of phosphorus to retain the phosphorus in the sediment. Consequently, the release of phosphorous from anoxic sediments further increase the eutrophication. In order to increase the phosphorous retention a solution of aluminum (Al) chloride was mixed of into the anoxic and azoic sediments (>6 meters water depth) during year 2012 and 2013. Al permanently binds phosphorous. The use of aluminum chloride to bind phosphorus and thereby reduce eutrophication is a common method of treating lakes. Within the Living coast project, this method was used for the first time in a marine environment.

Read the entire article Capturing past eutrophication in coastal sediments – Towards water-quality goals here.

To read more about Living coast, please visit the projects homepage here.