New phosphorus paradigm for the Baltic Sea

A paper with BOX-WIN project leader Anders Stigebrandt as first author and staff member Malin Ödalen as one of the co-authors regarding the phosphorus dynamics in the Baltic proper and the Bornholm Basin has just been published in the journal AMBIO.

The paper can be downloaded from our Downloads-page and is found under the topic “Other publications”.

Abstract

The external phosphorus (P) loading has been halved, but the P content in the water column and the area of anoxic bottoms in Baltic proper has increased during the last 30 years. This can be explained by a temporary internal source of dissolved inorganic phosphorus (DIP) that is turned on when the water above the bottom sediment becomes anoxic. A load-response model, explaining the evolution from 1980 to 2005, suggests that the average specific DIP flux from anoxic bottoms in the Baltic proper is about 2.3 g P m-2 year-1. This is commensurable with fluxes estimated in situ from anoxic bottoms in the open Baltic proper and from hydrographic data in the deep part of Bornholm Basin. Oxygenation of anoxic bottoms, natural or manmade, may quickly turn off the internal P source from anoxic bottoms. This new P-paradigm should have far-reaching implications for abatement of eutrophication in the Baltic proper.