Balticsea 2020

Understanding the importance of coastal zone for restoration efforts in the Baltic Sea

Knowledge of the dead bottoms in the open Baltic Sea has improved significantly in recent years. In spite of this, little is known about the bottoms depleted of oxygen in shallow near coastal waters. In fact, we do not know the location or the extent of these hypoxic areas. In the project “Understanding the importance of the coastal zone for restoration efforts in the Baltic Sea” the coastal zone is in focus.

Background
The coastal zone acts as a filter between land and sea, trapping phosphorus and enhancing nitrogen losses through denitrification. Yet an unknown, but presumably large area of sediments, especially in the Stockholm and Finnish archipelagos, is devoid of macroscopic life, i.e. can be considered ecologically dead. Coastal ecosystems have lost their natural cleansing ability and simultaneously reduced habitat quality for fisheries.

In January 2008 the BalticSea2020 funded workshop series “Understanding hypoxia in the Baltic Sea” concluded with a seminar on “Possible solutions to oxygen problems in the Baltic Sea”. One of the conclusions of the project was that the coastal zone is a key area if the conditions in the open Baltic Sea are to be improved. In the coastal zone it could be worthwhile to try manipulative remedies in local or regional “hot-spots” of eutrophication.

Objectives
The aim of the project was to identify the areas of concern, quantify the amounts of nutrients removed in the coastal zone, and identify the most cost-effective areas to focus restoration efforts.