The Application of Fucus vesiculosus as a Bioindicator of 60Co Concentrations in the Danish Straits

The occurrence of 60Co in the Danish Straits is investigated by applying the seaweed Fucus vesiculosus as a bioindicator. In order to describe different dispersion situations, three areas have been studied separately: the North Sea, where it is possible to measure 60Co from sources in France and/or the UK; the Kattegat, where the sources are the Swedish nuclear power plants Ringhals and Barsebäck; and the Sound, where the initial mixing of the release from Barsebäck takes place. A power function can be estimated for the Kattegat and the Sound describing the content of 60Co in Fucus as a function of distance from Barsebäck. Problems of uncertainty related to differences in environmental parameters are discussed and new investigations to improve the use of Fucus as a bioindicator are suggested.