‘h 
vestigated as far as to the layers given (Table 7). Both sediments 
are to be characterized as being sandy sediments with a high propor- 
tion of mud, and for that reason should be comparable in their ad- 
sorption properties. In both cases, the nuclides which are charac- 
teristic for the Chernobyl Fallout (Cs 134, Ru 103, Ru 106) have al- 
ready penetrated to a depth of 3 to 6 cm. Although Ru 106 was also 
detectable in sediment samples from the German Bight even before the 
Chernobyl accident. The infiltration of the Chernobyl activity into 
deeper sediment layers can not only be accounted for from bioturba- 
tion effects but also from pore water diffusion. Further investiga- 
tions will provide information about that. 
Further monitoring projects 
In August 1987, the Baltic Sea voyage of Oct./Nov. 1986 with Re- 
search Vessel "Gauss” with international participation is to be re- 
peated. This investigation is intended to provide further data about 
the changing of the distribution and the whereabouts of the radioac- 
tive substances in the whole of the Baltic Sea system. Large-scale 
investigations in the North Sea will be continued in the same man- 
ner, in future, as in previous years. Owing to the North Sea's water 
exchange with the Atlantic, no prolonged contamination of the North 
Sea water by the Chernobyl Fallout is expected. 
The smaller scale investigations in the German Bight and in the 
Western Baltic Sea will be continued as hitherto, in order to be 
also further informed about the temporal development. The particular 
emphasis thereby will be centred upon the coastal waters. 
For the future, an intensified monitoring of the sediments appears 
to be indicated, because a part of the isotopes in the input will be 
concentrated in the sediments and will thereby gain entry into the 
nutrient chain of the benthic fauna,