The relevant laws stipulate that extensive biological, chemical and ecotoxicological analyses have to be carried out prior to dumping in order to prevent damage to the biotic community on the seafloor (benthic zone). Unfortunately the statutory provisions do not include an examination of bacterial communities. However, bacteria make a key contribution to the basis of any ecosystem. They remineralise the substances that plants and animals have taken up from the ecosystem over various trophic levels in the food web. The only reason there is a functioning cycle is because bacteria decompose minerals. Bacterial communities with their universal genetic make-up react directly and very quickly to change in their surroundings: whether in the form of activity on the part of certain resistance or turnover genes or even changes in entire communities. This trophic level thus has “a lot to say”!

In a pilot project supported by HPA (Hamburg Port Authority), LLUR (Schleswig-Holsteinisches Landesamt für Landwirtschaft, Umwelt und ländliche Räume), NLWKN (Niedersächsischer Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz) and BfG (Bundesanstalt für Gewässerkunde) the Alfred Wegener Institute examines the dumping of dredged material in the German Bight. Using modern molecular biology methods, the project looks at the impacts of this intervention on the bacterial community of the benthic zone. The aim is to develop a set of methods that can be applied as part of modern and up-to-date environmental monitoring in future.