The Applied Aquatic Toxicology group investigates the input and distribution of pollutants in aquatic systems and their effects on organisms and communities. For this purpose, we use ecotoxicological test systems individually and in combination to estimate the effect of pollutants on organisms. This allows us to indicate a possible present or future threat to the habitat “water body”. Our particular focus in our applied research here is on sediment assessment, as pollutants accumulate in sediments. The organisms living in these sediments are exposed to a “cocktail” of chemical substances.
Prospectively, we investigate the biological effects of so-called “new” pollutants such as nano-titanium dioxide and nano-cocktails, and rare earth elements in aquatic systems.
In order to assess the effect of contaminants on organisms we apply a number of standardized ecotoxi- cological tests during which specific test organisms are exposed to environmental samples and moni- tored whether these samples lead to retardations in growth, reduction of fecundity, mobility, physiological activity etc. If an organism is negatively impacted by a water or sediment sample, this could indicate that this effect can also occur in the environment. By applying different test organisms in so-called biotest combinations, the different modes of action of contaminants, different exposure pathways, the effects of multiple stressors and the impact of not known or not chemically determined substances are examined (project “Sullied Sediments”).
In cooperation with the Technical Unversity Hamburg-Harburg, we developed an ecotoxicological classi-fication system for sediments, which allows a rapid evaluation and comparison of toxicity potentials in an area. The overall aim is to combine ecotoxicological data with chemical and biological data and come to an integrated assessment of environ-mental quality for a specific area. Internationally, these topics have been addressed by projects in Africa and Asia (projects “Morogoro” and “Riskcycle”).
For some “new” or “emerging” substances, such as rare earth elements and nano-titanium dioxide, relatively little is known about the impact that they may have on aquatic organisms. For that reason, we study the effects of these substances on test organisms under controlled laboratory conditions with the aim to gain more information on a potential risk that they may pose.