Multiple stressors and pollutants
Freshwaters are used intensively by humans, meaning that they are exposed to a number of stressors. We explore the complex interrelations and impacts of the different stressors: How do nutrients and contaminants enter our surface waters, which factors play a central role in this process, and where are rivers and lakes in a particularly poor state? Nutrient inputs of nitrogen and phosphate, for example, may affect water quality, leading to algal blooms. It is often impossible to completely remove pharmaceuticals and biocides during wastewater treatment. They then end up in rivers and lakes, where they may affect the hormonal metabolism of fish and amphibians. Mining may lead to the contamination of adjacent freshwaters with potash and sulphate. Land use change, urbanisation, water control structures and the increasing use of artificial lighting at night (light pollution) exert additional pressure on our freshwaters. In our research, we acknowledge that use by humans is an important part of reality – only then can future-oriented solutions be developed.
Related News
Selected publications
Mixtures of organic micropollutants exacerbated in vitro neurotoxicity of prymnesins and contributed to aquatic toxicity during a toxic algal bloom
This study investigated how organic micropollutants and the algal toxins prymnesins interact as mixtures in water extracts from the Oder River using neurotoxic effects on human nerve cells in vitro. The authors showed that prymnesins dominate the neurotoxic effects, but many of the detected organic micropollutants exacerbate the lethal effect of prymnesins.
Unpredicted ecosystem response to compound human impacts in a European river
The authors have compiled and analyzed the key environmental factors that led to the mass development of the brackish water alga Prymnesium parvum in the Oder in the summer of 2022. The data synthesis shows how multiple stressors combined to allow an alga that normally thrives in stagnant salt water to proliferate en masse in a completely atypical habitat.
Temperatures and hypolimnetic oxygen in German lakes: Observations, future trends and adaptation potential
A study of oxygen and temperature trends in 46 German lakes showed that temperatures have risen mainly at the surface, but not in the deep water. This led to increased stratification and lower oxygen concentrations. Scenarios showed that these effects of climate change on oxygen content could be compensated by reducing nutrients.
Widely used herbicide metolachlor can promote harmful bloom formation by stimulating cyanobacterial growth and driving detrimental effects on their chytrid parasites
The study investigated the effects of the herbicide metolachlor on host-parasite interactions, using the host-parasite system of the toxigenic cyanobacterium Planktothrix agardhii and its chytrid parasite Rhizophydium megarrhizum. Metolachlor promoted cyanobacteria growth and caused multi and transgenerational detrimental effects on parasite fitness. However, these effects are reversible.
Exposure protocol for ecotoxicity testing of microplastics and nanoplastics
Despite the increasing concern about the harmful effects of micro- and nanoplastics (MNPs), so far, there exist no harmonised guidelines for testing the ecotoxicity of MNPs. An international research team with IGB has now developed protocols to assess the toxicity of these substances in soil and aquatic ecosystems.
