News

The Red List of freshwater fish and lampreys in Germany has been updated for the first time since 2009. It shows a clear negative trend over the last 14 years: 21 species have been classified threatened. This means that more than half of the native species are now considered threatened or already extinct. With 10 per cent of fish species extinct, Germany is well above the European average of 2.5 per cent.

Clonal fish that are reared under nearly identical, highly standardised environments systematically differ in the number and size of offspring per reproduction cycle, two crucial indicators of biological fitness.

A research team under the lead of IGB has identified the most important risk species among aquatic pets for Germany and developed a three-step risk assessment method that can serve as a screening tool and as a basis for legislation to restrict future releases of unwanted animals. This is essential, as the study also shows that 97 per cent of the freshwater species sold in Germany are not native.

Researchers from TU Berlin and IGB have studied how the water budget and quality have developed over the last 60 years: Restoration measures between 1985 and 1995 have significantly improved the chemical water quality. But climate change can reverse this positive development: Heavy rainfall and dry periods change the chemodynamics of the river.

A team of researchers led by the University of Iceland's Research Center at Snæfellsnes and IGB has now used unusual Citizen Science data from several decades to show that the American mink has decimated the native eider duck in the Brokey archipelago by about 60 percent.

For most pollutants, there are standard protocols for assessing the risks to ecosystems. 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.

From a scientific perspective, a misleading story is being told about the detection of low concentrations of the toxin-producing brackish water algae Prymnesium parvum in various waters in Brandenburg (Germany): The interpretation spread in the media with reference to the Landesfischereiverband Brandenburg / Berlin e. V. (Brandenburg Fisheries Association) and taken up by institutions, that this result disproves the correlation between algae growth and salt concentration, is scientifically incorrect. 

In water bodies, stones, aquatic plants or the substrate often feel slippery. The cause of this is the so-called biofilm, a wafer-thin layer of countless microbes. They form the basis of aquatic food webs, cleaning and detoxifying the water by breaking down organic pollutants. Using lakes in the French Pyrenees as an example, researchers from the Institut National Polytechnique de Toulouse and the IGB have now shown that the microbial biofilm composition is changing rapidly as a result of climate change and that toxic cyanobacteria are increasing.