Hot summer days attract many people to lakes and rivers. However, so-called ‘blue-green algae blooms’ repeatedly lead to bathing bans. What many people do not know is that these warnings are caused by cyanobacteria – microscopic organisms that are not only potentially harmful to health but also play a central role in the ecological balance.
Ecological significance and new challenges
Cyanobacteria – often referred to as ‘blue-green algae’ – are natural components of the biotic community of lakes, rivers and ponds. They produce oxygen, bind nitrogen and serve as a food source for other microorganisms. Under certain conditions – such as high temperatures and excess nutrients – they can multiply en masse and form so-called ‘blue-green algae blooms’. Some species produce toxins that can be harmful to humans and animals. Longer periods of heat caused by climate change favour the increased occurrence of algal blooms and toxins, as the water layers in lakes and reservoirs remain stable for longer.
CyanoTox research project
As part of a newly launched research project, TZW: DVGW-Technologiezentrum Wasser (German Water Centre) aims to establish new detection and quantification methods for relevant cyanobacteria and their toxins in order to enable better monitoring of emerging algal blooms and potential toxin release. These also pose a problem for the water supply, as the removal of dissolved toxins is challenging depending on the type of treatment. Furthermore, algal blooms can lead to odour and taste problems in treated drinking water. Early detection of such cyanobacterial blooms is essential so that water suppliers can respond appropriately. The aim of the project is to develop adequate and robust analytical methods for cyanobacteria, their toxins and any odour and taste substances. Molecular biological methods are being developed for the rapid identification and quantification of cyanobacteria and their toxin formation potential. In addition, analysis methods for toxins and odour substances are being expanded and optimised. This will increase knowledge about cyanobacterial species, which are becoming more prevalent due to climate change, and their potential threat to drinking water through toxin release.
The project CyanoTox (Project page) will run from 2025 to 2028 and is funded by DVGW (Deutscher Verein des Gas- und Wasserfaches e.V.). In addition to TZW, project partners are Gelsenwasser AG and the Arbeitsgemeinschaft Trinkwassertalsperren e. V.
