NaToxAq on Swiss TV
The Swiss TV channel SRF visited Eawag in September 2019 to report about cyanobacteria and their toxins in local lakes. The TV crew joint on a lake sampling trip at Greifensee. Regiane Natumi Sanches (ESR 10) uses samples from Greifensee for her studies on production dynamics of cyanotoxins and Daria Filatova (ESR 6) inspected these samples for cyanotoxins during her secondment at Eawag this summer.
In the video, one can see how we take the boat out to the Eawag monitoring station on the Greifensee. Here we have automated probes installed that monitor water quality parameters along the water column and an underwater camera that takes microscope images of cyanobacteria. All data is sent automatically to a server for analysis but we need to inspect the equipment on site regularly. The report also points out to the general public that despite the name “blue green algae” we are in fact dealing with bacteria. We explain that while we can see the cyanobacteria under the microscope, we need to take water samples back to the laboratory for chemicals analysis because we cannot simply see the toxins.

The TV team joins us back in the laboratory where we show them the evaluation of the online data acquired at the monitoring station and our cyanobacterial cultures of common species such as Microcystis or Planktothrix. We explain that not all cyanobacteria are toxic and that genetic variation defines their ability to produce these bioactive compounds.
In the report, it is explained that severe cyanobacterial blooms are rather rate in Switzerland while in Germany 32 bathing restrictions had to be enforced in July and August 2019 alone. The last time the concentration of cyanobacteria was health threatening in Greifensee was in 2011. They interviewed a local man who grew up at the lake and Mr. Bosshard remembers that it felt like fine powder at the top of the water column and that the authorities told the public that that was a so-called algae bloom.
The TV crew had a sincere interest to learn about our work on natural toxins and the report was perceived very well all around.