You can find the original article in German
here!
In the inlet from the Weichselbrunner pond into the Bodenwöhrer Hammersee there were found striking readings of cyanobacteria.The pond is part of a big protected landscape and no sampling and no treatment is allowed. So the best choice was to treat the Hammersee directly. Therefore ultrasonic treatment was used. With the help of bbe fluorometer the results could be measured and had shown that the methode works very well.
In 2013 up to 190 micrograms per liter of blue-green algae concentration has been found. After the start of ultrasound treatment in 2017, the lake has recovered significantly. "The peak load of blue-green algae was already in 2016 as low as 53 micrograms per liter." In July 2017, even no blue-green algae could be measured in the short term; an interim algal bloom at that time was due to non-toxic green algae.
A detailed measurement program is linked to the treatment, which continuously provides lots of important results, for example visibility depth, oxygen content, composition of the plankton, possible sources, water temperature and of course, algae concentration. Most of the investigations are carried
out by the municipality with a newly procured AlgaeTorch. The ease of use also allowed the involvement of mayors and other "non scientific staff" directly in the measuring program.
(Fig. Alois Köppl, Gleiritsch)
