Daphnia are currently appearing in large swarms in the secondary clarifier and are sensitive to pollutants
in the Griesheim wastewater treatment plant . These tiny organisms, known as Daphnia, appear in large swarms in the secondary clarifier basins. According to the city, their presence is an indicator of the water quality there.
Daphnia are only about one to five millimeters long and have a transparent shell. They typically live in ponds, pools, lakes, and ditches, among other places. They feed by filtering plankton and algae from the water.
Large swarms in the secondary clarifier
The insects are currently present in particularly large numbers at the Griesheim wastewater treatment plant. Such massive outbreaks are known as "Daphnia bloom".
According to the city, the water fleas contribute to further purifying the water by filtering out plankton and algae.
Daphnia react to pollutants
Daphnia are sensitive to changes in water quality. Their movement patterns can change when the water is contaminated with pollutants. Very slow or absent movements can therefore indicate a deterioration in water quality.
The city interprets the current large number of water fleas in the secondary clarification process as a sign that the small organisms are finding suitable living conditions there.
(GRIESHEIM – RED/PSG)
