environmental pollution
Institute: Massive algal bloom in Oder at the beginning of August
Daniel Hühn, fisheries scientist from the IGB Leibniz Institute for Freshwater Ecology and Inland Fisheries, sits in a barge that is reflected in the German-Polish border river Oder, to investigate the background to the environmental catastrophe. photo
© Patrick Pleul/dpa
Scientists from the Leibniz Institute of Freshwater Ecology and Inland Fisheries see clear signs that a toxic alga is to blame for the mass death of fish. What have you found out so far?
The Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB) has gained further insights in its search for the cause of the great fish kill in the Oder. According to the scientists, the spread of a massive algal bloom in the river was already evident in early August near Wroclaw (Poland).
Evaluations of satellite data showed a sudden increase in chlorophyll concentrations in the entire course of the river from August 3rd to 4th, as the IGB further announced on Thursday. These are considered indicators of algal blooms. These values were also increased from July 19th to 20th.
Where did the salt come from?
The experts at the Leibniz Institute for Freshwater Ecology and Inland Fisheries see clear signs that a toxic alga is to blame for the massive fish deaths. Researcher Tobias Goldhammer said that the strong growth of the algae, which actually thrives in brackish water, is due to salt being introduced into the river. Where the salt comes from is still unclear. According to the scientists, other factors also played a role, including low water and increased water temperature. The institute had detected the poison in the water of the Oder.
According to the researchers, it is not yet possible to conclusively assess whether the algal blooms in July and August are directly related. What is clearly recognizable, however, is the very rapid spread of the bloom that followed and which from August 10th covered almost the entire Oder. In the following two weeks, the chlorophyll concentrations reportedly decreased again. Only at the end of August did they return to the medium level.