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Border river: The Oder - here at the Brandenburg Reitwein - separates Germany and Poland
Photo: Frank Hammerschmidt / dpa
Increased salinity has been found in the German-Polish border river Oder.
Only in the summer there had been a massive fish kill in the river.
Why the increased load came again remained unclear at the weekend.
In August there was an environmental disaster in the Oder.
Experts saw salt discharged into the river combined with low water and high temperatures as the reasons for the fish deaths.
This led to a massive proliferation of a toxic species of algae (Prymnesium parvum).
»Now twice as much water in the Oder«
The Ministry of the Environment in Potsdam recently announced that no mass proliferation of the algae is to be expected at the lower water temperatures of 13 degrees.
more on the subject
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Evaluation of satellite data: Massive algae blooms in the Oder began at the beginning of August
Disaster on the Oder: illegal sewage, algae and a blind warning system by Hannes Schrader, Sandra Sperber and Lisa Göllert
In order to assess the salt content in water, the electrical conductivity is measured.
The values now observed are below the peak values measured in summer, but well above the average values of the past few years.
The values in the river are still being observed, according to the Ministry of the Environment.
"Zeit online" was the first to report the high values again.
The Middle Oder from Ratzdorf to Kietz (Oder-Spree district) has been carrying high salt loads for years, the state ministry said.
The »cohabitation« found in the Oder has obviously adapted both to the high basic load and to the fluctuations and peaks that have been recorded.
"The water temperatures are now too low for an algal bloom," said the water ecologist Christian Wolter from the Leibniz Institute for Freshwater Ecology and Inland Fisheries "Zeit online".
“But we now have twice as much water in the Oder.
That means the amount of salt is at least as high or even higher than in summer.«
At that time, an estimated 400 tons of fish were suffocated.
As a result of the mass deaths, there had been violent disagreements between the governments of neighboring countries.
The Polish Minister for the Environment has meanwhile described reports that poison had gotten into the Oder in Poland as “fake news”.
In addition, the governments are arguing about an expansion of the river.
mpz/dpa
