Germany and Poland suspect that toxic algae killed thousands of fish

Authorities in Germany and Poland said Monday they suspected toxic algae was largely responsible for the deaths of more than 100 tons of fish in the Oder River that runs through the two countries.

“Examinations carried out so far have confirmed the presence of ‘toxic’ algae prymnesium parvum,” Polish Deputy Environment Minister Jacek Ozdoba tweeted.

On the German side, the latest results from “the Leibniz Institute and the University of Vienna confirm the suspicion that the massive development of a toxic algae could be responsible for the death of the fish,” added a spokesman for the German Environment Ministry. , Andreas Kübler, at a regular press conference in Berlin.

abnormal salinity of the river.

The spokesman, however, stressed that the causes that explain such a massive death of fish and mussels are “multiple”.

The incriminated microalgae, also called “golden algae”, is common in estuaries and normally develops in brackish waters with a salt content lower than that of the sea.

If it could proliferate to this extent in the fresh waters of the Oder, this indicates abnormal salinity in the river, which could have industrial causes, the spokesman said. The high salt level may also have been favored by low water levels and high temperatures, experts said.

Absence of “toxic substances”

Berlin and Warsaw are trying to establish the cause of this massive contamination of the Oder, the extent of which was revealed in mid-August.

Both sides suspected from the start that chemicals played a role. However, Polish Environment Minister Anna Moskwa later clarified that “none of the samples analyzed so far” had “shown toxic substances”.

The disaster has somewhat strained relations between the two countries. Therefore, Germany has accused Poland of being slow in informing it of the extent of the contamination. On Saturday, Anna Moskwa warned of “a new fake news broadcast in Germany”, after Brandenburg’s Environment Minister had hypothesized that there were pesticides in the water.

The Polish Minister drew a parallel with previous declarations by the authorities of this Land according to which traces of mercury had been detected in the water, an affirmation that had not been verified.

In Poland, the government has been criticized for not taking swift action. The first reports of mass fish kills in the Oder came from Polish locals and fishermen on July 28. In recent years, the Oder was known to be a relatively clean river, with around 40 species of fish living there.