Toxic species of algae identified in Oder – cause of fish kills?

Updated on 08/17/2022 at 5:28 p.m

  • Could an alga be the cause of the fish kill in the Oder?
  • Researchers have detected the toxic microalgae species Prymnesium parvum in the river’s water.
  • The species is “known for occasional fish kills.”

You can find more panorama themes here

On the Search for the cause of the mass death of fish in the Oder the researchers are also keeping an eye on a toxic type of algae that has developed rapidly in the river. In the meantime, the microalgae with the name Prymnesium parvum has been identified, said the water ecologist Christian Wolter of the German Press Agency on Wednesday. “The species is known to occasionally cause fish kills.”

It is still unclear whether the toxin of the algae is the reason for the fish deaths in the Oder. The researcher at the Berlin Leibniz Institute for Freshwater Ecology and Inland Fisheries emphasized whether it produced toxins in this case. He spoke of a massive algal bloom with 200 micrograms per liter and more than 100,000 cells per milliliter of water. However, the toxin of the algae is harmless to humans.

Algae species actually lives in brackish water

The type of algae actually lives in brackish water, Wolter described. This typically occurs at estuaries where fresh and salt water mix. But in a saline environment, they can grow well, said the aquatic ecologist. In addition, the algae need high pH values. “As a brackish water species, it would otherwise not form a mass development in the Oder”.

For the expert there is a clear connection between the introduction of salt and the development of algae. He personally does not believe in an accident, said Wolter. Initially, several media reported about the algae, including rbb and t-online.

Poland’s public prosecutor is hearing more than 220 witnesses

In Poland, too, the search for the cause of the fish kill continues. So far, the Polish public prosecutor’s office has heard 228 witnesses as part of their investigations. The investigators, together with witnesses, also made twelve site visits to different sections of the river, said Deputy Attorney General Krzysztof Sierak on Wednesday. “It is not clear from previous activities what caused the massive fish kill.”

The death of fish on the Oder has been worrying people who live on the river in Poland and Germany for days. Poland’s government assumes that a large amount of chemical waste was discharged into the river. The Polish police have offered a reward of the equivalent of 210,000 euros for information on the perpetrator or perpetrators.

So far no evidence of toxins in the water

According to the Polish government, no toxic substances that could have caused the fish kill have been discovered in the water samples examined. In addition, no evidence of pesticides was found in the samples of dead fish, said Poland’s Environment Minister Anna Moskwa on Tuesday in Warsaw.

The Brandenburg State Environment Agency evaluated the first laboratory results on Monday. The website of the State Environment Agency shows that the values ​​in the river changed dramatically from August 7th. The oxygen content, the pH value, the turbidity and other values ​​suddenly went up, while the amount of nitrate nitrogen dropped significantly. (dpa/mgb)

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.