Fish deaths: Researchers see suspicion of algae poison confirmed

Created: 08/22/2022Updated: 08/22/2022 15:47

A dead fish that's already badly decomposed.

© Patrick Pleul/dpa/archive image

From the point of view of the Leibniz Institute for Aquatic Ecology, the riddle surrounding the massive death of fish in the Oder includes indications that the animals died from a poison produced by algae.

The strong growth of the algae, which actually thrives in brackish water, is in turn due to salt input into the river, said researcher Tobias Goldhammer on Monday of the German Press Agency.

Berlin - "This is our currently most likely hypothesis."

Last week, the Berlin institute pointed out the strong growth of the algae species Prymnesium parvum, which can form a poison that is deadly for fish.

At the weekend, the institute added that this poison had actually been detected in the water of the Oder.

In addition, satellite data would have shown a massive algal bloom in the Oder.

Initial tests on fish eggs with the Oder water had confirmed the deadly effect, Goldhammer told the dpa.

"In the chain of evidence, it is very likely that this algal bloom is the cause of this fish kill." However, this has not yet been definitively proven.

It is also important that the algal bloom is not a natural event, but is due to human influences, namely the increased salt load in the river water.

It is currently not possible to prove where the salt came from.

Other factors also likely played a role, including low water and increased water temperature, Goldhammer said.

He is a research group leader in the Department of Ecohydrology and Biogeochemistry at the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB).

dpa