Toxic algae blamed for 300 tons of dead fish in Oder River on German-Polish border: "A man-made environmental disaster"

Germany said Friday that mass fish deaths in the Oder River were a "man-made environmental disaster," blaming toxic algae growth sparked by the introduction of salt into the waters.

Presenting a report into the disaster that saw at least 300 tons of dead fish pulled from the river in Germany and Poland this summer, the German environment ministry said the most likely cause was "a sudden increase in salinity."

The "introduced salt" led to "massive proliferation of a brackish water algae that is toxic to fish," it said.