The Oder River, which runs between Germany and Poland, is still in an alarming condition after this summer's massive fish kill, the environment minister of the state of Brandenburg, Alex Vogel, said on Wednesday.
Vogel called on Poland to disclose information about salt discharges, which experts have said led to the killing of the fish.
"The Oder is doing very poorly," he told radio broadcaster RBB on Tuesday.
At the moment, the salt loads are back in the same proportions as they were in the summer, he added. "We cannot give the all-clear at all."
According to Vogel, salt is still being discharged into the Oder. "We know that it comes from Poland."
The Polish side has not yet submitted a discharge register.
"The Poles are very tight-lipped when it comes to revealing who discharges how much authorised quantities. Who discharges illegally, the Polish authorities probably don't know either," Vogel said.
The EU should put pressure on Poland to disclose the information, Vogel said. He fears that there could be mass fish kills in the river again.
In August, massive amounts of fish were found dead in the Oder. Experts believe that the cause of this was salt discharges combined with low water and high temperatures, which led to the mass reproduction of a toxic algae species (Prymnesium parvum).
