11.08.2022, Brandenburg, Genschmar: Unzählige tote Fische treiben im flachen Wasser des deutsch-polnischen Grenzflusses Oder. Das Fischsterben in der Oder beunruhigt seit Tagen die Menschen in Brandenburg an der Grenze zu Polen. Das Fischsterben in der Oder ist nach Angaben der polnischen Umweltschutzbehörde wahrscheinlich von einer Wasserverschmutzung durch die Industrie ausgelöst worden. (zu dpa "Behörden suchen weiter nach Ursache für Fischsterben in der Oder") Foto: Patrick Pleul/dpa +++ dpa-Bildfunk +++

The death of fish in the Oder has been worrying people in Brandenburg on the border with Poland for days. Thousands of dead fish were discovered in the river, some of them near the city of Frankfurt (Oder) and surrounding towns. The cause is still completely unclear – there are reports of chemical waste, increased mercury concentrations and dissolved salts.

According to Polish Prime Minister Mateusz Morawiecki, the mass deaths were apparently triggered by the introduction of chemical waste. “It is likely that a huge amount of chemical waste was dumped in the river, and with full knowledge of the risks and consequences,” Morawiecki said in a video message published on Facebook on Friday.

Morawiecki emphasized that all responsible authorities had been put on high alert. Water is taken from the river every day, and the veterinary and health authorities are also involved. “But the most important task now is to find the perpetrator, the poisoner.” This is no ordinary crime, as the damage could remain for years, Poland’s head of government continued. “We will not rest until the guilty are severely punished.”

He also wrote: “One just wants to scream with anger”. Morawiecki drew personnel consequences on Friday: Because they are said to have reacted too slowly to the fish deaths in the Oder, he fired two top officials. The head of the water authority and the head of the environmental authority would have to vacate their offices with immediate effect, Morawiecki wrote on Twitter.

“I share the fears and outrage over the poisoning of the Oder. This situation could not have been foreseen in any way, but the response of the responsible authorities should have been quicker.” In Poland, as in Germany, there has been a lot of criticism of how his government and the Polish authorities are handling the situation.

“The Polish side has had information about the poisoning since July 26, Germany since the day before yesterday. After almost two days, they announced that the cause could be highly toxic mercury compounds. Poland’s government does not know this to this day, even though the disaster happened two weeks ago,” Mayor of Krosno Odrzanskie, Marek Cebula, told Gazeta Wyborcza newspaper.

The test results of masses of dead fish should be available on Sunday at the earliest. So far, the State Research Institute in Pulawy has not received any fish, director Krzysztof Niemczuk told the PAP news agency on Friday. “We are still waiting and expect to receive the first batch of fish for testing tonight.”

The fish are to be examined for metals, pesticides and other toxic substances. Niemczuk: “There are so many substances that could have caused the fish kill that we cannot say at this point what the cause might be.”

Not only the analysis of the dead fish, but also the water samples from the Oder in Poland continue. On Thursday, Deputy Infrastructure Minister Grzegorz Witkowski said that the analysis results of the river water would be presented “within a week at the most”.

Water samples in Brandenburg have shown evidence of significant mercury pollution. “The first results have been available since yesterday evening. We don’t have it officially yet, but it does point to massive exposure to mercury as a factor,” said the head of the environmental administration in the Märkisch-Oderland district, Gregor Beyer, on Friday morning on RBB Inforadio. “We don’t know whether that’s the only one.”

The thesis that too little oxygen could be the cause of the fish deaths was rejected by the district administration from the start. “We now know that too,” said Beyer. “We have, quite unusually, even more oxygen in the Oder.”

There is currently a lot of speculation about the origin of the mercury or other toxins, said Beyer. “The most annoying part of this is that the entries, which obviously came from the direction of Poland, were not reported via the appropriate warning systems, so we could only react when a fish kill was directly observed.”

Brandenburg’s Environment Minister Axel Vogel (Greens), however, doubted that mercury was the cause of the mass deaths. This has a more long-term effect than fish poison, he said on Friday evening on RBB television. Vogel has another suspicion: the Oder has “very much increased salt loads”. That was “absolutely atypical”.

Vogel’s ministry said the measured atypical salt loads could be related to the fish kill. “According to current knowledge, however, it will not be a single factor that caused the fish kill in the Oder,” it said in a statement. The term salt loads refers to salts dissolved in the water.

The ministry explained that these are the first further results from the Berlin-Brandenburg state laboratory on the daily samples that were taken at the automatic measuring station in Frankfurt (Oder) by Friday. The results are “not yet fully meaningful and not conclusive”.

Further investigation data “in particular on heavy metals, mercury (in other samples) and other elements” are still being clarified in the laboratory and should be available in the coming week. “Today’s data indicate multi-causal relationships, which include the currently very low discharge rates and high water temperatures,” it said.

With a view to possibly increased mercury levels, Vogel said that this would be checked further. It could be a local phenomenon. When asked whether groundwater or drinking water could be contaminated, Vogel replied: “We don’t hope so.” In any case, it was “a deadly cargo” that was transported in the river. But he would not go so far as to see the groundwater resources in danger.

“We don’t know at the moment what they really died from,” Vogel had previously said about the dead fish in Schwedt. A combination of several factors such as heat, low water supply and toxins is possible, said Vogel. “It is quite possible that these are substances that have been introduced into the Oder for a long time, but normally do not pose a problem at all at mean water levels.” Currently, however, there are historically low water levels on the Oder.

Such small amounts of water meant that every substance in the water was present in a higher concentration, according to the Environment Minister. Therefore, it could well be that substances that are normally not so serious in the dosage are now dangerous due to the increased dose. It has now been clarified that fish would also die in Germany and not only dead animals from Poland had been washed ashore, said Vogel.

The district administrator for the Uckermark district, Karina Dörk, said that the area along the Oder will be flown over with drones to see how the fish kill is developing. A mission to collect the dead fish is planned for this Saturday.

According to the Senate for the Environment, Berlin is currently not at risk of contaminated water flowing from the Oder to Berlin without human intervention. “Berlin’s waters are not affected, and that is not to be expected,” says the authority.

The reason is the topography: because the two waterways that connect the capital with the border river lead, so to speak, “over the mountain”. The Oder-Spree Canal, which flows into the Seddinsee in Berlin-Köpenick – and thus indirectly into the Spree and Dahme – begins at its eastern end in Eisenhüttenstadt with a lock, which, seen from the Oder, overcomes a 14 meter high step. From this plateau, it descends almost eight meters to Berlin via three other locks.

Even more striking is the plateau on the Oder-Havel Canal, which connects the north of the capital with the border river: the difference in height between the Oderbruch and the Barnim is 36 meters, which is overcome at the Niederfinow ship lift.

At the Lehnitz lock near Oranienburg, it then descends around five and a half meters to connect to the Berlin waters. While the Oderbruch is only about one meter above sea level at its lowest point, the Berlin waters are about 30 meters above it.

In Brandenburg, conservationists are meanwhile assuming far-reaching consequences for the Lower Oder Valley National Park. “The effects are just terrible,” said deputy national park manager Michael Tautenhahn on Friday morning to the German Press Agency. “This is simply a disaster for the national park.”

Animals and plants are affected, as is the development of tourism in the region. “The wave of poisoning went completely through the Oder,” said Tautenhahn. Dead fish were seen floating across the entire width of the river. Zander, catfish, gudgeons and loach are affected. Sea eagles and other birds could ingest poison from the dead fish.

Tautenhahn expects the national park’s image to be damaged. “It’s a poisoned disaster area.” He feared that many people would now avoid the national park. The Lower Oder Valley National Park in the very east of Brandenburg is one of the most species-rich habitats in Germany.

Environment Minister Vogel said that the consequences would be felt for years to come: “For the Oder as an ecologically valuable body of water, this is a blow from which it will probably not recover for several years.” The fish stocks would first have to be rebuilt slowly.

“Even if the zooplankton, i.e. the small creatures in the Oder, are damaged – and this is to be expected – it will take a long time before sufficient food for the fish can be found in the Oder again.” A serious one Vogel, on the other hand, does not see any danger to the Baltic Sea from toxic substances that could get there via the river: “First of all, I would assume that whatever is in the Oder at the moment is diluted to such an extent that there is none in the Baltic Sea will do more damage.”

However, there are still no reliable findings on this: “Our problem is that we are still groping in the dark, that we do not know which substances were actually introduced into the Oder,” said Vogel. “We have indications from the Polish side that around July 28 near Oppeln, i.e. near Wroclaw, substances got into the Oder, which caused a fish kill there that rolled down the Oder to us.”

However, there is no clear information about which substances these are exactly. “And we also have no knowledge of the extent to which these substances accumulate in the fish and may have led to these fish being poisonous.” This could then also affect other animals, such as storks or birds of prey, if they were to eat such fish .

“At the moment we don’t know whether these fish should be declared as hazardous waste,” Vogel said. “Depending on this, different disposal methods have to be chosen. But it is absolutely clear that disposal has to take place.” For this, personnel and, for example, appropriate containers for removing the dead fish would have to be made available.

There is clear criticism of the Polish authorities from the ranks of the Greens in Brandenburg. “I’m shaken. Not only because of the fish dying thousands of times, but also because of the failure of the information chain from Poland,” said the Greens parliamentary group leader in the Brandenburg state parliament, Benjamin Raschke, on Friday. If simple reporting chains do not work in the event of an ecological catastrophe, there is a fundamental need for discussion. “We have often noticed that there are very different views on both sides of the Oder with regard to the future development of the Oder.”

The Greens spokeswoman in Frankfurt (Oder), Alena Karaschinski, said the frustration was deep about the breach of trust in the room. “A repeated failure to provide information and possibly even an attempt to cover up an environmental disaster. This will have to be dealt with at federal level between Germany and Poland.”