Tale of Two Rivers: Cause of Fish Die-off Likely From Russian Factory

In June of this year, some dead fish were found floating in the Seym River, which flows through Russia and across the border into Ukraine. On Aug. 20, reports of fish dying en masse in the river within Ukraine’s border regions began appearing on social networks. 

The next day, the Sumy regional military administration banned swimming in rivers in several communities.

By Aug. 29, polluted water had reached the Chernihiv region and flowed into the Desna River, of which the Seym is a tributary. Local social networks and TV channels were flooded with videos of farmers removing dead fish from the water in industrial quantities. Over time, there were so many that the Environmental Inspectorate and the State Emergency Service had to intervene.

In just three weeks, more than 30 tons of dead fish were removed from the Seym and Desna (not counting other river organisms like snails), according to the Ministry of Ecology of Ukraine. Panic ensued on social media.

As ecologist and former First Deputy Chairman of the State Water Resources Agency Mykhailo Khorev notes, the state made a mistake by not immediately conducting the necessary tests and thus failing to inform the public about the source of the pollution.

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“This is a bureaucratic process. Initially, the source was not searched for. When it became public, they started searching. They announced that it was organic pollution, but ‘organic’ is too general a concept. The necessary tests should have been conducted immediately, and the public should have been informed clearly,” Khorev told Kyiv Post.

According to Chernihiv ecologist Serhiy Tsybulya, Director of the Educational and Scientific Institute of Technologies of Chernihiv National Technological University, the analysis does not fully show the presence or absence of pollution.

“It was clear that the Seym was polluted from Russian territory, but tests on the 47 most likely indicators – for heavy metals, and so on – showed that everything was normal, although there are several thousand possible pollutants. Since the test results were generally neutral, no one could say with 100% certainty that there was no contamination,” Tsybulya said.

In early September, the situation became so severe that even representatives of the Kyiv water utility, which draws drinking water from the Desna River, a tributary of the Dnipro flowing through Kyiv, began to warn that in the worst-case scenario, the centralized drinking water supply in Kyiv could be disrupted.

At the same time, the first test results were released. It was revealed that the main pollutant was organic compounds, likely from a Russian sugar factory on the Seym River near the border with Ukraine.

Contamination mechanism

According to Kyiv Post sources, the organic substances from the sugar factory – probably molasses – triggered a chain reaction in the river.

“There was oxidation of organic compounds in the water, which consumed the oxygen in it. This chemical reaction depleted the oxygen levels, dropping from 7 milligrams per liter to 0.2-0.4 mg per liter, whereas 4 mg per liter is already a critical level. As a result, the fish and other aquatic life began to die en masse from suffocation. The cause of the die-off in the Desna and Seym was not chemical poisoning but hypoxia,” Tsybulya said.

This was confirmed by the installation of aeration stations, which began to work on the river – fish that had survived began to gather near these stations. This saved part of the fish population.

However, according to other experts, the aeration plants made only a small contribution to the Desna River.

“The Desna is much more full-flowing than the Seym and has a faster current. Aeration plants are unlikely to cover such a large volume of water. In this case, self-cleaning occurs naturally,” said Yevhen Dykyj, a biologist and director of the National Antarctic Research Center.

Khorev added that the relatively slower and narrower Seym suffered the most.

By the time the pollution reached a few hundred kilometers from Kyiv, it had sufficiently diluted and oxidized to no longer pose a threat. There were no restrictions on water supply in Kyiv.

On Sept. 16, Deputy Chairman of the State Water Agency Ihor Hopchak stated in a national TV marathon that the oxygen levels in the water had been restored to within permissible limits.

“At the water intake point in Brovary [northeast of Kyiv], there has been a slight change in chemical oxygen demand, from 28.37 to 33.2 mg per cubic decimeter, with a norm of 30 mg per cubic decimeter. Dissolved oxygen is higher than normal, though it has slightly decreased from 6.22 to 5.4 mg per cubic decimeter. There are no risks to water intake. The pollution in the Desna River is now less concentrated than it was initially in the Seym River and at the water extraction points in the Chernihiv region,” Hopchak said.

At a final press conference, Serhiy Afanasyev, Director of the Institute of Hydrobiology of the National Academy of Sciences of Ukraine, said that the ecosystems of the Seym and Desna rivers could recover in two to three years.

Prime suspect

On Sept. 10, Prime Minister of Ukraine Denys Shmyhal named a sugar factory in the village of Tetkino, in Russia, as the source of the waste that polluted the Seym and Desna.

During a press conference on Sept. 12, Volodymyr Osadchy, a hydrochemist at the National Academy of Sciences of Ukraine, used satellite images to estimate that around 5,600 tons of contaminated water had entered the Seym River from the sugar factory in the Kursk region.

“This was evident not only because the sugar factory in Tetkino is located right on the Seym River, a few kilometers from the Ukrainian border. Satellite images showed that its aeration fields were empty, and the composition of the pollution indicated a structure typical of sugar factories. Each type of production has a distinct structure and composition of wastewater. You can easily distinguish the wastewater from a sugar factory from that of a dairy or meat processing plant,” Khorev explained.

However, determining whether the discharge was intentional is difficult. Some experts argue that if it had been caused by military operations (the Russian side has repeatedly reported shelling in Tetkino), Russia would have publicized it heavily.

“Yes, Tetkino is in a border area near military operations. But if this were caused by Ukrainian shelling, Russia would have filed numerous criminal cases and made thousands of statements. Instead, there is silence. The Russian side has not commented on the incident,” a Kyiv Post source in law enforcement said.

Environmentalists believe that the more likely cause of the incident was a violation of safety regulations at the plant. Such incidents have happened at this plant before.

“In my memory, discharges from this plant have at least twice led to fish die-offs in the Seym, both since 2006. This plant has been involved in such accidents multiple times. The difference is that those were local events, while this incident has had much broader consequences,” Khorev noted.

Environmentalists say that the Desna and Seym, can quickly restore their biodiversity. As for the settlements along the rivers, water pollution has not affected Chernihiv, where the city water supply comes from wells, or other settlements, because well water is not connected to river water.