The war in Ukraine is threatening the ecosystem of the Black Sea

Elena Sokolovska's pink trousers and warm smile contrast with the dusty equipment, peeling walls and long corridors of her laboratory in Odesa, southern Ukraine. We are on the fifth floor of the Ukrainian Scientific Centre for Marine Ecology* (UkrNCEM), where this phytoplankton specialist works alone. Since the start of the war, most of her colleagues have left the port city. They are fleeing both bombs and empty coffers, given that their state funding has dried up.

With a steady hand, the biologist picks up water samples taken an hour earlier, and has a last close look at the greenish liquid. It has to be shipped to Kyiv before 6pm. "The post office lorry will not wait for us", she sighs as she slips on her backpack.

In the capital, the vials will be delivered to Alexander Krakhmalny, a national authority on marine biology. He will be checking the samples for cyanobacteria, the blue-green microscopic algae that cause the water to change colour in certain areas of the Black Sea. Some varieties, such as Nodularia spumigena, are toxic to humans.

Sokolovska sees her day job as a way of helping in the war against Russia. Before leaving the laboratory, she tersely reminds us: "No photos of the windows, please". A single snap could make the laboratory an easy target for a Russian air attack.

The samples are essential evidence for documenting "one of the greatest ecological disasters in Europe since Chernobyl", as Ukraine's deputy foreign minister, Andriy Melnyk, has described it. On 6 June 2023, at 2.50 am, the Kakhovka hydroelectric dam on the Dnieper river burst in an explosion later attributed to Russian forces. The 240-kilometre reservoir upstream of the dam contained more than 18 billion tonnes of water.

A few days later, in condemning Russia's war crimes, the European Parliament deemed the destruction of the dam to be a case of ecocide. Several hours after the explosion, the surge of floodwater devastated dozens of villages and caused the deaths of 58 Ukrainians. Contaminated by fertilisers, fuel and sewage, the water then spilled into the Black Sea. Ukraine estimates the cost of the disaster at €3.8 billion.

Vladislav Balinskyy, a marine biologist and member of the NGO Green Leaf, immediately saw the extent of the tragedy. "Concentrations of heavy-metal salts and other toxic substances were dozens of times higher than normal", he recalls grimly as he prepares for a routine dive into the dark waters of the Black Sea. "The drop in water salinity killed off certain aquatic organisms and crustaceans such as fish eggs and fry. But the worst devastation was suffered by the colonies of mussels, a species that is both endemic and emblematic in the Black Sea.”

Armed with his camera and flippers, Balinskyy regularly checks up on the creatures along the Ukrainian coast. At a depth of two metres, mussel shells of a strange white hue now litter the sea bed. Only a few dozen metres separate us from the crowded beaches of Odesa. With his snorkel removed, Balinskyy recalls the aftermath of the disaster: "I would even come across frogs on the sand after the tragedy at the dam..."

On his YouTube channel, where he shares the results of his weekly dives, Balyinskyy is emphatic: "I would advise you to refrain from eating the local mussels and seafood for the time being". The Black Sea has now returned to normal salinity levels and mussels are beginning to reappear, but "heavy metals take a very long time to be eliminated from biological systems and are transmitted through food chains". He believes that this warning is being ignored by Ukrainian and Romanian restaurateurs, whose businesses rely heavily on shellfish dishes.

The impact of war on mammals

Molluscs are not the only animals suffering from the war. In 2023, scientists at the Touzly nature reserve, including Ivan Rusev, observed a massive rise in the mortality rate for cetaceans throughout most of the Black Sea. Three species in particular were seriously affected: the bottlenose dolphin, the white-sided dolphin and the harbour porpoise. In the first year of the war, around 1,000 individuals died off, two to three times more than in the years before Vladimir Putin launched his "special operation".

In addition to the explosions produced by heavy fighting between the two belligerents, the use of sonar by submarines has been a major hazard to mammals. Their sound pollution can be a veritable trauma for cetaceans, affecting their ability to move, hunt and feed.

Pavel Goldin, another scientist in the Odesa region, has played a major role in documenting the impact of the war on wildlife. In a report published with five colleagues in July 2023, he summarises the situation in stark terms: "Russia's war operations have targeted the most vulnerable and best-preserved ecosystem of the northern Black Sea, which is a hotspot for endemic and other local species of global importance.”

When corruption gets in the way of science

The war has made it particularly difficult to work as a biologist. Vladislav Balinskyy, Elena Sokolovska and Galyna Terenko all agree that the profession in Ukraine is heavily affected by corruption. The acute shortage of public funding is a further impediment to ongoing research.

Elena Sokolovska, one of the few to remain at the Odesa laboratory, earns just €150 a month. Smiling sheepishly, she prefers to make light of the situation: "I'm the best volunteer in Ukraine!" Over the months, her pay has gradually decreased without explanation. As of October 2024, the average wage in Ukraine is estimated to be just over €470 a month.

Galyna Terenko, a colleague of Elena before the war, now works at the Concarneau Marine Station in Brittany, western France. She says the corruption and money shortfalls were problems before February 2022: "I could write a film script about my life: 'How to survive 25 years in Ukrainian science'. It would win awards!"

The biologist gives details of how high-ranking figures have embezzled part of the budget normally earmarked for scientific institutions. But Terenko is not keen to dwell on the subject: "I've already received threats." None of the officials concerned wished to answer our questions. Ukraine's environment minister, Ruslan Strelets, was dismissed by President Volodymyr Zelensky in a reshuffle on 4 September 2024.

Although Terenko now works in France, she continues to be involved in research on the Black Sea ecosystem: "I am exporting specialist equipment to Ukraine that the relevant authorities don't even know exists. The [Ukrainian] environment ministry is run by people who are far removed from this field."

On the beach in Odesa after his dive, Vladislav Balinskyy of the NGO Green Leaf, also mentions problems with officialdom: "Most of our court cases are against the authorities themselves. They are acting like South American farm barons and grabbing land belonging to national nature reserves, in defiance of the law." The working conditions of scientists, already difficult before the start of the war, have thus worsened at a critical time.

An international impact

In the Black Sea, borders are no limit to the effects of war. Off the coast of Constanța, in Romania, Matei Datcu and his crew of fishermen meet every morning at five o'clock to spread their nets out at sea. On this balmy August morning, the crew know that the apparent calm is deceptive. Eyes etched by a short night, they know they cannot let their guard down. For the last two and a half years, these Romanians have faced a worse peril than desalination or sonar: that of mines, adrift at the mercy of the currents.

Although Datcu is equally concerned about the haul of fish he hopes to bring back to port, the new peril is a constant worry: "Since the start of the war, a dozen mines have washed into our fishing zone. We have had to move away from the Ukrainian coast."

Pushed around by currents and storms, mines have struck commercial vessels on several occasions. On 27 December 2023, a Panamanian grain ship en route to a Ukrainian port was hit in the Gulf of the Danube, injuring two crew members. It happened in the fishing zone where Matei Datcu and his men usually go.

Although the Kakhovka dam water flowed as far as the Romanian coast, Matei Datcu claims that it had no impact on the quantity of fish in his nets. Yet he cannot help noticing that the water is increasingly polluted: "When we fish in the open sea, the rubbish we collect in our nets fills up three dustbins."

Today, hundreds or even thousands of waterborne mines may have been laid by Russia and Ukraine. Even when undisturbed, this military equipment releases chemical compounds, residues and heavy metals into the marine environment. Fortunately, Matei Datcu's crew have not yet come across any of them. A single one would be enough to blow his little wooden boat to smithereens.

🤝 This article is published within the Come Together collaborative project.