Ukrainian scientists confirmed that after the Russian oil spill in the Kerch Strait, all Black Sea countries have found themselves in a risk zone. For some, these are oil spills, for others – birds in fuel oil or fish and water, polluted with toxins. But pollution affected all the coasts.
Several days later, oil clots and dead fish were found in almost all the Black Sea countries, but it turned out to be complicated to prove that these were the consequences of the spill of that very Russian oil. Yet, Ukrainian scientists developed a model to forecast the movement of oil in the sea and proved this fact. They also forecast that the swimming season will not pass without surprises – oil that went to the bottom in the cold season rises to the surface in summer.
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On the early morning of December 15, the Russian oil tanker, “Volgoneft-212”, sent out a signal of distress. The waves of a powerful storm broke the ship with oil products, intended for export to India, in half. 13 crew members had to wait for their rescue in the open sea for a day, and one seaman died. The same day, another oil tanker, “Volgoneft-239”, also sent out an SOS signal. Both ships transported fuel oil M-100 a brand of fuel used for heat production, shipping, and industry and were banned from winter navigation in the sea. They were designed in the 1960s, and modernised later – their middle part was cut out. After the impact of stormy waves, both ships broke along these very welded seams for “modernisation”.
This double catastrophe resulted in the release of four to eight thousand tons of fuel oil into the water, and they are still spreading along the entire area of the Black Sea. According to the data of the Ukrainian Ministry of Environment, during the first month after the catastrophe, the direct effect of toxic fuel oil resulted in the death of over 700 sea birds and over 60 dolphins. In Russian Anapa, one student died after cleaning the shores from oil, about 300 more volunteers sought medical help due to poisoning with oil product vapours.
While all this was happening, two messages were recurrent in Moscow: the accident had been caused by force majeure circumstances, and the spill had affected only the Russian coast. Both messages are lies. The first one is easily refuted by checking the weather forecast for those days, which shows that these oil tankers had no right to enter the sea On December 14, the storm warning was announced at the Kerch crossing. As per the words of Andrii Klymenko, the head of the Black Sea Institute for Strategic Studies, the mentioned oil tankers belong to the “river” class, the maximum height of waves for them is 3 m. At the time of the accident, the waves reached 3.5 m. .
As for the statement about the effect of the oil spill being limited to the Russian coast, it required the analysis of satellite images and mathematical modelling, which nobody in the world had even attempted. This is what scientists in the Ukrainian Scientific Centre of Ecology of the Sea started doing a few days after the catastrophe.
Where did fuel oil go?
Pursuant to international conventions “On Protection of the Black Sea from Pollution” and “On Transborder Impact of Industrial Accidents”, Russia had to inform other Black Sea countries about the fuel oil spill as soon as possible. The logic of these documents lies in the fact that a fast response will help the countries coordinate their joint efforts and overcome a natural disaster or an accident.
However, as Viktor Komorin, acting director of the Ukrainian Scientific Centre of Ecology of the Sea, states, Russians not only failed to transmit the data but also continued to spread their cynical lies about the spill affecting only their coast.
“However, it concerns all the Black Sea countries, of course. So, in December, we created an international group of scientists to refute the lie and explain the long-term consequences of the spill,” Komorin recollects.
The group consisted of Mark Zhelezniak from IER Fukushima University (Japan), Maksym Sorokin from the Institute of Mathematical Machines and Systems Problems of the NASU (Ukraine), Pavlo Tkalich from the Tropical Marine Science Institute at the National University of Singapore (Singapore) and Viktor Komorin. These scientists began analysing satellite images, social networks, and models of oil movement in water to conduct evaluations that would demonstrate the movement directions of oil spills.
According to Mark Zhelezniak, who was invited to study the consequences of the nuclear power plant accident in Fukushima 12 years ago, his task was to create a complex simulation of oil spreading in the Black Sea, which nobody had ever done before.
“In this story with the spill in the Kerch Strait, we were wondering where the fuel oil was going to. We know that at first, an oil film is formed on the water, then waves drag it to the greater depths. In water, oil products break down into clots. We wanted to find out where the clots would go further,” Mark Zhelezniak explained to NGL.media.
The scientists have worked at the simulation in OpenDrift for several months software package, a platform for modelling of drifting particles, developed to study the movement of different objects in water, air, or other media. OpenDrift is open-source software; its code is available for use and modification to everyone , which considers temperature, wind velocity, current, and even density of oil products. In early June, they finished their work on forecasting, which reconstructed the movement of spilt fuel oil from December till late March. They explained that there was no sense in further modelling, since during this period, fuel oil turned into small tarballs, which, by the end of March, either were thrown by waves to the shores or descended to the bottom and didn’t move yet.
The main hypothesis of scientists was that fuel oil penetrated the main Black Sea current, which was moving counter clockwise, thus it has spread throughout the entire sea and will reach the shore of all the Black Sea countries with waves. The simulation confirmed it.
“We have made two models: for lighter and heavier oil, to show these two main scenarios. Our purpose was to demonstrate what has happened and to give instruments for the future in case this scenario is repeated,” Mark Zhelezniak explained.
“At first, we saw that the current was moving from the Kerch Strait to the Azov Sea and towards the Krasnodar Krai. And two weeks later, the situation changed radically – oil products were circulating along the centre of the Black Sea, penetrating the main Black Sea current. Oil on the surface moves fast and mostly reaches the shores. The oil, which got to the depth, is moving more slowly,” Mark Zhelezniak says.
Oil traces on the shores of the Black Sea
In Odesa region, the first reports about the tarballs, thrown on the shore, were registered in January 2025, near the villages of Lyman and Lebedivka in the Bilhorod-Dnistrovskyi district. The State Ecology Inspection selected several samples of tarballs and submitted them to the Ukrainian Centre of Ecology of the Sea. The testing confirmed that all the samples originated from the same source and got to the shore during the storm.
Officially, no other Black Sea country Six countries have access to the Black Sea – Ukraine, Georgia, Turkey, Bulgaria, Romania, and Russia , except Ukraine, has declared the spills of Russian oil on their shores. That was probably caused by their fear of spoiling relations with Russia. However, NGL.media received confirmation of oil findings from local activists and scientists. According to Pavlo Holdin from the Ukrainian I.I. Schmalhausen Institute of Zoology, satellite images confirmed that as of early January, oil products were already present in the sea near the shore of Turkey.
“In reality, all the Black Sea countries are in the risk zone, none can expect to avoid danger. Anyway, all the Black Sea currents intercross,” Pavlo Holdin explained in the comments for NGL.media.
The traces of fuel oil on the Turkish shore were confirmed for NGL.media by Professor Bayram Ozturk from the Turkish Marine Research Foundation in Istanbul. For instance, oil spills were registered between the cities of Sinop and Trabzon. Turkish scientists also reported that the birds had traces of fuel oil on their wings.
Archil Guchmanidze, a Georgian ecologist, also reported finding birds with traces of fuel oil on the shore. “In recent days, there have been many cases of finding birds, covered in fuel oil, on the shores of Georgia (Gonio, Batumi, Kobuleti, Ureki, Poti, Anaklia). In this period, the migration of water fowl passes the area of the fuel oil spill in the Black Sea; these facts are related. Such cases will become more frequent,” Archil Guchmanidze wrote in January.
A bird contaminated with fuel oil on the coast near the Georgian village of Shekvetili, January 1, 2025 (photo by volunteers)
Georgian volunteers tried to document in detail the cases of finding birds, covered in fuel oil, in Batumi.
According to the simulation by Ukrainian scientists, a considerable amount of Russian fuel oil was present in the waters near Bulgarian shores, though this possibility was officially denied. Miroslav Borshosh, the Minister of Tourism, was also persuading that Bulgaria is located at a safe distance and the fuel oil spill in the Kerch Strait would not affect the local tourism sector.
Romania didn’t provide any official comments about the pollution of its shores, but Mircea Fechet, the Minister of Environment, Water and Forests declared their willingness to exchange information about possible consequences with Ukraine.
Consequences for nature
The largest spill of oil products of the Russian brand M-100 in the world took place in 2002 in the Bay of Biscay a part of the Atlantic Ocean between the northern shore of Spain and the western shore of France . The accident involving the oil tanker Prestige resulted in the spill of over 60 thousand tons of Russian fuel oil into the water.
Scientists documented the accident year by year and came to the conclusion that the consequences were evident for about 20 years. Among other things, it is related to DNA changes in those people who were involved in cleaning the shoreline or had direct contact with polluted water. For instance, two years after the spill, scientists detected chromosomal changes related to the higher risk of cancer development.
“There is no reason to think that we will have something different. Toxins accumulate in living organisms, for instance, in fish fat or liver, and then enter dolphins, black-backed gulls, or humans. Toxicity may be very high and will pose a threat to health,” explains Pavlo Holdin from the Ukrainian Institute of Zoology.
Considering that fish, caught in Turkey and Bulgaria, is sold in Ukraine, Holdin recommends being careful with such purchases. His colleague, Viktor Komorin, adds that the consequences of eating fish with toxins may be fatal.
“For instance, fish can accumulate harmful substances and feel normal for some time, but if it is eaten by a dolphin, the latter will die. One cannot forecast all the consequences,” Viktor Komorin explains.
The Ministry of Environment replied to the NGL.media’s inquiry that according to the preliminary evaluations, the fuel oil spill caused damage to the ecosystem of the Black Sea for the total amount of over USD 14 billion The damage was assessed by the State Ecology Inspection according to the method of evaluating damage, caused to the environment within the territorial waters, exclusive marine (economic) zone and internal sea waters of Ukraine in the Sea of Azov and the Black Sea . According to the evaluation of the State Ecology Inspection, Ukraine’s losses are USD 493.5 million.
NGL.media were informed by the Prosecutor General’s Office that criminal proceedings were initiated on December 20 pursuant to part 1 of Art. 243 of the CCU “Sea pollution” related to the fact of the oil spill in the Kerch Strait. Currently, there is little progress in this case.
What will happen to the swimming season?
Viktor Komorin from the Ukrainian Scientific Centre of Ecology of the Sea says that with the increase in temperature, oil products are most likely to come to the surface.
“Most likely, these will be oil products, dissolved in water. This water will penetrate the near-shore zones, so it is necessary to check the level of pollution constantly. We do it near Odesa every week. In addition, the State Ecology Inspection deals with it,” Komorin explains in the conversation with NGL.media.
One has to be especially careful after storms, which can bring tarballs into the upper water layers and throw them onto the shore.
As for the Russian coast, most beaches near Anapa are currently closed for swimming and even walking. At the same time, as of June, tarballs are still being found in areas where swimming has been allowed. Local bloggers even conducted an experiment: they walked along the shore wearing white socks to show that fuel oil was still being thrown onto local beaches even six months after the accident.
As of this June, volunteers in Georgia still find birds covered with fuel oil.
Shadow fleet
The situation that occurred in the Kerch Strait can happen anywhere where Russian shadow fleet oil tankers navigate – this is the belief of Yulia Pavytska, the head of the analytical direction at the KSE Institute Sanctions Team. She and her colleagues trace the movement of Russian tankers since the beginning of the full-scale invasion.
“This is just a matter of time. Everyone is sitting on this barrel of gunpowder, waiting for another spill to happen somewhere,” Yulia Pavytska thinks.
According to the information of KSE, now about 85% of Russian crude oil is transported by shadow tankers. These ships are mostly very old and have no international insurance for accidental oil spills. As a rule, they are used to bypass the limitations on Russian oil supplies It is about price limitations for Russian tanker-transported oil, which were set by G7 countries after the full-scale invasion of Russia into Ukraine. The main purpose was to diminish the export revenues of Russia. Since 2022, the cost of one barrel of Russian oil, transported by sea, has not been more than USD 60 .
The international environmental organisation Greenpeace has also frequently stated the ecological risks posed by the shadow fleet. Three months prior to the oil spill in the Kerch Strait, this organisation had warned about the risks of oil spills from old tankers in the Baltic Sea, where their number increased by 70%.
“If you have good binoculars, then while walking along the German Darss-Zingst peninsula or Fehmarn Island, you will notice the ships of the Russian shadow fleet. These are old vessels with cheap insurance which go along the Baltic shore every day, transporting oil. Our data show that in recent years, the risk of oil catastrophe has increased enormously,” says the report of Greenpeace.
Author Mariana Verbovska, editor Oleh Onysko, infographics Nazarіі Tuziak, translation Nelya Plakhota, cover Viktoria Demchuk