Russia’s Role in Black Sea Dolphin Deaths

December 18th, 2022 - by Elizabeth Fitt / Mongabay

A dead dolphin washed up on shores of Black Sea.

Black Sea Dolphin Deaths Prompt
Ecocide Allegations Against Russia

Elizabeth Fitt / Mongabay

(December 16, 2022) — On May 9, Bogdan Bulete, head ranger at the Danube Delta Biosphere Reserve in Romania, received what he thought was yet another routine call to check out a possible dolphin stranding near the town of Sulina. But when he reached the beach this time, the sight that met his eyes was “overwhelming,” he told Mongabay. Up to 30 dolphins lay dead on the sand.

“Some of them looked burned, and all of them had marks of nets around their tail or their belly,” he said.

Following an unprecedented number of reports of dead dolphins and porpoises on Black Sea beaches since Russia invaded Ukraine, Ukrainian President Volodymyr Zelenskyy on Dec. 7 accused Russia of ecocide during COP15, the UN biodiversity summit in Montreal. His statement followed an announcement in July by the Odesa Regional Prosecutor’s Office that it would mount an inquiry into suing Russia for ecocide over the cetacean deaths.

Mounting evidence is slowly painting a clearer picture of the mass mortality of Black Sea cetaceans. But estimates of the death toll vary and scientists diverge on whether research has progressed far enough to scientifically conclude the war’s effect. The situation highlights the difficulty, and the necessity, of conducting wartime science.

Ukraine’s Zelenskyy oaccused Russia of ecocide during COP15

A few days before Zelenskyy’s accusation, researchers presented the first scientific analysis of changes in cetacean deaths and movement patterns since the war began in February. Data show that harbor porpoise numbers in Bulgarian waters, south of the fighting, were five times higher in the spring of 2022 than during the same period in 2021.

The data also highlight a tenfold jump in dolphins and porpoises found entangled in Bulgarian turbot-fishing gill nets compared to the past three years.

Representatives of Switzerland-based marine conservation consultancy Ocean Care shared the findings with Mongabay prior to presenting them on Dec. 2 at a conference in Malta of state signatories to the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS).

“Increased noise levels as a result of the war could have led to displacement of cetaceans to the south,” Dimitar Popov of Bulgarian environmental research organization Green Balkans, who collected and analyzed the data, told Mongabay.

Ivan Rusev, scientific department head at Tuzlovsky Limany National Park in Ukraine, said there’s no doubt about what caused all the reported deaths: “Such a number of shell-shocked animals in the history of the Black Sea cetaceans has not yet been recorded, it is directly related to the impact of sonars and bombardment in the active phase of the war,” he told Mongabay.

Correlation or Cause and Effect?
“On February 24, shelling by the Russians began … and literally in the first week of March, dolphins started washing up,” said Pavel Gol’din, a researcher at Ukraine’s National Academy of Sciences in Kyiv who necropsied some of these dolphins.

Meanwhile, national parks along Ukraine’s Azov and Black Sea coasts, where scientists usually carry out cetacean monitoring, were occupied by Russia. All except one: Tuzlovsky Limany National Park. There, Rusev recorded 45 dead cetaceans between February and July, along the scant 6 kilometers (3.7 miles) of coastline the military allowed access to. Just three had washed up along the park’s entire 44-km (27-mi) beachfront the previous year.

Strandings continued in the park “until the moment when the armed forces of Ukraine drove the [Russians] out of Zmiinyi Island and the ships with their powerful sonar went to Sevastopol and beyond,” Rusev said.

Gol’din and other scientists Mongabay spoke with said the war may have displaced and killed unprecedented numbers of cetaceans, but that ongoing scientific analysis must be completed to prove it definitively.

”The search for evidence requires time and accuracy,” Karina Vishnyakova, head of the marine vertebrate laboratory at the Ukrainian Scientific Centre of Ecology of the Sea in Odessa, told Mongabay.

How many dead?

Estimates vary for how many cetaceans have died since the war began. Vishnyakova has confirmed some 900 marine mammals stranded on beaches across Ukraine, Romania, Bulgaria and Turkey, based on reports from researchers and citizen scientists. She said that figure is surely lower than the true death toll, but declined to estimate how much without further research.

For his part, Rusev estimates total cetacean deaths since February at more than 50,000, a figure widely reported in the media. He bases this on reports of 2,500 stranded cetaceans he has tallied from contacts in Ukraine, Romania, Bulgaria, Turkey, Russia and Georgia, and the Internet.

He pointed to research showing the vast majority of cetaceans that die at sea sink, never to be seen or counted. Scavengers often remove beached carcasses before they are noticed, and vast lengths of Black Sea coastline were not monitored for strandings at all, he added.

Indeed, Bulete estimated that more than 100 stranded cetaceans went unreported internationally in the Romanian Danube Delta region alone, including the dolphins in Sulina on May 9.

Further research is needed to establish the exact impact, Vishnyakova said, but changes to cetacean populations such as she is seeing in her as-yet-unpublished stranding data are likely to destabilize the entire ecosystem to an unknown degree.

Black Sea harbor porpoises (Phocoena phocoena relicta) and Black Sea bottlenose dolphins (Tursiops truncatus ponticus) are endangered, while Black Sea common dolphins (Delphinus delphis ponticus) are vulnerable, according to the IUCN Red List.

Vishnyakova describes these animals, found only in the Black Sea, as keystone species, or “the wolves of the sea”: they balance the ecosystem by keeping prey populations in check. She and other scientists expressed concern that significant losses will harm the Black Sea ecology and the livelihoods and fisheries worth $251 million that depend on it.

Black Sea ecocide

The initiative launched by the Odesa Regional Prosecutor’s Office in July aims to hold Russia accountable for ecocide under Ukrainian law. The office did not respond to Mongabay’s requests for comment.

It is extremely difficult to prosecute another country for ecocide at the best of times, mainly because ecocide is not yet criminalized under international law. The International Criminal Court (ICC) is also not recognized by Russia.

Ecocide was legally defined as “unlawful or wanton acts committed with knowledge that there is a substantial likelihood of severe and either widespread or long-term damage to the environment” in 2021 by an international group of 12 lawyers. They proposed amending the ICC’s Rome Statute to criminalize ecocide internationally.

To try and prove beyond doubt that Russia has caused the deaths of Black Sea cetaceans, the prosecutor’s office’s inquiry includes dolphin necropsies (like an autopsy, but for animals) carried out by Gol’din.

He said his necropsies revealed hemorrhaging and other tissue damage to echolocation organs. Whether these are attributable to war-related noise exposure will be determined by biologists and vets slated to interpret Gol’din’s samples.

The samples will also undergo evaluation for signs of acoustic trauma in European laboratories, and pathology and toxicology tests to rule out other causes, such as disease.

Russia’s war is not only killing civilians, but also damaging wildlife. Thousands of dolphins died in Black Sea. This is why one of ten elements of @ZelenskyyUA’s Peace formula is ‘Protection of nature’. We urge partners to join us in countering Russia’s ecocide.
— Dmytro Kuleba (@DmytroKuleba) December 7, 2022

Back in May, when dead cetaceans began drawing attention, Irina Logominova, a Russian biologist at the Karaday Scientific Station in Crimea, said disease, not war, is likely a major culprit, according to Russian news site RIA Novosti Crimea. She described the number of deaths then as “within the framework of annual statistics.” She did not respond to Mongabay’s requests for comment for this story.

European and New Zealand COP15 delegates castigated Russia for environmental damage in Ukraine following Zelenskyy’s ecocide accusation. Russian delegate Denis Rebrikov said such allegations were “outside the scope” of the meeting.

War Noise
Porpoises and dolphins use sound waves to echolocate food and find their way around. They are “extremely sensitive” to explosions and other powerful sounds, Vishnyakova said.

As well as causing acute stress, disorientation and sometimes death, explosions can damage echolocation organs even from a distance. Necropsies of stranded harbor porpoises found injuries to middle ear bones and soft tissue following NATO’s managed detonation of 42 British WWII-era mines in a marine protected area of the Baltic Sea in 2021, according to research.

No one knows how many mines have been deployed or exploded in the Black Sea since February. Russia and Ukraine have accused each other of laying hundreds and the Ukrainian government prohibited coastal swimming in June after defensively mining its own coast.

An “armada of submarines and ships with powerful sonars” assailed the northwestern Black Sea, between February and July, Rusev said. Sonar directly interferes with echolocation.

Large-scale explosions have also been plentiful around ports and strategic outposts. The Ukrainian fleet has been all but wiped out, oil rigs and civilian ships hit with heavy artillery, and Ukraine’s ministry of defense reports 16 losses to the Russian Navy’s Black Sea fleet.

These include its flagship, the Moskva, on April 14, and a landing craft sunk under heavy bombardment near Zmiinyi Island (of “Russian warship, go f**k yourself” fame) on May 7.

Both offensives reverberated 40 km (25 mi) away in Sulina, Romania, blowing open Bulete’s office doors and windows. He said they felt like earthquakes and described the sound of low-flying fighter jets as “terrifying.”

The May 9 mass mortality, the largest on his 200-km-long (124-mi) shoreline beat so far, occurred two days after the offensive that sank the landing craft. Bulete said the dolphins could have swum into nets in panic while fleeing explosions, or sustained injuries that rendered them unable to detect the nets.

“Ukraine is paying a huge price to uphold its right to life and liberty,” Vishnyakova said. “But we have to work, do research and draw public attention to the fact that not only people but also nature is under serious threat.”


  • Moore, M. J., Mitchell, G. H., Rowles, T. K., … Early, G. (2020). Dead cetacean? Beach, bloat, float, sink.Frontiers in Marine Science, 7. doi:10.3389/fmars.2020.00333
  • Siebert, U., Stürznickel, J., Schaffeld, T., Oheim, R., Rolvien, T., Prenger-Berninghoff, E., … Morell, M. (2022). Blast injury on harbour porpoises (Phocoena phocoena) from the Baltic Sea after explosions of deposits of World War II ammunition.Environment International, 159, 107014. doi:10.1016/j.envint.2021.107014

Posted in accordance with Title 17, Section 107, US Code, for noncommercial, educational purposes.