The ongoing Russian invasion of Ukraine may have killed over a hundred Black Sea dolphins in the month of April alone, according to scientists.
Ukrainian biologist Ivan Rusev, head of the research Department of the Tuzly Estuaries National Park, said in a Facebook post that “more than a hundred dead dolphins” have been registered washing up in Sevastopol—a major port in Crimea, in the Black Sea—and other shores nearby.
Many of the dead dolphins had symptoms showing they were “likely affected by military sonar.” Most were Black Sea bottlenose dolphins, the scientist said.
However, this April, there has been no Russian military operations near the Tuzly Estuaries National Park, Snake Island or the general in the Northwest, Rusev said, “as was very alarming in April 2022.” Rusev said during April 2022, there were “horrific mass whale deaths.”
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According to Rusev, the data comes from “Russian open sources.” It is not the first time Rusev has posted his concerns relating to ocean wildlife and warfare. In October 2022, he said the war in Ukraine could have killed up to 50,000 dolphins in the Black Sea.
A study published at the beginning of April by The Royal Society said tens of thousands of cetaceans have died in the Black Sea.
Scientists involved in the study—including Rusev—assessed data from social media, from around 2,500 cetacean corpses that stranded along the shores of the Black Sea across three months.
It is not uncommon for cetaceans to wash ashore. Marine mammal strandings are a common phenomenon and happen globally, usually due to illness or factors such as human interference.
So, to find out whether warfare increased these strandings, scientists compared their assessment to pre-war data. They found that deaths increased by 9 to 14 times, depending on the location.
Scientists also estimated that based on the 2,500 documented strandings, there were likely 37,500 to 48,000 animals dead during these three months of war. This is because many dead cetaceans sink to the bottom of the ocean, rather than washing ashore.
Eoghan Darbyshire, an environmental scientist at The Conflict and Environment Observatory, a charity based in the U.K, told Newsweek in October that the impacts of marine life during conflict are perhaps “the most difficult environmental damages to monitor during war.”
“The most visible sign of damage is the washing up of cetaceans (dolphins, whales) on the beaches around the Black Sea. Anecdotally numbers are higher than in previous years, suggesting a link with the conflict—most likely military sonar, where there is a relatively well-established link to behavioral change in cetaceans,” Darbyshire said.
Dolphins have their own sonar for navigating the ocean. They use them to get around and seek out prey.
However, military sonars can interfere with this as they directly affect the part of the brain used.
Ewa Węgrzyn, an author of the Royal Society study at the University of Rzeszów, Poland, told Newsweek in April, that “without these activities dolphins cannot survive.”
“Previous research on the effect of military exercises on cetaceans showed that exposure to sonar signals led to a great energy deficit in whales. Energy loss over 40 percent is a lethal threat to cetaceans and it may result from only ten days of fasting,” Węgrzyn said.
“It has been documented that sonar signals can disrupt cetacean behavior over distances of up to 90 nautical miles suggesting that the extended and large-scale military operations during the war may have left little undisturbed space for cetaceans in the Black Sea.”
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