Russian naval activity due to the war in Ukraine may have killed more than 100 dolphins in the Black Sea last month, scientists are reporting.
Ivan Rusev, Head of the Research Department of the Tuzly Estuaries National Park in southwest Ukraine, reported the mammals' deaths in a May 1 Facebook post.
Many of the dead dolphins had symptoms showing they were "likely affected by military sonar," said Rusev, also a doctor of ecology. Most were Black Sea bottlenose dolphins, the scientist said.
"Unfortunately, during April 2023 , more than a hundred dead dolphins have already been registered in the bays of Sevastopol and other shores of the occupied Crimea and nearby Novorossyska, Sochi, Gelendzhik... affected by military sonarami," Rusev wrote.
Novorossyska, Sochi, Gelendzhik are all port cities or nearby resort towns along the Black Sea coast.
In his post, Rusev also wrote 77 dead whales have also been identified in the Crimea since January.
While at least 100 dead animals have already been registered, the death toll is much higher, with scientists believing the number surpasses 1,000, the post continues.
"This is confirmation of the fact that the activity of hostile submarines and submarines in that part of the Black Sea near Crimea and Novorossiysk," Rusev wrote.
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No evidence of fishing injury
In January, the BBC reported dolphins and porpoises have been washing up dead on the shores of the Black Sea in unusually high numbers with scientists pointing the finger at increased Russian military action.
When Rusev found dead animals in that area in previous years, the outlet reported, many had marks on their bodies suggesting they had got caught up in fishing gear.
Just like the marine mammals found in April, he reported those animals had none.
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The uptick in deaths is unusual, Rusev said: Earlier this year, he told the outlet he finds three to four dead dolphins along the 27 miles of shoreline in the park annually.
But when the war began, the military closed a large portion of shoreline. Between February and August 2022, Rusev said he and his team discovered 35 dead marine mammals along the 3 miles of shoreline still accessible, according to the BBC.
"His team spoke to their counterparts in other Black Sea countries, except Russia and Georgia. Some of Ukraine's national parks, including one near the devastated city of Mariupol, are now in Russian occupied territory," the outlet reported.
When they added up the numbers they learned at least 2,500 dead dolphins had washed up on shore between February 2022, when the war started, and May of last year. Because most dead dolphins simply sink to the bottom of the sea and are never counted, the outlet reported, Rusev believes the actual number is much higher.
Natalie Neysa Alund covers breaking and trending news for USA TODAY. Reach her at firstname.lastname@example.org and follow her on Twitter @nataliealund.
This article originally appeared on USA TODAY: Hundreds of Black Sea dolphin deaths due to war in Ukraine: scientists