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.