At least 32 dolphins have washed up among a total of 61 dead cetaceans in the three weeks since fuel oil spilled out of two stricken tankers in the Kerch Strait, the stretch of water separating the Crimean Peninsula from Russia’s southern Krasnodar region, an animal rescue group has reported.

Russia’s Delfa Dolphin Rescue and Research Centre said the deaths of the marine mammals are “most likely related to the fuel oil spill”, an event which Russian president, Vladimir Putin, himself has called “an ecological disaster”.

Reporting the deaths on the messaging app Telegram, the Centre said that a total of 61 dead cetaceans had been recorded since the emergency but indicated that the condition of the bodies suggested that half these deaths had occurred before the spill.

It’s most likely, however, that the deaths of the more than 30 dolphins – most of which were from the endangered Azov species, a species of harbour porpoise native to the Sea of Azov – had been caused by the spill itself.

“Judging by the condition of the bodies, most likely the majority of these cetaceans died in the first ten days of the disaster. And now the sea continues to wash them up,” wrote the Centre.

The oil spill began three weeks ago, on December 15, when two ageing Russian tankers were caught in a storm off the Kerch Strait. One sank and the other ran aground, pouring around 2,400 tonnes of a heavy fuel oil, called mazut, into the surrounding waters. 

On Saturday, Russia-appointed officials in occupied Crimea declared a regional emergency after oil was detected on the shores of Sevastopol, the peninsula’s largest city situated some 155 miles from the Kerch Strait. Russia’s Emergency Ministry has said that, in the three weeks since the spill began, around 96,000 tonnes of contaminated sand and soil has been removed by officials and volunteers on the shoreline of the Krasnodar region.

On December 23, the ministry estimated that up to 200,000 tonnes in total may have been contaminated with mazut.

The Kerch Strait is an important global shipping route and provides passage from the inland Sea of Azov to the Black Sea. It has also been a key point of conflict between Russia and Ukraine after Moscow annexed the peninsula in 2014. 

Mykhailo Podolyak, an adviser to the head of Ukrainian president, Volodymyr Zelenskyy’s office, has described the oil spill as a “large-scale environmental disaster” and called for additional sanction on Russian tankers.

This article includes additional reporting from Associate Press.

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