A race is on to clean up shorelines off Crimea after tons of oil spills from damaged Russian ships

Cleanup continued in the Kerch Strait near Russian-occupied Crimea on Sunday, a week after at least 3,700 tons of low-grade fuel oil spilled out of two storm-stricken Russian tankers.

More than 7,500 people, many of them volunteers, raced to rescue wildlife and clean up shorelines blighted by mazut, a heavy, low-quality oil product, according to Russian news reports.

By Sunday afternoon, more than 12,000 tons of contaminated soil had been removed along 34 kilometers (21 miles) of shoreline, Russia's state Tass news agency reported.

Russia's Emergency Situations Ministry said oil continued to wash up along Crimea's coastline, despite announcing the night before that a cleanup operation had been successfully completed off the Crimean Peninsula, which Russia illegally annexed from Ukraine in 2014.

Russian authorities were still working to assess the spill's consequences. A local scientist, Tatyana Beley, told Russian state media on Sunday that her team had discovered 11 dead dolphins whose airways had been clogged by oil fuel.

According to Russia's emergencies ministry, a rescue operation was launched last Sunday after the Volgoneft-212 ran aground and had its bow torn away in storm conditions. One sailor in the 13-man crew died, officials said. A second tanker, the Volgoneft-239, was also left damaged and adrift. It later ran aground close to the port of Taman in the Krasnodar region and its 14 crew members were rescued.

The oil spill has impacted at least 60 kilometers (37 miles) of coastline, Greenpeace Ukraine said Tuesday. The charity has had no presence in Russia since 2023, when it was designated as an ''undesirable organization'' by the Russian government.

Some Russian media critical of the Kremlin, as well as Western outlets, cited Russian volunteers as saying that state support has been inadequate as they grapple with the oil spill. Some said they experienced headaches, nausea and vomiting after spending hours inhaling toxic fumes.

The Kerch Strait separates the Russian-occupied Crimean Peninsula from Russia and is an important global shipping route, providing passage from the 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 2016, Ukraine took Moscow to the Permanent Court of Arbitration, where it accused Russia of trying to seize control of the area illegally. In 2021, Russia closed the strait for several months.

Mykhailo Podolyak, an adviser to the head of the office of Ukrainian President Volodymyr Zelenskyy, described the oil spill as a ''large-scale environmental disaster'' of the war and called for additional sanctions on Russian tankers.