More than 30,000 birds have been killed by the thousands of tons of oil that leaked after a heavy storm broke a tanker apart near the Black Sea, the governor of the disaster-hit region said Monday, according to Russian news agencies. Countless other birds, weighed down by thick coatings of the fuel oil, hopped weakly along the shore or sat helplessly in the sand. Workers with pitchforks and shovels started the backbreaking labor of gathering up vast clumps of oil mixed with sand and seaweed, according to AP. The spill from a tanker that split apart Sunday in the strait connecting the Black and Azov Seas is seen as potentially the worst environmental disaster in the region in recent years. It prompted criticism that many Russian tankers aren't seaworthy. «Some 30,000 birds have died and it's not possible to count how many fish. The damages are so great that it's hard to assess. It can be equated with an ecological catastrophe,» said Alexander Tkachev, the governor of the Krasnodar region, according to the Interfax news agency. Another regional official, Sergei Zaitsev, was quoted as saying that much of the oil still on the water's surface could congeal in the wintry temperatures, forming globs that drop to the seabed. Russian President Vladimir Putin ordered Prime Minister Viktor Zubkov to fly to the region to assess the disaster and clean-up efforts. As many as 10 ships sank or ran aground in the storm, including the freighter Nakhichevan, which broke up and spilled a load of sulfur, officials said. The bodies of three sailors from the Nakhichevan washed up on shore Monday and rescuers were looking for five missing crewmen, said Emergency Situations Ministry spokesman Sergei Kozhemyaka. Two other freighters carrying sulfur also sank. Russian environmental officials said the sulfur spilled from the freighters did not appear to pose any environmental danger. Jim Farr, a chemist with the U.S. National Oceanic and Atmospheric Administration, compared the spill to dumping a load of sand in the water and smothering a reef, or covering a patch of grass with a blanket. However, he said that it was difficult to know the long-term effects without better knowledge of the area's depth and currents. The Volganeft-139 tanker was carrying about 4,800 metric tons (1.3 million gallons) of fuel oil when the storm sundered it. About half its load has leaked out already, officials estimated. The craft's 13 crew members were rescued. Alexei Knizhnikov, head of the World Wildlife Federation's Russian oil and gas program, said the Volganeft-139 was constructed for river use and was unfit to endure severe weather at sea. «In the Kerch Strait, river vessels and sea vessels change cargoes, as sea vessels cannot enter the Don and Volga rivers because of small water draft. But vessels constructed for rivers cannot stand strong sea storms,» he said. Anatoly Yanhuck, a regional coast guard officer, said workers would begin pumping oil from the tanker once the weather improves, then tow the ship to port. Investigators would be looking at the actions of the ship's captain, but he said the weather appeared to have been worse than forecast.