MOSCOW, Russia (CNN) -- Russian and Ukrainian authorities launched a rescue and cleanup operation in the Black Sea on Monday after fatal storms sank five ships, including an oil tanker and three ships carrying sulphur, and left at least two sailors dead and 20 sailors missing, officials and news agencies said.
One of several ships that were in distress near Russia that spilled fuel into a crucial waterway.
The oil tanker split in half and spilled more than 1,000 tons of fuel oil, and environmentalists expressed concern that the effects of the spill would last for years.
The official Russia Today Web site said five bodies were recovered. Two of those were confirmed to be sailors from the sunken ships, and Interfax said the other three were also believed to be seamen from the ships.
The Russian Rescue Service said 80 of its experts were working in the Black Sea along with 112 personnel from the Russian Navy's Black Sea fleet, who were focusing on the fuel cleanup. Three helicopters and 11 rescue boats were part of the joint operation, the rescue service said.
The ships sank Sunday during a fierce storm which generated hurricane-force winds and gigantic waves in the Black Sea and the Azov Sea to the north. At one point on Sunday, officials described 20-foot waves and 78 mph winds.
Four of the ships sank in the Kerch Strait, which connects the Black Sea and Azov Sea and separates Russia from Ukraine's Crimean Peninsula.
The Volganeft-139 oil tanker split in half and spilled more than a thousand tons of fuel oil into the strait, authorities said. All of its crew were rescued, Russia Today said.
Three cargo ships, each carrying more than 2,000 tons of sulphur, also sank in the Kerch Strait, authorities said. Two of them -- the Volnogorsk and the Nakhichevan -- were already sinking when the third, the Kovel, hit the Volnogorsk and went down, the RIA Novosti news agency reported.
Eight crew members from the Nakhichevan remained missing Monday, the Russian Rescue Service said.
Farther west, on the other side of the Crimean Peninsula, the storm caused a freighter carrying scrap metal to sink off the coast of Sevastopol. Two of the ship's crew were rescued but 15 remained missing Monday, Russia Today reported.
The strong winds also caused several more cargo ships to run aground. Among them were Turkish vessels, a Georgian and a Greek ship.
Oleg Mitvol, deputy head of Russia's environmental regulator and a member of the United Nations' International Panel for Sustainable Resource Management, said the sinking of the ships in the Kerch Strait was a serious disaster and that it would take 10 to 15 years to clean up the strait and its coastline. Find out more about the ecological effects. »
Vladimir Slivayak, a spokesman for Ecodefense in Moscow, also said the environmental consequences would last for a decade.
He estimated about 70 percent of the oil would stay on the water's surface, but the rest would sink to the seabed, where he said it would contaminate the sea and marine life.
"It's more or less possible to clean up our coast and clean the oil which you can see on the water," Slivayak told CNN.
"But if it goes down, it's nearly impossible to clean it from the bottom. So from my point of view, the consequences for the marine environment will last for (the) next decade."
The oil spill's effects on fish would damage the fishing industry in the region, Slivayak added.
The storm also cut power to Crimea, which led to a suspension of heating and water supplies on parts of the peninsula.
CNN Forecaster Lola Martinez said the storm was a result of a weather front that crossed through the Black Sea region from the west on Sunday, and she said more bad weather was on the way.
"Between today and tomorrow we could see the front will be moving away, but it will still be unsettled," Martinez said. "It's probably not until Tuesday evening that we will see a break, but then another front will come through."
The Kerch Strait is a key waterway for transporting fuel oil from the Caspian Sea onto tankers waiting in the Black Sea. Interfax reported the Volganeft was carrying fuel oil from the Russian city of Samarrah on the Volga River to an oil terminal in Ukraine.
Sunday's fuel spill was on a smaller scale than some previous fuel spills.
In November 2002, the Liberian oil tanker Prestige broke up and sank, spewing 64,000 tons of fuel oil into the waters and polluting thousands of miles along the Atlantic coast of France, Spain, and Portugal. E-mail to a friend
CNN Producer Igor Malakhov contributed to this report.