Some marine life thrives on oil bubbling up naturally from the seabed even though it cannot cope with giant single leaks like from BP's ruptured well in the Gulf of Mexico, experts say.
Natural seeps from thousands of spots from the Pacific Ocean to the North Sea account for about 45% of all oil entering the oceans in a typical year, according to the U.S. National Academy of Sciences. The rest is from leaks caused by people.
The little-understood seeps show that the oceans can absorb what is normally viewed as harmful pollution—a host of microbes can eat oil and gas, especially light compounds such as gasoline, while finding thicker tars indigestible.
"You can sometimes see oil from seeps as slicks on the surface," said Arne Jernelov of the Institute for Futures Studies in Stockholm, who led a UN environmental study of a huge blowout on the Mexican Ixtoc 1 rig in 1979.
"But a large concentrated spill is a totally different thing. . .nature cannot adapt," he said of BP's 85-day spill. Apart from being eaten by bacteria, oil can evaporate and is broken down by sunlight.
Environmentalists say that the existence of seeps should not be a backdoor justification for dumping oil in the seas that can kill creatures from turtles to pelicans.
"While these seeps can release large amounts of oil, the rate is usually very slow, which allows the surrounding ecosystems to adapt," environmental group Oceana said in a report. Other species are unable to adapt and die.
Natural seeps from thousands of spots from the Pacific Ocean to the North Sea account for about 45% of all oil entering the oceans in a typical year, according to the U.S. National Academy of Sciences. The rest is from leaks caused by people.
The little-understood seeps show that the oceans can absorb what is normally viewed as harmful pollution—a host of microbes can eat oil and gas, especially light compounds such as gasoline, while finding thicker tars indigestible.
"You can sometimes see oil from seeps as slicks on the surface," said Arne Jernelov of the Institute for Futures Studies in Stockholm, who led a UN environmental study of a huge blowout on the Mexican Ixtoc 1 rig in 1979.
"But a large concentrated spill is a totally different thing. . .nature cannot adapt," he said of BP's 85-day spill. Apart from being eaten by bacteria, oil can evaporate and is broken down by sunlight.
Environmentalists say that the existence of seeps should not be a backdoor justification for dumping oil in the seas that can kill creatures from turtles to pelicans.
"While these seeps can release large amounts of oil, the rate is usually very slow, which allows the surrounding ecosystems to adapt," environmental group Oceana said in a report. Other species are unable to adapt and die.
