Troubled waters

US: The news about BP’s oil spill keeps getting worse. Scientists say large quantities of methane gas escaping from the well are causing “dead zones ” in the ocean. The gas, which was found in levels up to 100,000 times higher than normal, causes a chain reaction that sucks oxygen out of the water.

“The water can go completely anoxic and that is a pretty serious situation for any oxygen-requiring organism,” says Dr Samantha Joye, a scientist at the University of Georgia, who is monitoring the spill. Joye reports that the well is producing up to 50 per cent as much methane and other gases as oil, and the gas is settling at a level of 1,000 to 1,300 metres under the surface of the water.

Larry Crowder "The animals are voting with their fins to get away from the oil"

"We haven't seen zero-oxygen water, but there is certainly enough gas in the water to draw oxygen down to zero," she says, adding that this could “wreak havoc” with plankton and other organisms at the bottom of the food chain. The extent of disruption to the ocean food chain will not be clear, however, until “we go out and measure that”.

In the meantime, scientists (and fishermen) are reporting unusual movements of marine life. For example, sharks are swimming far closer than normal to the Alabama coast. “The animals are already voting with their fins to get away from the oil,” Larry Crowder, a marine biologist at Duke University, told The Guardian. All this is bad news for the environment of the Gulf of Mexico. It already has 11,000 square kilometres of dead ocean caused by run-off from animal waste and farm fertilizer at the mouth of the Mississippi River.