A new Gulf danger — billions of cubic feet of choking natural gas released under water — threatens to create vast “dead zones” where nothing lives, scientists say.
The escape of methane from the sea floor poses a danger to giant squid as well as the endangered sperm whales that thrive on the squid, according to the researchers.
Since the April 20 explosion at a BP oil rig, at least 4.5 billion cubic feet of natural gas — and possibly almost twice that amount — have leaked, based on estimates from the US Geological Survey.
“This is the most vigorous methane eruption in modern human history,” said John Kessler, a Texas A&M University oceanographer.
Methane is a colorless, odorless and flammable substance that is a major component in the natural gas used to heat people’s homes. Petroleum engineers typically burn off excess gas attached to crude oil — as BP has been doing since it started capturing leaked gas 15 days ago.
But the huge amount of methane still being released “has the potential to harm the ecosystem in ways that we don’t know,” said David Garrison, a National Science Foundation program director.
In early June, a research team led by Samantha Joye of the Institute of Undersea Research and Technology at the University of Georgia investigated a 15-mile-long plume drifting southwest from the leak site. They said they found methane concentrations up to 10,000 times higher than normal and oxygen levels depleted by 40 percent or more.
The scientists found that some parts of the plume had oxygen concentrations just shy of the level that tips ocean waters into the category of “dead zone” — a region uninhabitable to fish, crabs, shrimp and other marine creatures.
Steven DiMarco, an oceanographer at Texas A&M University who has studied a long-known dead zone in the Gulf, said one example of marine life that could be affected by low oxygen levels in deeper waters would be giant squid, who live primarily in deep water and serve as the favored food of the endangered sperm-whale population.