Methane in water of Gulf 'astonishingly high'-US scientist

[Ronan Kelly]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

From earlier post by David Valentine (June 18);

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Disregarding the oily surface for now, the natural gas component of this spill is rather uninteresting in the surface waters. Concentrations are near background and at the most a factor of two high. However, the true complexity of this system is revealed down deep. Below approximately 1,000 meters, the concentration of natural gas and methane in the ocean waters jumps by a factor of one million. That's right, one million. The ramifications of this are the topics of our current studies. The oxygen depletion due to this methane is variable, with some sites displaying 20 percent to 30 percent reductions in oxygen and some having oxygen contents that are seemingly uninfluenced. Our measured rates of methane oxidation by microbiology seem low, but more measurements and calibrations are necessary to confirm this perplexing finding. Each new analysis of this deep water signal reveals a new layer of information that was previously hidden. While this environment is an oily mess, the hidden complexity of the natural gas and methane issue can only be described as beautiful.

http://www.scientificamerican.com/blog/post.cfm?id=deepwater-spill-survey-perplexing-m-2010-06-18

 

[Pathfinder]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

Biologists find 'dead zones' around BP oil spill in Gulf

Methane at 100,000 times normal levels have been creating oxygen-depleted areas devoid of life near BP's Deepwater Horizon spill, according to two independent scientists

<figure sizset="5" sizcache="4"><figcaption>Poggy, or menhaden, fish lie dead and stuck in oil from the BP spill in Bay Jimmy, Louisiana. Fish are fleeing the area of the Deepwater Horizon spill, biologists say. Photograph: Sean Gardner/Reuters</figcaption> </figure>

Scientists are confronting growing evidence that BP's ruptured well in the Gulf of Mexico is creating oxygen-depleted "dead zones" where fish and other marine life cannot survive.

In two separate research voyages, independent scientists have detected what were described as "astonishingly high" levels of methane, or natural gas, bubbling from the well site, setting off a chain of reactions that suck the oxygen out of the water. In some cases, methane concentrations are 100,000 times normal levels.


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In a conference call with reporters, Samantha Joye, a scientist at the University of Georgia who has been studying the effects of the spill at depth, said the ruptured well was producing up to 50% as much methane and other gases as oil.

The finding presents a new challenge to scientists who so far have been focused on studying the effects on the Gulf of crude oil, and the 5.7m litres of chemical dispersants used to break up the slick.

Joye said her preliminary findings suggested the high volume of methane coming out of the well could upset the ocean food chain. Such high concentrations, it is feared, would trigger the growth of microbes, which break up the methane, but also gobble up oxygen needed by marine life to survive, driving out other living things.

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A Texas A&M University oceanographer issued a similar warning last week on his return from a 10-day research voyage in the Gulf. John Kessler recorded "astonishingly high" methane levels in surface and deep water within a five-mile radius of the ruptured well. His team also recorded 30% depletion of oxygen in some locations.

Even without the gusher, the Gulf was afflicted by 6,000 to 7,000 square miles of dead zone at the mouth of the Mississippi river, caused by run-off from animal waste and farm fertiliser.

The run-off sets off a chain reaction. Algae bloom and quickly die, and are eaten up by microbes that also consume oxygen needed by marine life.

But the huge quantities of methane, or natural gas, being released from the well in addition to crude presents an entirely new danger to marine life and to the Gulf's lucrative fishing and shrimping industry.

"Things are changing, and what impacts there are on the food web are not going to be clear until we go out and measure that," said Joye.

http://www.guardian.co.uk/environment/2010/jun/30/biologists-find-oil-spill-deadzones