Despite a bloom in methane-consuming bacteria – and despite us saying last month all BP methane had been eaten – in fact the spilled gas is still present in large quantities, underwater.

Just last week a study in Nature Geoscience came up with an estimate of just how much methane had been spilled: some 500,000 tonnes – 40% of the total fossil fuel spill.

If that were to break through to the atmosphere it would have a climate forcing effect of some 12 megatonnes of CO2 – roughly 0.03 percent of global annual emissions. As it remains dissolved the breakdown processes can lead to oxygen shortages in the water column and associated ecological damage.

Saturday one of the Geoscience authors, University of Georgia Marine Sciences Professor Samantha Joye told the American Association for the Advancement of Science at their annual meeting that somehow the methane breakdown, which skyrocketed to 60,000 times above normal levels in the Gulf region now slowed down to just 30 times above background levels – but not because the methane bubble was running out.

Joye suggests another nutrient may have become a limiting factor to the microbes. Her new findings have not yet been published.

We are totally ignorant when it comes to microbial behaviour in the Gulf waters. We do know these waters are presently some 15 degrees colder than a couple of months ago. Partly that’s due to summer turning into winter. Partly it’s due to the present state of the Western Hemisphere Warm Pool, a term so cool we like to use it twice.

© Rolf Schuttenhelm | www.bitsofscience.org