CORVALLIS, Ore. Scientists have discovered a super-charged methane seep in the ocean off New Zealand that has created its own unique food web, resulting in much more methane escaping from the ocean floor into the water column.
Most of that methane, a greenhouse gas 23 times more potent than carbon dioxide at warming our atmosphere, is likely consumed by biological activity in the water, the scientists say. Thus it will not make it into the atmosphere, where it could exacerbate global warming. However, the discovery does highlight scientists' limited understanding of the global methane cycle and specifically the biological interactions that create the stability of the ocean system.
Results of the study, which was funded primarily by the National Oceanic and Atmospheric Administration and the Federal Ministry of Education and Research in Germany, have just been published online in the journal Limnology and Oceanography.
"We didn't discover any major 'burps' of methane escaping into the atmosphere," said Andrew R. Thurber, a post-doctoral researcher at Oregon State University and lead author on the study. "However, some of the methane seeps are releasing hundreds of times the amounts of methane we typically see in other locations, so the structure and interactions of this unique habitat certainly got our attention.
"What made this discovery most exciting was that it is one of the first and best examples of a direct link between a food web and the dynamics that control greenhouse gas emissions from the ocean," Thurber added.
The scientists first discovered this new series of methane seeps in 600 to 1,200 meters of water off North Island of New Zealand in 2006 and 2007. The amount of methane emitted from the seeps was surprisingly high, fueling a unique habitat dominated by polychaetes, or worms, from the family Ampharetidae.
"They were so abundant that the sediment was black from their dense tubes," Thu
|Contact: Andrew Thurber|
Oregon State University