There’s good news for folks worried that atmospheric CO2 levels in the Arctic have passed 400ppm for the first time: a vast CO2-sucking phytoplankton bloom has been discovered beneath Arctic ice – and it may thank global warming for its presence.
“This wasn’t just any phytoplankton bloom,” Stanford University marine scientist Kevin Arrigo toldThe Christian Science Monitor. “It was literally the most intense phytoplankton bloom I’ve ever seen in my 25 years of doing this type of research.”
Arrigo’s research, conducted in the Chukchi Sea last year as part of NASA’s ICESCAPE Arctic-research expedition, is discussed in the online issue of the journal Science in a report entitled “Life Blooms Under Arctic Ice“.
The massive under-ice bloom discovered during ICESCAPE was thoroughly unexpected. The meager amount of phytoplankton in that area’s open waters had led scientists to believe that under-ice phytoplankton would be even more rare. Not so. Due to the recent thinning of the Arctic ice sheets, enough light is now able to penetrate below the ice, enabling phytoplankton to thrive. […]
The amount of phytoplankton blooming beneath the ice, the theory goes, is so great that it contributes to the lack of blooms in open water – the under-ice blooms simply eat up all the available nutrients before they have a chance to make it out to the open ocean.
The huge amount of CO2 photosynthesized by the phytoplankton, in fact, may help explain why the ocean is absorbing more of that greenhouse gas than calculations would otherwise indicate: even though the amount of dissolved CO2 in Arctic waters is below predicted levels, that carbon is finding another home in the photosynthetic systems of the phytoplankton.