Deep ocean carbon mystery solved
13 Nov 2015 by Evoluted New Media
Scientists have discovered that hydrothermal vents are the reason dissolved organic carbon (DOC) levels remain constant in the oceans throughout the year.
Scientists have discovered that hydrothermal vents are the reason dissolved organic carbon (DOC) levels remain constant in the oceans throughout the year.
Dr Jeff Hawkes led a team from the National Oceanography Centre (NOC) and The University of Southampton to find these vents converted the biologically resistant long-lived carbon into more readily available carbon.
Dr Doug Connelly a co-author from the NOC, said: “This work finally gives us a mechanism for the deep ocean carbon cycle, addressing the long standing problem of why the DOC in the world’s oceans is not increasing.”
This conversion is the reason – despite the constant influx of DOC from the surface ocean – the level of DOC in the deep ocean is stable.
Dr Jeff Hawkes, said: “There has been a long outstanding question about whether hydrothermal vents are a source or sink of organic carbon to the oceans. We have shown that hydrothermal vent fluids contain almost none of the organic carbon which accumulates in the oceans, which means that vents are a sink for this unreactive ‘stored’ carbon.”
This study was based on both seafloor and laboratory based analysis with the NOC’s robotic vehicle Isis taking samples from seven vent sites in the Atlantic, Pacific and Southern oceans between 2009 and 2013. DOC is an important carbon pool, holding as much as our atmosphere, therefore understanding how the levels remain continual is important to understanding the global carbon cycle.
Author: Charlotte Allum recently finished her BSc in Zoology at the University of Southampton.
