Ecological significance of photoheterotrophic bacteria in the Western Arctic Ocean
We are looking for a foreign applicant for a postdoctoral fellowship at the Station Biologique (Roscoff, France).
We currently witness in the Arctic:
1) a decrease in summer ice cover that exposes sea surface to solar radiation and physical forcings,
2) permafrost thawing and increased river runoff, both leading to an increase in the export to the ocean of organic carbon previously sequestered in the Tundra, and
3) an increase in ultraviolet radiation.
These three phenomena favour a growing mineralization of organic carbon through photo-oxidation and bacterial activity, amplifying the increase in atmospheric CO2. At the same time, the exposure of a larger fraction of ocean surface to sun light and the increase in nutrients brought by rivers lead to larger autotrophic production and sequestration of organic carbon. To predict the balance of these processes, we will conduct an extensive study in the Mackenzie River/Beaufort Sea system in August 2009 onboard the Canadian research icebreaker Amundsen.
Photoheterotrophic bacteria, including proteorhodopsin-containing microorganisms are major components in the Arctic Ocean. Their abundance and hybrid metabolism (respiration and phototrophy) will probably make them key players of the actual changes (increased solar radiation and carbon availability).