Presentation: Future Aspects of Research on Marine Dinitrogen Fixation.
Biographical Information: Julie LaRoche obtained her Ph.D. in biology from Dalhousie University, Nova Scotia, Canada. She has worked as a biological oceanographer at Brookhaven National Laboratory, Upton, New York, USA, for 11 years before moving to Institute for Marine Research in Kiel, Germany. After spending the last 14 years in Germany working in the area of marine biogeochemistry, LaRoche has been awarded a Canada Research Chair tier 1 in marine biogeochemistry and microbial genomics in the Department of Biology at Dalhousie University. There she will continue and expand her work on marine phytoplankton, nitrogen fixation and the nitrogen cycle, combining marine genomics and stable isotope tracer studies.
Although the filamentous N2 fixing Trichodesmium has long been established as an important marine microorganism capable of fixing N2 gas, the last 15 years of research on marine N2 fixation have led to the realization that marine diazotrophs are a highly diverse group of microorganisms. Recent research has also established that the most widely applied method to measure N2 fixation in oceanic waters may have underestimated the true N2 fixation rates by a factor of 2 or more. Taken together the findings call for a standardization of rate measurement methodologies and a revaluation of the role of oceanic N2 fixation in the marine nitrogen cycle on a global scale.