This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2011, Broadening Participation. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Silvia Newell is "Activity of nitrogen fixers and denitrifiers in coastal sediments." The host institution for this fellowship is Boston University and the sponsoring scientist is Dr. Robinson Fulweiler.
Coastal systems are acutely vulnerable to nitrogen pollution, resulting in wide-spread reduced oxygen levels (hypoxia), decreased biodiversity, and increased harmful algal blooms. Nitrogen loading from wastewater into Waquoit Bay is documented and has more than doubled since 1938. Hypoxia in eutrophic coastal ecosystems can also stimulate puzzling microbial responses, including high rates of simultaneous denitrification (nitrogen removal) and nitrogen fixation. Continuing to fix nitrogen when fixed nitrogen is available is energetically unfavorable and leads to the central questions of this research: Why do bacteria turn on nitrogen fixation under nitrogen-replete conditions? Can nitrogen fixation exacerbate eutrophication and greenhouse gas production? This research investigates the distributions and activities of denitrifying and nitrogen-fixing bacteria within the sediment to determine if the patterns are consistent with the existence of highly localized, very rapid nitrogen transformations.
Training objectives include learning techniques of biogeochemistry including core incubation and isotope methods. Broader impacts include participation in the Women in Science program for 12-14 year olds at the Waquoit Bay National Estuarine Research Reserve, as well as outreach to local minority-serving high schools.