GCRC Program Summary |
Findings
Georgia Rivers Land Margin Ecosystem Research Program:
A comparative study of the transport and transformation of materials from rivers through the land-sea margin.
Bacterial communities:
Who are the important bacterial players that transform estuarine- and marsh-derived organic matter in the Georgia estuaries, and can we link bacterial community structure with the critical biogeochemical functions the communities mediate? New 'in situ' molecular-based methods for targeting individual bacteria and the functional genes they carry were developed and applied for the first time in the GARLMER estuaries (Hodson et al. 1995, Chen et al. 1997), and are being used to elucidate key steps in nitrogen and carbon transformations. Approaches based on bacterial 16S rRNA gene sequences have linked the first ecologically relevant group of marine bacterioplankton to its biogoechemical function (González & Moran 1997). The exclusively marine Roseobacter lineage accounts for up to 30% of the bacteria in the Georgia estuaries, and appears to play important roles in cycling of organic and inorganic forms of sulfur (González et al. 1999) and in the breakdown of naturally occurring aromatic compounds such as lignins and humic substances (Buchan et al., 2002). Funds from NSF, Office of Naval Research, and the Department of Energy provided essential supplemental funding for these projects.