This project is to investigate the distribution of key properties_abundance, community composition and community metabolic capabilities_of bacterial communities in the Arctic Ocean. The investigator plans to repeat measurements made at other times in previous SCICEX-95, -96, and -97 cruises, and to conduct investigations of sea ice communities. The investigator will examine the patterns of spatial and temporal variation of these properties and attempt to relate them to sources of organic matter associated with heterotrophic production. Community composition will be analyzed using a method based on separating partial sequences of the signal given by the 16S rRNA gene. Community metabolic capabilities will be assessed by the ability of bacteria to grow heterotrophically on a battery of different sole carbon sources. Bacterioplankton abundance will be determined by epifluorescence microscopy. In addition, water samples will be analyzed to determine the concentration of amino acids, carbohydrates, and dissolved organic carbon.
