Bacterial abundance, production and community composition in thin biological layers

David C. Smith

 Long Term Goal:

My long term goal is to understand how fine-scale vertical structure in the water column influences the abundance and activities of heterotrophic bacteria. Whether thin layers with high concentrations of chlorophyll and dissolved organic matter persist on time scales long enough to affect bacterial growth is a fundamental question. Equally important are questions regarding the influence that heterotrophic bacteria exert on water column properties such as the quality and quantity of organic matter and light scattering at these same scales. Superimposed on the above questions is how changes in the composition of the biological community affect bacterially mediated processes in thin layers.

Objectives:

My first objective was to measure bacterial abundance and growth rates in high-resolution vertical profiles during the 1998 thin layers field program. This was accomplished by measuring bacterial abundance and growth in water sampled either by a siphon system (Dian Gifford) or free-falling rosette package (Tim Cowles). The next objective is to correlate the bacterial data with other biological data (chlorophyll a), chemical data (dissolved organic matter) and physical data (density profiles) collected during the study.

© D.C. Smith 1998