Invited presentation to the Inaugural International Conference of the Engineering Mechanics Institute (EM08), Department of Civil Engineering, University of Minnesota, Minneapolis, Minnesota (USA). May 18-21, 2008.The potential increase in nutrient flux towards bacteria owing to turbulent motion is insignificant under normal environmental turbulent conditions because of the small size of bacteria (Karp-Boss et al, 1996). However, after a chlorophyll production peak, which provides the necessary organic matter for bacteria to grow, it is observed that the bacterial community composition changes, and bacteria that tend to aggregate or become filamentous are favorably selected. I argue that this effective increase in size may account for some observations of increased bacterial activity under turbulent conditions.NTAP (EVK3-CT-2000-00022) VARITEC (CTM2004-04442-C02)Peer reviewed