Center for Embedded Networked Sensing ENS Approaches for Observing and Sensing of Microbial Communities in Aquatic Ecosystems: An Overview Gaurav Sukhatme, David Caron, Carl Oberg, Bin Zhang, Amit Dhariwal, Beth Stauffer, Stefanie Moorthi, Arvind Pereira University of Southern California http://robotics.usc.edu/~namos Introduction: Project Goals Technological Goals • Development of robust, decentralized algorithms and supporting hardware • Acquisition of high-resolution, spatio-temporal information in near-real time of pertinent environmental factors that affect the distribution and dynamics of plankton assemblages. Application Goals • Use of this technology and conceptual approach to make real-time chemical and physical measurements within natural aquatic ecosystems • Generate and test novel hypotheses involving the dynamics of microbial taxa of societal and ecological relevance. Problem Description: Sensor Network Design & Construction NAMOS is a combination of static & mobile components Study Site: Lake Fulmor, CA • Static buoys provide high resolution on a temporal scale at several locations • Mobile Robotic Boat provides high resolution on a spatial scale in areas where buoys are not deployed • Mobile Robotic Boat also provides sampling capabilities • Buoys & Robotic Boat are outfitted with chlorophyll fluorometers & thermistors Multiple Deployments in Lake Fulmor have been conducted in NAMOS has allowed us to document seasonal differences in phytoplankton communities & unusual diel changes in chlorophyll distribution. Proposed Solution: Field & Laboratory Experimental Results Results & Figures NAMOS deployments in LF, 2005 & 2006 • Spatial & Temporal Patterns of Chlorophyll Distribution in Lake Fulmor: Multi-scale Measurements • Heterogeneous chlorophyll distribution along lake & seasonally • Diel variations in chlorophyll concentration indicate a highly migratory phytoplankton assemblage • Highly variable phytoplankton community • Shifts in community structure towards cyanobacteria dominance in late Summer • Current & future work includes additional measurements of environmental parameters meaningful for phytoplankton growth & success Laboratory investigations of Lingulodinium polyedrum • Prolonged red tides of L. polyedrum off CA coast in recent summers present excellent model system • Potential for toxin production • Experiments conducted in water column testbed to better understand vertical migration • New quantitative PCR method developed for identification & rapid enumeration of L. polyedrum in natural water samples UCLA – UCR – Caltech – USC – CSU – JPL – UC Merced