SS9.01 Ecosystem Science Practiced in an Urbanized Estuary: South San Francisco Bay Cloern, J, E, U.S. Geological Survey, Menlo Park, USA, jecloern@usgs.gov   SOUTH SAN FRANCISCO BAY: AN HNLC MARINE ECOSYSTEM SURROUNDED BY SILICON VALLEY South San Francisco Bay is a marine lagoon bounded by San Francisco, Oakland and Silicon Valley. For three decades, academic and government researchers have used the South Bay as a study site to learn how natural processes and human actions regulate water quality, biological communities and ecosystem functions in urban marine systems. Early hydrographic measurements revealed the South Bay as a high-nutrient low-chlorophyll (HNLC) marine system during most of the year, interrupted by episodic algal blooms during spring. Syntheses of observational data suggested hypotheses: (1) spring blooms result from salinity stratification that develops as a response to weak tidal stirring and inputs of freshwater as a source of buoyancy; and (2) the HNLC state occurs when stratification breaks down and allows strong top-down control of phytoplankton biomass by benthic suspension-feeders. These hypotheses were the foundation of two decades of research designed as iterations between field and modeling studies. This talk will develop the original guiding hypotheses, and the session will illustrate a mode of ecosystem science that integrates results from environmental monitoring, process measurements, retrospective analyses, and modeling.   Return to This Session's Schedule     Abstract Search