Suisun Bay San Francisco Bay Latitude:   38.0600     Longitude:  -122.0350 Associated Investigators: James_E. Cloern   Related Web Sites: [USGS Water Quality of San Francisco Bay]   Related Time Series: [ Central Bay ]   [ South Bay ]   [ San Pablo Bay ]   [ Suisun Bay ]   San Francisco Bay has a high degree of spatial variability in physical properties (e.g.suspended sediment concentrations, water depths, vertical mixing rates) that affect biological processes. For almost four decades the U.S. Geological Survey has maintained a program of research and observation in San Francisco Bay. Water quality measurements are made at a series of fixed stations from Rio Vista (lower Sacramento River) to South Bay mouth of Coyote Creek. Data are collected using a submersible instrument package that concurrently measures multiple water quality parameters (depth, conductivity, temperature, suspended solids, chlorophyll, light penetration, and dissolved oxygen). Vertical profiles are obtained at each sample station resulting in a two-dimensional (longitudinal and vertical) description of water quality for each sampling date (see our recently collected data). Continuous sampling along the 145-km transect takes 12-15 hours with the research vessel Polaris. These basic elements of water quality define the sustainability of the Bay as habitat for fish and organisms of the lower trophic levels.