Oceanographic and hydrographic monitoring data of a shallow-water placement of dredged sediment in South San Francisco Bay, California, 2023-2025

The U.S. Geological Survey Pacific Coastal and Marine Science Center collected oceanographic and hydrographic monitoring data for a pilot project to place dredged sediment in bay shallows to nourish marshes conducted by the US Army Corps of Engineers, San Francisco District. Dredged material was placed in the shallows of South San Francisco Bay during December 2023. Monitoring spanned from 2023 to 2025; data collection started prior to the placement of dredged sediment and continued during and after placement. Oceanographic time-series instruments were deployed along cross-shore and along-shore transects. The cross-shore transect comprised stations located on the marsh, in the intertidal and subtidal shallows, and near the navigational channel that traverses South San Francisco Bay. The along-shore transect stations were located north and south of the placement area. Oceanographic data includes pressure, salinity, temperature, turbidity, wave statistics, currents, suspended particle size distributions, and suspended sediment concentration. Bayfloor bathymetry was surveyed 2 times prior to placement and 7 times following placement. Sediment bed properties were measured and near surface sediment-bed profile images were collected several times during the study. Meteorological observations were collected from November 2023 to February 2025. Information on station location, instrumentation, and measured variables are included in a summary table; additional details are included in metadata files and data attributes.