San Francisco Bay Bathymetry Completed
USGS research vessel Parke Snavely
Collecting bathymetry in Alviso Slough, south San Francisco Bay, in 2011
Bathymetry of a dynamic tidal estuary, such as San Francisco Bay, provides the observable linkage between anthropogenic modifications of the landscape—such as evolving land use practices, flood control, and water diversions—and natural forces of climate-driven river flow, sea level change, tides, and wind. By examining our record of hydrographic surveys, spanning over 150 years, we can gain insights into the probable effect of future modification including efforts toward restoration.
In addition to historical change analysis, current bathymetry is critical for the calibration and interpretation of hydrodynamic and ecological models. Mass balance and sheer stress are driven by bathymetry—even ecological niches are influenced by bathymetry (depth, turbidity, particle size, light, turbulence, etc.).
Here, we provide information about the bathymetric data available for San Francisco Bay.
Methods
In the example sequence shown below, the first step in the preparation of regular grids displayed on this web site begins with irregular hydrographic survey data (soundings) that have been corrected to a common datum (1).
The National Oceanic and Atmospheric Administration (NOAA) is the primary resource for obtaining these original soundings. Other agencies, including the US Army Corps of Engineers, California Department of Water Resources, US Bureau of Reclamation, and the USGS, have contributed local studies. Once the soundings are in hand they are contoured, and shoreline and marsh perimeters are added and combined into a geographic information system (GIS) (2).
All data layers must be adjusted to a common horizontal and vertical datum and all depths must have the same orientation and units. At this point a grid can be generated.
Quality control is an iterative process, performed on the resulting grid by comparing it with the original soundings (3, 4).
Errors are computed, plotted and repaired when appropriate. Errors are usually a result of incorrect unit tags on the source data or digitizing mistakes, but some are due to gradients in bathymetry that cannot be resolved by a single grid cell.
The final grid (5) can be adjusted to a different tidal datum using an adjustment grid.
This grid is produced by assigning tide levels observed at shore stations to co-tidal lines from the TRIM-2D model (6, 7).
Geostatistics
Using this 100m grid cell representation of the Bay we can compute some primary geomorphic features of the basin--such as surface area and volume--for a given tidal datum, and compare these and other statistical properties in the sub-basins of San Francisco Bay.
Full Bay
TIDAL DATUM | VOLUME (Mm3) | SURFACE AREA (Mm2) | AVG. DEPTH VOL/AREA (m) |
MEDIAN DEPTH (m) |
MLLW | 7142 | 1138 | 6.3 | 2.8 |
MSL | 8446 | 1219 | 6.9 | 3.6 |
MHHW | 9570 | 1244 | 7.7 | 4.4 |
Properties based on the Mean Sea Level grid
PROPERTY | SOUTH BAY | CENTRAL BAY | SAN PABLO BAY | SUISUN BAY |
Area (Mm2) | 426.8 | 326.3 | 273.4 | 169.6 |
Volume (Mm3) | 1971 | 4388 | 1016 | 990 |
Average depth (m) | 4.6 | 13.4 | 3.7 | 5.8 |
Median depth (m) | 3.2 | 10.9 | 2.5 | 3.6 |
% Area < 5 m |
69 | 32 | 82 | 57 |
Bathymetry Change
As described in our METHODS section, a continuous surface representation of each bathymetric survey was created using Topogrid, an Arc/Info module that utilizes sounding and contour information to create a hydrodynamically correct surface. Input data was a combination of point soundings and hand-drawn depth contours (see table below). Once a bathymetric surface has been created for each hydrographic survey, the surfaces are adjusted to a common datum and we compute change or difference grids. These new ‘change’ surfaces identify areas of erosion and deposition.
Here is an example difference map of San Pablo Bay (1856-1887). During this period there was massive sediment accumulation related to hydraulic gold mining.
The data supporting historical change analysis is quite extensive. The following tables summarize the survey dates, digitized soundings, and contours used to produce the bathymetric surfaces and difference maps for San Francisco Bay.
SUISUN BAY | ||
SURVEY YEAR | NUMBER OF SOUNDINGS | CONTOUR INTERVALS (ft) |
1867 | 18,202 | -4, 0, 6, 12, 18, 30, 60, 90 |
1887 | 21,753 | -4, 0, 6, 12, 18, 30, 60, 90 |
1922 | 17,303 | -4, 0, 6, 12, 18, 30, 60, 90 |
1942 | 36,169 | -4, 0, 6, 12, 18, 30, 60, 90 |
1990 | 93,393 | -1, 2, 5, 10, 15, 20, 25, 30, 35, 45 (meters) |
SAN PABLO BAY | ||
SURVEY YEAR | NUMBER OF SOUNDINGS | CONTOUR INTERVALS (ft) |
1856 | 4973 | 0, 2, 3, 4, 6, 12, 18, 24, 36, 42, 48, 60 |
1887 | 3679 | -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 12, 24, 30, 36, 48, 60 |
1898 | 1994 | 0, 3, 6, 12, 18, 24, 30, 36, 60 |
1922 | 42,764 | -1, 0, 1, 2, 3, 4, 5, 6, 12, 18, 30, 60 |
1951 | 62,900 | 0, 6, 12, 30, 48 |
1983 | 65,739 | 0, 6, 12, 18, 30, 36, 60 |
CENTRAL BAY | ||
SURVEY YEAR | NUMBER OF SOUNDINGS | CONTOUR INTERVALS (ft) |
1855 | 21,052 | 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300 |
1895 | 289,282 | 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300, 360 |
1920 | 48,116 | 0, 6, 12, 18, 30, 60, 90, 120 |
1947 | 229,551 | 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300 |
1979 | 177,144 | 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300, 360 |
SOUTH BAY | ||
SURVEY YEAR | NUMBER OF SOUNDINGS | CONTOUR INTERVALS (ft) |
1858 | 20,036 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70 |
1898 | 99,399 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
1931 | 92,451 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
1956 | 100,748 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
1983 | 136,095 | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
2005 | ~2.7 million | 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 |
Official Publications
- San Pablo Bay Historical Analysis
USGS Open-File Report 98-759
Sedimentation and bathymetric change in San Pablo Bay, 1856-1983
- Suisun Bay Historical Analysis
USGS Open-File Report 99-563
Sedimentation and Bathymetry Changes in Suisun Bay: 1867-1990
- Central Bay Historical Analysis
USGS Open-File Report 2008-1312
Sediment Deposition, Erosion, and Bathymetric Change in Central San Francisco Bay: 1855–1979
- South Bay Historical Analysis Part 1
USGS Open-File Report 2004-1192
Deposition, Erosion, and Bathymetric Change in South San Francisco Bay: 1858-1983
- South Bay Historical Analysis Part 2
USGS Open-File Report 2006-1287
Sediment Deposition and Erosion in South San Francisco Bay, California from 1956 to 2005
Animations of change for North Bay
By linear interpolation, we can compute sedimentation maps for years between surveys and combine the maps to produce an animation of sedimentation for the North Bay. This animation gives an overall view of the system in time and space. We can see that, in the more active channels of Suisun Bay, surface sediment is deposited and erodes quickly in response to changing flows (floods/drought) and modifications (such as dredging the southern channel or long term mooring of the mothball fleet).
We assume:
- the sediment deposited in North San Francisco Bay between 1856 and 1887 was dominated by hydraulic mining debris;
- erosion observed in subsequent surveys was not re-deposited locally; and
- material deposited after 1887 was not mining debris.
Making these assumptions, we can predict the location and thickness of the original hydraulic mining debris. It is especially notable that the mercury employed in gold mining in the Sierra Nevada was refined liquid quicksilver or elemental mercury; this is a form of mercury much more likely to foster net methylation than is cinnabar, the form of mercury in most mercury mines. Approximately 10,000 tonnes of refined mercury were lost to the watershed during the Gold Rush mining era. Much of the mercury consumed by gold mining could have been incorporated into the 12 billion cubic meters of sediments extracted by the mining activities and released to the rivers of the Bay-Delta watershed. The mercury-laced hydraulic mining debris was ultimately transported to the bay-delta; it is known that large deposits of hydraulic mining debris remain in bay sediments. These wastes formed marshes, islands, or filled or diked marsh, or were deposited in shallow waters. Under the right circumstances this mercury contamination is transported through the food chain and concentrated in some commercial and sport fish. Human consumption of fish caught in the Bay is already restricted because of mercury contamination. Specifically, adults are advised to limit consumption of sport fish from the Bay to two times a month; pregnant or nursing women and children 6 or under should limit consumption to one time a month. Large shark and striped bass from the Bay should not be consumed at all. As we study the feasibility of restoration of marshes that were sinks for mining debris, the possibility of releasing mercury to the Bay must be considered.
Animations of mining debris deposition and subsequent erosion
Below are publications associated with this project.
Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada
A cold phase of the East Pacific triggers new phytoplankton blooms in San Francisco Bay
Holocene climates and connections between the San Francisco Bay Estuary and its watershed: A review
South San Francisco Bay, California
Effects of flow diversions on water and habitat quality: Examples from California's highly manipulated Sacramento–San Joaquin Delta
Reconstructing sediment age profiles from historical bathymetry changes in San Pablo Bay, California
Constancy of the relation between floc size and density in San Francisco Bay
Two-dimensional surface river flow patterns measured with paired RiverSondes
Anthropogenic influence on sedimentation and intertidal mudflat change in San Pablo Bay, California: 1856-1983
Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2004
Sediment deposition and erosion in south San Francisco Bay, California from 1956 to 2005
A history of intertidal flat area in south San Francisco Bay, California: 1858 to 2005
Below are partners associated with this project.
- Overview
Bathymetry of a dynamic tidal estuary, such as San Francisco Bay, provides the observable linkage between anthropogenic modifications of the landscape—such as evolving land use practices, flood control, and water diversions—and natural forces of climate-driven river flow, sea level change, tides, and wind. By examining our record of hydrographic surveys, spanning over 150 years, we can gain insights into the probable effect of future modification including efforts toward restoration.
In addition to historical change analysis, current bathymetry is critical for the calibration and interpretation of hydrodynamic and ecological models. Mass balance and sheer stress are driven by bathymetry—even ecological niches are influenced by bathymetry (depth, turbidity, particle size, light, turbulence, etc.).
Here, we provide information about the bathymetric data available for San Francisco Bay.
Methods
Sources/Usage: Public Domain. View Media DetailsIn the example sequence shown below, the first step in the preparation of regular grids displayed on this web site begins with irregular hydrographic survey data (soundings) that have been corrected to a common datum (1).
The National Oceanic and Atmospheric Administration (NOAA) is the primary resource for obtaining these original soundings. Other agencies, including the US Army Corps of Engineers, California Department of Water Resources, US Bureau of Reclamation, and the USGS, have contributed local studies. Once the soundings are in hand they are contoured, and shoreline and marsh perimeters are added and combined into a geographic information system (GIS) (2).
All data layers must be adjusted to a common horizontal and vertical datum and all depths must have the same orientation and units. At this point a grid can be generated.
Quality control is an iterative process, performed on the resulting grid by comparing it with the original soundings (3, 4).
Errors are computed, plotted and repaired when appropriate. Errors are usually a result of incorrect unit tags on the source data or digitizing mistakes, but some are due to gradients in bathymetry that cannot be resolved by a single grid cell.
The final grid (5) can be adjusted to a different tidal datum using an adjustment grid.
This grid is produced by assigning tide levels observed at shore stations to co-tidal lines from the TRIM-2D model (6, 7).
Geostatistics
Using this 100m grid cell representation of the Bay we can compute some primary geomorphic features of the basin--such as surface area and volume--for a given tidal datum, and compare these and other statistical properties in the sub-basins of San Francisco Bay.
Sources/Usage: Public Domain. View Media DetailsSources/Usage: Public Domain. View Media DetailsFull Bay
TIDAL DATUM VOLUME (Mm3) SURFACE AREA (Mm2) AVG. DEPTH
VOL/AREA (m)MEDIAN DEPTH (m) MLLW 7142 1138 6.3 2.8 MSL 8446 1219 6.9 3.6 MHHW 9570 1244 7.7 4.4 Properties based on the Mean Sea Level grid
PROPERTY SOUTH BAY CENTRAL BAY SAN PABLO BAY SUISUN BAY Area (Mm2) 426.8 326.3 273.4 169.6 Volume (Mm3) 1971 4388 1016 990 Average depth (m) 4.6 13.4 3.7 5.8 Median depth (m) 3.2 10.9 2.5 3.6 % Area
< 5 m69 32 82 57 Bathymetry Change
As described in our METHODS section, a continuous surface representation of each bathymetric survey was created using Topogrid, an Arc/Info module that utilizes sounding and contour information to create a hydrodynamically correct surface. Input data was a combination of point soundings and hand-drawn depth contours (see table below). Once a bathymetric surface has been created for each hydrographic survey, the surfaces are adjusted to a common datum and we compute change or difference grids. These new ‘change’ surfaces identify areas of erosion and deposition.
Here is an example difference map of San Pablo Bay (1856-1887). During this period there was massive sediment accumulation related to hydraulic gold mining.
The data supporting historical change analysis is quite extensive. The following tables summarize the survey dates, digitized soundings, and contours used to produce the bathymetric surfaces and difference maps for San Francisco Bay.
SUISUN BAY SURVEY YEAR NUMBER OF SOUNDINGS CONTOUR INTERVALS (ft) 1867 18,202 -4, 0, 6, 12, 18, 30, 60, 90 1887 21,753 -4, 0, 6, 12, 18, 30, 60, 90 1922 17,303 -4, 0, 6, 12, 18, 30, 60, 90 1942 36,169 -4, 0, 6, 12, 18, 30, 60, 90 1990 93,393 -1, 2, 5, 10, 15, 20, 25, 30, 35, 45 (meters) SAN PABLO BAY SURVEY YEAR NUMBER OF SOUNDINGS CONTOUR INTERVALS (ft) 1856 4973 0, 2, 3, 4, 6, 12, 18, 24, 36, 42, 48, 60 1887 3679 -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 12, 24, 30, 36, 48, 60 1898 1994 0, 3, 6, 12, 18, 24, 30, 36, 60 1922 42,764 -1, 0, 1, 2, 3, 4, 5, 6, 12, 18, 30, 60 1951 62,900 0, 6, 12, 30, 48 1983 65,739 0, 6, 12, 18, 30, 36, 60 CENTRAL BAY SURVEY YEAR NUMBER OF SOUNDINGS CONTOUR INTERVALS (ft) 1855 21,052 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300 1895 289,282 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300, 360 1920 48,116 0, 6, 12, 18, 30, 60, 90, 120 1947 229,551 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300 1979 177,144 0, 6, 12, 18, 30, 60, 90, 120, 180, 240, 300, 360 SOUTH BAY SURVEY YEAR NUMBER OF SOUNDINGS CONTOUR INTERVALS (ft) 1858 20,036 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70 1898 99,399 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 1931 92,451 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 1956 100,748 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 1983 136,095 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 2005 ~2.7 million 0, 3, 6, 12, 18, 24, 30, 36, 50, 60, 70, 80 Official Publications
- San Pablo Bay Historical Analysis
USGS Open-File Report 98-759
Sedimentation and bathymetric change in San Pablo Bay, 1856-1983
- Suisun Bay Historical Analysis
USGS Open-File Report 99-563
Sedimentation and Bathymetry Changes in Suisun Bay: 1867-1990
- Central Bay Historical Analysis
USGS Open-File Report 2008-1312
Sediment Deposition, Erosion, and Bathymetric Change in Central San Francisco Bay: 1855–1979
- South Bay Historical Analysis Part 1
USGS Open-File Report 2004-1192
Deposition, Erosion, and Bathymetric Change in South San Francisco Bay: 1858-1983
- South Bay Historical Analysis Part 2
USGS Open-File Report 2006-1287
Sediment Deposition and Erosion in South San Francisco Bay, California from 1956 to 2005
Animations of change for North Bay
Sources/Usage: Public Domain. View Media DetailsBy linear interpolation, we can compute sedimentation maps for years between surveys and combine the maps to produce an animation of sedimentation for the North Bay. This animation gives an overall view of the system in time and space. We can see that, in the more active channels of Suisun Bay, surface sediment is deposited and erodes quickly in response to changing flows (floods/drought) and modifications (such as dredging the southern channel or long term mooring of the mothball fleet).
We assume:
- the sediment deposited in North San Francisco Bay between 1856 and 1887 was dominated by hydraulic mining debris;
- erosion observed in subsequent surveys was not re-deposited locally; and
- material deposited after 1887 was not mining debris.
Making these assumptions, we can predict the location and thickness of the original hydraulic mining debris. It is especially notable that the mercury employed in gold mining in the Sierra Nevada was refined liquid quicksilver or elemental mercury; this is a form of mercury much more likely to foster net methylation than is cinnabar, the form of mercury in most mercury mines. Approximately 10,000 tonnes of refined mercury were lost to the watershed during the Gold Rush mining era. Much of the mercury consumed by gold mining could have been incorporated into the 12 billion cubic meters of sediments extracted by the mining activities and released to the rivers of the Bay-Delta watershed. The mercury-laced hydraulic mining debris was ultimately transported to the bay-delta; it is known that large deposits of hydraulic mining debris remain in bay sediments. These wastes formed marshes, islands, or filled or diked marsh, or were deposited in shallow waters. Under the right circumstances this mercury contamination is transported through the food chain and concentrated in some commercial and sport fish. Human consumption of fish caught in the Bay is already restricted because of mercury contamination. Specifically, adults are advised to limit consumption of sport fish from the Bay to two times a month; pregnant or nursing women and children 6 or under should limit consumption to one time a month. Large shark and striped bass from the Bay should not be consumed at all. As we study the feasibility of restoration of marshes that were sinks for mining debris, the possibility of releasing mercury to the Bay must be considered.
Animations of mining debris deposition and subsequent erosion
Sources/Usage: Public Domain. View Media DetailsSources/Usage: Public Domain. View Media Details - San Pablo Bay Historical Analysis
- Publications
Below are publications associated with this project.
Filter Total Items: 446Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada
Observed changes in the timing of snowmelt dominated streamflow in the western United States are often linked to anthropogenic or other external causes. We assess whether observed streamflow timing changes can be statistically attributed to external forcing, or whether they still lie within the bounds of natural (internal) variability for four large Sierra Nevada (CA) basins, at inflow points to mAuthorsE.P. Maurer, I.T. Stewart, Celine Bonfils, P. B. Duffy, D. CayanA cold phase of the East Pacific triggers new phytoplankton blooms in San Francisco Bay
Ecological observations sustained over decades often reveal abrupt changes in biological communities that signal altered ecosystem states. We report a large shift in the biological communities of San Francisco Bay, first detected as increasing phytoplankton biomass and occurrences of new seasonal blooms that began in 1999. This phytoplankton increase is paradoxical because it occurred in an era ofAuthorsJames E. Cloern, Alan D. Jassby, Janet K. Thompson, Kathryn HiebHolocene climates and connections between the San Francisco Bay Estuary and its watershed: A review
Climate over the watershed of the San Francisco Bay Delta estuary system varies on a wide range of space and time scales, and affects downstream estuarine ecosystems. The historical climate has included mild to severe droughts and torrential rains accompanied by flooding, providing important lessons for present-day resource managers. Paleoclimate records spanning the last 10,000 years, synthesizedAuthorsF. Malamud-Roam, M. Dettinger, B. Lynn Ingram, Malcolm K. Hughes, Joan FlorsheimSouth San Francisco Bay, California
The U.S. Geological Survey, in cooperation with the California Coastal Conservancy and the National Oceanic and Atmospheric Administration, mapped the floor of south San Francisco Bay and adjoining land using single-beam sonar and airborne lidar (light detection and ranging). To learn more, visit http://pubs.usgs.gov/sim/2007/2987/. View eastward. Elevations in mapped area color coded: purple (aAuthorsPeter Dartnell, Helen GibbonsEffects of flow diversions on water and habitat quality: Examples from California's highly manipulated Sacramento–San Joaquin Delta
We use selected monitoring data to illustrate how localized water diversions from seasonal barriers, gate operations, and export pumps alter water quality across the Sacramento-San Joaquin Delta (California). Dynamics of water-quality variability are complex because the Delta is a mixing zone of water from the Sacramento and San Joaquin Rivers, agricultural return water, and the San Francisco EstuAuthorsNancy E. Monsen, James E. Cloern, Jon R. BurauReconstructing sediment age profiles from historical bathymetry changes in San Pablo Bay, California
Sediment age profiles reconstructed from a sequence of historical bathymetry changes are used to investigate the subsurface distribution of historical sediments in a subembayment of the San Francisco Estuary. Profiles are created in a grid-based GIS modeling program that stratifies historical deposition into temporal horizons. The model's reconstructions are supported by comparisons to profiles ofAuthorsShawn A. Higgins, Bruce E. Jaffe, Christopher C. FullerConstancy of the relation between floc size and density in San Francisco Bay
The size and density of fine-sediment aggregates, or flocs, govern their transport and depositional properties. While the mass and volume concentrations of flocs can be measured directly or by optical methods, they must be determined simultaneously to gain an accurate density measurement. Results are presented from a tidal cycle study in San Francisco Bay, where mass concentration was determined dAuthorsN. K. Ganju, D. H. Schoellhamer, M.C. Murrell, J. W. Gartner, S.A. WrightTwo-dimensional surface river flow patterns measured with paired RiverSondes
Two RiverSondes were operated simultaneously in close proximity in order to provide a two-dimensional map of river surface velocity. The initial test was carried out at Threemile Slough in central California. The two radars were installed about 135 m apart on the same bank of the channel. Each radar used a 3-yagi antenna array and determined signal directions using direction finding. The slough isAuthorsC.C. Teague, D.E. Barrick, P.M. Lilleboe, R. T. ChengAnthropogenic influence on sedimentation and intertidal mudflat change in San Pablo Bay, California: 1856-1983
Analysis of a series of historical bathymetric surveys has revealed large changes in morphology and sedimentation from 1856 to 1983 in San Pablo Bay, California. In 1856, the morphology of the bay was complex, with a broad main channel, a major side channel connecting to the Petaluma River, and an ebb-tidal delta crossing shallow parts of the bay. In 1983, its morphology was simpler because all chAuthorsB. E. Jaffe, R. E. Smith, A.C. FoxgroverSummary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2004
No abstract available.AuthorsPaul A. Buchanan, Megan A. LionbergerSediment deposition and erosion in south San Francisco Bay, California from 1956 to 2005
Sediment deposition and erosion in South San Francisco Bay from 1956 to 2005 was studied by comparing bathymetric surveys made in 1956, 1983, and 2005. From 1956 to 1983, the region was erosional. In contrast, from 1983 to 2005, the region was depositional. Analysis of subregions defined by depth, morphology and location revealed similarities in behavior during both the erosional and depositionalAuthorsBruce Jaffe, Amy C. FoxgroverA history of intertidal flat area in south San Francisco Bay, California: 1858 to 2005
A key question in salt pond restoration in South San Francisco Bay is whether sediment sinks created by opening ponds will result in the loss of intertidal flats. Analyses of a series of bathymetric surveys of South San Francisco Bay made from 1858 to 2005 reveal changes in intertidal flat area in both space and time that can be used to better understand the pre-restoration system. This analysis aAuthorsBruce Jaffe, Amy C. Foxgrover - Partners
Below are partners associated with this project.