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Research about San Francisco Bay

Source-linked reports with geographic coverage including San Francisco Bay.

At least 379 records · Page 21Linked to original sources
USGS1979

Physical and chemical properties of San Francisco Bay waters, 1969-1976

Basic data on the physical and chemical properties of San Francisco Bay are presented here. Samples were collected over the period 1969-1976 at approximately six-week intervals at 36 stations. The stations were located along the axis of the Bay from Calaveras Point in South San Francisco Bay to the town of Rio Vista on the Sacramento River. On most cruises vertical profiles of the water properties were taken at 12 of the 36 stations. The samples were analyzed for the following core parameters: salinity, temperature, light transmission, chlorophyll a fluorescence, dissolved oxygen, orthophosphate, nitrate+nitrite, nitrite, ammonia, and silicate. Other analyses performed on selected samples included: particulate organic carbon, alkalinity, pH, pCO 2 , and suspended particulate weight. The results of these analyses and the analytical methods used are documented in this report.

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USGS1979

Particulate organic carbon in San Francisco Bay, California, 1971-1977

The organic-carbon content of suspended particulate matter is determined by wet oxidation and analysis of the resulting CO 2 with an infrared analyzer. Modifications of methods and improved designs of apparatus are presented. Results of particulate organic carbon (POC) analyses from 1971 through 1977 show that concentrations in North San Francisco Bay (estuary) typically decrease from the delta of the Sacramento and San Joaquin rivers to Golden Gate (seaward). Median winter (November through February) concentrations decrease from 85 to 30 µ g-at./L seaward. During March through October, median concentrations are higher and ranges are wider. Concentrations frequently exceed 250 µ g-at./L in the upper estuary. POC concentrations in South San Francisco Bay are highest at the southern reach. POC is more abundant during March through October than during winter, but POC is not as abundant in South San Francisco Bay as it is in the estuary.

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USGS1979

Hydrographic properties and primary productivity of San Francisco Bay waters, March 1976-July 1977

Data are presented on the quantitative relations between water chemistry and phytoplankton productivity in San Francisco Bay between March 1976 and July 1977. Spatial distributions are listed for: salinity, temperature, transmission, chlorophyll-a, fluorescence, dissolved oxygen, orthophosphate, nitrate + nitrite, nitrite, ammonia, particulate organic carbon, alkalinity, pH, pCO 2 , suspended sediment and turbidity. These samples were collected at 36 stations located along the axis of the Bay from Rio Vista on the Sacramento River to Calaveras Point in South San Francisco Bay, and along transects from the Golden Gate Bridge to the Farallon Islands. Also reported are the results of 59 experiments measuring in situ rates of micronutrient uptake and phytoplankton productivity at 9 locations throughout the Bay.

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USGS1979

Dispersal and migratory patterns of San Francisco Bay produced herons, egrets, and terns

San Francisco Bay, California, including its fringing marshes, supports a large and diverse water related avifauna (Grinnell and Wythe 19271 Sibley 1952, Gill 1973, 1977). Certain of man's alterations of the Bay's shallower wetlands have resulted in increased habitat diversity which has allowed colonization by several species of birds including some colonial nesting species. The extensive dikes associated with salt production and some areas of higher ground created by dredge spoils have provided increased tide-free substratum, some of it insular, suitable for nesting. The resulting numbers of Snowy Egrets ( Egretta thula) , Black-crowned Night Herons ( Nycticorax nycticorax ), Forster's Terns ( Sterna forsteri ), and Caspian Terns ( Sterna caspia ) using these areas now represent a significant portion of the northern California breeding populations of these species. In conjunction with a study of the breeding birds of the South San Francisco Bay Estuary (Gill 1973, 1977) from 1971 to 1973, we banded 187 Great Blue Herons ( Ardea herodias ), 1499 Snowy Egrets, 1615 Black-crowned Night Herons, 2943 Forster's Terns, and 743 Caspian Terns; often this represented a substantial portion of these species banded in the western states during these years (Table 1). Recoveries from these bandings through 1977 plus additional recoveries from a few earlier and some more recent bandings provide the data for this report on dispersal patterns and migration of San Francisco Bay produced herons, egrets, and terns.

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USGS1978

Numerical simulation of dissolved silica in the San Fancisco Bay

A two-dimensional (vertical) steady-state numerical model that simulates water circulation and dissolved-silica distributions is applied to northern San Francisco Bay. The model (1) describes the strong influence of river inflow on estuarine circulation and, in turn, on the biologically modulated silica concentration, and (2) shows how rates of silica uptake relate to silica supply and mixing rates in modifying a conservative behavior. Longitudinal silica distributions influenced by biological uptake (assuming both vertically uniform and vertically decreasing uptake situations) show that uptake rates of 1 to 10 μg-at. l −1 day −1 are sufficient to depress silica concentrations at river inflows of 100–400 m 3 s −1 , respectively, and that the higher rates appear ineffective at inflows above 400 m 3 s −1 . The simulations further indicate that higher silica utilization in the null zone is not essential to depress silica concentrations strongly there. Advective water-replacement times at river inflows of 400, 200 and 100 m 3 s −1 are computed to be less than 25, 45 and 75 days, respectively, for a 120-km estuary-river system.

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USGS1978

Map showing thickness of young bay mud, southern San Francisco Bay, California

Soft water-saturated estuarine deposits less than 10,000 years old underlie the southern part of San Francisco bay and the present and former marshlands that border the bay. Known locally as bay mud or as young bay mud, these deposits, and the estuarine environment that produces them, are of major importance in making decision on land use and development in the San Francisco Bay area. Knowledge of the distribution, thickness, and physical properties of young bay mud is critical to the feasibility, design, and maintenance of structures built on it. Fore this reason, numerous attempts have been made in the past to map or describe these characteristics (Mitchell, 1963; Goldman, 1969; McDonald and Nichols, 1974). The accompanying map of bay-mud thickness significantly revises part of an earlier compilation by Kahle and Goldman (1969) and includes new data from approximately 2400 boreholes, most of which have been drilled during the past 15 years. It also incorporates information on historic margins of San Francisco Bay and its tidal marshes (Nichols and Wright, 1971). Although this map was compelled mostly from data gathered during foundation investigations and construction projects, it is mostly from data gathered during foundation investigations and construction projects, it is not a substitute for such studies. Rather, the map provides regional information for land-use planning, seismic zonation, and design of foundation investigations.

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