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Sample records for san francisco-oakland bay

  1. Deep Borehole Instrumentation Along San Francisco Bay Bridges: 1996 - 2003 and Strong Ground Motion Systhesis Along the San Francisco/Oakland Bay Bridge

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, L; Foxall, W; Kasameyer, P; larsen, S; Hayek, C; Tyler-Turpin, C; Aquilino, J; Long, L

    2005-04-22

    As a result of collaboration between the Berkeley Seismographic Station, Lawrence Livermore National Laboratory, and Caltrans, instrument packages have been placed in bedrock in six boreholes and two surface sites along the San Francisco/Oakland Bay Bridge. Since 1996 over 200 local earthquakes have been recorded. Prior to this study few seismic recording instruments existed in bed-rock in San Francisco Bay. We utilized the data to perform analysis of ground motion variability, wave passage, site response, and up-and down-hole wave propagation along the Bay Bridge. We also synthesized strong ground motion at nine locations along the Bay Bridge. Key to these studies is LLNL's effort to exploit the information available in weak ground motions (generally from earthquakes < M=4.0) to enhance predictions of seismic hazards. We found that Yerba Island has no apparent site response at the surface relative to a borehole site. The horizontal to vertical spectral ratio method best revealed no site response, while the complex signal spectral ratio method had the lowest variance for spectral ratios and best predicted surface recordings when the borehole recording was used as input. Both methods identified resonances at about the same frequencies. Regional attenuation results in a significant loss of high frequencies in both surface and borehole recordings. Records are band limited at near 3 Hz. Therefore a traditional rock outcrop site response, flat to high frequency in displacement, is not available. We applied a methodology to predict and synthesize strong ground motion along the San Francisco/Oakland Bay Bridge from a M=7.25 earthquake along the Hayward fault, about12 km distant. We synthesized for three-components and broad-band (0.0-25.0 Hz) ground motion accelerations, velocities, and displacements. We examined two different possible rupture scenarios, a ''mean'' and ''one standard deviation'' model. We combined the high

  2. Creep and drying shrinkage of high performance concrete for the skyway structures of the new San Francisco-Oakland Bay Bridge and cement paste

    Science.gov (United States)

    2011-03-01

    The objective of this study was to determine the influence of admixtures on long term drying shrinkage and creep of high : strength concrete (HSC). Creep and shrinkage of the mix utilized in segments of the Skyway Structure of the San : Francisco-Oak...

  3. Malignant melanoma slide review project: Patients from non-Kaiser hospitals in the San Francisco Bay Area. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, P. [California Dept. of Health Services, Berkeley, CA (United States)

    1993-01-05

    This project was initiated, in response to concerns that the observed excess of malignant melanoma among employees of Lawrence Livermore National Laboratory (LLNL) might reflect the incidence of disease diagnostically different than that observed in the general population. LLNL sponsored a slide review project, inviting leading dermatopathology experts to independently evaluate pathology slides from LLNL employees diagnosed with melanoma and those from a matched sample of Bay Area melanoma patients who did not work at the LLNL. The study objectives were to: Identify all 1969--1984 newly diagnosed cases of malignant melanoma among LLNL employees resident in the San Francisco-Oakland Metropolitan Statistical Area, and diagnosed at facilities other than Kaiser Permanente; identify a comparison series of melanoma cases also diagnosed between 1969--1984 in non-Kaiser facilities, and matched as closely as possible to the LLNL case series by gender, race, age at diagnosis, year of diagnosis, and hospital of diagnosis; obtain pathology slides for the identified (LLNL) case and (non-LLNL) comparison patients for review by the LLNL-invited panel of dermatopathology experts; and to compare the pathologic characteristics of the case and comparison melanoma patients, as recorded by the dermatopathology panel.

  4. 77 FR 70891 - Safety Zone; Bay Bridge Construction, San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2012-11-28

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Bay Bridge Construction, San Francisco Bay..., CA in support of the Bay Bridge Construction Safety Zone from November 1, 2012 through July 31, 2013.... 1221 et seq.). CALTRANS will sponsor the Bay Bridge Construction Safety Zone on November 1, 2012...

  5. Description of gravity cores from San Pablo Bay and Carquinez Strait, San Francisco Bay, California

    Science.gov (United States)

    Woodrow, Donald L.; John L. Chin,; Wong, Florence L.; Fregoso, Theresa; Jaffe, Bruce E.

    2017-06-27

    Seventy-two gravity cores were collected by the U.S. Geological Survey in 1990, 1991, and 2000 from San Pablo Bay and Carquinez Strait, California. The gravity cores collected within San Pablo Bay contain bioturbated laminated silts and sandy clays, whole and broken bivalve shells (mostly mussels), fossil tube structures, and fine-grained plant or wood fragments. Gravity cores from the channel wall of Carquinez Strait east of San Pablo Bay consist of sand and clay layers, whole and broken bivalve shells (less than in San Pablo Bay), trace fossil tubes, and minute fragments of plant material.

  6. San Antonio Bay 1986-1989

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The effect of salinity on utilization of shallow-water nursery habitats by aquatic fauna was assessed in San Antonio Bay, Texas. Overall, 272 samples were collected...

  7. Historical methyl mercury in San Francisco Bay

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — San Francisco Bay, California is considered a mercury-impaired watershed. Elevated concentrations of mercury are found in water and sediment as well as fish and...

  8. 27 CFR 9.157 - San Francisco Bay.

    Science.gov (United States)

    2010-04-01

    ..., San Mateo, Santa Clara, Alameda, and Contra Costa, which border the San Francisco Bay. The area also... proceed along the San Francisco, San Mateo, and Santa Cruz County shoreline (across the Quadrangles of San... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false San Francisco Bay. 9.157...

  9. Modeling Magnetic Fields from a DC Power Cable Buried Beneath San Francisco Bay Based on Empirical Measurements.

    Science.gov (United States)

    Kavet, Robert; Wyman, Megan T; Klimley, A Peter

    2016-01-01

    The Trans Bay Cable (TBC) is a ±200-kilovolt (kV), 400 MW 85-km long High Voltage Direct Current (DC) buried transmission line linking Pittsburg, CA with San Francisco, CA (SF) beneath the San Francisco Estuary. The TBC runs parallel to the migratory route of various marine species, including green sturgeon, Chinook salmon, and steelhead trout. In July and August 2014, an extensive series of magnetic field measurements were taken using a pair of submerged Geometrics magnetometers towed behind a survey vessel in four locations in the San Francisco estuary along profiles that cross the cable's path; these included the San Francisco-Oakland Bay Bridge (BB), the Richmond-San Rafael Bridge (RSR), the Benicia-Martinez Bridge (Ben) and an area in San Pablo Bay (SP) in which a bridge is not present. In this paper, we apply basic formulas that ideally describe the magnetic field from a DC cable summed vectorially with the background geomagnetic field (in the absence of other sources that would perturb the ambient field) to derive characteristics of the cable that are otherwise not immediately observable. Magnetic field profiles from measurements taken along 170 survey lines were inspected visually for evidence of a distinct pattern representing the presence of the cable. Many profiles were dominated by field distortions unrelated to the cable caused by bridge structures or other submerged objects, and the cable's contribution to the field was not detectable. BB, with 40 of the survey lines, did not yield usable data for these reasons. The unrelated anomalies could be up to 100 times greater than those from the cable. In total, discernible magnetic field profiles measured from 76 survey lines were regressed against the equations, representing eight days of measurement. The modeled field anomalies due to the cable (the difference between the maximum and minimum field along the survey line at the cable crossing) were virtually identical to the measured values. The modeling

  10. Modeling Magnetic Fields from a DC Power Cable Buried Beneath San Francisco Bay Based on Empirical Measurements.

    Directory of Open Access Journals (Sweden)

    Robert Kavet

    Full Text Available The Trans Bay Cable (TBC is a ±200-kilovolt (kV, 400 MW 85-km long High Voltage Direct Current (DC buried transmission line linking Pittsburg, CA with San Francisco, CA (SF beneath the San Francisco Estuary. The TBC runs parallel to the migratory route of various marine species, including green sturgeon, Chinook salmon, and steelhead trout. In July and August 2014, an extensive series of magnetic field measurements were taken using a pair of submerged Geometrics magnetometers towed behind a survey vessel in four locations in the San Francisco estuary along profiles that cross the cable's path; these included the San Francisco-Oakland Bay Bridge (BB, the Richmond-San Rafael Bridge (RSR, the Benicia-Martinez Bridge (Ben and an area in San Pablo Bay (SP in which a bridge is not present. In this paper, we apply basic formulas that ideally describe the magnetic field from a DC cable summed vectorially with the background geomagnetic field (in the absence of other sources that would perturb the ambient field to derive characteristics of the cable that are otherwise not immediately observable. Magnetic field profiles from measurements taken along 170 survey lines were inspected visually for evidence of a distinct pattern representing the presence of the cable. Many profiles were dominated by field distortions unrelated to the cable caused by bridge structures or other submerged objects, and the cable's contribution to the field was not detectable. BB, with 40 of the survey lines, did not yield usable data for these reasons. The unrelated anomalies could be up to 100 times greater than those from the cable. In total, discernible magnetic field profiles measured from 76 survey lines were regressed against the equations, representing eight days of measurement. The modeled field anomalies due to the cable (the difference between the maximum and minimum field along the survey line at the cable crossing were virtually identical to the measured values. The

  11. 78 FR 58878 - Safety Zone; San Diego Shark Fest Swim; San Diego Bay, San Diego, CA

    Science.gov (United States)

    2013-09-25

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Shark Fest Swim; San Diego Bay... Diego Shark Fest Swim. This safety zone is necessary to provide for the safety of the participants, crew... this rule because the logistical details of the San Diego Shark Fest Swim were not finalized nor...

  12. Gravity cores from San Pablo Bay and Carquinez Strait, San Francisco Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data release contains information on gravity cores that were collected by the U.S. Geological Survey in the area of San Pablo Bay and Carquinez Strait,...

  13. An overview of San Francisco Bay PORTS

    Science.gov (United States)

    Cheng, Ralph T.; McKinnie, David; English, Chad; Smith, Richard E.

    1998-01-01

    The Physical Oceanographic Real-Time System (PORTS) provides observations of tides, tidal currents, and meteorological conditions in real-time. The San Francisco Bay PORTS (SFPORTS) is a decision support system to facilitate safe and efficient maritime commerce. In addition to real-time observations, SFPORTS includes a nowcast numerical model forming a San Francisco Bay marine nowcast system. SFPORTS data and nowcast numerical model results are made available to users through the World Wide Web (WWW). A brief overview of SFPORTS is presented, from the data flow originated at instrument sensors to final results delivered to end users on the WWW. A user-friendly interface for SFPORTS has been designed and implemented. Appropriate field data analysis, nowcast procedures, design and generation of graphics for WWW display of field data and nowcast results are presented and discussed. Furthermore, SFPORTS is designed to support hazardous materials spill prevention and response, and to serve as resources to scientists studying the health of San Francisco Bay ecosystem. The success (or failure) of the SFPORTS to serve the intended user community is determined by the effectiveness of the user interface.

  14. 75 FR 55975 - Safety Zone; San Diego Harbor Shark Fest Swim; San Diego Bay, San Diego, CA

    Science.gov (United States)

    2010-09-15

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Harbor Shark Fest Swim; San Diego... Shark Fest Swim, consisting of 600 swimmers swimming a predetermined course. The sponsor will provide 26...; San Diego Harbor Shark Fest Swim; San Diego Bay, San Diego, CA. (a) Location. The following area is a...

  15. San Francisco Bay National Wildlife Refuge Complex Annual Narrative Report 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Complex comprises of three refuges including the San Francisco Bay National Wildlife Refuge, the San Pablo Bay...

  16. San Francisco Bay National Wildlife Refuge Complex Annual Narrative Report 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Complex comprises of three refuges including the San Francisco Bay National Wildlife Refuge, the San Pablo Bay...

  17. San Francisco Bay National Wildlife Refuge Complex Annual Narrative Report 1979

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Complex comprises of three refuges including the San Francisco Bay National Wildlife Refuge, the San Pablo Bay...

  18. San Francisco Bay National Wildlife Refuge Complex Annual Narrative Report 1977

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Complex comprises of three refuges including the San Francisco Bay National Wildlife Refuge, the San Pablo Bay...

  19. ASTER Images San Francisco Bay Area

    Science.gov (United States)

    2000-01-01

    These images of the San Francisco Bay region were acquired on March 3, 2000 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite. Each covers an area 60 kilometers (37 miles) wide and 75 kilometers (47 miles) long. With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER will image the Earth for the next 6 years to map and monitor the changing surface of our planet.Upper Left: The color infrared composite uses bands in the visible and reflected infrared. Vegetation is red, urban areas are gray; sediment in the bays shows up as lighter shades of blue. Thanks to the 15 meter (50-foot) spatial resolution, shadows of the towers along the Bay Bridge can be seen.Upper right: A composite of bands in the short wave infrared displays differences in soils and rocks in the mountainous areas. Even though these regions appear entirely vegetated in the visible, enough surface shows through openings in the vegetation to allow the ground to be imaged.Lower left: This composite of multispectral thermal bands shows differences in urban materials in varying colors. Separation of materials is due to differences in thermal emission properties, analogous to colors in the visible.Lower right: This is a color coded temperature image of water temperature, derived from the thermal bands. Warm waters are in white and yellow, colder waters are blue. Suisun Bay in the upper right is fed directly from the cold Sacramento River. As the water flows through San Pablo and San Francisco Bays on the way to the Pacific, the waters warm up.Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of International Trade and Industry. A joint U.S./Japan science team is responsible for

  20. Benthic fluxes in San Francisco Bay

    Science.gov (United States)

    Hammond, Douglas E.; Fuller, C.; Harmon, D.; Hartman, Blayne; Korosec, M.; Miller, L.G.; Rea, R.; Warren, S.; Berelson, W.; Hager, S.W.

    1985-01-01

    Measurements of benthic fluxes have been made on four occasions between February 1980 and February 1981 at a channel station and a shoal station in South San Francisco Bay, using in situ flux chambers. On each occasion replicate measurements of easily measured substances such as radon, oxygen, ammonia, and silica showed a variability (??1??) of 30% or more over distances of a few meters to tens of meters, presumably due to spatial heterogeneity in the benthic community. Fluxes of radon were greater at the shoal station than at the channel station because of greater macrofaunal irrigation at the former, but showed little seasonal variability at either station. At both stations fluxes of oxygen, carbon dioxide, ammonia, and silica were largest following the spring bloom. Fluxes measured during different seasons ranged over factors of 2-3, 3, 4-5, and 3-10 (respectively), due to variations in phytoplankton productivity and temperature. Fluxes of oxygen and carbon dioxide were greater at the shoal station than at the channel station because the net phytoplankton productivity is greater there and the organic matter produced must be rapidly incorporated in the sediment column. Fluxes of silica were greater at the shoal station, probably because of the greater irrigation rates there. N + N (nitrate + nitrite) fluxes were variable in magnitude and in sign. Phosphate fluxes were too small to measure accurately. Alkalinity fluxes were similar at the two stations and are attributed primarily to carbonate dissolution at the shoal station and to sulfate reduction at the channel station. The estimated average fluxes into South Bay, based on results from these two stations over the course of a year, are (in mmol m-2 d-1): O2 = -27 ?? 6; TCO2 = 23 ?? 6; Alkalinity = 9 ?? 2; N + N = -0.3 ?? 0.5; NH3 = 1.4 ?? 0.2; PO4 = 0.1 ?? 0.4; Si = 5.6 ?? 1.1. These fluxes are comparable in magnitude to those in other temperate estuaries with similar productivity, although the seasonal

  1. San Pablo Bay National Wildlife Refuge Climate Adaptation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Future climate change is expected to cause dramatic changes in the physical and biological environment of the San Pablo Bay National Wildlife Refuge (Refuge). To...

  2. San Pablo Bay National Wildlife Refuge: Final Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on San Pablo Bay NWR for the next 15 years. This plan outlines the Refuge vision and...

  3. San Francisco Bay Interferometric Side Scan Imagery: Area B

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — High resolution sonar data were collected over ultra-shallow areas of the San Francisco Bay estuary system. Bathymetric and acoustic backscatter data were collected...

  4. San Francisco Bay, California 1 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1-second San Francisco Bay, California Elevation Grid provides bathymetric data in ASCII raster format of 1-second resolution in geographic coordinates. This...

  5. National Status and Trends: Bioeffects Program - San Francisco Bay Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study was based on the sediment quality triad (SQT) approach. A stratified probabilistic sampling design was utilized to characterize the San Francisco Bay...

  6. Narrative Report : San Francisco Bay NWR Complex : Fiscal Year 1974

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report details the conditions and management of San Francisco Bay National Wildlife Refuge in 1974. The report begins with a general...

  7. San Diego Bay National Wildlife Refuge: Sweetwater Marsh and South San Diego Bay Units: Comprehensive Conservation Plan and Environmental Impact Statement: Volume I

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on San Diego Bay NWR (Sweetwater Marsh and South San Diego Bay Units) for the next 15...

  8. San Francisco Bay Area Baseline Trash Loading Summary Results, San Francisco Bay Area CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Area stormwater permit sets trash control guidelines for discharges through the storm drain system. The permit covers Alameda, Contra Costa,...

  9. 76 FR 9709 - Water Quality Challenges in the San Francisco Bay/Sacramento-San Joaquin Delta Estuary

    Science.gov (United States)

    2011-02-22

    ... AGENCY 40 CFR Chapter I RIN-2009-ZA00 Water Quality Challenges in the San Francisco Bay/Sacramento-San... water quality conditions affecting aquatic resources in the San Francisco Bay/ Sacramento-San Joaquin... Estuary that would be constructive, including enforcement, research, revisions to water quality standards...

  10. Deep Borehole Instrumentation Along San Francisco Bay Bridges - 2000

    Energy Technology Data Exchange (ETDEWEB)

    Hutchings, L.; Kasameyer, P.; Turpin, C.; Long, L.; Hollfelder, J.; McEvilly, T.; Clymer, R.; Uhrhammer, R.

    2000-03-01

    This is a progress report on the Bay Bridges downhole network. Between 2 and 8 instruments have been spaced along the Dumbarton, San Mateo, Bay, and San Rafael bridges in San Francisco Bay, California. The instruments will provide multiple use data that is important to geotechnical, structural engineering, and seismological studies. The holes are between 100 and 1000 ft deep and were drilled by Caltrans. There are twenty-one sensor packages at fifteen sites. The downhole instrument package contains a three component HS-1 seismometer and three orthogonal Wilcox 731 accelerometers, and is capable of recording a micro g from local M = 1.0 earthquakes to 0.5 g strong ground motion form large Bay Area earthquakes. Preliminary results on phasing across the Bay Bridge, up and down hole wave amplification at Yerba Buena Island, and sensor orientation analysis are presented. Events recorded and located during 1999 are presented. Also, a senior thesis on the deep structure of the San Francisco Bay beneath the Bay Bridge is presented as an addendum.

  11. San Francisco Bay Water Quality Improvement Fund Points, SF Bay CA, 2015, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  12. Don Edwards San Francisco Bay National Wildlife Refuge: Annual Narrative Report: Calendar Year 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Don Edwards San Francisco Bay NWR, Antioch Dunes NWR, Farallon NWR, San Pablo Bay NWR, Ellicot Slough NWR, Salinas River NWR, and...

  13. San Francisco Bay National Wildlife Refuge: Annual Narrative Report: Calendar Year 1987

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for San Francisco Bay NWR, San Pablo Bay NWR, Antioch Dunes NWR, Farallon NWR, and Ellicott Slough NWR outlines Refuge accomplishments...

  14. San Francisco Bay National Wildlife Refuge Complex: Annual Narrative Report: Calendar Year 1989

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for San Francisco Bay NWR, San Pablo Bay NWR, Antioch Dunes NWR, Farallon NWR, Ellicott Slough NWR, and Salinas River NWR outlines...

  15. San Francisco Bay National Wildlife Refuge: Annual Narrative Report: Calendar Year 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for San Francisco Bay NWR, San Pablo Bay NWR, Antioch Dunes NWR, Farallon NWR, Ellicott Slough NWR, and Salinas River NWR outlines...

  16. Lessons from monitoring water quality in San Francisco Bay

    Science.gov (United States)

    Cloern, J.E.; Schraga, T.S.; Lopez, C.B.; Labiosa, R.

    2003-01-01

    San Francisco Bay is the defining landscape feature of the place we call ‘The Bay Area,’ but most of us only experience the Bay as we view it from an airplane window or drive across one of its bridges. These views from afar suggest that the Bay is static and sterile, but this impression is deceptive. If you are one of the many thousands of students who have experienced the Bay through a school excursion with the Marine Science Institute or other educational programs, you observed its rich plankton soup under a microscope, sorted clams and worms and crustaceans from mud samples, and identified the gobies, sole, halibut, bat rays, sharks, sardines, and smelt caught with trawls. San Francisco Bay is much more than a landscape feature. It is a dynamic ecosystem, continually changing and teeming with life. The Bay once supported the most valuable fisheries on the west coast of the United States, but commercial fishing for shellfish, shrimp, sturgeon, shad, salmon, and striped bass ended many decades ago because of habitat loss, pollution, invasive species and over harvest.

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

    Science.gov (United States)

    McDonald, Sandra D.; Nichols, Donald R.; Wright, Nancy A.; Atwater, Brian

    1978-01-01

    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.

  18. Sand waves at the mouth of San Francisco Bay, California

    Science.gov (United States)

    Gibbons, Helen; Barnard, Patrick L.

    2007-01-01

    The U.S. Geological Survey; California State University, Monterey Bay; U.S. Army Corps of Engineers; National Oceanic and Atmospheric Administration; and Center for Integrative Coastal Observation, Research and Education partnered to map central San Francisco Bay and its entrance under the Golden Gate Bridge using multibeam echosounders. View eastward, through the Golden Gate into central San Francisco Bay. Depth of sea floor color coded: red (less than 10 m deep) to purple (more than 100 m deep). Land from USGS digital orthophotographs (DOQs) overlaid on USGS digital elevation models (DEMs). Sand waves in this view average 6 m in height and 80 m from crest to crest. Golden Gate Bridge is about 2 km long. Vertical exaggeration is approximately 4x for sea floor, 2x for land.

  19. Estimates of suspended sediment entering San Francisco Bay from the Sacramento and San Joaquin Delta, San Francisco Bay, California

    Science.gov (United States)

    McKee, L.J.; Ganju, N.K.; Schoellhamer, D.H.

    2006-01-01

    This study demonstrates the use of suspended-sediment concentration (SSC) data collected at Mallard Island as a means of determining suspended-sediment load entering San Francisco Bay from the Sacramento and San Joaquin River watersheds. Optical backscatter (OBS) data were collected every 15 min during water years (WYs) 1995-2003 and converted to SSC. Daily fluvial advective sediment load was estimated by combining estimated Delta outflow with daily averaged SSC. On days when no data were available, SSC was estimated using linear interpolation. A model was developed to estimate the landward dispersive load using velocity and SSC data collected during WYs 1994 and 1996. The advective and dispersive loads were summed to estimate the total load. Annual suspended-sediment load at Mallard Island averaged 1.2??0.4 Mt (million metric tonnes). Given that the average water discharge for the 1995-2003 period was greater than the long -term average discharge, it seems likely that the average suspended-sediment load may be less than 1.2??0.4 Mt. Average landward dispersive load was 0.24 Mt/yr, 20% of the total. On average during the wet season, 88% of the annual suspended-sediment load was discharged through the Delta and 43% occurred during the wettest 30-day period. The January 1997 flood transported 1.2 Mt of suspended sediment or about 11% of the total 9-year load (10.9 Mt). Previous estimates of sediment load at Mallard Island are about a factor of 3 greater because they lacked data downstream from riverine gages and sediment load has decreased. Decreasing suspended-sediment loads may increase erosion in the Bay, help to cause remobilization of buried contaminants, and reduce the supply of sediment for restoration projects. ?? 2005 Elsevier B.V. All rights reserved.

  20. Microplastic contamination in the San Francisco Bay, California, USA.

    Science.gov (United States)

    Sutton, Rebecca; Mason, Sherri A; Stanek, Shavonne K; Willis-Norton, Ellen; Wren, Ian F; Box, Carolynn

    2016-08-15

    Despite widespread detection of microplastic pollution in marine environments, data describing microplastic abundance in urban estuaries and microplastic discharge via treated municipal wastewater are limited. This study presents information on abundance, distribution, and composition of microplastic at nine sites in San Francisco Bay, California, USA. Also presented are characterizations of microplastic in final effluent from eight wastewater treatment plants, employing varying treatment technologies, that discharge to the Bay. With an average microplastic abundance of 700,000particles/km(2), Bay surface water appears to have higher microplastic levels than other urban waterbodies sampled in North America. Moreover, treated wastewater from facilities that discharge into the Bay contains considerable microplastic contamination. Facilities employing tertiary filtration did not show lower levels of contamination than those using secondary treatment. As textile-derived fibers were more abundant in wastewater, higher levels of fragments in surface water suggest additional pathways of microplastic pollution, such as stormwater runoff. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The phytoplankton component of seston in San Francisco Bay

    Science.gov (United States)

    Wienke, S.M.; Cloern, J.E.

    1987-01-01

    Phytoplankton biomass (as carbon) was estimated from chlorophyll a concentrations (Chla) and a mean value for the ratio of phytoplankton carbon to chlorophyll a in San Francisco Bay. The ratio was determined as the slope of a Model II regression of POC' against (Chla), where POC' is total particulate organic carbon minus sediment-associated non-phytoplankton carbon. Samples from 30 fixed sites in the channel and lateral shoals of San Francisco Bay were collected once or twice a month from April to November 1980, and at irregular intervals in South Bay during 1984 and 1985. For all data the calculated mean value of phytoplankton C:Chla was 51 (95% confidence interval = 47-54). No significant differences were found in the C:Chla ratio between shallow and deep sites (where light availability differs) or between northern and southern San Francisco Bay (where phytoplankton community composition differs). Using the mean C:Chla ratio of 51, we calculated that phytoplankton biomass constitutes about one third of seston carbon under most circumstances, but this fraction ranges from about 95% during phytoplankton blooms to less than 20% during spring periods of low phytoplankton biomass and high suspended sediment concentration. ?? 1987.

  2. San Juan Bay Estuary watershed urban forest inventory

    Science.gov (United States)

    Thomas J. Brandeis; Francisco J. Escobedo; Christina L. Staudhammer; David J. Nowak; Wayne C. Zipperer

    2014-01-01

    We present information on the urban forests and land uses within the watershed of Puerto Rico’s 21 658-ha San Juan Bay Estuary based on urban forest inventories undertaken in 2001 and 2011. We found 2548 ha of mangrove and subtropical moist secondary forests covering 11.8 percent of the total watershed area in 2011. Red, black, and white mangroves (Rhizophora...

  3. Microbial diversity in restored wetlands of San Francisco Bay

    Energy Technology Data Exchange (ETDEWEB)

    Theroux, Susanna [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Hartman, Wyatt [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; He, Shaomei [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Univ. of Wisconsin, Madison, WI (United States); Tringe, Susannah [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.

    2013-12-09

    Wetland ecosystems may serve as either a source or a sink for atmospheric carbon and greenhouse gases. This delicate carbon balance is influenced by the activity of belowground microbial communities that return carbon dioxide and methane to the atmosphere. Wetland restoration efforts in the San Francisco Bay-Delta region may help to reverse land subsidence and possibly increase carbon storage in soils. However, the effects of wetland restoration on microbial communities, which mediate soil metabolic activity and carbon cycling, are poorly studied. In an effort to better understand the underlying factors which shape the balance of carbon flux in wetland soils, we targeted the microbial communities in a suite of restored and historic wetlands in the San Francisco Bay-Delta region. Using DNA and RNA sequencing, coupled with greenhouse gas monitoring, we profiled the diversity and metabolic potential of the wetland soil microbial communities along biogeochemical and wetland age gradients. Our results show relationships among geochemical gradients, availability of electron acceptors, and microbial community composition. Our study provides the first genomic glimpse into microbial populations in natural and restored wetlands of the San Francisco Bay-Delta region and provides a valuable benchmark for future studies.

  4. 77 FR 28895 - Don Edwards San Francisco Bay National Wildlife Refuge, Alameda, Santa Clara, and San Mateo...

    Science.gov (United States)

    2012-05-16

    ... Fish and Wildlife Service Don Edwards San Francisco Bay National Wildlife Refuge, Alameda, Santa Clara, and San Mateo Counties, CA AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of availability... Wildlife Refuge, located in the Alameda, Santa Clara, and San Mateo Counties of California, consists of...

  5. Reducing Nutrients to San Francisco Bay through Additional Wastewater Sidestream Treatment Project

    Science.gov (United States)

    Information about the SFBWQP Reducing Nutrients to San Francisco Bay Project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  6. Dioxin toxin equivalents, PCBs, and PBDEs in eggs of avian wildlife of San Francisco Bay

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — San Francisco Bay (Bay) is considered an impaired waterbody under section 303 (d) of the Clean Water Act due to polychlorinated biphenyls (PCB) and 2, 3, 7,...

  7. Final Environmental Statement : Acquisition of lands for the San Francisco Bay National Wildlife Refuge California

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Federal Government proposes to acquire approximately 23,000 acres of land in the South San Francisco Bay region, Alameda, San Mateo and Santa Clara Counties, to...

  8. Mercury-contaminated hydraulic mining debris in San Francisco Bay

    Science.gov (United States)

    Bouse, Robin M.; Fuller, Christopher C.; Luoma, Samuel N.; Hornberger, Michelle I.; Jaffe, Bruce E.; Smith, Richard E.

    2010-01-01

    The hydraulic gold-mining process used during the California Gold Rush and in many developing countries today contributes enormous amounts of sediment to rivers and streams. Commonly, accompanying this sediment are contaminants such as elemental mercury and cyanide used in the gold extraction process. We show that some of the mercurycontaminated sediment created by hydraulic gold mining in the Sierra Nevada, between 1852 and 1884, ended up over 250 kilometers (km) away in San Francisco Bay; an example of the far-reaching extent of contamination from such activities.

  9. San Francisco Bay Water Quality Improvement Fund Project Locations, San Francisco CA, 2017, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  10. San Francisco Bay Water Quality Improvement Fund Map Service, San Francisco CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The San Francisco Bay Water Quality Improvement Fund is a competitive grant program that is helping implement TMDLs to improve water quality, protect wetlands, and...

  11. 2010 Northern San Francisco Bay Area Lidar: Portions of Alameda, Contra Costa, Marin, Napa, San Francisco, Solano, and Sonoma Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Light Detection and Ranging (LiDAR) dataset is a survey of northern San Francisco Bay, California. The project area consists of approximately 437 square miles...

  12. Projected Bioclimatic Change for the San Francisco Bay Area

    Science.gov (United States)

    Torregrosa, A.; Taylor, M.; Flint, L. E.; Flint, A. L.; Weiss, S. B.

    2011-12-01

    Past and future climate data for the San Francisco Bay Area were classified using the Rivas-Martinez (R-M) system to group long-term annual climate averages into categories with biotic significance based on thermotypic and ombrotypic regimes. Bioclimate maps were generated at 270 meter resolution for ten San Francisco Bay Area counties for six 30-year periods from 1911 to 2100 which include the historical 1) 1911-1940, 2) 1941-1970, 3) 1971-2000, and future 4) 2011-2040, 5) 2041-2070, and 6) 2071-2100. Historic averages were generated from PRISM climate data. Future climate projections were generated from two IPCC-based future scenarios (A2 and B1) and two coupled atmosphere-ocean general circulation models (NOAA Geophysical Fluid Dynamics Laboratory and the Parallel Climate Model). Strong congruence was found among the boundaries for historic bioclimates and current vegetation types. However, future scenarios had varying patterns of losses and gains in bioclimate classes and these tracked mesoclimate gradients. Comparisons between projected bioclimatic categories and modeled future climatic water deficit show strong correspondence except in zones of deep alluvial deposits. Maps show areas of bioclimatic stability, e.g. areas that did not change under any future projection, versus areas with significant bioclimatic shifts in all future scenarios. These analyses and maps will be useful for assessing natural resource vulnerability to climate change and natural resource conservation-based climate adaptation decisions.

  13. Forecasting Selenium Discharges to the San Francisco Bay-Delta Estuary: Ecological Effects of A Proposed San Luis Drain Extension

    Science.gov (United States)

    Presser, Theresa S.; Luoma, Samuel N.

    2006-01-01

    Selenium discharges to the San Francisco Bay-Delta Estuary (Bay-Delta) could change significantly if federal and state agencies (1) approve an extension of the San Luis Drain to convey agricultural drainage from the western San Joaquin Valley to the North Bay (Suisun Bay, Carquinez Strait, and San Pablo Bay); (2) allow changes in flow patterns of the lower San Joaquin River and Bay-Delta while using an existing portion of the San Luis Drain to convey agricultural drainage to a tributary of the San Joaquin River; or (3) revise selenium criteria for the protection of aquatic life or issue criteria for the protection of wildlife. Understanding the biotransfer of selenium is essential to evaluating effects of selenium on Bay-Delta ecosystems. Confusion about selenium threats to fish and wildlife stem from (1) monitoring programs that do not address specific protocols necessary for an element that bioaccumulates; and (2) failure to consider the full complexity of the processes that result in selenium toxicity. Past studies show that predators are more at risk from selenium contamination than their prey, making it difficult to use traditional methods to predict risk from environmental concentrations alone. This report presents an approach to conceptualize and model the fate and effects of selenium under various load scenarios from the San Joaquin Valley. For each potential load, progressive forecasts show resulting (1) water-column concentration; (2) speciation; (3) transformation to particulate form; (4) particulate concentration; (5) bioaccumulation by invertebrates; (6) trophic transfer to predators; and (7) effects on those predators. Enough is known to establish a first-order understanding of relevant conditions, biological response, and ecological risks should selenium be discharged directly into the North Bay through a conveyance such as a proposed extension of the San Luis Drain. The approach presented here, the Bay-Delta selenium model, determines the mass, fate

  14. Perspective View with Landsat Overlay, San Francisco Bay Area, Calif.

    Science.gov (United States)

    2002-01-01

    The cities of San Francisco and the East Bay are highlighted in this computer-generated perspective viewed from west of the Golden Gate. San Francisco occupies the peninsula jutting into the picture from the right. Golden Gate Park is the long rectangle near its left end and the Presidiois the green area at its tip, from which Golden Gate Bridge crosses to Marin. Treasure Island is the bright spot above San Francisco and Alcatraz Island is the small smudge below and to the left. Across the bay from San Francisco lie Berkeley (left) and Oakland (right). Mount Diablo, a landmark visible for many miles, rises in the distance at the upper right.This three-dimensional perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced false-color Landsat 5 satellite image. Colors are from Landsat bands 3, 2, and 1 as red, green and blue, respectively. Topographic expression is exaggerated two times.Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive.The Landsat Thematic Mapper image used here came from an on-line mosaic of Landsat images for the continental United States (http://mapus.jpl.nasa.gov), a part of NASA's Digital Earth effort.Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission

  15. Effect of distal Sacramento-San Joaquin Delta outflow on suspended-sediment flux in Lower South San Francisco Bay

    Science.gov (United States)

    Livsey, D. N.; Downing-Kunz, M.; Schoellhamer, D. H.; Shellenbarger, G.; Wright, S. A.

    2016-12-01

    Tidal marshes are an important component of estuarine ecosystems. Within the San Francisco Bay Estuary (SFB) tidal marshes play an important role in food web dynamics, are home to an array of endemic mammals, birds, and fishes, filter pollutants, and dampen coastal flooding. With 80% of SFB tidal marshes lost to human development, numerous restoration efforts are underway. The largest tidal marsh restoration project in SFB, the South Bay Salt Pond Restoration Project, is underway in Lower South San Francisco Bay to restore 60,000 ha of this critical habitat; however, rising sea levels, could jeopardize these gains without concomitant vertical accretion rates of the marsh surface via organic matter accumulation and sediment deposition. Recent work in Lower South Bay using continuously collected data from water years (WY) 2009-11 indicates that the direction of net springtime residual sediment flux is related to the amount of springtime Sacramento-San Joaquin Delta (Delta) outflow. Large outflow freshens the Central Bay, causing a density gradient and inverse gravitational circulation that flushes Lower South Bay. In this study we extend the sediment budget for Lower South Bay from WY 2011 to present using 15-minute turbidity and velocity data paired with Acoustic Doppler Current Profiler cross-sectional measurements and in situ suspended-sediment concentration samples to: 1) further examine the mechanisms controlling net springtime residual sediment flux, and 2) further test the hypothesis that Delta outflow controls the direction of net sediment flux for Lower South Bay.

  16. Microbial diversity and carbon cycling in San Francisco Bay wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Theroux, Susanna [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Hartman, Wyatt [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; He, Shaomei [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.; Univ. of Wisconsin, Madison, WI (United States); Tringe, Susannah [Lawrence Berkeley National Lab. (LBNL), Walnut Creek, CA (United States). Dept. of Energy Joint Genome Inst.

    2014-03-21

    Wetland restoration efforts in San Francisco Bay aim to rebuild habitat for endangered species and provide an effective carbon storage solution, reversing land subsidence caused by a century of industrial and agricultural development. However, the benefits of carbon sequestration may be negated by increased methane production in newly constructed wetlands, making these wetlands net greenhouse gas (GHG) sources to the atmosphere. We investigated the effects of wetland restoration on below-ground microbial communities responsible for GHG cycling in a suite of historic and restored wetlands in SF Bay. Using DNA and RNA sequencing, coupled with real-time GHG monitoring, we profiled the diversity and metabolic potential of wetland soil microbial communities. The wetland soils harbor diverse communities of bacteria and archaea whose membership varies with sampling location, proximity to plant roots and sampling depth. Our results also highlight the dramatic differences in GHG production between historic and restored wetlands and allow us to link microbial community composition and GHG cycling with key environmental variables including salinity, soil carbon and plant species.

  17. Constraints on the sedimentation history of San Francisco Bay from 14C and 10Be

    Science.gov (United States)

    VanGeen, A.; Valette-Silver, N. J.; Luoma, S.N.; Fuller, C.C.; Baskaran, M.; Tera, F.; Klein, J.

    1999-01-01

    Industrialization and urbanization around San Francisco Bay as well as mining and agriculture in the watersheds of the Sacramento and San Joaquin rivers have profoundly modified sedimentation patterns throughout the estuary. We provide some constraints on the onset of these erosional disturbances with 10Be data for three sediment cores: two from Richardson Bay, a small embayment near the mouth of San Francisco Bay, and one from San Pablo Bay, mid-way between the river delta and the mouth. Comparison of pre-disturbance sediment accumulation determined from three 14C-dated mollusk shells in one Richardson Bay core with more recent conditions determined from the distribution of 210Pb and 234Th [Fuller, C.C., van Geen, A., Baskaran, M, Anima, R.J., 1999. Sediment chronology in San Francisco Bay, California, defined by 210Pb, 234Th, 239,240Pu.] shows that the accumulation rate increased by an order of magnitude at this particular site. All three cores from San Francisco Bay show subsurface maxima in 10Be concentrations ranging in magnitude from 170 to 520 x 106 atoms/g. The transient nature of the increased 10Be input suggests that deforestation and agricultural develop- ment caused basin-wide erosion of surface soils enriched in 10Be. probably before the turn of the century.

  18. San Francisco Bay NWR Complex : Annual Narrative Report : Calendar Year 1978

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report details the conditions and management of San Francisco Bay National Wildlife Refuge in 1978. The report begins with a general...

  19. Physical and chemical properties of San Francisco Bay waters, 1969-1976 (NODC Accession 8400194)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — One magnetic tape containing the physical and chemical properties of San Francisco Bay waters was forwarded to NODC by Mr. Richard Smith of the U.S Geological Survey...

  20. Stream Habitat Reach Summary - San Francisco Bay, Central Coast [ds159

    Data.gov (United States)

    California Department of Resources — The Stream Habitat - San Francisco Bay, Central and South Coasts [ds159] shapefile contains four years of in-stream salmonid habitat data at the reach level. The...

  1. San Francisco Bay National Wildlife Refuge Complex : Annual Narrative Report : 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report details the conditions and management of San Francisco Bay National Wildlife Refuge in 1990. The report begins with highlights from the...

  2. San Francisco Bay National Wildlife Refuge Complex : Annual Narrative Report : 1988

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report details the conditions and management of San Francisco Bay National Wildlife Refuge in 1988. The report begins with highlights from the...

  3. San Francisco Bay National Wildlife Refuge Complex : Annual Narrative Report : 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report details the conditions and management of San Francisco Bay National Wildlife Refuge in 1986. The report begins with highlights from the...

  4. Annual Narrative Report : San Francisco Bay National Wildlife Refuge Complex : 1984

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report details the conditions and management of San Francisco Bay National Wildlife Refuge in 1984. The report begins with highlights from the...

  5. San Francisco Bay National Wildlife Refuge Complex : Annual Narrative Report : 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report details the conditions and management of San Francisco Bay National Wildlife Refuge in 1982. The report begins with highlights from the...

  6. Proposed South San Diego Bay National Wildlife Refuge: Level III preaquisition survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A Level III Contaminant Preaquisition Survey was conducted during 1992 in the south San Diego Bay area to evaluate potential hazards to trustee resources and/or...

  7. San Francisco Bay ecotone vegetation restoration & management : 2009-10 grant report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a report on vegetation restoration and management at Don Edwards San Francisco Bay National Wildlife Refuge. Restoring vegetation adjacent to the tidal...

  8. Final Mosquito Management Plan and Environmental Assessment for the San Pablo Bay National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document provides a standard process for San Pablo Bay National Wildlife Refuge to follow when making decisions regarding management of mosquitos and...

  9. San Francisco Bay ecotone vegetation restoration & management : 2008-09 grant report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a report on vegetation restoration and management at Don Edwards San Francisco Bay National Wildlife Refuge. Vegetation management is often straightforward:...

  10. Advancement of Salinity and Flow Monitoring in the San Francisco Bay Delta

    Science.gov (United States)

    This report describes the utility and approximate cost of expanding the salinity water quality monitoring network along the axis of the San Francisco Estuary from Suisun Bay to Rio Vista on the Sacramento River.

  11. Beneficial Uses of Dredged Material Case Study: San Francisco Bay Region

    Science.gov (United States)

    A major interagency, regional planning effort led to the development of the Long-Term Management Strategy and other planning programs in the San Francisco Bay area. These programs incorporate beneficial uses of dredged material into local projects.

  12. Breeding Season Study of the California Clapper Rail in San Francisco Bay, 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goals of this study were to further investigate the suitability of brackish marshes in south San Francisco Bay to support breeding rails and to examine how the...

  13. Factors affecting reproductive success of the California clapper rail (Rallus longirostris obsoletus) in San Francisco Bay

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We assessed the reproductive success of the California clapper rail (Rallus longirostris obsoletus), an endangered species restricted to San Francisco Bay, and the...

  14. Don Edwards San Francisco Bay National Wildlife Refuge : Refuge Master Plan : 1974

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The San Francisco Bay National Wildlife Refuge Master Plan guides the longrange development of the Refuge by identifying and integrating appropriate habitats,...

  15. 75 FR 32209 - North San Pablo Bay Restoration and Reuse Project

    Science.gov (United States)

    2010-06-07

    ... Recycling Program. The purpose of the Project is to create a regional wastewater reuse project to provide... Bureau of Reclamation North San Pablo Bay Restoration and Reuse Project AGENCY: Bureau of Reclamation..., and Sonoma County Water Agency (SCWA), acting as project administrator of the North Bay Water Reuse...

  16. Investigating Causes and Consequences of 150 Years of Channel Morphology Evolution in San Pablo Bay, California

    Science.gov (United States)

    Wegen, M. V.; Roelvink, J.; Jaffe, B. E.

    2010-12-01

    The Delta is an area where rivers draining the Central Valley and Sierras of California, including the Sacramento and San Joaquin Rivers, meet before discharging into the northeastern end of the San Francisco Estuary. San Pablo Bay, a sub-embayment in the northern Estuary, is circular with an area of about 250 km2 and an average tidal range of about 1.5 m. It is rather shallow (depths generally less than 4 m, average depth San Pablo Bay has changed markedly since the Gold Rush. Deposition of more than a quarter billion cubic meters of hydraulic gold mining debris reduced the average depth of San Pablo Bay by 85 cm in the middle and late 1800s. In the late 1900s the intertidal flats narrowed and the major channel in the Bay deepened as more sediment was lost to the sea than entered from rivers. Processes of sediment redistribution caused the main channel to become narrower as well, a trend observed over the last 150 years. It is not clear what is causing the change in channel geometry and the implications of the change in geometry on the seaward transport of sediment through San Pablo Bay. This study investigates the cause of this channel geometry development and its impact on the conveyance of sediment through and distribution within San Pablo Bay using a process-based, numerical model (Delft3D). The Delft3D model developed for this study is a 3D model that includes the k-ɛ turbulence model, wind, waves, multiple mud and sand fractions and salt-fresh water density differences, as well as schematized tidal and river flow boundary conditions. The approach is to perform different runs with equal forcing on different historic bathymetries. By keeping the bed in a fixed, non-erodible state, we can analyze the impact of the evolving San Pablo Bay morphology on the conveyance efficiency of water and sediments. Model results show what happens with sediment supplied by the Sacramento River and San Joaquin River as well as the behavior of different sediment classes on

  17. DISTRIBUTION AND COMPOSITION OF DISSOLVED AND PARTICULATE ORGANIC CARBON IN NORTHERN SAN FRANCISCO BAY DURING LOW FRESHWATER FLOW CONDITIONS

    Science.gov (United States)

    The distribution of organic matter was studied in northern San Francisco Bay monthly through spring and summer 1996 along the salinity gradient from the Sacramento River to Central Bay. Dissolved constituents included monosaccharides (MONO), total carbohydrates (TCHO), dissolved ...

  18. Phytoplankton community ecology: Principles applied in San Francisco Bay

    Science.gov (United States)

    Cloern, J.E.; Dufford, R.

    2005-01-01

    In his seminal 1961 paper 'The paradox of the plankton' Am Nat 95:137-147, G. E. Hutchinson asked why many species of phytoplankton can coexist while competing for a small number of limiting resources in an unstructured habitat. Hutchinson anticipated the resolution of his paradox, recognizing that communities are organized by processes beyond resource competition including species interactions, habitat variability and dispersal. Since 1961 we have made fundamental discoveries that have revolutionized our conceptual understanding of pelagic ecology, including (1) habitat heterogeneity at all scales relevant to plankton population dynamics, (2) community shifts in response to global climate cycles, (3) fast and selective predation as a powerful top-down force to shape phytoplankton communities, (4) turbulent mixing as a physical process that selects species on the basis of their size and form, (5) mixotrophy that allows some algal species to tap organic nutrient pools and function at multiple trophic levels, (6) taxon-specific life cycles including alternating vegetative and resting stages, and (7) the pelagic as an open system where communities are continually reshaped by species immigration. Here we synthesize these discoveries to show how they validate and amplify Hutchinson's hypothesis that phytoplankton communities are assembled by many processes. Our synthesis is built around observations of phytoplankton species composition from a decade of study in San Francisco Bay, used as a case study to illustrate the contemporary principles of phytoplankton community ecology. We apply these principles to address 2 central questions: (1) What processes assemble phytoplankton communities? (2) How does phytoplankton community composition influence ecosystem functions such as production in pelagic and benthic food webs?

  19. Regional Air Toxics Modeling in California's San Francisco Bay Area

    Science.gov (United States)

    Martien, P. T.; Tanrikulu, S.; Tran, C.; Fairley, D.; Jia, Y.; Fanai, A.; Reid, S.; Yarwood, G.; Emery, C.

    2011-12-01

    Regional toxics modeling conducted for California's San Francisco Bay Area (SFBA) estimated potential cancer risk from diesel particulate matter (DPM) and four key reactive toxic gaseous pollutants (1,3-butadiene, benzene, formaldehyde, and acetaldehyde). Concentrations of other non-cancerous gaseous toxic air contaminants, including acrolein, were also generated. In this study, meteorological fields generated from July and December periods in 2000 and emissions from 2005 provided inputs to a three-dimensional air quality model at high spatial resolution (1x1 km^2 grid), from which a baseline set of annual risk values was estimated. Simulated risk maps show highest annual average DPM concentrations and cancer risks were located near and downwind of major freeways and near the Port of Oakland, a major container port in the area. Population weighted risks, using 2000 census data, were found to be highest in highly urbanized areas adjacent to significant DPM sources. For summer, the ratio of mean measured elemental carbon to mean modeled DPM was 0.78, conforming roughly to expectations. But for winter the ratio is 1.13, suggesting other sources of elemental carbon, such as wood smoke, are important. Simulated annual estimates for benzene and 1-3, butadiene compared well to measured annual estimates. Simulated acrolein and formaldehyde significantly under-predicted observed values. Simulations repeated using projected 2015 toxic emissions predicted that potential cancer risk dropped significantly in all areas throughout the SFBA. Emissions estimates for 2015 included the State of California's recently adopted on-road truck rule. Emission estimates of DPM are projected to drop about 70% between 2005 and 2015 in the SFBA, with a commensurate reduction in potential cancer risks. However, due to projected shifts in population during this period, with urban densification close to DPM sources outpacing emission reductions, there are some areas where population-weighted risks

  20. Time scales of change in the San Francisco Bay benthos

    Science.gov (United States)

    Nichols, F.H.; Thompson, J.K.

    1985-01-01

    Results from multi-year investigations in the San Francisco Bay estuary show that large abundance fluctuations within benthic macroinvertebrate populations reflect both (1) within-year periodicity of reproduction, recruitment, and mortality that is not necessarily coincident with seasonal changes of the environment (e.g., the annual temperature cycle), and (2) aperiodic density changes (often larger than within-year fluctuations) following random perturbations of the environment. Density peaks of the small, short-lived estuarine invertebrates that comprise the vast majority of individuals in the bay's relatively homogeneous benthic community normally occur between spring and autumn depending on the species, in large part a reflection of reproductive periodicity. However, because mild winters permit reproductive activity in some of the common species throughout much of the year, other factors are important to within-year density fluctuations in the community. Seasonally predictable changes in freshwater inflow, wind and tidal mixing, microalgal biomass, and sediment erosion/deposition patterns all contribute to observed seasonal changes in abundance. For example, the commonly observed decline in abundance during winter reflects both short-lived species that die after reproducing and the stress of winter conditions (e.g., inundation by less saline, sediment-laden water and the decline in both planktonic and benthic algal biomass - a direct source of food for the shallow-water benthos). On the other hand, data from several studies suggest that observed 'recruitment' and 'mortality' may in fact be the migration of juveniles and adults to and from study sites. For example, the common amphipod Ampelisca abdita apparently moves from shallow to deep water, or from up-estuary to down-estuary locations, coincident with periods of high river runoff in winter. Growth of individuals within the few studied species populations is also highly seasonal, and appears to be coincident

  1. Does centennial morphodynamic evolution lead to higher channel efficiency in San Pablo Bay, California?

    Science.gov (United States)

    van der Wegen, M.; Jaffe, B.E.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Measured bathymetries on 30 year interval over the past 150 years show that San Pablo Bay experienced periods of considerable deposition followed by periods of net erosion. However, the main channel in San Pablo Bay has continuously narrowed. The underlying mechanisms and consequences of this tidal channel evolution are not well understood. The central question of this study is whether tidal channels evolve towards a geometry that leads to more efficient hydraulic conveyance and sediment throughput. We applied a hydrodynamic process-based, numerical model (Delft3D), which was run on 5 San Pablo Bay bathymetries measured between 1856 and 1983. Model results shows increasing energy dissipation levels for lower water flows leading to an approximately 15% lower efficiency in 1983 compared to 1856. During the same period the relative seaward sediment throughput through the San Pablo Bay main channel increased by 10%. A probable explanation is that San Pablo Bay is still affected by the excessive historic sediment supply. Sea level rise and Delta surface water area variations over 150 years have limited effect on the model results. With expected lower sediment concentrations in the watershed and less impact of wind waves due to erosion of the shallow flats, it is possible that energy dissipations levels will decrease again in future decades. Our study suggests that the morphodynamic adaptation time scale to excessive variations in sediment supply to estuaries may be on the order of centuries.

  2. Chronic Sublethal Effects of San Francisco Bay Sediments on Nereis (Neanthes) arenaceodentata; Interpretative Guidance for a Growth End Point

    Science.gov (United States)

    1993-09-01

    experimentally. Once nereid eggs begin developing in the coelom , secretion of a separate tropic hormone initiates vitellogenesis (Baskin 1976). In N...Material Management in San Francisco Bay .............................. 2 Overview of Sediment Toxicity Test Development in the United States...Material in San Francisco Bay ......................... 3 Table 2. Milestones in Scientific Development of Sediment Toxicity Tests

  3. Transcendence and Son Jarocho as Practiced in the San Francisco Bay Area

    OpenAIRE

    Sacolick, Robin

    2016-01-01

    AbstractTranscendence and Son Jarocho as Practiced in the San Francisco Bay AreaRobin SacolickPeople of emerging or non-dominant ethnicities in multicultural, diasporic societies need ways to establish identities, merge strengths, and transcend difficulties. This study explores one way: community practices, by Latina/os and others in the Bay Area, of son jarocho, a centuries-old genre of Mexican music, dance and poetry. While their project revives traditional folklore, it also offers experien...

  4. Record-high specific conductance and water temperature in San Francisco Bay during water year 2015

    Science.gov (United States)

    Work, Paul; Downing-Kunz, Maureen; Livsey, Daniel

    2017-02-22

    The San Francisco estuary is commonly defined to include San Francisco Bay (bay) and the adjacent Sacramento–San Joaquin River Delta (delta). The U.S. Geological Survey (USGS) has operated a high-frequency (15-minute sampling interval) water-quality monitoring network in San Francisco Bay since the late 1980s (Buchanan and others, 2014). This network includes 19 stations at which sustained measurements have been made in the bay; currently, 8 stations are in operation (fig. 1). All eight stations are equipped with specific conductance (which can be related to salinity) and water-temperature sensors. Water quality in the bay constantly changes as ocean tides force seawater in and out of the bay, and river inflows—the most significant coming from the delta—vary on time scales ranging from those associated with storms to multiyear droughts. This monitoring network was designed to observe and characterize some of these changes in the bay across space and over time. The data demonstrate a high degree of variability in both specific conductance and temperature at time scales from tidal to annual and also reveal longer-term changes that are likely to influence overall environmental health in the bay.In water year (WY) 2015 (October 1, 2014, through September 30, 2015), as in the preceding water year (Downing-Kunz and others, 2015), the high-frequency measurements revealed record-high values of specific conductance and water temperature at several stations during a period of reduced freshwater inflow from the delta and other tributaries because of persistent, severe drought conditions in California. This report briefly summarizes observations for WY 2015 and compares them to previous years that had different levels of freshwater inflow.

  5. A history of intertidal flat area in south San Francisco Bay, California: 1858 to 2005

    Science.gov (United States)

    Jaffe, Bruce; Foxgrover, Amy

    2006-01-01

    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 also documents baseline conditions of intertidal flats that may be altered by restoration efforts. From 1858 to 2005, intertidal flat area decreased by about 25% from 69.2 +6.4/-7.6 km2 to 51.2 +4.8/-5.8 km2. Intertidal flats in the north tended to decrease in area during the period of this study whereas those south of Dumbarton Bridge were either stable or increased in area. From 1983 to 2005, intertidal flats south of Dumbarton Bridge increased from 17.6 +1.7/-2.5 km2 to 24.2 +1.0/-1.8 km2. Intertidal flats along the east shore of the bay tended to be more erosional and decreased in area while those along the west shore of the bay did not significantly change in area. Loss of intertidal flats occurred intermittently along the eastern shore of the bay north of the Dumbarton Bridge. There was little or no loss from 1931 to 1956 and from 1983 to 2005. Predictions of future change in intertidal flat area that do not account for this spatial and temporal variability are not likely to be accurate. The causes of the spatial and temporal variability in intertidal flat area in South San Francisco Bay are not fully understood, but appear related to energy available to erode sediments, sediment redistribution from north to south in the bay, and sediment available to deposit on the flats. Improved understanding of sediment input to South San Francisco Bay, especially from Central Bay, how it is likely to change in the future, the redistribution of sediment within the bay, and ultimately its effect on intertidal flat area would aid in the management of restoration of South San

  6. Anthropogenic influences on shoreline and nearshore evolution in the San Francisco Bay coastal system

    Science.gov (United States)

    Dallas, K.L.; Barnard, P.L.

    2011-01-01

    Analysis of four historical bathymetric surveys over a 132-year period has revealed significant changes to the morphology of the San Francisco Bar, an ebb-tidal delta at the mouth of San Francisco Bay estuary. From 1873 to 2005 the San Francisco Bar vertically-eroded an average of 80 cm over a 125 km2 area, which equates to a total volume loss of 100 ± 52 million m3 of fine- to coarse-grained sand. Comparison of the surveys indicates the entire ebb-tidal delta contracted radially, with the crest moving landward an average of 1 km. Long-term erosion of the ebb-tidal delta is hypothesized to be due to a reduction in the tidal prism of San Francisco Bay and a decrease in coastal sediment supply, both as a result of anthropogenic activities. Prior research indicates that the tidal prism of the estuary was reduced by 9% from filling, diking, and sedimentation. Compilation of historical records dating back to 1900 reveals that a minimum of 200 million m3 of sediment has been permanently removed from the San Francisco Bay coastal system through dredging, aggregate mining, and borrow pit mining. Of this total, ~54 million m3 of sand-sized or coarser sediment was removed from central San Francisco Bay. With grain sizes comparable to the ebb-tidal delta, and its direct connection to the bay mouth, removal of sediments from central San Francisco Bay may limit the sand supply to the delta and open coast beaches. SWAN wave modeling illustrates that changes to the morphology of the San Francisco Bar have altered the alongshore wave energy distribution at adjacent Ocean Beach, and thus may be a significant factor in a persistent beach erosion ‘hot spot’ occurring in the area. Shoreline change analyses show that the sandy shoreline in the shadow of the ebb-tidal delta experienced long-term (1850s/1890s to 2002) and short-term (1960s/1980s to 2002) accretion while the adjacent sandy shoreline exposed to open-ocean waves experienced long-term and short-term erosion. Therefore

  7. Sedimentation and bathymetric change in San Pablo Bay, 1856-1983

    Science.gov (United States)

    Jaffe, Bruce E.; Smith, Richard E.; Torresan, Laura Zink

    1998-01-01

    A long-term perspective of erosion and deposition in San Francisco Bay is vital to understanding and managing wetland change, harbor and channel siltation, and other sediment-related phenomena such as particle and particle-associated substance (pollutants, trace metals, etc.) transport and deposition. A quantitative comparison of historical hydrographic surveys provides this perspective. This report presents results of such a comparison for San Pablo Bay, California. Six hydrographic surveys from 1856 to 1983 were analyzed to determine long-term changes in the sediment system of San Pablo Bay. Each survey was gridded using surface modeling software. Changes between survey periods were computed by differencing grids. Patterns and volumes of erosion and deposition in the Bay are derived from difference grids. More than 350 million cubic meters of sediment was deposited in San Pablo Bay from 1856 to 1983. This is equivalent to a Baywide accumulation rate of approximately 1 cm/yr. However, sediment deposition was not constant over time or throughout the Bay. Over two-thirds of that sediment was debris from hydraulic mining that accumulated from 1856 to 1887. During this period, deposition occurred in nearly the entire Bay. In contrast, from 1951 to 1983 much of the Bay changed from being depositional to erosional as sediment supply diminished and currents and waves continued to remove sediment from the Bay. The decrease in sediment supply is likely the result of upstream flood-control and water-distribution projects that have reduced peak flows, which are responsible for the greatest sediment transport. One consequence of the change in sedimentation was a loss of about half of the tidal flat areas from the late 1800's to the 1980's. Change in sedimentation must also have affected flow in the Bay, areas where polluted sediments were deposited, exchange of sediment between the nearshore and wetlands, and wave energy reaching the shoreline that was available to erode

  8. 78 FR 18238 - Safety Zone; SFPD Training Safety Zone; San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2013-03-26

    ... William Hawn, U.S. Coast Guard Sector San Francisco; telephone (415) 399-7442 or email at D11-PF-Marine... navigable waters around the SFPD's maritime interdiction training exercises. The SFPD Training Safety ] Zone... Hunters Point in San Francisco, CA in support of the San Francisco Police Department's maritime...

  9. Developing a spatially-explicit climate adaptation framework for estuarine ecosystems of the San Francisco Bay: Climate Adaptation for Decision Support (CADS Phase 1)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides recommended resource allocations for conserving four subregions of San Francisco (SF) Bay, including North Bay, Suisun, Central Bay and South...

  10. The critical role of islands for waterbird breeding and foraging habitat in managed ponds of the South Bay Salt Pond Restoration Project, South San Francisco Bay, California

    Science.gov (United States)

    Ackerman, Joshua T.; Hartman, C. Alex; Herzog, Mark P.; Smith, Lacy M.; Moskal, Stacy M.; De La Cruz, Susan E. W.; Yee, Julie L.; Takekawa, John Y.

    2014-01-01

    The South Bay Salt Pond Restoration Project aims to restore 50–90 percent of former salt evaporation ponds into tidal marsh in South San Francisco Bay, California. However, large numbers of waterbirds use these ponds annually as nesting and foraging habitat. Islands within ponds are particularly important habitat for nesting, foraging, and roosting waterbirds. To maintain current waterbird populations, the South Bay Salt Pond Restoration Project plans to create new islands within former salt ponds in South San Francisco Bay. In a series of studies, we investigated pond and individual island attributes that are most beneficial to nesting, foraging, and roosting waterbirds.

  11. The State of Latino Education in the San Francisco Bay Area: A Crisis in Student Performance.

    Science.gov (United States)

    Chacon, Mario

    A study examined educational attainment among Latino students in the six-county San Francisco Bay Area. California's Standardized Testing and Reporting (STAR) Program results for 1998-99 were used to assess student achievement in reading and mathematics for grades 4, 7, and 10. Data were also collected on enrollment, dropout rates, percentage of…

  12. EPA Administrator and San Francisco Bay Area government agencies celebrate nations largest solar energy partnership

    Science.gov (United States)

    SAN FRANCISCO - Today, U.S. EPA Administrator Gina McCarthy joined Bay Area agencies to celebrate the Regional Renewable Energy Procurement Project (R-REP), the nation's largest solar energy government collaboration and the launch of the Federal Agg

  13. A nowcast model for tides and tidal currents in San Francisco Bay, California

    Science.gov (United States)

    Cheng, Ralph T.; Smith, Richard E.

    1998-01-01

    National Oceanographic and Atmospheric Administration (NOAA) installed Physical Oceanographic Real-Time System (PORTS) in San Francisco Bay, California to provide observations of tides, tidal currents, and meteorological conditions. PORTS data are used for optimizing vessel operations, increasing margin of safety for navigation, and guiding hazardous material spill prevention and response. Because tides and tidal currents in San Francisco Bay are extremely complex, limited real-time observations are insufficient to provide spatial resolution for variations of tides and tidal currents. To fill the information gaps, a highresolution, robust, semi-implicit, finite-difference nowcast numerical model has been implemented for San Francisco Bay. The model grid and water depths are defined on coordinates based on Mercator projection so the model outputs can be directly superimposed on navigation charts. A data assimilation algorithm has been established to derive the boundary conditions for model simulations. The nowcast model is executed every hour continuously for tides and tidal currents starting from 24 hours before the present time (now) covering a total of 48 hours simulation. Forty-eight hours of nowcast model results are available to the public at all times through the World Wide Web (WWW). Users can view and download the nowcast model results for tides and tidal current distributions in San Francisco Bay for their specific applications and for further analysis.

  14. Mudflat Morphodynamics and the Impact of Sea Level Rise in South San Francisco Bay

    NARCIS (Netherlands)

    van der Wegen, Mick; Jaffe, Bruce E.; Foxgrover, Amy; Roelvink, D.

    2016-01-01

    Estuarine tidal mudflats form unique habitats and maintain valuable ecosystems. Historic measurements of a mudflat in San Fancsico Bay over the past 150 years suggest the development of a rather stable mudflat profile. This raises questions on its origin and governing processes as well as on the

  15. Sediment transport in the San Francisco Bay Coastal System: An overview

    Science.gov (United States)

    Barnard, Patrick L.; Schoellhamer, David H.; Jaffe, Bruce E.; Lester J. McKee,

    2013-01-01

    The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal-estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin-Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~ 8 x 109 m3/day, in addition to the transport of mud, sand, biogenic material, nutrients, and pollutants. Despite this physical, biological and chemical connection, resource management and prior research have often treated the Delta, Bay and adjacent ocean as separate entities, compartmentalized by artificial geographic or political boundaries. The body of work herein presents a comprehensive analysis of system-wide behavior, extending a rich heritage of sediment transport research that dates back to the groundbreaking hydraulic mining-impact research of G.K. Gilbert in the early 20th century.

  16. Sediment transport in the San Francisco Bay Coastal System: an overview

    Science.gov (United States)

    Barnard, Patrick L.; Schoellhamer, David H.; Jaffe, Bruce E.; McKee, Lester J.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    The papers in this special issue feature state-of-the-art approaches to understanding the physical processes related to sediment transport and geomorphology of complex coastal–estuarine systems. Here we focus on the San Francisco Bay Coastal System, extending from the lower San Joaquin–Sacramento Delta, through the Bay, and along the adjacent outer Pacific Coast. San Francisco Bay is an urbanized estuary that is impacted by numerous anthropogenic activities common to many large estuaries, including a mining legacy, channel dredging, aggregate mining, reservoirs, freshwater diversion, watershed modifications, urban run-off, ship traffic, exotic species introductions, land reclamation, and wetland restoration. The Golden Gate strait is the sole inlet connecting the Bay to the Pacific Ocean, and serves as the conduit for a tidal flow of ~ 8 × 109 m3/day, in addition to the transport of mud, sand, biogenic material, nutrients, and pollutants. Despite this physical, biological and chemical connection, resource management and prior research have often treated the Delta, Bay and adjacent ocean as separate entities, compartmentalized by artificial geographic or political boundaries. The body of work herein presents a comprehensive analysis of system-wide behavior, extending a rich heritage of sediment transport research that dates back to the groundbreaking hydraulic mining-impact research of G.K. Gilbert in the early 20th century.

  17. System designed for issuing landslide alerts in the San Francisco Bay area

    Science.gov (United States)

    Finley, D.

    1987-01-01

    A system for forecasting landslides during major storms has been developed for the San Francisco Bay area by the U.S Geological Survey and was successfully tested during heavy storms in the bay area during February 1986. Based on the forecasts provided by the USGS, the National Weather Service (NWS) included landslide warnings in its regular weather forecasts or in special weather statements transmitted to local radio and television stations and other news media. USGS scientists said the landslide forecasting and warning system for the San Francisco Bay area can be used as a prototype in developing similar systems for other parts of the Nation susceptible to landsliding. Studies show damage from landslides in the United States averages an estimated $1.5 billion per year. 

  18. A Proximate Biological Survey of San Diego Bay, California

    Science.gov (United States)

    1975-01-01

    Ulothrlx sp. (green algae) Viva lattsslma (sea lettuce) Yucca schldlgera (Mohave yucca) Zostera marina (eelgrass) B. Marine Invertebrates Porifera ... Invertebrates (eont.) Annelids AnnanJia hloculata (polychaete) Capitata ambiscta (polychaete) Glycera amerlcana (polychaete) Haploscoloposvlongatus...numbers but only at mouth of bay; prefers open ocean. M, WR. Occurs annually in small numbers. Feeds on fish and invertebrates in shallow waters

  19. Comparison of sediment supply to San Francisco Bay from watersheds draining the Bay Area and the Central Valley of California

    Science.gov (United States)

    McKee, L.J.; Lewicki, M.; Schoellhamer, D.H.; Ganju, N.K.

    2013-01-01

    Quantifying suspended sediment loads is important for managing the world's estuaries in the context of navigation, pollutant transport, wetland restoration, and coastal erosion. To address these needs, a comprehensive analysis was completed on sediment supply to San Francisco Bay from fluvial sources. Suspended sediment, optical backscatter, velocity data near the head of the estuary, and discharge data obtained from the output of a water balance model were used to generate continuous suspended sediment concentration records and compute loads to the Bay from the large Central Valley watershed. Sediment loads from small tributary watersheds around the Bay were determined using 235 station-years of suspended sediment data from 38 watershed locations, regression analysis, and simple modeling. Over 16 years, net annual suspended sediment load to the head of the estuary from its 154,000 km2 Central Valley watershed varied from 0.13 to 2.58 (mean = 0.89) million metric t of suspended sediment, or an average yield of 11 metric t/km2/yr. Small tributaries, totaling 8145 km2, in the nine-county Bay Area discharged between 0.081 and 4.27 (mean = 1.39) million metric t with a mean yield of 212 metric t/km2/yr. The results indicate that the hundreds of urbanized and tectonically active tributaries adjacent to the Bay, which together account for just 5% of the total watershed area draining to the Bay and provide just 7% of the annual average fluvial flow, supply 61% of the suspended sediment. The small tributary loads are more variable (53-fold between years compared to 21-fold for the inland Central Valley rivers) and dominated fluvial sediment supply to the Bay during 10 out of 16 yr. If San Francisco Bay is typical of other estuaries in active tectonic or climatically variable coastal regimes, managers responsible for water quality, dredging and reusing sediment accumulating in shipping channels, or restoring wetlands in the world's estuaries may need to more carefully

  20. Mercury concentrations and loads in a large river system tributary to San Francisco Bay, California, USA

    Science.gov (United States)

    David, N.; McKee, L.J.; Black, F.J.; Flegal, A.R.; Conaway, C.H.; Schoellhamer, D.H.; Ganju, N.K.

    2009-01-01

    In order to estimate total mercury (HgT) loads entering San Francisco Bay, USA, via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n = 78) to suspended sediment concentrations (SSC). During infrequent large floods, HgT concentrations relative to SSC were approximately twice as high as observed during smaller floods. This difference indicates the transport of more Hg-contaminated particles during high discharge events. Daily HgT loads in the Sacramento-San Joaquin River at Mallard Island ranged from below the limit of detection to 35 kg. Annual HgT loads varied from 61 ?? 22 kg (n = 5) in water year (WY) 2002 to 470 ?? 170 kg (n = 25) in WY 2006. The data collected will assist in understanding the long-term recovery of San Francisco Bay from Hg contamination and in implementing the Hg total maximum daily load, the long-term cleanup plan for Hg in the Bay. ?? 2009 SETAC.

  1. Towards the Development of the National Ocean Service San Francisco Bay Operational Forecast System

    Directory of Open Access Journals (Sweden)

    Machuan Peng

    2014-03-01

    Full Text Available The National Ocean Service (NOS, Center for Operational Products and Services installed a Physical Oceanographic Real Time System (PORTS in San Francisco Bay during 1998 to provide water surface elevation, currents at PORTS prediction depth as well as near-surface temperature and salinity. To complement the PORTS, a new nowcast/forecast system (consistent with NOS procedures has been constructed. This new nowcast/forecast system is based on the Finite Volume Coastal Ocean Model (FVCOM using a computational domain, which extends from Rio Vista on the Sacramento River and Antioch on the San Joaquin River through Suisun and San Pablo Bays and Upper and Lower San Francisco Bay out onto the continental shelf. This paper presents the FVCOM setup, testing, and validation for tidal and hindcast scenarios. In addition, the San Francisco Bay Operational Forecast System (SFBOFS setup within the NOS Coastal Ocean Model Framework (COMF is discussed. The SFBOFS performance during a semi-operational nowcast/forecast test period is presented and the production webpage is also briefly introduced. FVCOM, the core of SFBOFS, has been found to run robustly during the test period. Amplitudes and epochs of the M2 S2, N2, K2, K1, O1, P1, and Q1 constituents from the model tide-only simulation scenario are very close to the observed values at all stations. NOS skill assessment and RMS errors of all variables indicate that most statistical parameters pass the assessment criteria, and the model predictions are in agreement with measurements for both hindcast and semi-operational nowcast/forecast scenarios.

  2. Neogene contraction between the San Andreas fault and the Santa Clara Valley, San Francisco Bay region, California

    Science.gov (United States)

    McLaughlin, R.J.; Langenheim, V.E.; Schmidt, K.M.; Jachens, R.C.; Stanley, R.G.; Jayko, A.S.; McDougall, K.A.; Tinsley, J.C.; Valin, Z.C.

    1999-01-01

    In the southern San Francisco Bay region of California, oblique dextral reverse faults that verge northeastward from the San Andreas fault experienced triggered slip during the 1989 M7.1 Loma Prieta earthquake. The role of these range-front thrusts in the evolution of the San Andreas fault system and the future seismic hazard that they may pose to the urban Santa Clara Valley are poorly understood. Based on recent geologic mapping and geophysical investigations, we propose that the range-front thrust system evolved in conjunction with development of the San Andreas fault system. In the early Miocene, the region was dominated by a system of northwestwardly propagating, basin-bounding, transtensional faults. Beginning as early as middle Miocene time, however, the transtensional faulting was superseded by transpressional NE-stepping thrust and reverse faults of the range-front thrust system. Age constraints on the thrust faults indicate that the locus of contraction has focused on the Monte Vista, Shannon, and Berrocal faults since about 4.8 Ma. Fault slip and fold reconstructions suggest that crustal shortening between the San Andreas fault and the Santa Clara Valley within this time frame is ~21%, amounting to as much as 3.2 km at a rate of 0.6 mm/yr. Rates probably have not remained constant; average rates appear to have been much lower in the past few 100 ka. The distribution of coseismic surface contraction during the Loma Prieta earthquake, active seismicity, late Pleistocene to Holocene fluvial terrace warping, and geodetic data further suggest that the active range-front thrust system includes blind thrusts. Critical unresolved issues include information on the near-surface locations of buried thrusts, the timing of recent thrust earthquake events, and their recurrence in relation to earthquakes on the San Andreas fault.

  3. A Tidally Averaged Sediment-Transport Model for San Francisco Bay, California

    Science.gov (United States)

    Lionberger, Megan A.; Schoellhamer, David H.

    2009-01-01

    A tidally averaged sediment-transport model of San Francisco Bay was incorporated into a tidally averaged salinity box model previously developed and calibrated using salinity, a conservative tracer (Uncles and Peterson, 1995; Knowles, 1996). The Bay is represented in the model by 50 segments composed of two layers: one representing the channel (>5-meter depth) and the other the shallows (0- to 5-meter depth). Calculations are made using a daily time step and simulations can be made on the decadal time scale. The sediment-transport model includes an erosion-deposition algorithm, a bed-sediment algorithm, and sediment boundary conditions. Erosion and deposition of bed sediments are calculated explicitly, and suspended sediment is transported by implicitly solving the advection-dispersion equation. The bed-sediment model simulates the increase in bed strength with depth, owing to consolidation of fine sediments that make up San Francisco Bay mud. The model is calibrated to either net sedimentation calculated from bathymetric-change data or measured suspended-sediment concentration. Specified boundary conditions are the tributary fluxes of suspended sediment and suspended-sediment concentration in the Pacific Ocean. Results of model calibration and validation show that the model simulates the trends in suspended-sediment concentration associated with tidal fluctuations, residual velocity, and wind stress well, although the spring neap tidal suspended-sediment concentration variability was consistently underestimated. Model validation also showed poor simulation of seasonal sediment pulses from the Sacramento-San Joaquin River Delta at Point San Pablo because the pulses enter the Bay over only a few days and the fate of the pulses is determined by intra-tidal deposition and resuspension that are not included in this tidally averaged model. The model was calibrated to net-basin sedimentation to calculate budgets of sediment and sediment-associated contaminants. While

  4. Integrating Fluvial and Oceanic Drivers in Operational Flooding Forecasts for San Francisco Bay

    Science.gov (United States)

    Herdman, Liv; Erikson, Li; Barnard, Patrick; Kim, Jungho; Cifelli, Rob; Johnson, Lynn

    2016-04-01

    The nine counties that make up the San Francisco Bay area are home to 7.5 million people and these communties are susceptible to flooding along the bay shoreline and inland creeks that drain to the bay. A forecast model that integrates fluvial and oceanic drivers is necessary for predicting flooding in this complex urban environment. The U.S. Geological Survey ( USGS) and National Weather Service (NWS) are developing a state-of-the-art flooding forecast model for the San Francisco Bay area that will predict watershed and ocean-based flooding up to 72 hours in advance of an approaching storm. The model framework for flood forecasts is based on the USGS-developed Coastal Storm Modeling System (CoSMoS) that was applied to San Francisco Bay under the Our Coast Our Future project. For this application, we utilize Delft3D-FM, a hydrodynamic model based on a flexible mesh grid, to calculate water levels that account for tidal forcing, seasonal water level anomalies, surge and in-Bay generated wind waves from the wind and pressure fields of a NWS forecast model, and tributary discharges from the Research Distributed Hydrologic Model (RDHM), developed by the NWS Office of Hydrologic Development. The flooding extent is determined by overlaying the resulting water levels onto a recently completed 2-m digital elevation model of the study area which best resolves the extensive levee and tidal marsh systems in the region. Here we present initial pilot results of hindcast winter storms in January 2010 and December 2012, where the flooding is driven by oceanic and fluvial factors respectively. We also demonstrate the feasibility of predicting flooding on an operational time scale that incorporates both atmospheric and hydrologic forcings.

  5. Probabilistic estimation of numbers and costs of future landslides in the San Francisco Bay region

    Science.gov (United States)

    Crovelli, R.A.; Coe, J.A.

    2009-01-01

    We used historical records of damaging landslides triggered by rainstorms and a newly developed Probabilistic Landslide Assessment Cost Estimation System (PLACES) to estimate the numbers and direct costs of future landslides in the 10-county San Francisco Bay region. Historical records of damaging landslides in the region are incomplete. Therefore, our estimates of numbers and costs of future landslides are minimal estimates. The estimated mean annual number of future damaging landslides for the entire 10-county region is about 65. Santa Cruz County has the highest estimated mean annual number of damaging future landslides (about 18), whereas Napa, San Francisco, and Solano Counties have the lowest estimated mean numbers of damaging landslides (about 1 each). The estimated mean annual cost of future landslides in the entire region is about US $14.80 million (year 2000 $). The estimated mean annual cost is highest for San Mateo County ($3.24 million) and lowest for Solano County ($0.18 million). The annual per capita cost for the entire region will be about $2.10. Santa Cruz County will have the highest annual per capita cost at $8.45, whereas San Francisco County will have the lowest per capita cost at $0.31. Normalising costs by dividing by the percentage of land area with slopes equal to or greater than 17% indicates that San Francisco County will have the highest cost per square km ($7,101), whereas Santa Clara County will have the lowest cost per square km ($229). These results indicate that the San Francisco Bay region has one of the highest levels of landslide risk in the United States. Compared with landslide cost estimates from the rest of the world, the risk level in the Bay region seems high, but not exceptionally high.

  6. Mercury-Contaminated Hydraulic Mining Debris in San Francisco Bay

    OpenAIRE

    Bouse, Robin M; Fuller, Christopher C.; Luoma, Sam; Hornberger, Michelle I; Jaffe, Bruce E; Smith, Richard E.

    2010-01-01

    The hydraulic gold-mining process used during the California Gold Rush and in many developing countries today contributes enormous amounts of sediment to rivers and streams. Commonly, accompanying this sediment are contaminants such as elemental mercury and cyanide used in the gold extraction process. We show that some of the mercury-contaminated sediment created by hydraulic gold mining in the Sierra Nevada, between 1852 and 1884, ended up over 250 kilometers (km) away in San Franci...

  7. Environmental Sensitivity Index (ESI) Atlas: San Francisco Bay - 1998, maps and geographic information systems data (NODC Accession 0036884)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) maps for the shoreline of San Francisco Bay. ESI data characterize estuarine environments and...

  8. Environmental Sensitivity Index (ESI) Atlas: San Francisco Bay, California maps and geographic information systems data (NODC Accession 0013224)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set comprises the Environmental Sensitivity Index (ESI) maps for the shoreline of San Francisco Bay. ESI data characterize estuarine environments and...

  9. Shifting shoals and shattered rocks : How man has transformed the floor of west-central San Francisco Bay

    Science.gov (United States)

    Chin, John L.; Wong, Florence L.; Carlson, Paul R.

    2004-01-01

    San Francisco Bay, one of the world's finest natural harbors and a major center for maritime trade, is referred to as the 'Gateway to the Pacific Rim.' The bay is an urbanized estuary that is considered by many to be the major estuary in the United States most modified by man's activities. The population around the estuary has grown rapidly since the 1850's and now exceeds 7 million people. The San Francisco Bay area's economy ranks as one of the largest in the world, larger even than that of many countries. More than 10 million tourists are estimated to visit the bay region each year. The bay area's population and associated development have increasingly changed the estuary and its environment. San Francisco Bay and the contiguous Sacramento-San Joaquin Delta encompass roughly 1,600 square miles (4,100 km2) and are the outlet of a major watershed that drains more than 40 percent of the land area of the State of California. This watershed provides drinking water for 20 million people (two thirds of the State's population) and irrigates 4.5 million acres of farmland and ranchland. During the past several decades, much has been done to clean up the environment and waters of San Francisco Bay. Conservationist groups have even bought many areas on the margins of the bay with the intention of restoring them to a condition more like the natural marshes they once were. However, many of the major manmade changes to the bay's environment occurred so long ago that the nature of them has been forgotten. In addition, many changes continue to occur today, such as the introduction of exotic species and the loss of commercial and sport fisheries because of declining fish populations. The economy and population of the nine counties that surround the bay continue to grow and put increasing pressure on the bay, both direct and indirect. Therefore, there are mixed signals for the future health and welfare of San Francisco Bay. The San Francisco Bay estuary consists of three

  10. Anthropogenic influence on recent bathymetric change in west-central San Francisco Bay

    Science.gov (United States)

    Barnard, Patrick L.; Kvitek, Rikk G.

    2010-01-01

    Two multibeam sonar surveys of west-central San Francisco Bay, California, were conducted in 1997 and 2008. Bathymetric change analysis between the two surveys indicates a loss of 14.1 million cubic meters (-3.1 cm/yr-1) of sediment during this time period, representing an approximately three-fold acceleration of the rate that was observed from prior depth change analysis from 1947 to 1979 for all of Central Bay, using more spatially coarse National Ocean Service (NOS) soundings. The portions of the overlapping survey areas between 1997 and 2008 designated as aggregate mining lease sites lost sediment at five times the rate of the remainder of west-central San Francisco Bay. Despite covering only 28% of the analysis area, volume change within leasing areas accounted for 9.2 million cubic meters of sediment loss, while the rest of the area lost 4.9 million cubic meters of sediment. The uncertainty of this recent analysis is more tightly constrained due to more stringent controls on vertical and horizontal position via tightly coupled, inertially aided differential Global Positioning Systems (GPS) solutions for survey vessel trajectory that virtually eliminate inaccuracies from traditional tide modeling and vessel motion artifacts. Further, quantification of systematic depth measurement error can now be calculated through comparison of static surfaces (e.g., bedrock) between surveys using seafloor habitat maps based on acoustic backscatter measurements and ground-truthing with grab samples and underwater video. Sediment loss in the entire San Francisco Bay Coastal System during the last half-century,as estimated from a series of bathymetric change studies, is 240 million cubic meters, and most of this is believed to be coarse sediment (i.e., sand and gravel) from Central Bay and the San Francisco Bar, which is likely to limit the sand supply to adjacent, open-coast beaches. This hypothesis is supported by a calibrated numerical model in a related study that indicates

  11. Remotely Sensing Pollution: Detection and Monitoring of PCBs in the San Francisco Bay

    Science.gov (United States)

    Hilton, A.; Kudela, R. M.; Bausell, J.

    2016-12-01

    While the EPA banned polychlorinated biphenyls (PCBs) in 1977, they continue to persist in San Francisco Bay (SF Bay), often at dangerously high concentrations due to their long half-life. However, in spite of their associated health and environmental risks, PCB monitoring within SF Bay is extremely limited, due in large part to the high costs, both in terms of labor and capital that are associated with it. In this study, a cost effective alternative to in-situ PCB sampling is presented by demonstrating the feasibility of PCB detection via remote sensing. This was done by first establishing relationships between in-situ measurements of sum of 40 PCB concentrations and total suspended sediment concentration (SSC) collected from 1998-2006 at 37 stations distributed throughout SF Bay. A correlation was discovered for all stations at (R2 =0.32), which improved markedly upon partitioning stations into north bay, (R2 =0.64), central bay (R2 =0.80) and south bay (R2 =0.52) regions. SSC was then compared from three USGS monitoring stations with temporally consistent Landsat 8 imagery. The resulting correlation between Landsat 8 (Rrs 654) and SSC measured at USGS stations (R2 =0.50) was validated using an Airborne Visible/ Infrared Imaging Spectrometer (AVIRIS) image. The end product is a two-step empirical algorithm that can derive PCB from Landsat 8 imagery within SF Bay. This algorithm can generate spatial PCB concentration maps for SF Bay, which can in turn be utilized to increase ability to forecast PCB concentration. The observation that correlation between AVIRIS (Rrs 657) and SSC was stronger than that of Landsat 8 suggests that the accuracy of this algorithm could be enhanced with improved atmospheric correction.

  12. The Long Road from Babylon to Brentwood: Crisis and Restructuring in the San Francisco Bay Area

    OpenAIRE

    Schafran, Alex B.

    2010-01-01

    AbstractThis dissertation integrates policy analysis, archival research, ethnographic field work, GIS mapping and statistical analysis to build a broad geo-historical understanding of the role of planning, policy, capital and race in the production of the foreclosure crisis in the San Francisco Bay Area. It begins from the premise that an explanation of the foreclosure crisis that focuses solely on either finance capital or the action of homeowners misses the critical importance of history, g...

  13. Heat wave brings an unprecedented red tide to San Francisco Bay

    Science.gov (United States)

    Cloern, James E.; Schraga, Tara S.; Lopez, Cary B.

    2005-01-01

    An exceptional red tide in San Francisco Bay was observed on 8 September 2004. The red tide had chlorophyll concentrations approaching 200 mg/m3 (Figure 1) in red/purple surface streaks containing high abundances of the dinoflagellate Akashiwo sanguinea. Red tides and harmful algal blooms (HABs) are common features of coastal ecosystems, and their growing frequency is a suspected outcome of coastal eutrophication.

  14. Groundwater quality in the North San Francisco Bay shallow aquifer, California

    Science.gov (United States)

    Bennett, George L.; Fram, Miranda S.

    2018-02-23

    Groundwater provides more than 40 percent of California’s drinking water. To protect this vital resource, the State of California created the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The Priority Basin Project of the GAMA Program provides a comprehensive assessment of the State’s groundwater quality and increases public access to groundwater-quality information. The North San Francisco Bay Shallow Aquifer constitutes one of the study units being evaluated.

  15. Microbial cycling of mercury in contaminated pelagic and wetland sediments of San Pablo Bay, California

    Science.gov (United States)

    Marvin-DiPasquale, M. C.; Agee, J.L.; Bouse, R.M.; Jaffe, B.E.

    2003-01-01

    San Pablo Bay is an estuary, within northern San Francisco Bay, containing elevated sediment mercury (Hg) levels because of historic loading of hydraulic mining debris during the California gold-rush of the late 1800s. A preliminary investigation of benthic microbial Hg cycling was conducted in surface sediment (0-4 cm) collected from one salt-marsh and three open-water sites. A deeper profile (0-26 cm) was evaluated at one of the open-water locations. Radiolabeled model Hg-compounds were used to measure rates of both methylmercury (MeHg) production and degradation by bacteria. While all sites and depths had similar total-Hg concentrations (0.3-0.6 ppm), and geochemical signatures of mining debris (as eNd, range: -3.08 to -4.37), in-situ MeHg was highest in the marsh (5.4??3.5 ppb) and ??? 0.7 ppb in all open-water sites. Microbial MeHg production (potential rate) in 0-4 surface sediments was also highest in the marsh (3.1 ng g-1 wet sediment day-1) and below detection (San Pablo Bay represent important zones of MeHg production, more so than similarly Hg-contaminated adjacent open-water areas. This has significant implications for this and other Hg-impacted systems, where wetland expansion is currently planned.

  16. 78 FR 1246 - Otay River Estuary Restoration Project; South San Diego Bay Unit and Sweetwater Marsh Unit of the...

    Science.gov (United States)

    2013-01-08

    ... Sweetwater Marsh Unit of the San Diego Bay National Wildlife Refuge, California; Intent To Prepare an... restoration of estuarine and salt marsh (subtidal and intertidal wetlands) habitats within the western... Diego Bay National Wildlife Refuge-Sweetwater Marsh Unit. We originally published a notice of intent on...

  17. Talus Lex: Regulatory Approaches to Reducing Mercury Concentrations in San Francisco Bay Fish.

    Science.gov (United States)

    Abu-Saba, D. E.; Flegal, D. R.; Ganguli, P. M.; Whyte, D. C.; Mumley, D. E.; Mason, D. P.

    2001-12-01

    The history of mercury in California is recorded in the sediments of San Francisco Bay. The Bay is downstream of 40 percent of the land area of California. Its watershed receives 80 percent of the rainfall in the State, because it rains more in the north. Three billion kilograms of sediments are annually flushed from the Central Valley watershed and deposited in San Francisco Bay. Because mercury preferentially binds to sediments, we calculate mercury loads to the Bay by considering how various sources affect mercury concentrations in Bay sediments. During and after the Gold Rush, over seventy thousand tons of mercury was produced in Coast Range cinnabar mines. Much of this mercury was used as quicksilver to extract gold from placer formations in the Sierra foothills, and later in the production of munitions, electronics, health care and commercial products. Today, we can see the legacy of mining sources, from both remote and local watersheds, superimposed on air deposition, the climate and geography of California, heavily managed water supply and flood control projects, wetland restoration and rehabilitation, urbanization, wastewaster discharge and water reclamation. We already regulate wastewater and urban runoff through issuance of permits and waste discharge requirements. We can regulate mercury inputs from inoperative mines by demonstrating the link between mercury-polluted sediments and violation of existing numeric water quality objectives. We can use the same approach to regulate the disposal of mercury-containing electronic devices. But to reduce mercury levels in fish, we will also have to consider controllable water quality factors that promote mercury methylation in the aquatic ecosystem. Some of these water quality factors are already subject to regulation. For example, we can show that mercury methylation in the northern reach of the Bay increases when dissolved oxygen drops below 6 mg/L; current regulations require dissolved oxygen concentrations of

  18. Bathymetry and digital elevation models of Coyote Creek and Alviso Slough, South San Francisco Bay, California

    Science.gov (United States)

    Foxgrover, Amy C.; Finlayson, David P.; Jaffe, Bruce E.; Fregoso, Theresa A.

    2011-01-01

    In 2010 the U.S. Geological Survey (USGS), Coastal and Marine Geology Program completed three cruises to map the bathymetry of the main channel and shallow intertidal mudflats in the southernmost part of south San Francisco Bay. The three surveys were merged to generate comprehensive maps of Coyote Creek (from Calaveras Point east to the railroad bridge) and Alviso Slough (from the bay to the town of Alviso) to establish baseline bathymetry prior to the breaching of levees adjacent to Alviso and Guadalupe Sloughs as part of the South Bay Salt Pond Restoration Project http://www.southbayrestoration.org. Since 2010 we have conducted four additional surveys to monitor bathymetric change in this region as restoration progresses.

  19. Hydrodynamic properties of San Quintin Bay, Baja California: Merging models and observations.

    Science.gov (United States)

    Melaku Canu, Donata; Aveytua-Alcázar, Leslie; Camacho-Ibar, Victor F; Querin, Stefano; Solidoro, Cosimo

    2016-07-15

    We investigated the physical dynamics of San Quintin Bay, a coastal lagoon located on the Pacific coast of northern Baja California, Mexico. We implemented, validated and used a finite element 2-D hydrodynamic model to characterize the spatial and temporal variability of the hydrodynamic of the bay in response to variability in the tidal regime and in meteorological forcing patterns. Our analysis of general circulation, residual currents, residence times, and tidal propagation delays allowed us to characterize spatial variability in the hydrodynamic basin features. The eulerian water residence time is -on average and under reference conditions- approximately 7days, although this can change significantly by region and season and under different tidal and meteorological conditions. Ocean upwelling events that bring colder waters into the bay mouth affect hydrodynamic properties in all areas of the lagoon and may affect ecological dynamics. A return to pre-upwelling conditions would take approximately 10days. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Effects of Climate Change on Range Forage Production in the San Francisco Bay Area

    Science.gov (United States)

    Chaplin-Kramer, Rebecca; George, Melvin R.

    2013-01-01

    The San Francisco Bay Area in California, USA is a highly heterogeneous region in climate, topography, and habitats, as well as in its political and economic interests. Successful conservation strategies must consider various current and future competing demands for the land, and should pay special attention to livestock grazing, the dominant non-urban land-use. The main objective of this study was to predict changes in rangeland forage production in response to changes in temperature and precipitation projected by downscaled output from global climate models. Daily temperature and precipitation data generated by four climate models were used as input variables for an existing rangeland forage production model (linear regression) for California’s annual rangelands and projected on 244 12 km x 12 km grid cells for eight Bay Area counties. Climate model projections suggest that forage production in Bay Area rangelands may be enhanced by future conditions in most years, at least in terms of peak standing crop. However, the timing of production is as important as its peak, and altered precipitation patterns could mean delayed germination, resulting in shorter growing seasons and longer periods of inadequate forage quality. An increase in the frequency of extremely dry years also increases the uncertainty of forage availability. These shifts in forage production will affect the economic viability and conservation strategies for rangelands in the San Francisco Bay Area. PMID:23472102

  1. Effects of climate change on range forage production in the San Francisco Bay Area.

    Directory of Open Access Journals (Sweden)

    Rebecca Chaplin-Kramer

    Full Text Available The San Francisco Bay Area in California, USA is a highly heterogeneous region in climate, topography, and habitats, as well as in its political and economic interests. Successful conservation strategies must consider various current and future competing demands for the land, and should pay special attention to livestock grazing, the dominant non-urban land-use. The main objective of this study was to predict changes in rangeland forage production in response to changes in temperature and precipitation projected by downscaled output from global climate models. Daily temperature and precipitation data generated by four climate models were used as input variables for an existing rangeland forage production model (linear regression for California's annual rangelands and projected on 244 12 km x 12 km grid cells for eight Bay Area counties. Climate model projections suggest that forage production in Bay Area rangelands may be enhanced by future conditions in most years, at least in terms of peak standing crop. However, the timing of production is as important as its peak, and altered precipitation patterns could mean delayed germination, resulting in shorter growing seasons and longer periods of inadequate forage quality. An increase in the frequency of extremely dry years also increases the uncertainty of forage availability. These shifts in forage production will affect the economic viability and conservation strategies for rangelands in the San Francisco Bay Area.

  2. Effects of climate change on range forage production in the San Francisco Bay Area.

    Science.gov (United States)

    Chaplin-Kramer, Rebecca; George, Melvin R

    2013-01-01

    The San Francisco Bay Area in California, USA is a highly heterogeneous region in climate, topography, and habitats, as well as in its political and economic interests. Successful conservation strategies must consider various current and future competing demands for the land, and should pay special attention to livestock grazing, the dominant non-urban land-use. The main objective of this study was to predict changes in rangeland forage production in response to changes in temperature and precipitation projected by downscaled output from global climate models. Daily temperature and precipitation data generated by four climate models were used as input variables for an existing rangeland forage production model (linear regression) for California's annual rangelands and projected on 244 12 km x 12 km grid cells for eight Bay Area counties. Climate model projections suggest that forage production in Bay Area rangelands may be enhanced by future conditions in most years, at least in terms of peak standing crop. However, the timing of production is as important as its peak, and altered precipitation patterns could mean delayed germination, resulting in shorter growing seasons and longer periods of inadequate forage quality. An increase in the frequency of extremely dry years also increases the uncertainty of forage availability. These shifts in forage production will affect the economic viability and conservation strategies for rangelands in the San Francisco Bay Area.

  3. Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

    Science.gov (United States)

    Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

    1999-01-01

    Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that

  4. 75 FR 15611 - Safety Zone; United Portuguese SES Centennial Festa, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2010-03-30

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; United Portuguese SES Centennial Festa, San... United Portuguese SES Centennial Festa. This temporary safety zone is necessary to provide for the safety... Spectaculars is sponsoring the United Portuguese SES Centennial Festa, which will include a fireworks...

  5. 77 FR 57494 - Safety Zone; Fleet Week Fireworks, San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2012-09-18

    ... area of responsibility during the dates and times noted below. This action is necessary to protect life and property of the maritime public from the hazards associated with the fireworks display. During the... regulated area. The PATCOM shall be designated by the Commander, Coast Guard Sector San Francisco. The...

  6. Carbon Sequestration in Mediterranean Tidal Wetlands: San Francisco Bay and the Ebro River Delta (Invited)

    Science.gov (United States)

    Callaway, J.; Fennessy, S.; Ibanez, C.

    2013-12-01

    Tidal wetlands accumulate soil carbon at relatively rapid rates, in large part because they build soil to counteract increases in sea-level rise. Because of the rapid rates of carbon sequestration, there is growing interest in evaluating carbon dynamics in tidal wetlands around the world; however, few measurements have been completed for mediterranean-type tidal wetlands, which tend to have relatively high levels of soil salinity, likely affecting both plant productivity and decomposition rates. We measured sediment accretion and carbon sequestration rates at tidal wetlands in two mediterranean regions: the San Francisco Bay Estuary (California, USA) and the Ebro River Delta (Catalonia, Spain). Sampling sites within each region represented a range of conditions in terms of soil salinity and plant communities, and these sites serve as potential analogs for long-term carbon sequestration in restored wetlands, which could receive credits under emerging policies for carbon management. Within San Francisco Bay, we collected six sediment cores per site at four salt marshes and two brackish tidal wetlands (two transects with three stations per transect at each site) in order to identify spatial variation both within and among wetlands in the Estuary. At the Ebro Delta, individual sediment cores were collected across 14 tidal wetland sites, including salt and brackish marshes from impounded areas, river mouths, coastal lagoon, and open bay settings. Cores were collected to 50 cm, and cores were dated using 137Cs and 210Pb. Most sites within San Francisco accreted 0.3-0.5 cm/yr, with slightly higher rates of accretion at low marsh stations; accretions rates based on 137Cs were slightly higher than those based on 210Pb, likely because of the shorter time frame covered by 137Cs dating. Accretion rates from the Ebro Delta sites were similar although more variable, with rates based on 137Cs ranging from 0.1 to 0.9 cm/yr and reflecting the wide range of conditions and management

  7. Forecasting selenium discharges to the San Francisco Bay-Delta Estuary: ecological effects of a proposed San Luis drain extension

    Science.gov (United States)

    Luoma, Samuel N.; Presser, Theresa S.

    2000-01-01

    During the next few years, federal and state agencies may be required to evaluate proposals and discharge permits that could significantly change selenium (Se) inputs to the San Francisco Bay-Delta Estuary (Bay-Delta), particularly in the North Bay (i.e., Suisun Bay and San Pablo Bay). These decisions may include discharge requirements for an extension of the San Luis Drain (SLD) to the estuary to convey subsurface agricultural drainage from the western San Joaquin Valley (SJV), a renewal of an agreement to allow the existing portion of the SLD to convey subsurface agricultural drainage to a tributary of the San Joaquin River (SJR) (coincident with changes in flow patterns of the lower SJR), and refinements to promulgated Se criteria for the protection of aquatic life for the estuary. Understanding the biotransfer of Se is essential to evaluating the fate and impact of proposed changes in Se discharges to the Bay-Delta. However, past monitoring programs have not addressed the specific protocols necessary for an element that bioaccumulates. Confusion about Se threats in the past have stemmed from failure to consider the full complexity of the processes that result in Se toxicity. Past studies show that predators are more at risk from Se contamination than their prey, making it difficult to use traditional methods to predict risk from environmental concentrations alone. In this report, we employ a novel procedure to model the fate of Se under different, potentially realistic load scenarios from the SJV. For each potential load, we progressively forecast the resulting environmental concentrations, speciation, transformation to particulate form, bioaccumulation by invertebrates, trophic transfer to predators, and effects in those predators. Enough is known to establish a first order understanding of effects should Se be discharged directly into the North Bay via a conveyance such as the SLD. Our approach uses 1) existing knowledge concerning the biogeochemical

  8. Particulate Matter Concentrations in San Francisco Bay Area Rapid Transit (BART) Train Stations

    Science.gov (United States)

    Newsome, L.; Macias, S.; Romero, N.; Lockett, N.; Polar, J.; Madrigal, C.; Lopez, F.; Sanchez, R.; Webster, D.; Torio, M.; Rios, V.; Marks-Block, T.; Toli, F.

    2012-12-01

    As part of a general effort to assess air quality in different regions of the San Francisco Bay Area, we collected Particulate Matter (PM) data within passenger train cars along multiple commuter train lines simultaneously during the summer and fall of 2012. We visited numerous Bay Area Rapid Transit (BART) system stations, including those along the Fremont, Pittsburg and SF/Daly City lines. In conducting this study we used a Dustrak 8530 aerosol sensor equipped with a Global Positioning System (GPS) receiver to measure PM size 2.5 μm concentrations every second. Of all the BART stations we visited, average PM concentration levels at the Embarcadero station in San Francisco were the highest during multiple visits, with a value of 104.95 μg/m3. We also noted that high levels of PM 2.5 were released when the cloth seats on the trains were struck, which resulted in significant, temporary increases of hazardous PM levels of up to 3000 μg/m3! Embarcadero station's high PM concentration correlates to past research in other underground train stations throughout the world, where PM produced through the abrasive interaction of train wheels and tracks or brake pads becomes trapped. Compared to levels measured at outdoor stations (average of 8.52μg/m3) and other underground stations, levels detected at the Embarcadero station are particularly alarming. We believe this is due to the fact that this station is located at one end of a long, underground and underwater transbay tunnel that connects the East San Francisco Bay area to San Francisco to the west. To reduce PM exposure risk to BART employees and passengers, we suggest increasing and/or installing filtration and ventilation systems, which should substantially reduce PM concentrations at Embarcadero station.

  9. 78 FR 34895 - Safety Zone; San Francisco Independence Day Fireworks Display, San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2013-06-11

    ... Display in the Captain of the Port, San Francisco area of responsibility during the dates and times noted below. This action is necessary to protect life and property of the maritime public from the hazards.... The PATCOM is empowered to forbid entry into and control the regulated area. The PATCOM shall be...

  10. Genetic population structure of the recently introduced Asian clam, Potamocorbula amurensis, in San Francisco Bay

    Science.gov (United States)

    Duda, T. F.

    1994-01-01

    The genetic population structure of the recently introduced Asian clam, Potamocorbula amurensis, in San Francisco Bay was described using starch gel electrophoresis at eight presumptive loci. Specimens were taken from five environmentally distinct sites located throughout the bay. The population maintains a high degree of genetic variation, with a mean heterozygosity of 0.295, a mean polymorphism of 0.75, and an average of 3.70 alleles per locus. The population is genetically homogeneous, as evidenced from genetic distance values and F-statistics. However, heterogeneity of populations was indicated from a contingency chi-square test. Significant deviations from Hardy-Weinberg equilibrium and heterozygote deficiencies were found at the Lap-1 locus for all populations and at the Lap-2 locus for a single population. High levels of variability could represent a universal characteristic of invading species, the levels of variability in the source population(s), and/or the dynamics of the introduction. Lack of differentiation between subpopulations may be due to the immaturity of the San Francisco Bay population, the “general purpose” phenotype genetic strategy of the species, high rates of gene flow in the population, and/or the selective neutrality of the loci investigated.

  11. The Dinner Menu: Spatial Distribution of Organic Carbon Composition Across the San Francisco Bay-Delta

    Science.gov (United States)

    Harfmann, J.; Hernes, P.; Bergamaschi, B. A.

    2016-12-01

    The San Francisco Bay-Delta is a dynamic tidal system with multiple sources of carbon, both autochthonous (e.g. phytoplankton, submersed or floating aquatic vegetation, or non-phytoplankton microalgae) and allochthonous (e.g. riverine detritus, agricultural drainage, and urban runoff). Spatial variability in organic carbon (OC) sources translates into varying degrees of food quantity and quality for the aquatic food web, and yet surprisingly little is known about the implications of carbon source variability on the health of zooplankton populations, which form the base of the lower food chain. Particulate organic carbon (POC) is a critical component of zooplankton diet, and with the assistance of the microbial loop, dissolved organic carbon (DOC) may supplement their food. As part of a larger study linking OC sources with zooplankton growth, we collected water samples along a transect from San Pablo Bay to the Sacramento-San Joaquin Delta. Samples were analyzed for bulk POC and DOC, lignin, chlorophyll a, δ13C, and δ15N. Feeding experiments with the calanoid copepod Eurytemora affinis will be conducted in order to assess the relative bioavailability of collected OC across the transect.

  12. Development, implementation, and validation of a modeling system for the San Francisco Bay and Estuary

    Science.gov (United States)

    Chao, Yi; Farrara, John D.; Zhang, Hongchun; Zhang, Yinglong J.; Ateljevich, Eli; Chai, Fei; Davis, Curtiss O.; Dugdale, Richard; Wilkerson, Frances

    2017-07-01

    A three-dimensional numerical modeling system for the San Francisco Bay is presented. The system is based on an unstructured grid numerical model known as Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM). The lateral boundary condition is provided by a regional coastal ocean model. The surface forcing is provided by a regional atmospheric model. The SCHISM results from a decadal hindcast run are compared with available tide gauge data, as well as a collection of temperature and salinity profiles. An examination of the observed climatological annual mean salinities at the United States Geological Survey (USGS) stations shows the highest salinities to be in the open ocean and the lowest well north (upstream) of the Central Bay, a pattern that does not change substantially with season. The corresponding mean SCHISM salinities reproduced the observed variations with location quite well, though with a fresh bias. The lowest values within the Bay occur during spring and the highest values during autumn, mirroring the seasonal variations in river discharge. The corresponding observed mean temperatures within the Bay were 2 to 3° C cooler in the Central Bay than to either the north or south. This observed pattern of a cooler Central Bay was not particularly well reproduced in the SCHISM results, which also showed a cold bias. Examination of the seasonal means revealed that the cool Central Bay pattern is found only during summer in the SCHISM results. The persistent cold and fresh biases in the model control run were nearly eliminated in a sensitivity run with modifications to the surface heat flux and river discharge. The surface atmospheric forcing and the heat flux at the western boundary are found to be the two major terms in a SCHISM-based heat budget analysis of the mean seasonal temperature cycle for the Central Bay. In the Central Bay salt budget, freshwater discharged by rivers into upstream portions of the Bay to the north balanced by the

  13. Estuarine sedimentation, sediment character, and foraminiferal distribution in central San Francisco Bay, California

    Science.gov (United States)

    Chin, John L.; Woodrow, Donald L.; McGann, Mary; Wong, Florence L.; Fregoso, Theresa; Jaffe, Bruce E.

    2010-01-01

    Central San Francisco Bay is the deepest subembayment in the San Francisco Bay estuary and hence has the largest water volume of any of the subembayments. It also has the strongest tidal currents and the coarsest sediment within the estuary. Tidal currents are strongest over the west-central part of central bay and, correspondingly, this area is dominated by sand-size sediment. Much of the area east of a line from Angel Island to Alcatraz Island is characterized by muddy sand to sandy mud, and the area to the west of this line is sandy. The sand-size sediment over west-central bay furthermore is molded by the energetic tidal currents into bedforms of varying sizes and wavelengths. Bedforms typically occur in water depths of 15-25 m. High resolution bathymetry (multibeam) from 1997 and 2008 allow for subdivision of the west-central bayfloor into four basic types based on morphologic expression: featureless, sand waves, disrupted/man-altered, and bedrock knobs. Featureless and sand-wave morphologies dominate the bayfloor of west-central bay. Disrupted bayfloor has a direct association with areas that are undergoing alteration due to human activities, such as sand-mining lease areas, dredging, and disposal of dredge spoils. Change detection analysis, comparing the 1997 and 2008 multibeam data sets, shows that significant change has occurred in west-central bay during the roughly 10 years between surveys. The surveyed area lost about 5.45 million m3 of sediment during the decade. Sand-mining lease areas within west-central bay lost 6.77 million m3 as the bayfloor deepened. Nonlease areas gained 1.32 million m3 of sediment as the bayfloor shallowed slightly outside of sand-mining lease areas. Furthermore, bedform asymmetry did not change significantly, but some bedforms did migrate some tens of meters. Gravity cores show that the area east of Angel and Alcatraz Islands is floored by clayey silts or silty sand whereas the area to the west of the islands is floored

  14. Trace metals in an urbanized estuarine sea turtle food web in San Diego Bay, CA.

    Science.gov (United States)

    Komoroske, Lisa M; Lewison, Rebecca L; Seminoff, Jeffrey A; Deustchman, Douglas D; Deheyn, Dimitri D

    2012-02-15

    San Diego Bay is an anthropogenically impacted waterway that is also a critical habitat for many sensitive species such as the green sea turtle (Chelonia mydas). In this study, we quantified trace metal concentrations in sediment and organisms composing the green sea turtle diet, and identified bioaccumulation patterns for a suite of trace metals. We found Ag, Cd, Cu, Mn, Se, and Zn exhibited the highest bioaccumulation levels in this food web. Cu and Mn concentrations in resident biota displayed a strong spatial gradient from the mouth to the head of the Bay, which was different from the patterns found in the sediment itself. Sediment median concentrations followed a general pattern across the bay of Al>Mn>Cu≈Zn>Pb>As>Cd>Ag>Se>Hg. In contrast, eelgrass displayed differential patterns in the mouth versus the back of the Bay (three front Bay sites: Al>Mn>Zn>Cu>Pb>Se>Cd≈Ag>As; five back Bay sites: Mn>Al>Zn>Cu>Pb≈Se>Cd>Ag>Hg>As) with the exception of Shelter Island where levels of Zn and Cu were elevated as a result of anti-fouling paint pollution. Observed differences between sediment and biota metal patterns are likely due to complex processes related to trace metals input and bioavailability, habitat characteristics and specific metabolic functioning of the trace metals for each member of the food web. These data highlight the fact that for the San Diego Bay ecosystem, the current use of toxicity reference values scaled up from sediment and invertebrate testing ex-situ is likely to be inaccurate when transposed to the green sea turtle. Here, we illustrate how identifying spatial variability in metal exposure can improve our understanding of habitat utilization by sea turtles in highly urbanized estuaries. Monitoring contaminants directly in food webs of sensitive vertebrates may greatly improve our understanding of their direct and indirect exposure to potentially deleterious contamination, and should be considered in the future to improve traditional risk

  15. Characterizing exposure and potential impacts of contaminants on seabirds nesting at South San Diego Bay Unit of the San Diego National Wildlife Refuge (Salt Works, San Diego Bay)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 2005, a two-year USFWS study (1261-1N74) was initiated to characterize contaminant exposure by seabirds that nest in colonies at the South Bay Salt Works, within...

  16. Analysis of sediment, water, and biological samples from the Bay Farm Borrow Area, San Francisco Bay, California

    Energy Technology Data Exchange (ETDEWEB)

    Thom, R.M.; Lefkovitz, L.F. (Battelle/Marine Sciences Lab., Sequim, WA (United States))

    1991-08-01

    The Bay Farm Borrow Area (BFBA) of San Francisco Bay, California, is under consideration as a dredged-material disposal site by the US Army Corps of Engineers (USACE). As part of the analysis of the site, information is required on the quality of benthic biota, sediment, and water in the BFBA. The objective of this report was to provide data on infauna communities, sediment, and water chemistry from samples collected from the BFBA. The samples were collected, and the data will be analyzed by Science Applications International (SAIC). A total of four samples for sediment chemistry, four samples for water chemistry, and 7 samples for infauna communities were analyzed by the Battelle/Marine Sciences Laboratory (MSL). Water analyses included tests for dissolved organic carbon, total suspended solids, four metals, butyltins, polychlorinated biphenyls (PCBs), chlorinated pesticides, polynuclear aromatic hydrocarbons (PAHs), four phenols, and total phenol. Sediment samples were analyzed for percent solids, total organic carbon, total oil and grease, total petroleum hydrocarbons, grain size, 10 metals, butyltins, PCBs, chlorinated pesticides, PAHs, four phenols, and total phenol. The data along with controls and spike recovery analyses, are presented in tables, and the results are discussed in the text. The quality assurance/quality control criteria were met for the analyses as were the detection limits specified by the sponsor.

  17. Effect of water conservation on water demands. [San Francisco Bay area

    Energy Technology Data Exchange (ETDEWEB)

    Maddaus, W.O.; Feuerstein, D.L.

    1979-09-01

    A new method for predicting long-range water demands was developed to quantify the post-drought effectiveness of water conservation in the San Francisco Bay area. The method relates water use and population density with employee density in the area. The projection model was used to test several alternative water conservation programs and the water savings were found to range from 4 to 16% by the year 2000. When the costs of water conservation were compared with those for building new water supply projects, it was concluded that water conservation is the most cost-effective source of water supply. 14 references.

  18. Remote sensing analysis of water quality in the San Francisco Bay-delta

    Science.gov (United States)

    Khorram, S.

    1979-01-01

    Water quality parameters in the San Francisco Bay-delta area using remotely sensed data combined with in situ data are investigated. The parameters included suspended solids, chlorophyll, turbidity, and electrical conductivity; the ocean color scanner (OCS) data were acquired from a NASA U-2 aircraft, and water quality samples were obtained from boats. It was concluded that areas with high biological activity were clearly discernible on enhanced imagery from OCS data, and it was impossible to locate such areas on aerial photography taken with conventional or infrared sensitive color films.

  19. Deposition, erosion, and bathymetric change in South San Francisco Bay: 1858-1983

    Science.gov (United States)

    Foxgrover, Amy C.; Higgins, Shawn A.; Ingraca, Melissa K.; Jaffe, Bruce E.; Smith, Richard E.

    2004-01-01

    Since the California Gold Rush of 1849, sediment deposition, erosion, and the bathymetry of South San Francisco Bay have been altered by both natural processes and human activities. Historical hydrographic surveys can be used to assess how this system has evolved over the past 150 years. The National Ocean Service (NOS) (formerly the United States Coast and Geodetic Survey (USCGS), collected five hydrographic surveys of South San Francisco Bay from 1858 to 1983. Analysis of these surveys enables us to reconstruct the surface of the bay floor for each time period and quantify spatial and temporal changes in deposition, erosion, and bathymetry. The creation of accurate bathymetric models involves many steps. Sounding data was obtained from the original USCGS and NOS hydrographic sheets and were supplemented with hand drawn depth contours. Shorelines and marsh areas were obtained from topographic sheets. The digitized soundings and shorelines were entered into a Geographic Information System (GIS), and georeferenced to a common horizontal datum. Using surface modeling software, bathymetric grids with a horizontal resolution of 50 m were developed for each of the five hydrographic surveys. Prior to conducting analyses of sediment deposition and erosion, we converted all of the grids to a common vertical datum and made adjustments to correct for land subsidence that occurred from 1934 to 1967. Deposition and erosion that occurred during consecutive periods was then computed by differencing the corrected grids. From these maps of deposition and erosion, we calculated volumes and rates of net sediment change in the bay. South San Francisco Bay has lost approximately 90 x 106 m3 of sediment from 1858 to 1983; however within this timeframe there have been periods of both deposition and erosion. During the most recent period, from 1956 to 1983, sediment loss approached 3 x 106 m3/yr. One of the most striking changes that occurred from 1858 to 1983 was the conversion of more

  20. Handbook of Techniques and Guides for the Study of the San Francisco Bay-Delta-Estuary Complex, Part 2. Key to the Phytoplankton Phyla and Genera.

    Science.gov (United States)

    Helrich, Jane

    Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. This document is the second of a series of guides designed to help students and teachers gather data concerning the San Francisco Bay-Delta-Estuary Complex and to organize these data to make a contribution to the literature of…

  1. Selenium bioaccumulation and body condition in shorebirds and terns breeding in San Francisco Bay, California, USA

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.

    2009-01-01

    The present study evaluated Se bioaccumulation in four waterbird species (n = 206 birds) that breed within San Francisco Bay, California, USA: American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster's terns (Sterna forsteri), and Caspian terns (Hydroprogne caspia). Selenium concentrations were variable and influenced by several factors, including species, region, reproductive stage, age, and sex. Adult Se concentrations (μg/g dry wt) in livers ranged from 3.07 to 48.70 in avocets (geometric mean ± standard error, 7.92 ± 0.64), 2.28 to 41.10 in stilts (5.29 ± 0.38), 3.73 to 14.50 in Forster's terns (7.13 ± 0.38), and 4.77 to 14.40 in Caspian terns (6.73 ± 0.78). Avocets had higher Se concentrations in the North Bay compared to the South Bay, whereas stilt Se concentrations were similar between these regions and Forster's terns had lower Se concentrations in the North Bay compared to the South Bay. Female avocets had higher Se concentrations than male avocets, but this was not the case for stilts and Forster's terns. Of the factors assessed, reproductive stage had the most consistent effect among species. Prebreeding birds tended to have higher liver Se concentrations than breeding birds, but this trend was statistically significant only for Forster's terns. Forster's tern chicks had lower Se concentrations than Forster's tern adults, whereas avocet and stilt adults and chicks were similar. Additionally, body condition was negatively related to liver Se concentrations in Forster's tern adults but not in avocet, stilt, or Caspian tern adults and chicks. These variable results illustrate the complexity of Se bioaccumulation and highlight the need to sample multiple species and examine several factors to assess the impact of Se on wildlife.

  2. Sub-tidal benthic habitats of central San Francisco Bay and offshore Golden Gate area: A review

    Science.gov (United States)

    Greene, H. Gary; Endris, Charles; Vallier, Tracy; Golden, Nadine E.; Cross, Jeffery; Ryan, Holly F.; Dieter, Bryan; Niven, Eric; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Deep-water potential estuarine and marine benthic habitat types were defined from a variety of new and interpreted data sets in central San Francisco Bay and offshore Golden Gate area including multibeam echosounder (MBES), side-scan sonar and bottom grab samples. Potential estuarine benthic habitats identified for the first time range from hard bedrock outcrops on island and mainland flanks and some Bay floor

  3. Modeling Magnetic Fields from a DC Power Cable Buried Beneath San Francisco Bay Based on Empirical Measurements

    OpenAIRE

    Kavet, Robert; Wyman, Megan T.; Klimley, A. Peter

    2016-01-01

    The Trans Bay Cable (TBC) is a ±200-kilovolt (kV), 400 MW 85-km long High Voltage Direct Current (DC) buried transmission line linking Pittsburg, CA with San Francisco, CA (SF) beneath the San Francisco Estuary. The TBC runs parallel to the migratory route of various marine species, including green sturgeon, Chinook salmon, and steelhead trout. In July and August 2014, an extensive series of magnetic field measurements were taken using a pair of submerged Geometrics magnetometers towed behind...

  4. Empirical model of Skeletonema costatum photosynthetic rate, with applications in the San Francisco Bay estuary

    Science.gov (United States)

    Cloern, J.E.

    1978-01-01

    An empirical model of Skeletonema costatum photosynthetic rate is developed and fit to measurements of photosynthesis selected from the literature. Because the model acknowledges existence of: 1) a light-temperature interaction (by allowing optimum irradiance to vary with temperature), 2) light inhibition, 3) temperature inhibition, and 4) a salinity effect, it accurately estimates photosynthetic rates measured over a wide range of temperature, light intensity, and salinity. Integration of predicted instantaneous rate of photosynthesis with time and depth yields daily net carbon assimilation (pg C cell-1 day-1) in a mixed layer of specified depth, when salinity, temperature, daily irradiance and extinction coefficient are known. The assumption of constant carbon quota (pg C cell-1) allows for prediction of mean specific growth rate (day-1), which can be used in numerical models of Skeletonema costatum population dynamics. Application of the model to northern San Francisco Bay clearly demonstrates the limitation of growth by low light availability, and suggests that large population densities of S. costatum observed during summer months are not the result of active growth in the central deep channels (where growth rates are consistently predicted to be negative). But predicted growth rates in the lateral shallows are positive during summer and fall, thus offering a testable hypothesis that shoals are the only sites of active population growth by S. costatum (and perhaps other neritic diatoms) in the northern reach of San Francisco Bay. ?? 1978.

  5. Biological communities in San Francisco Bay track large-scale climate forcing over the North Pacific

    Science.gov (United States)

    Cloern, James E.; Hieb, Kathryn A.; Jacobson, Teresa; Sansó, Bruno; Di Lorenzo, Emanuele; Stacey, Mark T.; Largier, John L.; Meiring, Wendy; Peterson, William T.; Powell, Thomas M.; Winder, Monika; Jassby, Alan D.

    2010-11-01

    Long-term observations show that fish and plankton populations in the ocean fluctuate in synchrony with large-scale climate patterns, but similar evidence is lacking for estuaries because of shorter observational records. Marine fish and invertebrates have been sampled in San Francisco Bay since 1980 and exhibit large, unexplained population changes including record-high abundances of common species after 1999. Our analysis shows that populations of demersal fish, crabs and shrimp covary with the Pacific Decadal Oscillation (PDO) and North Pacific Gyre Oscillation (NPGO), both of which reversed signs in 1999. A time series model forced by the atmospheric driver of NPGO accounts for two-thirds of the variability in the first principal component of species abundances, and generalized linear models forced by PDO and NPGO account for most of the annual variability of individual species. We infer that synchronous shifts in climate patterns and community variability in San Francisco Bay are related to changes in oceanic wind forcing that modify coastal currents, upwelling intensity, surface temperature, and their influence on recruitment of marine species that utilize estuaries as nursery habitat. Ecological forecasts of estuarine responses to climate change must therefore consider how altered patterns of atmospheric forcing across ocean basins influence coastal oceanography as well as watershed hydrology.

  6. Modeling the periodic stratification and gravitational circulation in San Francisco Bay, California

    Science.gov (United States)

    Cheng, Ralph T.; Casulli, Vincenzo

    1996-01-01

    A high resolution, three-dimensional (3-D) hydrodynamic numerical model is applied to San Francisco Bay, California to simulate the periodic tidal stratification caused by tidal straining and stirring and their long-term effects on gravitational circulation. The numerical model is formulated using fixed levels in the vertical and uniform computational mesh on horizontal planes. The governing conservation equations, the 3-D shallow water equations, are solved by a semi-implicit finite-difference scheme. Numerical simulations for estuarine flows in San Francisco Bay have been performed to reproduce the hydrodynamic properties of tides, tidal and residual currents, and salt transport. All simulations were carried out to cover at least 30 days, so that the spring-neap variance in the model results could be analyzed. High grid resolution used in the model permits the use of a simple turbulence closure scheme which has been shown to be sufficient to reproduce the tidal cyclic stratification and well-mixed conditions in the water column. Low-pass filtered 3-D time-series reveals the classic estuarine gravitational circulation with a surface layer flowing down-estuary and an up-estuary flow near the bottom. The intensity of the gravitational circulation depends upon the amount of freshwater inflow, the degree of stratification, and spring-neap tidal variations.

  7. Incidental catch and mortality of striped bass, Morone saxatilis, in the commercial bay shrimp trawl fishery in the San Francisco estuarine complex

    OpenAIRE

    Reilly, Paul N.

    1991-01-01

    The commercial bay shrimp fishery was monitored from April 1989 to September 1990 in south San Francisco Bay, and from September 1989 to September 1990 in San Pablo Bay and Carquinez Strait, to estimate incidental catch and mortality of young-of-the-year (YOY), juvenile and adult striped bass. Of the total estimated by-catch of 44,000 to 52,000 YOY bass, 98.5% were taken in San Pablo Bay. Of the total estimated bycatch of 3160 to 3570 older bass, approximately 75% w...

  8. Review of wastewater problems and wastewater-management planning in the San Francisco Bay region, California

    Science.gov (United States)

    Hines, Walter G.

    1973-01-01

    The San Francisco Bay region has suffered adverse environmental effects related to the discharge of municipal-, industrial-, and agricultural- wastewater and storm-water runoff. Specific pollutional properties of theses discharges are not well understood in all cases although the toxic materials and aquatic-plant nutrients (biostimulants) found in municipal and industrial waterwater are considered to be a major cause of regional water-quality problems. Other water-quality problems in the region are commonly attributed to pesticides found in agricultural wastewater and potentially pathogenic bacteria in municipal-wastewater discharges and in storm-water runoff. The geographical distribution and magnitude of wastewater discharges in the bay region, particularly those from municipalities and industries, is largely a function of population, economic growth, and urban development. As might be expected, the total volume of wastewater has increased in a trend paralleling this growth and development. More significant, perhaps, is the fact that the total volume parameters such as BOD (biochemical oxygen demand), biostimulant concentrations, and toxicity, has increased despite large expenditures on new and improved municipal- and industrial-wastewater-treatment plants. Also, pollutant loadings from other major source, such as agriculture and storm-water runoff, have increased. At the time of writing (1972), many Federal, State, regional, and local agencies are engaged in a comprehensive wastewater-management-planning effort for the entire bay region. Initial objectives of this planning effort are: (1) the consolidation and coordination of loosely integrated wastewater-management facilities and (2) the elimination of wastewater discharges to ecologically sensitive areas, such as fresh-water streams and shallow extremities of San Francisco Bay. There has been some investigation of potential long-range wastewater-management alternatives based upon disposal in deep water in the

  9. Factors controlling floc settling velocity within San Francisco Bay, USA and comparisons with parameterisation approaches

    Science.gov (United States)

    Manning, Andrew; Schoellhamer, David

    2014-05-01

    Much of the sediment within San Francisco Bay (SFB) is cohesive and can therefore act as transport mechanism for pollutants which adsorb to clay minerals. Furthermore, muddy sediment can flocculate when resuspended; this significantly alters their transport characteristics, which poses a serious complication to the modelling of sediment pathways. The aim of this research was to determine the factors that affect floc settling velocity along a longitudinal transect in an estuary. We collected and analysed data on flocs and on potential controlling factors along a 147 km transect the length of San Francisco Bay, USA, on June 17th, 2008. The INSSEV-LF video system, which includes the novel video-based LabSFLOC instrument (developed by Manning) was used to measure floc diameters and settling velocities at 30 stations at a height of 0.7 m above the estuary bed. Floc sizes (D) ranged from 22 microns to 639 microns settling velocities (Ws) ranged between 0.04 mm/s to 15.8 mm/s during the longitudinal transect. Nearbed turbulent shear stresses throughout the transect duration were within the 0.2-0.5 Pa range which typically stimulates flocculation growth. Individual D-Ws-floc density plots suggest the suspended sediments encountered throughout SFB were composed of both mud and mixed sediment flocs. The macroflocs and microflocs (demarcation at 160 microns) sub-populations demonstrated parameterised settling velocities which spanned nearly double the range of the sample mean settling velocities (Ws_mean spanned 0.6-6 mm/s). The macroflocs tended to dominate the suspended mass (up to 77% of the ambient suspended solids concentration; SSC) from San Pablo Bay through to Carquinez Strait (the vicinity of the turbidity maximum zone). Microfloc mass was particularly significant (typically 60-100% of the SSC) in the northern section of South Bay and most of Central Bay. During slack tide, larger and faster settling flocs deposited, accounting for most of the longitudinal

  10. River discharge controls phytoplankton dynamics in the northern San Francisco Bay estuary

    Science.gov (United States)

    Cloern, J.E.; Alpine, A.E.; Cole, B.E.; Wong, R.L.J.; Arthur, J.F.; Ball, M.D.

    1983-01-01

    Phytoplankton dynamics in the upper reach of the northern San Francisco Bay estuary are usually characterized by low biomass dominated by microflagellates or freshwater diatoms in winter, and high biomass dominated by neritic diatoms in summer. During two successive years of very low river discharge (the drought of 1976-77), the summer diatom bloom was absent. This is consistent with the hypothesis that formation of the diatom population maximum is a consequence of the same physical mechanisms that create local maxima of suspended sediments in partially-mixed estuaries: density-selective retention of particles within an estuarine circulation cell. Because the estuary is turbid, calculated phytoplankton growth rates are small in the central deep channel but are relatively large in lateral shallow embayments where light limination is less severe. When river discharge falls within a critical range (100-350 m3 s-1) that positions the suspended particulate maximum adjacent to the productive shallow bays, the population of neritic diatoms increases. However, during periods of high discharge (winter) or during periods of very low discharge (drought), the suspended particulate maximum is less well-defined and is uncoupled (positioned downstream or upstream) from the shallow bays of the upper estuary, and the population of neritic diatoms declines. Hence, the biomass and community composition of phytoplankton in this estuary are controlled by river discharge. ?? 1983.

  11. Deployment of the National Transparent Optical Network around the San Francisco Bay Area

    Energy Technology Data Exchange (ETDEWEB)

    McCammon, K.; Haigh, R.; Armstrong, G. [and others

    1996-06-01

    We report on the deployment and initial operation of the National Transparent Optical Network, an experimental WDM network testbed around the San Francisco Bay Area, during the Optical Fiber Conference (OFC`96) held in San Jose, CA. The deployment aspects of the physical plant, optical and SONET layers are examined along with a discussion of broadband applications which utilized the network during the OFC`96 demonstration. The network features dense WDM technology, transparent optical routing technology using acousto- optic tunable filter based switches, and network modules with add/drop, multicast, and wavelength translation capabilities. The physical layer consisted of over 300 km of Sprint and Pacific Bell conventional single mode fiber which was amplified with I I optical amplifiers deployed in pre-amp, post-amp, and line amp configurations. An out-of-band control network provided datacom channels from remote equipment sites to the SONET network manager deployed at the San Jose Convention Center for the conference. Data transport over five wavelengths was achieved in the 1550 nm window using a variety of signal formats including analog and digital signal transmission on different wavelengths on the same fiber. The network operated throughout the week of OFC`96 and is still in operation today.

  12. Holocene Climates and Connections between the San Francisco Bay Estuary and its Watershed: A Review

    Directory of Open Access Journals (Sweden)

    Frances Malamud-Roam

    2007-02-01

    Full Text Available 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, synthesized across the Estuary, watershed and key regions beyond, provide a basis for increased understanding of how variable California’s climate can be and how it affects the Bay Delta system. This review of paleoclimate records reveals a gradual warming and drying in California from about 10,000 years to about 4,000 years before present. During this period, the current Bay and Delta were inundated by rising sea level so that by 4,000 years ago the Bay and Delta had taken on much of their present shape and extent. Between about 4,000 and 2,000 years ago, cooler and wetter conditions prevailed in the watershed, lowering salinity in the Estuary and altering local ecosystems. Those wetter conditions gave way to increasing aridity during the past 2,000 years, a general trend punctuated by occasional prolonged and severe droughts and occasional unusually wet, cool periods. California’s climate since A.D. 1850 has been unusually stable and benign, compared to climate variations during the previous 2,000 or more years. Thus, climate variations in California’s future may be even more (perhaps much more challenging than those of the past 100 years. To improve our understanding of these past examples of climate variability in California, and of the linkages between watershed climate and estuarine responses, greater emphases on paleoclimate records in and around the Estuary, improved temporal resolutions in several record types, and linked watershed-estuary paleo-modeling capabilities are needed.

  13. Reducing methylmercury accumulation in the food webs of San Francisco Bay and its local watersheds

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J.A., E-mail: jay@sfei.org [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Looker, R.E. [San Francisco Bay Regional Water Quality Control Board, 1515 Clay Street, Suite 1400, Oakland, CA 94612 (United States); Yee, D. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Marvin-Di Pasquale, M. [U.S. Geological Survey, Water Resources Division/MS 480, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Grenier, J.L. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Austin, C.M. [San Francisco Bay Regional Water Quality Control Board, 1515 Clay Street, Suite 1400, Oakland, CA 94612 (United States); McKee, L.J.; Greenfield, B.K. [San Francisco Estuary Institute, 4911 Central Avenue, Richmond, CA 94804 (United States); Brodberg, R. [California Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, 1001 I Street, Sacramento, CA 95812 (United States); Blum, J.D. [Department of Geological Sciences, University of Michigan, 1100 North University Avenue, Ann Arbor, MI 48109 (United States)

    2012-11-15

    San Francisco Bay (California, USA) and its local watersheds present an interesting case study in estuarine mercury (Hg) contamination. This review focuses on the most promising avenues for attempting to reduce methylmercury (MeHg) contamination in Bay Area aquatic food webs and identifying the scientific information that is most urgently needed to support these efforts. Concern for human exposure to MeHg in the region has led to advisories for consumption of sport fish. Striped bass from the Bay have the highest average Hg concentration measured for this species in USA estuaries, and this degree of contamination has been constant for the past 40 years. Similarly, largemouth bass in some Bay Area reservoirs have some of the highest Hg concentrations observed in the entire US. Bay Area wildlife, particularly birds, face potential impacts to reproduction based on Hg concentrations in the tissues of several Bay species. Source control of Hg is one of the primary possible approaches for reducing MeHg accumulation in Bay Area aquatic food webs. Recent findings (particularly Hg isotope measurements) indicate that the decades-long residence time of particle-associated Hg in the Bay is sufficient to allow significant conversion of even the insoluble forms of Hg into MeHg. Past inputs have been thoroughly mixed throughout this shallow and dynamic estuary. The large pool of Hg already present in the ecosystem dominates the fraction converted to MeHg and accumulating in the food web. Consequently, decreasing external Hg inputs can be expected to reduce MeHg in the food web, but it will likely take many decades to centuries before those reductions are achieved. Extensive efforts to reduce loads from the largest Hg mining source (the historic New Almaden mining district) are underway. Hg is spread widely across the urban landscape, but there are a number of key sources, source areas, and pathways that provide opportunities to capture larger quantities of Hg and reduce loads

  14. 33 CFR 334.1170 - San Pablo Bay, Calif.; gunnery range, Naval Inshore Operations Training Center, Mare Island...

    Science.gov (United States)

    2010-07-01

    ... range, Naval Inshore Operations Training Center, Mare Island, Vallejo. 334.1170 Section 334.1170... Operations Training Center, Mare Island, Vallejo. (a) The Danger Zone. A sector in San Pablo Bay delineated..., Vallejo, California, will conduct gunnery practice in the area during the period April 1 through September...

  15. 33 CFR 334.1160 - San Pablo Bay, Calif.; target practice area, Mare Island Naval Shipyard, Vallejo.

    Science.gov (United States)

    2010-07-01

    ... practice area, Mare Island Naval Shipyard, Vallejo. 334.1160 Section 334.1160 Navigation and Navigable... REGULATIONS § 334.1160 San Pablo Bay, Calif.; target practice area, Mare Island Naval Shipyard, Vallejo. (a..., Mare Island Naval Shipyard, Vallejo, California, will conduct target practice in the area at intervals...

  16. Airport and airline choice in a multiple airport system: an empirical analysis for the San Fransisco Bay area

    NARCIS (Netherlands)

    Pels, E.; Nijkamp, P.; Rietveld, P.

    2001-01-01

    Pels E. Nijkamp P. and Rietveld P. (2001) Airport and airline choice in a multiple airport region: an empirical analysis for the San Francisco Bay area, Reg. Studies 35, 1-9. In this paper a nested logit model is used to describe passenger preferences concerning airports and airlines. A statistical

  17. Comparative analysis of long-term chlorophyll data with generalized additive model - San Francisco Bay and St. Lucie Estuary

    Science.gov (United States)

    The health of estuarine ecosystems is often influenced by hydraulic and nutrient loading from upstream watersheds. We examined four decades of monitoring data of nutrient export into the Indian River Lagoon and San Francisco Bay, both of which have received considerable attentio...

  18. Interannual variability in dissolved inorganic nutrients in northern San Francisco Bay estuary

    Science.gov (United States)

    Peterson, D.H.; Smith, R.E.; Hager, S.W.; Harmon, D.D.; Herndon, R.E.; Schemel, L.E.

    1985-01-01

    Nearly two decades of seasonal dissolved inorganic nutrient-salinity distributions in northern San Francisco Bay estuary (1960-1980) illustrate interannual variations in effects of river flow (a nutrient source) and phytoplankton productivity (a nutrient sink). During winter, nutrient sources dominate the nutrient-salinity distribution patterns (nutrients are at or exceed conservative mixing concentrations). During summer, however, the sources and sinks are in close competition. In summers of wet years, the effects of increased river flow often dominate the nutrient distributions (nutrients are at or less than conservative mixing concentrations), whereas in summers of dry years, phytoplankton productivity dominates (the very dry years 1976-1977 were an exception for reasons not yet clearly known). Such source/sink effects also vary with chemical species. During summer the control of phytoplankton on nutrient distributions is apparently strongest for ammonium, less so for nitrate and silica, and is the least for phosphate. Furthermore, the strength of the silica sink (diatom productivity) is at a maximum at intermediate river flows. This relation, which is in agreement with other studies based on phytoplankton abundance and enumeration, is significant to the extent that diatoms are an important food source for herbivores. The balance or lack of balance between nutrient sources and sinks varies from one estuary to another just as it can from one year to another within the same estuary. At one extreme, in some estuaries river flow dominates the estuarine dissolved inorganic nutrient distributions throughout most of the year. At the other extreme, phytoplankton productivity dominates. In northern San Francisco Bay, for example, the phytoplankton nutrient sink is not as strong as in less turbid estuaries. In this estuary, however, river effects, which produce or are associated with near-conservative nutrient distributions, are strong even at flows less than mean

  19. Tap water isotopes reveal the San Francisco Bay Area's plumbing and responses to a major drought

    Science.gov (United States)

    Tipple, B. J.; Jameel, M. Y.; Chau, T. H.; Mancuso, C. J.; Bowen, G. J.; Dufour, A.; Chesson, L. A.; Ehleringer, J. R.

    2016-12-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. The demands for and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between population centers, water transport and usage, and the impacts of climate change on water resources and infrastructure. To better understand these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters from the San Francisco Bay Area during seven collection campaigns across 21 months during 2013-2015. San Francisco Bay Area was selected as it has well-known water management strategies and its water resources were dramatically affected by the 2012-2105 drought. Consistent with known water management strategies and previous reports of tap water isotope values, we found large spatiotemporal variations in the δ2H and δ18O values of tap waters, indicative of complex water transport systems and municipality-scale management decisions. We observed δ2H and δ18O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of measured tap water data grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Water management responses to the drought, such as source switching, bringing in new sources, and conservation, could be observed within the isotope data from each of

  20. Copper toxicity to larval stages of three marine invertebrates and copper complexation capacity in San Diego Bay, California.

    Science.gov (United States)

    Rivera-Duarte, Ignacio; Rosen, Gunther; Lapota, David; Chadwick, David B; Kear-Padilla, Lora; Zirino, Alberto

    2005-03-15

    Temporal and spatial measurements of the toxicity (EC50), chemical speciation, and complexation capacity (Cu-CC) of copper in waters from San Diego Bay suggest control of the Cu-CC over copper bioavailability. While spatial distributions of total copper (CuT) indicate an increase in concentration from the mouth toward the head of San Diego Bay, the distribution of aqueous free copper ion (Cu(II)aq) shows the opposite trend. This suggests that the bioavailability of copper to organisms decreases toward the head of the bay, and is corroborated by the increase in the amount of copper needed to reach an EC50, observed for larval stages of three marine invertebrates (Mediterranean mussel, Mytilus galloprovincialis, sand dollar, Dendraster excentricus, and purple sea urchin, Strongylocentrotus purpuratus), and by the increase in Cu-CC heading into the head of the bay. The amount of Cu(II)aq required to produce a 50% reduction in normal larval development (referred to here as pCuTox,) of the mussel, the most sensitive of the three marine invertebrates, was generally at or above approximately 1 x 10(-11) mol L(-1) equivalents of Cu (i.e., pCuTox approximately 11 = -(log [Cu(II)aq])). These results suggest that the copper complexation capacity in San Diego Bay controls copper toxicity by keeping the concentration of Cu(II)aq at nontoxic levels.

  1. Geology and natural history of the San Francisco Bay area: A field-trip guidebook

    Science.gov (United States)

    Stoffer, Philip W.; Gordon, Leslie C.

    2001-01-01

    A National Association of Geoscience Teachers Far Western Section (NAGT-FWS) field conference is an ideal forum for learning about the geology and natural history of the San Francisco Bay area. We visit classic field sites, renew old friendships, and make new ones. This collection of papers includes field guides and road logs for all of the Bay-area trips held during the NAGT-FWS 2001 Fall Field Conference and supplemental chapters on other aspects of the area’s natural and human history. The trips touch on many aspects of the geology and natural hazards of the Bay area, especially urban problems associated with living on an active tectonic plate margin: earthquake faults, coastal erosion, landslides, and the utilization of land and natural resources. We hope this conference not only provides a two-day learning opportunity for conference participants but that students and educators will use this field guidebook for future teaching and research.Many thanks are due to the U.S. Geological Survey (USGS) and San José State University (SJSU) for cohosting the conference. We are grateful to each of the field trip leaders for preparing the trips and writing the accompanying guides. We especially appreciate the many hours put in by the guidebook reviewers, Robert I. Tilling (USGS) and Paula Messina (SJSU), and to the USGS Western Publications Group for editing, layout, and web posting. Additional guidebook contributions include articles by John Galloway, Scott Starratt, Page Mosier, and Susan Toussaint. During the conference guest speakers include Robert I. Tilling (USGS Volcano Hazards Team) and Ross Stein (USGS Earthquake Hazards Team). Workshops prepared for the conference include GIS in the classroom, using USGS data by John Vogel (USGS) and Paula Messina (SJSU), and The Best of BAESI (Bay Area Earth Science Institute), a teacher training organization under the direction of Ellen Metzger (SJSU) and Richard Sedlock (SJSU). The conference provides an opportunity to

  2. Estimating methane emissions from biological and fossil-fuel sources in the San Francisco Bay Area

    Science.gov (United States)

    Jeong, Seongeun; Cui, Xinguang; Blake, Donald R.; Miller, Ben; Montzka, Stephen A.; Andrews, Arlyn; Guha, Abhinav; Martien, Philip; Bambha, Ray P.; LaFranchi, Brian; Michelsen, Hope A.; Clements, Craig B.; Glaize, Pierre; Fischer, Marc L.

    2017-01-01

    We present the first sector-specific analysis of methane (CH4) emissions from the San Francisco Bay Area (SFBA) using CH4 and volatile organic compound (VOC) measurements from six sites during September - December 2015. We apply a hierarchical Bayesian inversion to separate the biological from fossil-fuel (natural gas and petroleum) sources using the measurements of CH4 and selected VOCs, a source-specific 1 km CH4 emission model, and an atmospheric transport model. We estimate that SFBA CH4 emissions are 166-289 Gg CH4/yr (at 95% confidence), 1.3-2.3 times higher than a recent inventory with much of the underestimation from landfill. Including the VOCs, 82 ± 27% of total posterior median CH4 emissions are biological and 17 ± 3% fossil fuel, where landfill and natural gas dominate the biological and fossil-fuel CH4 of prior emissions, respectively.

  3. Notes on a Mesodinium rubrum red tide in San Francisco Bay (California, USA)

    Science.gov (United States)

    Cloern, James E.; Cole, Brian E.; Hager, Stephen W.

    1994-01-01

    Discrete red patches of water were observed in South San Francisco Bay (USA) on 30 April 1993, and examination of live samples showed that this red tide was caused by surface accumulations of the pigmented ciliate Mesodinium rubrum . Vertical profiles showed strong salinity and temperature stratification in the upper 5 m, peak chlorophyll fluorescence in the upper meter, and differences in the small-scale density structure and fluorescence distribution among red patches. Events preceding this Mesodinium red tide included: (i) heavy precipitation and run-off, allowing for strong salinity stratification; (ii) a spring diatom bloom where the chlorophyll a concentration reached 50 mg m −3 ; (ii) depletions of dissolved inorganic N and Si in the photic zone; and (iv) several days of rapid warming and stabilization of the upper surface layer. These conditions may be general prerequisites for M.rubrum blooms in temperate estuaries.

  4. Bed composition generation for morphodynamic modeling: Case study of San Pablo Bay in California, USA

    Science.gov (United States)

    van der Wegen, M.; Dastgheib, A.; Jaffe, B.E.; Roelvink, D.

    2011-01-01

    Applications of process-based morphodynamic models are often constrained by limited availability of data on bed composition, which may have a considerable impact on the modeled morphodynamic development. One may even distinguish a period of "morphodynamic spin-up" in which the model generates the bed level according to some ill-defined initial bed composition rather than describing the realistic behavior of the system. The present paper proposes a methodology to generate bed composition of multiple sand and/or mud fractions that can act as the initial condition for the process-based numerical model Delft3D. The bed composition generation (BCG) run does not include bed level changes, but does permit the redistribution of multiple sediment fractions over the modeled domain. The model applies the concept of an active layer that may differ in sediment composition above an underlayer with fixed composition. In the case of a BCG run, the bed level is kept constant, whereas the bed composition can change. The approach is applied to San Pablo Bay in California, USA. Model results show that the BCG run reallocates sand and mud fractions over the model domain. Initially, a major sediment reallocation takes place, but development rates decrease in the longer term. Runs that take the outcome of a BCG run as a starting point lead to more gradual morphodynamic development. Sensitivity analysis shows the impact of variations in the morphological factor, the active layer thickness, and wind waves. An important but difficult to characterize criterion for a successful application of a BCG run is that it should not lead to a bed composition that fixes the bed so that it dominates the "natural" morphodynamic development of the system. Future research will focus on a decadal morphodynamic hindcast and comparison with measured bathymetries in San Pablo Bay so that the proposed methodology can be tested and optimized. ?? 2010 The Author(s).

  5. Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

    Science.gov (United States)

    Wong, Florence L.; Woodrow, Donald L.; McGann, Mary

    2013-01-01

    Heavy or high-specific gravity minerals make up a small but diagnostic component of sediment that is well suited for determining the provenance and distribution of sediment transported through estuarine and coastal systems worldwide. By this means, we see that surficial sand-sized sediment in the San Francisco Bay Coastal System comes primarily from the Sierra Nevada and associated terranes by way of the Sacramento and San Joaquin Rivers and is transported with little dilution through the San Francisco Bay and out the Golden Gate. Heavy minerals document a slight change from the strictly Sierran-Sacramento mineralogy at the confluence of the two rivers to a composition that includes minor amounts of chert and other Franciscan Complex components west of Carquinez Strait. Between Carquinez Strait and the San Francisco Bar, Sierran sediment is intermingled with Franciscan-modified Sierran sediment. The latter continues out the Gate and turns southward towards beaches of the San Francisco Peninsula. The Sierran sediment also fans out from the San Francisco Bar to merge with a Sierran province on the shelf in the Gulf of the Farallones. Beach-sand sized sediment from the Russian River is transported southward to Point Reyes where it spreads out to define a Franciscan sediment province on the shelf, but does not continue southward to contribute to the sediment in the Golden Gate area.

  6. Air Quality Benefits of Ship Fuel Regulations in the San Francisco Bay Area

    Science.gov (United States)

    Tao, L.; Harley, R. A.; Fairley, D.; Martien, P. T.

    2012-12-01

    Ocean-going vessels burning high-sulfur heavy fuel oil are an important emission source of air pollutants such as sulfur dioxide and particulate matter. Beginning July 1, 2009, an emission control area was put into effect at ports and along the California coastline, requiring use of low-sulfur marine fuels in place of heavy fuel oil in main engines of ships. To assess impacts of the fuel changes on air quality at the Port of Oakland and in the surrounding San Francisco Bay area, we analyzed speciated fine particle composition data from 4 urban sites and 2 more remote sites (Point Reyes and Pinnacles) from the IMPROVE network. Measured changes in concentrations of vanadium, a useful and specific tracer for heavy fuel oil combustion, are related to overall changes in primary aerosol emissions from ships. The results indicate a substantial reduction in vanadium concentrations after the fuel change, and a 13 to 38% decrease in SO2 concentration, with the SO2 decrease varying depending on proximity to shipping lanes. We inferred from emission factors documented in the literature that marine vessel contributions to primary fine particulate matter mass in the Bay Area, prior to the fuel change, were on the order of 1 to 5%.

  7. Climate Change and Conservation Planning in California: The San Francisco Bay Area Upland Habitat Goals Approach

    Science.gov (United States)

    Branciforte, R.; Weiss, S. B.; Schaefer, N.

    2008-12-01

    Climate change threatens California's vast and unique biodiversity. The Bay Area Upland Habitat Goals is a comprehensive regional biodiversity assessment of the 9 counties surrounding San Francisco Bay, and is designing conservation land networks that will serve to protect, manage, and restore that biodiversity. Conservation goals for vegetation, rare plants, mammals, birds, fish, amphibians, reptiles, and invertebrates are set, and those goals are met using the optimization algorithm MARXAN. Climate change issues are being considered in the assessment and network design in several ways. The high spatial variability at mesoclimatic and topoclimatic scales in California creates high local biodiversity, and provides some degree of local resiliency to macroclimatic change. Mesoclimatic variability from 800 m scale PRISM climatic norms is used to assess "mesoclimate spaces" in distinct mountain ranges, so that high mesoclimatic variability, especially local extremes that likely support range limits of species and potential climatic refugia, can be captured in the network. Quantitative measures of network resiliency to climate change include the spatial range of key temperature and precipitation variables within planning units. Topoclimatic variability provides a finer-grained spatial patterning. Downscaling to the topoclimatic scale (10-50 m scale) includes modeling solar radiation across DEMs for predicting maximum temperature differentials, and topographic position indices for modeling minimum temperature differentials. PRISM data are also used to differentiate grasslands into distinct warm and cool types. The overall conservation strategy includes local and regional connectivity so that range shifts can be accommodated.

  8. A Pilot Study of Retail 'Vape Shops' in the San Francisco Bay Area.

    Science.gov (United States)

    Burbank, Andrea D; Thrul, Johannes; Ling, Pamela M

    2016-01-01

    The use of electronic cigarettes or vape devices is increasing, and products are evolving rapidly. This study assessed retail vape shops in the San Francisco Bay Area to describe store characteristics, products offered, advertisements and health claims, as well as employees' perceptions of their customers' demographics, and practices to support smoking cessation. We conducted store audits of shops that exclusively sell vape devices with physical addresses in San Francisco and Alameda counties (n=23, response rate 72%) and interviewed vape shop owners/employees. While all stores carried second and third generation vape devices, 83% of stores did not carry first generation devices. Employees estimated the majority of their customers bought devices for smoking cessation or to replace tobacco, and a small minority purchased for first-time recreational use. Employees most frequently recommended dosing nicotine based on usual cigarette consumption, adjusting doses based on "throat hit" or cravings, use of a second or third generation e-cigarette, and encouraged customers to experiment and customize to "whatever works for you" as smoking cessation advice. Vape shops report a significant number of their customers are interested in smoking cessation, and employees are giving smoking cessation advice. A subpopulation of customers includes some nicotine novices. Studies of vape shops should include both observations and interviews with employees in order to detect important informal practices that may differ from posted signs or printed advertising. These practices include cessation counseling, product claims, and custom discount prices or bargaining.

  9. A Pilot Study of Retail ‘Vape Shops’ in the San Francisco Bay Area

    Science.gov (United States)

    Burbank, Andrea D; Thrul, Johannes; Ling, Pamela M

    2016-01-01

    INTRODUCTION The use of electronic cigarettes or vape devices is increasing, and products are evolving rapidly. This study assessed retail vape shops in the San Francisco Bay Area to describe store characteristics, products offered, advertisements and health claims, as well as employees’ perceptions of their customers’ demographics, and practices to support smoking cessation. METHODS We conducted store audits of shops that exclusively sell vape devices with physical addresses in San Francisco and Alameda counties (n=23, response rate 72%) and interviewed vape shop owners/employees. RESULTS While all stores carried second and third generation vape devices, 83% of stores did not carry first generation devices. Employees estimated the majority of their customers bought devices for smoking cessation or to replace tobacco, and a small minority purchased for first-time recreational use. Employees most frequently recommended dosing nicotine based on usual cigarette consumption, adjusting doses based on “throat hit” or cravings, use of a second or third generation e-cigarette, and encouraged customers to experiment and customize to “whatever works for you” as smoking cessation advice. CONCLUSIONS Vape shops report a significant number of their customers are interested in smoking cessation, and employees are giving smoking cessation advice. A subpopulation of customers includes some nicotine novices. Studies of vape shops should include both observations and interviews with employees in order to detect important informal practices that may differ from posted signs or printed advertising. These practices include cessation counseling, product claims, and custom discount prices or bargaining. PMID:28393129

  10. Recent warming in the San Francisco Bay and the California coastal ocean

    Science.gov (United States)

    Chao, Yi; Farrara, John; Zhang, Carrie

    2017-05-01

    During 2014 exceptionally warm water temperatures developed across a wide area off the California coast and within San Francisco Bay (SFB) and persisted through the middle of 2016. Observations and numerical model output are used to document this warming and its origins. The coastal warming was mostly confined to the upper 100 meters of the ocean and was manifested strongly in the two leading modes of upper ocean (0-100 m) temperature variability in the extra-tropical eastern Pacific. Observations in the suggest that the coastal warming in 2014 propagated into nearshore regions from the west and later indicate a warming influence that propagates from south to north into the region associated with the 2015-16 El Niño event. An analysis of the upper ocean (0-100 m) heat budget in a Regional Ocean Modeling System hindcast simulation confirmed this scenario. The results from a set of sensitivity runs with the model in which the lateral boundary conditions varied supports the conclusions drawn from the heat budget analysis. Concerning the warming in the SFB, an examination of the observations and the heat budget in an unstructured-grid numerical model simulation suggests that the warming during the second half of 2014 and early 2016 originates in the adjacent California coastal ocean and propagates through the Golden Gate into the Bay. The finding that the coastal and Bay warming are due to the relatively slow propagation of signals from remote sources raise the possibility that such warming events may be predictable several months in advance.

  11. 75 FR 8106 - Don Edwards San Francisco Bay National Wildlife Refuge, Alameda, Santa Clara, and San Mateo...

    Science.gov (United States)

    2010-02-23

    ..., and San Mateo Counties, CA AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of intent to... located in Alameda, Santa Clara, and San Mateo Counties of California. We provide this notice in... Clara, and San Mateo Counties, CA. This notice complies with our CCP policy to (1) advise other Federal...

  12. How Will the San Francisco Bay-Delta Ecosystem Respond to Climate Change and Continued Population Growth?

    Science.gov (United States)

    Cloern, J.

    2008-12-01

    Programs to ensure sustainability of coastal ecosystems and the biological diversity they harbor require ecological forecasting to assess habitat transformations from the coupled effects of climate change and human population growth. A multidisciplinary modeling project (CASCaDE) was launched in 2007 to develop 21st-century visions of the Sacramento-San Joaquin Delta and San Francisco Bay under four scenarios of climate change and increasing demand for California's water resource. The process begins with downscaled projections of daily weather from GCM's and routes these to a watershed model that computes runoff and an operations model that computes inflows to the Bay-Delta. Hydrologic and climatic outputs, including sea level rise, drive models of tidal hydrodynamics-salinity-temperature in the Delta, sediment inputs and evolving geomorphology of San Francisco Bay. These projected habitat changes are being used to address priority questions asked by resource managers: How will changes in seasonal streamflow, salinity and water temperature, frequency of extreme weather and hydrologic events, and geomorphology influence the sustainability of native species that depend upon the Bay-Delta and the ecosystem services it provides?

  13. Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

    Science.gov (United States)

    Cloern, J.E.; Jassby, A.D.

    2012-01-01

    Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion; human modification of sediment supply; introduction of non-native species; sewage input; environmental policy; and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion; decreasing turbidity; restructuring of plankton communities; nutrient enrichment; elimination of hypoxia and reduced metal contamination of biota; and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The wide range of variability time scales and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs. But the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

  14. A Modeling Study of the San Francisco Bay and Delta Ecosystem in High and Low River Flow Years

    Science.gov (United States)

    Liu, Q.; Rao, S. A.; Chai, F.; Dugdale, R. C.; Wilkerson, F. P.; Chao, Y.; Zhang, H.

    2016-02-01

    A coupled physical-biogeochemical model is used to study the nutrient and biomass cycles in the San Francisco Bay and Delta Ecosystem (SFE). With high population density, SFE has important interplay with human population and economics. To assist the ecosystem-based management and ecological risk assessment for the California fisheries and water management, we study the nutrient and biomass cycles in the San Francisco Bay by coupling the Carbon, Silicate, and Nitrogen Ecosystem (CoSiNE) model with an unstructured grid, Semi-Implicit Cross-scale Hydroscience Integrated System Model (SCHISM). The model is constrained by USGS water quality observation for the Sacramento, San Joaquin, Napa rivers and the Coyote Creek sewage plant discharge, and tested successfully by the comparisons with USGS water quality observations. This study examines the bay's response to river forcing by simulating two contrasting years, 2011 (a high river flow year) and 2012 (a low river flow year). In addition, an 11-year simulation from 2004 to 2015 is conducted to investigate the long-term cycle of the bay nutrients and biomass.

  15. Under the Golden Gate bridge: views of the sea floor near the entrance to San Francisco Bay, California

    Science.gov (United States)

    Dartnell, Peter; Barnard, Patrick L.; Chin, John L.; Hanes, Daniel; Kvitek, Rikk G.; Iampietro, Pat J.; Gardner, James V.

    2006-01-01

    San Francisco Bay in Northern California is one of the largest and most altered estuaries within the United States. The sea floor within the bay as well as at its entrance is constantly changing due to strong tidal currents, aggregate mining, dredge disposal, and the creation of new land using artificial fill. Understanding this dynamic sea floor is critical for addressing local environmental issues, which include defining pollution transport pathways, deciphering tectonics, and identifying benthic habitats. Mapping commercial interests such as safe ship navigation and dredge disposal is also significantly aided by such understanding. Over the past decade, the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), and California State University, Monterey Bay (CSUMB) in cooperation with the U.S. Army Corps of Engineers (USACOE) and the Center for Integrative Coastal Observation, Research and Education (CICORE) have partnered to map central San Francisco Bay and its entrance under the Golden Gate Bridge using multibeam echosounders. These sonar systems can continuously map to produce 100 percent coverage of the sea floor at meter-scale resolution and thus produce an unprecedented view of the floor of the bay. This poster shows views of the sea floor in west-central San Francisco Bay around Alcatraz and Angel Islands, underneath the Golden Gate Bridge, and through its entrance from the Pacific Ocean. The sea floor is portrayed as a shaded relief surface generated from the multibeam data color-coded for depth from light blues for the shallowest values to purples for the deepest. The land regions are portrayed by USGS digital orthophotographs (DOQs) overlaid on USGS digital elevation models (DEMs). The water depths have a 4x vertical exaggeration while the land areas have a 2x vertical exaggeration.

  16. Sand sources and transport pathways for the San Francisco Bay coastal system, based on X-ray diffraction mineralogy

    Science.gov (United States)

    Hein, James R.; Mizell, Kira; Barnard, Patrick L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    The mineralogical compositions of 119 samples collected from throughout the San Francisco Bay coastal system, including bayfloor and seafloor, area beaches, cliff outcrops, and major drainages, were determined using X-ray diffraction (XRD). Comparison of the mineral concentrations and application of statistical cluster analysis of XRD spectra allowed for the determination of provenances and transport pathways. The use of XRD mineral identifications provides semi-quantitative compositions needed for comparisons of beach and offshore sands with potential cliff and river sources, but the innovative cluster analysis of XRD diffraction spectra provides a unique visualization of how groups of samples within the San Francisco Bay coastal system are related so that sand-sized sediment transport pathways can be inferred. The main vector for sediment transport as defined by the XRD analysis is from San Francisco Bay to the outer coast, where the sand then accumulates on the ebb tidal delta and also moves alongshore. This mineralogical link defines a critical pathway because large volumes of sediment have been removed from the Bay over the last century via channel dredging, aggregate mining, and borrow pit mining, with comparable volumes of erosion from the ebb tidal delta over the same period, in addition to high rates of shoreline retreat along the adjacent, open-coast beaches. Therefore, while previously only a temporal relationship was established, the transport pathway defined by mineralogical and geochemical tracers support the link between anthropogenic activities in the Bay and widespread erosion outside the Bay. The XRD results also establish the regional and local importance of sediment derived from cliff erosion, as well as both proximal and distal fluvial sources. This research is an important contribution to a broader provenance study aimed at identifying the driving forces for widespread geomorphic change in a heavily urbanized coastal-estuarine system.

  17. Wed. May 13, Hayward, Calif. -- EPA Administrator McCarthy joins San Francisco Bay Area agencies to celebrate nations largest solar energy partnership

    Science.gov (United States)

    SAN FRANCISCO - On Wednesday, May 13, U.S. EPA Administrator Gina McCarthy will join Bay Area agencies to celebrate the nation's largest local government collaborative for solar power and launch the nation's first federal solar partnership. Administ

  18. Amendment to refuge hunting plan for waterfowl on 5,500 acres of former commercial salt ponds : Don Edwards San Francisco Bay NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This amendment to the 1982 Don Edwards San Francisco Bay NWR waterfowl hunting plan was written to address 5,500 acres of salt pond recently acquisitioned by the...

  19. Establishing baseline conditions to inform adaptive management of South San Francisco Bay salt ponds: A comparison of waterbird abundance from the 1980s to the 2000s

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The 30,000 acres of wetlands within the Don Edwards San Francisco Bay National Wildlife Refuge (Refuge) provide critical habitat for over one million waterbirds...

  20. Towards a real-time forecasting system for the San Francisco bay/estuary and rive delta

    Science.gov (United States)

    Zhang, H.; Chao, Y.; Farrara, J. D.; Chai, F.; Dugdale, R. C.; Wilkerson, F. P.; Zhang, Y. J.; Ateljevich, E.

    2016-02-01

    An unstructured grid model based on SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) is being developed to address complex resource management questions in the San Francisco Bay/Estuary and Sacramento-San Joaquin River Delta (Bay-Delta). The air-sea fluxes are provided by a high-resolution (3-km) mesoscale atmospheric model (COAMPS). The river discharge data are used as the lateral boundary condition upstream. The coastal ocean boundary condition is derived from a structured grid California coastal ocean model based on ROMS. Results from a 10-year (2004-2015) hindcast will be presented focusing on variability on multiple time scales from tides, weather, annual to interannual. The recent warming during 2014 in response to the Pacific and California coastal warming will be described. Adding a sediment transport model as well as a biogeochemical/ecosystem model will be discussed.

  1. Mercury in birds of San Francisco Bay-Delta, California: trophic pathways, bioaccumulation, and ecotoxicological risk to avian reproduction

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Heinz, Gary; De La Cruz, Susan E. W.; Takekawa, John Y.; Miles, A. Keith; Adelsbach, Terrence L.; Herzog, Mark P.; Bluso-Demers, Jill D.; Demers, Scott A.; Herring, Garth; Hoffman, David J.; Hartman, Christopher A.; Willacker, James J.; Suchanek, Thomas H.; Schwarzbach, Steven E.; Maurer, Thomas C.

    2014-01-01

    San Francisco Bay Estuary in northern California has a legacy of mercury contamination, which could reduce the health and reproductive success of waterbirds in the estuary. The goal of this study was to use an integrated field and laboratory approach to evaluate the risks of mercury exposure to birds in the estuary. We examined mercury bioaccumulation, and other contaminants of concern, in five waterbird species that depend heavily on San Francisco Bay Estuary for foraging and breeding habitat: American avocets (Recurvirostra americana), black-necked stilts (Himantopus mexicanus), Forster’s terns (Sterna forsteri), Caspian terns (Hydroprogne caspia), and surf scoters (Melanitta perspicillata). These species have different foraging habitats and diets that represent three distinct foraging guilds within the estuary’s food web. In this report, we provide an integrated synthesis of the primary findings from this study and results are synthesized from 54 peer-reviewed publications generated to date with other unpublished results.

  2. What Determines Water Temperature Dynamics in the San Francisco Bay-Delta System?

    Science.gov (United States)

    Vroom, J.; van der Wegen, M.; Martyr-Koller, R. C.; Lucas, L. V.

    2017-11-01

    Water temperature is an important factor determining estuarine species habitat conditions. Water temperature is mainly governed by advection (e.g., from rivers) and atmospheric exchange processes varying strongly over time (day-night, seasonally) and the spatial domain. On a long time scale, climate change will impact water temperature in estuarine systems due to changes in river flow regimes, air temperature, and sea level rise. To determine which factors govern estuarine water temperature and its sensitivity to changes in its forcing, we developed a process-based numerical model (Delft3D Flexible Mesh) and applied it to a well-monitored estuarine system (the San Francisco Estuary) for validation. The process-based approach allows for detailed process description and a physics-based analysis of governing processes. The model was calibrated for water year 2011 and incorporated 3-D hydrodynamics, salinity intrusion, water temperature dynamics, and atmospheric coupling. Results show significant skill in reproducing temperature observations on daily, seasonal, and yearly time scales. In North San Francisco Bay, thermal stratification is present, enhanced by salinity stratification. The temperature of the upstream, fresh water Delta area is captured well in 2-D mode, although locally—on a small scale—vertical processes (e.g., stratification) may be important. The impact of upstream river temperature and discharge and atmospheric forcing on water temperatures differs throughout the Delta, possibly depending on dispersion and residence times. Our modeling effort provides a sound basis for future modeling studies including climate change impact on water temperature and associated ecological modeling, e.g., clam and fish habitat and phytoplankton dynamics.

  3. State of transition: Marijuana use among young adults in the San Francisco Bay Area.

    Science.gov (United States)

    Holmes, Louisa M; Popova, Lucy; Ling, Pamela M

    2016-09-01

    California may vote on marijuana legalization in 2016. Young adults have the highest rates of marijuana use, but little is known about the correlates of use in this age group, including factors that may be affected by policy change. We investigated whether there are differences in marijuana use by sociodemographic characteristics, psychological distress, loneliness and social support, controlling for risk factors such as alcohol and cigarette use as well as perceived harm of marijuana. Bivariate and multivariable analysis of past 30day marijuana use using the 2014 San Francisco Bay Area Young Adult Health Survey, a probabilistic multi-mode survey of (N=1324) young adults (aged 18-26years) residing in Alameda and San Francisco Counties, stratified by race/ethnicity. 291 (27%) sample participants reported current marijuana use. Compared to non-Hispanic Whites (referent) Asian/Pacific Islander respondents were less likely to use marijuana (AOR, 0.42; 95% CI, 0.22-0.80) while multiracial participants were twice as likely (AOR, 2.27; 95% CI, 1.06-4.85). Psychological distress was not related to marijuana use, but social support (AOR, 1.42; 95% CI, 1.08-1.88) and loneliness (AOR, 1.42; 95% CI, 1.09-1.86) were. Perceived harm of marijuana was inversely related to marijuana use (AOR, 0.60; 95% CI, 0.51-0.70), while smoking cigarettes (AOR, 3.95; 95% CI, 2.28-6.84) and binge drinking (AOR, 1.13; 95% CI, 1.03-1.24) were positively related. Legalization policies should include public education campaigns addressing potential harms of marijuana use particularly targeting multiracial young adults who also engage in other risk behaviors, such as cigarette smoking and binge drinking. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Redundancy in Public Transit - Vol III. The Political Economy of Transit in the San Francisco Bay Area, 1945-63

    OpenAIRE

    Seymour Adler

    1980-01-01

    This report focuses on two concrete developments. One is the historical process that produced the Bay Area Rapid Transit District in 1957 and the district's particular regional rapid transit plan, approved by the voters of Alameda, Contra Costa, and San Francisco counties in November, 1962. The other is the process that produced the Alameda-Contra Costa Transit District in 1955 and 1956, and the particular transit service this District began operating in 1960. The relation between the two dis...

  5. Acoustic doppler velocimeter backscatter for quantification of suspended sediment concentration in South San Francisco Bay

    Science.gov (United States)

    Ozturk, Mehmet; Work, Paul

    2016-01-01

    A data set was acquired on a shallow mudflat in south San Francisco Bay that featured simultaneous, co-located optical and acoustic sensors for subsequent estimation of suspended sediment concentrations (SSC). The optical turbidity sensor output was converted to SSC via an empirical relation derived at a nearby site using bottle sample estimates of SSC. The acoustic data was obtained using an acoustic Doppler velocimeter. Backscatter and noise were combined to develop another empirical relation between the optical estimates of SSC and the relative backscatter from the acoustic velocimeter. The optical and acoustic approaches both reproduced similar general trends in the data and have merit. Some seasonal variation in the dataset was evident, with the two methods differing by greater or lesser amounts depending on which portion of the record was examined. It is hypothesized that this is the result of flocculation, affecting the two signals by different degrees, and that the significance or mechanism of the flocculation has some seasonal variability. In the earlier portion of the record (March), there is a clear difference that appears in the acoustic approach between ebb and flood periods, and this is not evident later in the record (May). The acoustic method has promise but it appears that characteristics of flocs that form and break apart may need to be accounted for to improve the power of the method. This may also be true of the optical method: both methods involve assuming that the sediment characteristics (size, size distribution, and shape) are constant

  6. Acoustic Doppler velocimeter backscatter for quantification of suspended sediment concentration in South San Francisco Bay, USA

    Science.gov (United States)

    Öztürk, Mehmet; Work, Paul

    2016-01-01

    A data set was acquired on a shallow mudflat in south San Francisco Bay that featured simultaneous, co-located optical and acoustic sensors for subsequent estimation of suspended sediment concentrations (SSC). The optical turbidity sensor output was converted to SSC via an empirical relation derived at a nearby site using bottle sample estimates of SSC. The acoustic data was obtained using an acoustic Doppler velocimeter. Backscatter and noise were combined to develop another empirical relation between the optical estimates of SSC and the relative backscatter from the acoustic velocimeter. The optical and acoustic approaches both reproduced similar general trends in the data and have merit. Some seasonal variation in the dataset was evident, with the two methods differing by greater or lesser amounts depending on which portion of the record was examined. It is hypothesized that this is the result of flocculation, affecting the two signals by different degrees, and that the significance or mechanism of the flocculation has some seasonal variability. In the earlier portion of the record (March), there is a clear difference that appears in the acoustic approach between ebb and flood periods, and this is not evident later in the record (May). The acoustic method has promise but it appears that characteristics of flocs that form and break apart may need to be accounted for to improve the power of the method. This may also be true of the optical method: both methods involve assuming that the sediment characteristics (size, size distribution, and shape) are constant.

  7. Dietary mercury exposure to endangered California Clapper Rails in San Francisco Bay

    Science.gov (United States)

    Casazza, Michael L.; Ricca, Mark A.; Overton, Cory T.; Takekawa, John Y.; Merritt, Angela M.; Ackerman, Joshua T.

    2015-01-01

    California Clapper Rails (Rallus longirostris obsoletus) are an endangered waterbird that forage in tidal-marsh habitats that pose risks from mercury exposure. We analyzed total mercury (Hg) in six macro-invertebrate and one fish species representing Clapper Rail diets from four tidal-marshes in San Francisco Bay, California. Mercury concentrations among individual taxa ranged from lowest at Colma Creek (mean range: 0.09–0.2 μg/g dw) to highest at Cogswell (0.2–0.7), Laumeister (0.2–0.9) and Arrowhead Marshes (0.3–1.9). These spatial patterns for Hg matched patterns reported previously in Clapper Rail blood from the same four marshes. Over 25% of eastern mudsnails (Ilyanassa obsolete) and staghorn sculpin (Leptocottus armatus) exceeded dietary Hg concentrations (ww) often associated with avian reproductive impairment. Our results indicate that Hg concentrations vary considerably among tidal-marshes and diet taxa, and Hg concentrations of prey may provide an appropriate proxy for relative exposure risk for Clapper Rails.

  8. Preliminary location and age database for invertebrate fossils collected in the San Francisco Bay region, California

    Science.gov (United States)

    Parker, John M.; West, William B.; Malmborg, William T.; Brabb, Earl E.

    2003-01-01

    Most geologic maps published for central California in the past century have been made without the benefit of microfossils. The age of Cretaceous and Tertiary rocks in the structurally complex sedimentary formations of the Coast Ranges is critical in determining stratigraphic succession and in determining whether the juxtapositon of similar appearing formations means that a fault is present. Since the 1930’s, at least, oil company geologists have used microfossils to assist them in geologic mapping and in determining the environments of deposition of sedimentary rocks. This information has been confidential, but in the past 20 years the attitude of petroleum companies about this information has changed, and much material is now available. We report here on approximately 4,700 samples, largely foraminifers, from surface localities in the San Francisco Bay region of California. The information contained here can be used to update geologic maps, to analyze the depth and temperature of ocean water covering parts of California during the Mesozoic and Cenozoic eras, and for solving other geologic problems.

  9. Mudflat morphodynamics and the impact of sea level rise in South San Francisco Bay

    Science.gov (United States)

    Van der Wegen, Mick; Jaffe, Bruce E.; Foxgrover, Amy; Roelvink, Dano

    2017-01-01

    Estuarine tidal mudflats form unique habitats and maintain valuable ecosystems. Historic measurements of a mudflat in San Fancsico Bay over the past 150 years suggest the development of a rather stable mudflat profile. This raises questions on its origin and governing processes as well as on the mudflats’ fate under scenarios of sea level rise and decreasing sediment supply. We developed a 1D morphodynamic profile model (Delft3D) that is able to reproduce the 2011 measured mudflat profile. The main, schematised, forcings of the model are a constant tidal cycle and constant wave action. The model shows that wave action suspends sediment that is transported landward during flood. A depositional front moves landward until landward bed levels are high enough to carry an equal amount of sediment back during ebb. This implies that, similar to observations, the critical shear stress for erosion is regularly exceeded during the tidal cycle and that modelled equilibrium conditions include high suspended sediment concentrations at the mudflat. Shear stresses are highest during low water, while shear stresses are lower than critical (and highest at the landward end) along the mudflat during high water. Scenarios of sea level rise and decreasing sediment supply drown the mudflat. In addition, the mudflat becomes more prone to channel incision because landward accumulation is hampered. This research suggests that sea level rise is a serious threat to the presence of many estuarine intertidal mudflats, adjacent salt marshes and their associated ecological values.

  10. Delineating incised stream sediment sources within a San Francisco Bay tributary basin

    Science.gov (United States)

    Bigelow, Paul; Benda, Lee; Pearce, Sarah

    2016-07-01

    Erosion and sedimentation pose ubiquitous problems for land and watershed managers, requiring delineation of sediment sources and sinks across landscapes. However, the technical complexity of many spatially explicit erosion models precludes their use by practitioners. To address this critical gap, we demonstrate a contemporary use of applied geomorphometry through a straightforward GIS analysis of sediment sources in the San Francisco Bay Area in California, USA, designed to support erosion reduction strategies. Using 2 m lidar digital elevation models, we delineated the entire river network in the Arroyo Mocho watershed (573 km2) at the scale of ˜ 30 m segments and identified incised landforms using a combination of hillslope gradient and planform curvature. Chronic erosion to the channel network was estimated based on these topographic attributes and the size of vegetation, and calibrated to sediment gage data, providing a spatially explicit estimate of sediment yield from incised channels across the basin. Rates of erosion were summarized downstream through the channel network, revealing patterns of sediment supply at the reach scale. Erosion and sediment supply were also aggregated to subbasins, allowing comparative analyses at the scale of tributaries. The erosion patterns delineated using this approach provide land use planners with a robust framework to design erosion reduction strategies. More broadly, the study demonstrates a modern analysis of important geomorphic processes affected by land use that is easily applied by agencies to solve common problems in watersheds, improving the integration between science and environmental management.

  11. On Lagrangian Residual Currents With Applications in South San Francisco Bay, California

    Science.gov (United States)

    Cheng, Ralph T.; Casulli, Vincenzo

    1982-12-01

    The Lagrangian residual circulation has often been introduced as the sum of the Eulerian residual circulation and the Stokes' drift. Unfortunately, this definition of the Lagrangian residual circulation is conceptually incorrect because both the Eulerian residual circulation and the Stokes' drift are Eulerian variables. In this paper a classification of various residual variables are reviewed and properly defined. The Lagrangian residual circulation is then studied by means of a two-stage formulation of a computer model. The tidal circulation is first computed in a conventional Eulerian way, and then the Lagrangian residual circulation is determined by a method patterned after the method of markers and cells. To demonstrate properties of the Lagrangian residual circulation, application of this approach in South San Francisco Bay, California, is considered. With the aid of the model results, properties of the Eulerian and Lagrangian residual circulation are examined. It can be concluded that estimation of the Lagrangian residual circulation from Eulerian data may lead to unacceptable error, particularly in a tidal estuary where the tidal excursion is of the same order of magnitude as the length scale of the basin. A direction calculation of the Lagrangian residual circulation must be made and has been shown to be feasible.

  12. High-Resolution Remote Sensing of Water Quality in the San Francisco Bay-Delta Estuary.

    Science.gov (United States)

    Fichot, Cédric G; Downing, Bryan D; Bergamaschi, Brian A; Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark; Thompson, David R; Gierach, Michelle M

    2016-01-19

    The San Francisco Bay-Delta Estuary watershed is a major source of freshwater for California and a profoundly human-impacted environment. The water quality monitoring that is critical to the management of this important water resource and ecosystem relies primarily on a system of fixed water-quality monitoring stations, but the limited spatial coverage often hinders understanding. Here, we show how the latest technology in visible/near-infrared imaging spectroscopy can facilitate water quality monitoring in this highly dynamic and heterogeneous system by enabling simultaneous depictions of several water quality indicators at very high spatial resolution. The airborne portable remote imaging spectrometer (PRISM) was used to derive high-spatial-resolution (2.6 × 2.6 m) distributions of turbidity, and dissolved organic carbon (DOC) and chlorophyll-a concentrations in a wetland-influenced region of this estuary. A filter-passing methylmercury vs DOC relationship was also developed using in situ samples and enabled the high-spatial-resolution depiction of surface methylmercury concentrations in this area. The results illustrate how high-resolution imaging spectroscopy can inform management and policy development in important inland and estuarine water bodies by facilitating the detection of point- and nonpoint-source pollution, and by providing data to help assess the complex impacts of wetland restoration and climate change on water quality and ecosystem productivity.

  13. Measurements of gamma radiation levels and spectra in the San Francisco Bay Area

    Science.gov (United States)

    Lo, B. T.; Brozek, K. P.; Angell, C. T.; Norman, E. B.

    2011-10-01

    Much of the radiation received by an average person is emitted by naturally-occurring radioactive isotopes from the thorium, actinium, and uranium decay series, or potassium. In this study, we have measured gamma radiation levels at various locations in the San Francisco Bay Area and the UC Berkeley campus from spectra taken using an ORTEC NOMAD portable data acquisition system and a large-volume coaxial HPGe detector. We have identified a large number of gamma rays originating from natural sources. The most noticeable isotopes are 214Bi, 40K, and 208Tl. We have observed variations in counting rates by factors of two to five between different locations due to differences in local conditions - such as building, concrete, grass, and soil compositions. In addition, in a number of outdoor locations, we have observed 604-, 662-, and 795-keV gamma rays from 134,137Cs, which we attribute to fallout from the recent Fukushima reactor accident. The implications of these results will be discussed. This work was supported in part by a grant from the U. S. Dept. of Homeland Security.

  14. San Francisco Bay-Delta bathymetric/topographic digital elevation model (DEM)

    Science.gov (United States)

    Fregoso, Theresa; Wang, Rueen-Fang; Ateljevich, Eli; Jaffe, Bruce E.

    2017-01-01

    bathymetry data collected by the COE and USGS scientists, expanding the DEM to include the northernmost areas of the Sacramento-San Joaquin Delta, and by making use of a two-meter seamless bathymetric/topographic DEM from the USGS EROS Data Center (2013) of the San Francisco Bay region.The resulting 10-meter USGS DEM encompasses the entirety of Suisun Bay, beginning with the Carquinez Strait in the west, east to California Interstate 5, north following the path of the Yolo Bypass and the Sacramento River up to Knights Landing, and the American River northeast to the Nimbus Dam, and south to areas around Tracy. The DEM incorporates the newest available bathymetry data at the time of release, as well as including, at minimum, a 100-meter band of available topography data adjacent to most shorelines. No data areas within the DEM are areas where no elevation data exists, either due to a gap in the land/water interface, or because lidar was collected over standing water that was then cut out of the DEM.Environmental Systems Research Institute, Inc., 2015, Topo to Raster:  http://desktop.arcgis.com/en/desktop/latest/tools/3d-analyst-toolbox/topo-to-raster.htmFoxgrover, A., Smith, R.E., and Jaffe, B.E., 2005, Suisun Bay and Delta Bathymetry: http://sfbay.wr.usgs.gov/sediment/delta/index.htmlUSGS EROS Data Center, 2013, 2 m Coastal National Elevation Dataset: http://topotools.cr.usgs.gov/topobathy_viewer/Wang, R-F., and Ateljevich, E., 2012, A continuous surface elevation map for modeling, chapter 6 in California Department of Water Resources, Methodology for flow and salinity estimates in the Sacramento-San Joaquin Delta and Suisun Marsh, 33rd Annual Progress Report to the StateWater Resources Control Board:  California Department of Water Resources, Bay-Delta Office, Delta Modeling Section, http://baydeltaoffice.water.ca.gov/modeling/deltamodeling/AR2012/Chapter%206_2012_Web.pdf

  15. A new seamless, high-resolution digital elevation model of the San Francisco Bay-Delta Estuary, California

    Science.gov (United States)

    Fregoso, Theresa; Wang, Rueen-Fang; Ateljevich, Eli; Jaffe, Bruce E.

    2017-06-14

    Climate change, sea-level rise, and human development have contributed to the changing geomorphology of the San Francisco Bay - Delta (Bay-Delta) Estuary system. The need to predict scenarios of change led to the development of a new seamless, high-resolution digital elevation model (DEM) of the Bay – Delta that can be used by modelers attempting to understand potential future changes to the estuary system. This report details the three phases of the creation of this DEM. The first phase took a bathymetric-only DEM created in 2005 by the U.S. Geological Survey (USGS), refined it with additional data, and identified areas that would benefit from new surveys. The second phase began a USGS collaboration with the California Department of Water Resources (DWR) that updated a 2012 DWR seamless bathymetric/topographic DEM of the Bay-Delta with input from the USGS and modifications to fit the specific needs of USGS modelers. The third phase took the work from phase 2 and expanded the coverage area in the north to include the Yolo Bypass up to the Fremont Weir, the Sacramento River up to Knights Landing, and the American River up to the Nimbus Dam, and added back in the elevations for interior islands. The constant evolution of the Bay-Delta will require continuous updates to the DEM of the Delta, and there still are areas with older data that would benefit from modern surveys. As a result, DWR plans to continue updating the DEM.

  16. Preliminary Results from Real-Time GPS Monitoring in the San Francisco Bay Area

    Science.gov (United States)

    Langbein, J. O.; Guillemot, C.

    2013-12-01

    A web-based monitoring system has been implemented to display displacement estimates in real-time for various combinations of USGS, Plate Boundary Observatory (PBO) and Bay Area Regional Deformation (BARD) network stations in the San Francisco Bay area. Tools and utilities developed in-house are used to visually analyze the quality of estimated positions and gain a better understanding of the challenges involved in integrating displacement data into earthquake early warning (EEW) algorithms. Comparisons of results between differential and precise position estimates obtained from a variety of software packages have led to a closer examination of the epoch-per-epoch latencies, or delays with which those estimates are generated. For example, although position estimates from precise point positioning, with ambiguity resolution, (PPP-AR) computed in real-time are reasonably stable over short-time scales, latencies of 50 seconds or more currently preclude their useful incorporation into EEW algorithms. On the other hand, the latencies for differential position range between less than a second to 10 seconds. The large latencies for PPP-AR are partly due to the fact that displacement estimates obtained from GPS cannot yet be generated at the source but must rely on centralized processing that incorporates instantaneous clock corrections which, in turn must be obtained from external agencies. The latencies, however, are not as critical for the study of post-seismic deformation that occurs minutes to hours following an earthquake. Computation of the power spectra of time series provides a quantitative means to compare the precision of estimated positions that are obtained from various software that process the data in real-time. To first order, the current set of processing algorithms, including those using differential position and PPP-AR, provides nearly equal performance in terms of temporal correlations which is represented by their power spectra. At the shortest periods

  17. Butyltin compounds and their relation with organic matter in marine sediments from San Vicente Bay-Chile.

    Science.gov (United States)

    Pinochet, Hugo; Tessini, Catherine; Bravo, Manuel; Quiroz, Waldo; De Gregori, Ida

    2009-08-01

    Tributyltin and its degradation products, mono-and dibutyltin have been determined in sediments collected in some representative sites in San Vicente Bay, Chile. The organic matter contents of sediments and water collected simultaneously from the same sampling sites were also determined. High levels of total organic carbon were found in sediments, especially in those from the northern part of the bay (1.80-8.87%). Good correlations were found between total organic carbon and the oxidizable and refractory carbon fractions. Among the butyltin species determined, TBT presented the highest levels, ranging from 14 to 1,560 ng Sn g(-1) dry weight. Concentration ratios of TBT to DBT ranged between 1.33 and 3.10, showing a high degree of contamination in sediments of this Chilean bay. All data obtained were analysed by the chemometric method of principal components analysis. A strong correlation was found between TBT and DBT concentrations in sediments, the different organic matter contents in sediments and water. In marine organisms only TBT was detected, containing the filterer organism Semele solida higher level than Perumytilus purpuratus and Pyura chilensis (220, 150 and 120 ng Sn g(-1) dry weight, respectively). For the alga Rodoficea iridae the TBT concentration was 60 ng Sn g(-1) dw. Comparatively, these values are higher than those reported for the same kind of marine organisms worldwide. The different samples from San Vicente Bay were found to be contaminated by TBT. This contamination can be attributed to the different anthropogenic activities taking place in the bay.

  18. 78 FR 66269 - Safety Zone, Sea World Fireworks; Mission Bay, San Diego, CA

    Science.gov (United States)

    2013-11-05

    ... establishing a temporary safety zone on the navigable waters of Mission Bay, south of Fiesta Island, for a... Bay, south of Fiesta Island. Persons and vessels are prohibited from entering into, transiting through...

  19. San Joaquin Bay Delta Legal Boundary, California, 2007, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Sacramento-San Joaquin Delta (the Delta) and Suisun Marsh are at the confluence of the Sacramento River and San Joaquin River basins, which drain about 40...

  20. Data from theodolite measurements of creep rates on San Francisco Bay region faults, California: 1979-2001

    Science.gov (United States)

    Galehouse, Jon S.

    2002-01-01

    My purpose is to make our creep data on San Francisco Bay region active faults available to the scientific research community. My student research assistants and I measured creep (aseismic slip) rates on these faults from 1979 until my retirement from the project in 2001. These data are further described in my final technical report as principal investigator, which summarizes results from 22 September 1979 through 28 February 2001 (Galehouse, 2001). We made over 2,600 creep measurements, about one-third in the ten years prior to the Loma Prieta earthquake (LPEQ) and two-thirds in the 11.4 years following it. The measurements are continuing to be made by members of the Geosciences Department at San Francisco State University (SFSU) under the direction of Karen Grove and John Caskey. A complete analysis of our results obtained on the Hayward fault is presented in Lienkaemper, Galehouse, and Simpson (2001). A formal report based on the entire San Francisco Bay region data set is in preparation. Data sheets for each site along the fault are available for downloading in Excel format to facilitate analysis of the data. They are also available as tab-delimited raw data. The data include all regular measurement sites, SF–1 through SF–34, and the 20 SFSU and U.S. Geological Survey (USGS) afterslip sites on the Hayward fault.

  1. Fire history of the San Francisco East Bay region and implications for landscape patterns

    Science.gov (United States)

    Keeley, J.E.

    2005-01-01

    The San Francisco East Bay landscape is a rich mosaic of grasslands, shrublands and woodlands that is experiencing losses of grassland due to colonization by shrubs and succession towards woodland associations. The instability of these grasslands is apparently due to their disturbance-dependent nature coupled with 20th century changes in fire and grazing activity. This study uses fire history records to determine the potential for fire in this region and for evidence of changes in the second half of the 20th century that would account for shrubland expansion. This region has a largely anthropogenic fire regime with no lightning-ignited fires in most years. Fire suppression policy has not excluded fire from this region; however, it has been effective at maintaining roughly similar burning levels in the face of increasing anthropogenic fires, and effective at decreasing the size of fires. Fire frequency parallels increasing population growth until the latter part of the 20th century, when it reached a plateau. Fire does not appear to have been a major factor in the shrub colonization of grasslands, and cessation of grazing is a more likely immediate cause. Because grasslands are not under strong edaphic control, rather their distribution appears to be disturbance-dependent, and natural lightning ignitions are rare in the region, I hypothesize that, before the entrance of people into the region, grasslands were of limited extent. Native Americans played a major role in creation of grasslands through repeated burning and these disturbance-dependent grasslands were maintained by early European settlers through overstocking of these range lands with cattle and sheep. Twentieth century reduction in grazing, coupled with a lack of natural fires and effective suppression of anthropogenic fires, have acted in concert to favor shrubland expansion.

  2. Predicted Surface Displacements for Scenario Earthquakes in the San Francisco Bay Region

    Science.gov (United States)

    Murray-Moraleda, Jessica R.

    2008-01-01

    In the immediate aftermath of a major earthquake, the U.S. Geological Survey (USGS) will be called upon to provide information on the characteristics of the event to emergency responders and the media. One such piece of information is the expected surface displacement due to the earthquake. In conducting probabilistic hazard analyses for the San Francisco Bay Region, the Working Group on California Earthquake Probabilities (WGCEP) identified a series of scenario earthquakes involving the major faults of the region, and these were used in their 2003 report (hereafter referred to as WG03) and the recently released 2008 Uniform California Earthquake Rupture Forecast (UCERF). Here I present a collection of maps depicting the expected surface displacement resulting from those scenario earthquakes. The USGS has conducted frequent Global Positioning System (GPS) surveys throughout northern California for nearly two decades, generating a solid baseline of interseismic measurements. Following an earthquake, temporary GPS deployments at these sites will be important to augment the spatial coverage provided by continuous GPS sites for recording postseismic deformation, as will the acquisition of Interferometric Synthetic Aperture Radar (InSAR) scenes. The information provided in this report allows one to anticipate, for a given event, where the largest displacements are likely to occur. This information is valuable both for assessing the need for further spatial densification of GPS coverage before an event and prioritizing sites to resurvey and InSAR data to acquire in the immediate aftermath of the earthquake. In addition, these maps are envisioned to be a resource for scientists in communicating with emergency responders and members of the press, particularly during the time immediately after a major earthquake before displacements recorded by continuous GPS stations are available.

  3. Novel Technique for Assessing Ammonium Utilization by Phytoplankton in the San Francisco Bay-Delta Estuary

    Science.gov (United States)

    Schmidt, C. M.; Kendall, C.; Young, M. B.; Kraus, T. E. C.; Silva, S. R.; Richter, M. T.

    2015-12-01

    High concentrations of NH4+ in the San Francisco Bay-Delta Estuary (SFE) have been shown to inhibit the growth of phytoplankton, which are an important food source to zooplankton at the base of the pelagic food web. Here we present results from a study which used a stable isotope mixing model to quantify the proportion of nitrogen assimilated as NH4+ by phytoplankton in situ in a portion of the Sacramento River where NH4+ concentration is elevated downstream of the Sacramento Regional Wastewater Treatment Plant (SRWTP). To determine the δ15N value of phytoplankton, a novel method was developed to isolate phytoplankton from bulk particulate organic matter using flow cytometry prior to isotopic analysis. Modifications were made to an elemental analyzer to allow measurement of the δ15N values of samples containing as little as 0.5 µg N with an analytical precision of 0.2‰ (determined from replicate analysis of standards). During fall and spring field campaigns, two parcels of Sacramento River water (one with wastewater effluent and one without) were tracked and sampled in a Lagrangian sampling scheme over ~80 hours of travel downstream of the SRWTP. Water samples were analyzed for nutrient and chlorophyll concentrations as well δ15N-NO3 and δ15N-NH4+. In addition, approximately ten million phytoplankton cells were sorted from each sample for analysis of δ15N-phytoplankton. In parcels of Sacramento River water without wastewater effluent, NH4+ concentrations remained low and trends in δ15N-phytoplankton followed trends in δ15N-NO3-. In contrast, in the parcels containing SRWTP effluent phytoplankton uptake of N as NH4+ gradually increased from 15% immediately downstream of the SRWTP to as high as 90% after 80 hours of downstream transit. Previous mesocosm incubation experiments have demonstrated depressed growth rates and a rapid switch from NO3- to NH4+ uptake downstream of the SRWTP, suggesting that the apparent gradual increase in the proportion of N

  4. Sedimentological study in San Ignacio y Navachiste bays in Sinaloa, Mexico; Estudio sedimentologico de las bahias de San Ignacio y Navachiste en Sinaloa, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Vergara-Mendez, S.; Ortiz-Gallarza, S.M.; Garcia-Leal, M.L. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2001-03-01

    In order to contribute to the knowledge on the marine system and the nature of its bottom for the proliferation of species such as shrimps and oysters, a sedimentological study at the northern coast of Sinaloa (San Ignacio and Navachiste Bays), as well as a partial study of the continental shelf, were performed in October 1991. The grain size distribution and the organic matter and carbonates content were determined in 56 sediment samples. In addition, a counting was made of the different sizes of particles under the stereoscopic microscope by the bands method in some of the samples. The physiographic features identified in the area include old beach bars, antique river flood plains, beaches, tombolos and hooks, remainders of coastal formations. The tidal sediments were classified into four textural groups varying from coarse sands, to very fine silts. The predominant group corresponds to fine to very fine sands, which represents 78% of the analysed samples, widely distributed in the bays and continental shelf substrata. The percentual content of total carbonates varies from 2 to 94%, and the modal values fluctuate between 4 and 20%; the largest percentages were obtained inside the Navachiste Bay, at the northwest (55%) and northeast (94%) boundaries, respectively. The values smaller than 2 to 7% in general correspond to sandy sediments of the shelf. The sediments covering the San Ignacio and Navachiste Bays, as well as those of the platform, have a continental origin and have been transported to the settling basin principally by the Fuerte an Sinaloa rivers. [Spanish] Como aportacion al conocimiento del sistema marino y la naturaleza de su fondo para la proliferacion de especies como el camaron, en octubre de 1991 centrales mexicanas y se comparan con otras centrales ende Sinaloa, bahias de San Ignacio y Navachiste; y parcialmente, la plataforma continental. Fueron determinadas la granulometria y los contenidos de materia organica y carbonatos en 56 muestras de

  5. Impacts of an underwater high voltage DC power cable on fish migration movements in the San Francisco Bay.

    Science.gov (United States)

    Wyman, M. T.; Kavet, R.; Klimley, A. P.

    2016-02-01

    There is an increasingly strong interest on a global scale in offshore renewable energy production and transportation. However, there is concern that the electromagnetic fields (EMF) produced by these underwater cables may alter the behavior and physiology of marine species. Despite this concern, few studies have investigated these effects in free-living species. In 2009, a 85 km long high-voltage DC (HVDC) power cable was placed within the San Francisco Bay, running parallel, then perpendicular to, the migration route of anadromous species moving from the inland river system to the oceans. In this study, we assess the impacts of this HVDC cable on the migration behaviors of EMF-sensitive fish, including juvenile salmonids (Chinook salmon, Oncorhynchus tshawytscha, and steelhead trout, Oncorhynchus mykiss) and adult green sturgeon, Acipenser medirostris. Acoustic telemetry techniques were used to track fish migration movements through the San Francisco Bay both before and after the cable was activated; individuals implanted with acoustic transmitters were detected on cross-channel hydrophone arrays at key locations in the system. Magnetic fields were surveyed and mapped at these locations using a transverse gradiometer, and models of the cable's magnetic field were developed that closely matched the empirically measured values. Here, we present our analyses on the relationships between migration-related behavioral metrics (e.g., percent of successful migrations, duration of migration, time spent near vs. far from cable location, etc.) and environmental parameters, such as cable activation and load level, local magnetic field levels, depth, and currents.

  6. Disease Risk & Landscape Attributes of Tick-Borne Borrelia Pathogens in the San Francisco Bay Area, California.

    Science.gov (United States)

    Salkeld, Daniel J; Nieto, Nathan C; Carbajales-Dale, Patricia; Carbajales-Dale, Michael; Cinkovich, Stephanie S; Lambin, Eric F

    2015-01-01

    Habitat heterogeneity influences pathogen ecology by affecting vector abundance and the reservoir host communities. We investigated spatial patterns of disease risk for two human pathogens in the Borrelia genus-B. burgdorferi and B. miyamotoi-that are transmitted by the western black-legged tick, Ixodes pacificus. We collected ticks (349 nymphs, 273 adults) at 20 sites in the San Francisco Bay Area, California, USA. Tick abundance, pathogen prevalence and density of infected nymphs varied widely across sites and habitat type, though nymphal western black-legged ticks were more frequently found, and were more abundant in coast live oak forest and desert/semi-desert scrub (dominated by California sagebrush) habitats. We observed Borrelia infections in ticks at all sites where we able to collect >10 ticks. The recently recognized human pathogen, B. miyamotoi, was observed at a higher prevalence (13/349 nymphs = 3.7%, 95% CI = 2.0-6.3; 5/273 adults = 1.8%, 95% CI = 0.6-4.2) than recent studies from nearby locations (Alameda County, east of the San Francisco Bay), demonstrating that tick-borne disease risk and ecology can vary substantially at small geographic scales, with consequences for public health and disease diagnosis.

  7. Avian response to early tidal salt marsh restoration at former commercial salt evaporation ponds in San Francisco Bay, California, USA

    Science.gov (United States)

    Athearn, Nicole D.; Takekawa, John Y.; Shinn, Joel

    2009-01-01

    Restoration of former commercial salt evaporation ponds in the San Francisco Bay estuary is intended to reverse a severe decline (>79%) in tidal salt marshes. San Francisco Bay is a critical migratory stopover site and wintering area for shorebirds and waterfowl, and salt ponds are important high tide roosting and foraging areas. Conservation of past bird abundance is a stated goal of area restoration projects, and early adaptive management will be critical for achieving this objective. However, initial avian response at sites restored to tidal flow may not be indicative of long-term results. For example, winter shorebirds at a 529 ha pond breached in 2002 showed a marked increase in shorebird abundance following breaching. Shorebirds comprised 1% of area totals during 1999-2002 and increased to 46% during 2003-2008. These changes accompanied increased tidal range and sedimentation, but minimal vegetation establishment. Conversely, a fully vegetated, restored 216 ha pond in the same system consistently supported less than 2% of all waterbirds in the region. Early restoration may temporarily increase habitat, but managed ponds will be needed for long-term waterbird abundance within a restored pond-marsh system.

  8. Metals from mine waste as potential cause of oxidative stress in burrowing crab Neohelice granulata from San Antonio bay.

    Science.gov (United States)

    Giarratano, Erica; Gil, Mónica N; Marinho, Carmen H; Malanga, Gabriela

    2016-10-01

    The Natural Protected Area San Antonio bay is of particular importance for its congregation of migratory shorebirds and it has been declared one of the Western Hemisphere Shorebird Reserve Network International site (WHSRN). Present study represents the first assessment of variation on oxidative stress biomarkers in male crab Neohelice granulata from San Antonio bay (Río Negro, Argentina) under field conditions, associated mainly to metal contamination coming from passive mining wastes. Three sites were sampled once every three months from November 2012 to August 2013 within this sea inlet (Pile, Fishery and Port) and a control site at the southeast of the bay (Punta Perdices). Accumulation of Ni, Zn, Cr and Al varied only with seasons although without a constant trend, meanwhile Cd, Cu and Pb also varied among sites being highest in Pile and Port. Biochemical results indicated that variations in catalase activity was only site specific being maximum in Pile; meanwhile lipid radical, α-tocopherol and metallothioneins were only seasonal specific being higher in autumn and winter. Seasonal variation was also found for total thioles, being the content higher in summer and autumn than in winter. Correlation analysis revealed that malondialdehyde and α-tocopherol have a positive association with Al and negative with Ni, meanwhile GST has a positive association with Fe. Crabs from the closest area to the waste pile did not exhibit a differentiated oxidative pressure despite the higher accumulation of metals. It is possible that crabs from contaminated areas have developed a tolerance to metals, indicating a strong ecotoxicological selective pressure. More studies are needed to assess whether there is a transfer of metals through the food chain. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Understanding processes controlling sediment transports at the mouth of a highly energetic inlet system (San Francisco Bay, CA)

    Science.gov (United States)

    Elias, Edwin P.L.; Hansen, Jeff E.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    San Francisco Bay is one of the largest estuaries along the U.S. West Coast and is linked to the Pacific Ocean through the Golden Gate, a 100 m deep bedrock inlet. A coupled wave, flow and sediment transport model is used to quantify the sediment linkages between San Francisco Bay, the Golden Gate, and the adjacent open coast. Flow and sediment transport processes are investigated using an ensemble average of 24 climatologically derived wave cases and a 24.8 h representative tidal cycle. The model simulations show that within the inlet, flow and sediment transport is tidally dominated and driven by asymmetry of the ebb and flood tides. Peak ebb velocities exceed the peak flood velocities in the narrow Golden Gate channel as a result of flow convergence and acceleration. Persistent flow and sediment gyres at the headland tips are formed that limit sediment transfer from the ebb-tidal delta to the inlet and into the bay. The residual transport pattern in the inlet is dominated by a lateral segregation with a large ebb-dominant sediment transport (and flow) prevailing along the deeper north side of the Golden Gate channel, and smaller flood dominant transports along the shallow southern margin. The seaward edge of the ebb-tidal delta largely corresponds to the seaward extent of strong tidal flows. On the ebb-tidal delta, both waves and tidal forcing govern flow and sediment transport. Wave focusing by the ebb-tidal delta leads to strong patterns of sediment convergence and divergence along the adjacent Ocean Beach.

  10. Process-based, morphodynamic hindcast of decadal deposition patterns in San Pablo Bay, California, 1856-1887

    Science.gov (United States)

    van der Wegen, M.; Jaffe, B.E.; Roelvink, J.A.

    2011-01-01

    This study investigates the possibility of hindcasting-observed decadal-scale morphologic change in San Pablo Bay, a subembayment of the San Francisco Estuary, California, USA, by means of a 3-D numerical model (Delft3D). The hindcast period, 1856-1887, is characterized by upstream hydraulic mining that resulted in a high sediment input to the estuary. The model includes wind waves, salt water and fresh water interactions, and graded sediment transport, among others. Simplified initial conditions and hydrodynamic forcing were necessary because detailed historic descriptions were lacking. Model results show significant skill. The river discharge and sediment concentration have a strong positive influence on deposition volumes. Waves decrease deposition rates and have, together with tidal movement, the greatest effect on sediment distribution within San Pablo Bay. The applied process-based (or reductionist) modeling approach is valuable once reasonable values for model parameters and hydrodynamic forcing are obtained. Sensitivity analysis reveals the dominant forcing of the system and suggests that the model planform plays a dominant role in the morphodynamic development. A detailed physical explanation of the model outcomes is difficult because of the high nonlinearity of the processes. Process formulation refinement, a more detailed description of the forcing, or further model parameter variations may lead to an enhanced model performance, albeit to a limited extent. The approach potentially provides a sound basis for prediction of future developments. Parallel use of highly schematized box models and a process-based approach as described in the present work is probably the most valuable method to assess decadal morphodynamic development. Copyright ?? 2011 by the American Geophysical Union.

  11. Hydrological and management responses to scenarios of climate change in the San Francisco Bay-Delta watershed

    Science.gov (United States)

    Knowles, N.; Cronkite-Ratcliff, C.

    2016-12-01

    Downscaled meteorology from CMIP5 climate scenarios were used to drive a model of unimpaired hydrology of the San Francisco Bay-Delta watershed which in turn drove models of operational responses and managed flows. Twenty daily climate change scenarios from WY1980-2099 were evaluated with the goal of producing inflow boundary conditions for a watershed sediment model and a downstream estuarine hydrodynamic model. The resulting time series of managed flows were analyzed for century-scale trends. All of the twenty scenarios portrayed warming trends, and most had increasing annual managed flows. Nearly all exhibited increasing frequency of extreme flows and earlier flow timing downstream of the watershed's major reservoirs. Trends in annual mean flow, flow timing, and frequency of extreme flows were found to be highly correlated across GCM runs. Managed-flow timing trends were driven more by precipitation trends than by trends in air temperature. Scenarios for evaluation by hydrodynamic and ecological models of the Bay-Delta were selected based on these and other trends as part of a large interdisciplinary modeling project aimed at understanding potential ecological impacts in the Bay-Delta estuary of climate change and other major changes, CASCaDE II.

  12. Land rent and housing policy: a case study of the San Francisco Bay area rental housing market.

    Science.gov (United States)

    Barton, Stephen E

    2011-01-01

    In the San Francisco Bay Area, where residential rent is among the highest in the United States, an analysis of data from several sources demonstrates that high rent cannot be accounted for by higher quality, higher operating costs, or higher construction costs. At least one-third of the total rent paid is land rent. Despite increases in real incomes, very-low-income tenants in the Bay Area today have less income remaining after payment of rent than tenants did in 1960. High land rent is a long-term feature of the Bay Area rental market that results mostly from its geography, the density of its urban centers, and a strong economy, rather than from regulatory barriers to new multifamily construction. Deregulation is not a sufficient response to the effects of land rent on low-income tenants. Government should subsidize non-profit housing organizations, particularly land trusts that remove residential land from the market. Taxes on land rent would be a particularly appropriate funding source.

  13. Probabilistic Methodology for Estimation of Number and Economic Loss (Cost) of Future Landslides in the San Francisco Bay Region, California

    Science.gov (United States)

    Crovelli, Robert A.; Coe, Jeffrey A.

    2008-01-01

    The Probabilistic Landslide Assessment Cost Estimation System (PLACES) presented in this report estimates the number and economic loss (cost) of landslides during a specified future time in individual areas, and then calculates the sum of those estimates. The analytic probabilistic methodology is based upon conditional probability theory and laws of expectation and variance. The probabilistic methodology is expressed in the form of a Microsoft Excel computer spreadsheet program. Using historical records, the PLACES spreadsheet is used to estimate the number of future damaging landslides and total damage, as economic loss, from future landslides caused by rainstorms in 10 counties of the San Francisco Bay region in California. Estimates are made for any future 5-year period of time. The estimated total number of future damaging landslides for the entire 10-county region during any future 5-year period of time is about 330. Santa Cruz County has the highest estimated number of damaging landslides (about 90), whereas Napa, San Francisco, and Solano Counties have the lowest estimated number of damaging landslides (5?6 each). Estimated direct costs from future damaging landslides for the entire 10-county region for any future 5-year period are about US $76 million (year 2000 dollars). San Mateo County has the highest estimated costs ($16.62 million), and Solano County has the lowest estimated costs (about $0.90 million). Estimated direct costs are also subdivided into public and private costs.

  14. San Antonio-Espiritu Santo Bay, Texas Four band, 1meter resolution, UltraCam orthoimage

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Office for Coastal Management purchased digital Vexcel Ultracam imagery and digital elevation models of the Texas coastline at Espiritu-Santo Bay in 2007....

  15. [Don Edwards San Francisco Bay National Wildlife Refuge: Final Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) executive summary was written to guide management on Don Edwards San Francisco National Wildlife Refuge for the next 15...

  16. San Francisco Bay-Delta bathymetric/topographic digital elevation model(DEM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A high-resolution (10-meter per pixel) digital elevation model (DEM) was created for the Sacramento-San Joaquin Delta using both bathymetry and topography data. This...

  17. Handbook of Techniques and Guides for the Study of the San Francisco Bay-Delta-Estuary Complex, Part 3. Key to the Invertebrates.

    Science.gov (United States)

    Shettler, James

    Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. As part of meeting this goal, it is hoped that students and teachers can see the results of their efforts being put to practical use. This guide is the third of a series produced to help students and teachers gather data…

  18. A Sr-Nd isotopic study of sand-sized sediment provenance and transport for the San Francisco Bay coastal system

    Science.gov (United States)

    Rosenbauer, Robert J.; Foxgrover, Amy C.; Hein, James R.; Swarzenski, Peter W.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    A diverse suite of geochemical tracers, including 87Sr/86Sr and 143Nd/144Nd isotope ratios, the rare earth elements (REEs), and select trace elements were used to determine sand-sized sediment provenance and transport pathways within the San Francisco Bay coastal system. This study complements a large interdisciplinary effort (Barnard et al., 2012) that seeks to better understand recent geomorphic change in a highly urbanized and dynamic estuarine-coastal setting. Sand-sized sediment provenance in this geologically complex system is important to estuarine resource managers and was assessed by examining the geographic distribution of this suite of geochemical tracers from the primary sources (fluvial and rock) throughout the bay, adjacent coast, and beaches. Due to their intrinsic geochemical nature, 143Nd/144Nd isotopic ratios provide the most resolved picture of where sediment in this system is likely sourced and how it moves through this estuarine system into the Pacific Ocean. For example, Nd isotopes confirm that the predominant source of sand-sized sediment to Suisun Bay, San Pablo Bay, and Central Bay is the Sierra Nevada Batholith via the Sacramento River, with lesser contributions from the Napa and San Joaquin Rivers. Isotopic ratios also reveal hot-spots of local sediment accumulation, such as the basalt and chert deposits around the Golden Gate Bridge and the high magnetite deposits of Ocean Beach. Sand-sized sediment that exits San Francisco Bay accumulates on the ebb-tidal delta and is in part conveyed southward by long-shore currents. Broadly, the geochemical tracers reveal a complex story of multiple sediment sources, dynamic intra-bay sediment mixing and reworking, and eventual dilution and transport by energetic marine processes. Combined geochemical results provide information on sediment movement into and through San Francisco Bay and further our understanding of how sustained anthropogenic activities which limit sediment inputs to the system (e

  19. The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California

    Science.gov (United States)

    Jachens, Robert C.; Wentworth, Carl M.; Graymer, Russell W.; Williams, Robert; Ponce, David A.; Mankinen, Edward A.; Stephenson, William J.; Langenheim, Victoria

    2017-01-01

    The Evergreen basin is a 40-km-long, 8-km-wide Cenozoic sedimentary basin that lies mostly concealed beneath the northeastern margin of the Santa Clara Valley near the south end of San Francisco Bay (California, USA). The basin is bounded on the northeast by the strike-slip Hayward fault and an approximately parallel subsurface fault that is structurally overlain by a set of west-verging reverse-oblique faults which form the present-day southeastward extension of the Hayward fault. It is bounded on the southwest by the Silver Creek fault, a largely dormant or abandoned fault that splays from the active southern Calaveras fault. We propose that the Evergreen basin formed as a strike-slip pull-apart basin in the right step from the Silver Creek fault to the Hayward fault during a time when the Silver Creek fault served as a segment of the main route by which slip was transferred from the central California San Andreas fault to the Hayward and other East Bay faults. The dimensions and shape of the Evergreen basin, together with palinspastic reconstructions of geologic and geophysical features surrounding it, suggest that during its lifetime, the Silver Creek fault transferred a significant portion of the ∼100 km of total offset accommodated by the Hayward fault, and of the 175 km of total San Andreas system offset thought to have been accommodated by the entire East Bay fault system. As shown previously, at ca. 1.5–2.5 Ma the Hayward-Calaveras connection changed from a right-step, releasing regime to a left-step, restraining regime, with the consequent effective abandonment of the Silver Creek fault. This reorganization was, perhaps, preceded by development of the previously proposed basin-bisecting Mount Misery fault, a fault that directly linked the southern end of the Hayward fault with the southern Calaveras fault during extinction of pull-apart activity. Historic seismicity indicates that slip below a depth of 5 km is mostly transferred from the Calaveras

  20. Hydrogeology and geochemistry of aquifers underlying the San Lorenzo and San Leandro areas of the East Bay Plain, Alameda County, California

    Science.gov (United States)

    Izbicki, John A.; Borchers, James W.; Leighton, David A.; Kulongoski, Justin T.; Fields, Latoya; Galloway, Devin L.; Michel, Robert L.

    2003-01-01

    The East Bay Plain, on the densely populated eastern shore of San Francisco Bay, contains an upper aquifer system to depths of 250 feet below land surface and an underlying lower aquifer system to depths of more than 650 feet. Injection and recovery of imported water has been proposed for deep aquifers at two sites within the lower aquifer system. Successful operation requires that the injected water be isolated from surface sources of poor-quality water during storage and recovery. Hydraulic, geochemical, and isotopic data were used to evaluate the isolation of deeper aquifers. Ground-water responses to tidal changes in the Bay suggest that thick clay layers present within these deposits effectively isolate the deeper aquifers in the northern part of the study area from overlying surficial deposits. These data also suggest that the areal extent of the shallow and deep aquifers beneath the Bay may be limited in the northern part of the study area. Despite its apparent hydraulic isolation, the lower aquifer system may be connected to the overlying upper aquifer system through the corroded and failed casings of abandoned wells. Water-level measurements in observation wells and downward flow measured in selected wells during nonpumped conditions suggest that water may flow through wells from the upper aquifer system into the lower aquifer system during nonpumped conditions. The chemistry of water from wells in the East Bay Plain ranges from fresh to saline; salinity is greater than seawater in shallow estuarine deposits near the Bay. Water from wells completed in the lower aquifer system has higher pH, higher sodium, chloride, and manganese concentrations, and lower calcium concentrations and alkalinity than does water from wells completed in the overlying upper aquifer system. Ground-water recharge temperatures derived from noble-gas data indicate that highly focused recharge processes from infiltration of winter streamflow and more diffuse recharge processes from

  1. Water quality measurements in San Francisco Bay by the U.S. Geological Survey, 1969–2015

    Science.gov (United States)

    Schraga, Tara; Cloern, James E.

    2017-01-01

    The U.S. Geological Survey (USGS) maintains a place-based research program in San Francisco Bay (USA) that began in 1969 and continues, providing one of the longest records of water-quality measurements in a North American estuary. Constituents include salinity, temperature, light extinction coefficient, and concentrations of chlorophyll-a, dissolved oxygen, suspended particulate matter, nitrate, nitrite, ammonium, silicate, and phosphate. We describe the sampling program, analytical methods, structure of the data record, and how to access all measurements made from 1969 through 2015. We provide a summary of how these data have been used by USGS and other researchers to deepen understanding of how estuaries are structured and function differently from the river and ocean ecosystems they bridge.

  2. User's guide to the LIRAQ model: an air pollution model for the San Francisco Bay Area

    Energy Technology Data Exchange (ETDEWEB)

    MacCracken, M.C.

    1975-12-19

    The Livermore Regional Air Quality (LIRAQ) model comprises a set of computer programs that have been integrated into an easily used tool for the air quality planner. To assemble and modify the necessary data files and to direct model execution, a problem formulation program has been developed that makes possible the setup of a wide variety of studies involving perturbation of the emission inventory, changes to the initial and boundary conditions, and different choices of grid size and problem domain. In addition to describing the types of air quality problems for which the LIRAQ model may be used, this User's Guide provides detailed information on how to set up and conduct model simulations. Also included are descriptions of the formats of input data files so that the LIRAQ model may be applied to regions other than the San Francisco Bay Area.

  3. Pollutant body burdens and reproduction in Platichthys stellatus from San Francisco Bay. Annual progress report, year I

    Energy Technology Data Exchange (ETDEWEB)

    Spies, R.; Rice, D.; Ireland, R.; Beach, J.

    1983-08-01

    The effects of sublethal levels of pollutants in the tissues of estuarine fish on reproductive success were determined. The relationships among several measures of reproductive success (percent fertilization, hatching success, abnormal larvae) and biochemical measures of pollutant exposure (induced mixed-function oxidase) as well as direct measures of chemical pollutants in tissues were examined. Populations were sampled during active gametogenesis and during the spawning season. Tissues have been preserved for pollutant analyses. The reproductive success of captured spawning females was evaluated, and mixed-function oxidase (MFO) activity measured in captured fish. The results indicate the reproductive success of starry flounder in San Francisco Bay is being impaired by organic pollutants. 14 references, 8 figures, 11 tables.

  4. Susceptibility of seagrass to oil spills: A case study with eelgrass, Zostera marina in San Francisco Bay, USA.

    Science.gov (United States)

    Fonseca, Mark; Piniak, Gregory A; Cosentino-Manning, Natalie

    2017-02-15

    Existing literature illustrates inconsistent responses of seagrasses to oil exposure, both in the field and in the laboratory. Here, we add a new study that combined morphometric, demographic and photophysiology assessments to determine the potential oiling impacts to eelgrass (Zostera marina) from the 2007 Cosco Busan event in San Francisco Bay. Shoot densities, reproductive status, and rhizome elongation of Z. marina were examined at sites with pre-spill data, and eelgrass photosynthetic efficiency was measured post-spill. Shoot densities and percent elongation of rhizome internodes formed after the oil spill varied but with no consistent relationship to adjacent shoreline cleanup assessment team (SCAT) oiling categories. Similarly, differences in seagrass photosynthetic efficiency were not consistent with SCAT oiling categories. While thresholds for negative impacts on seagrass in general remain to be defined, conclusive oiling indicators for degree and duration of exposure would be important considerations and need examination under controlled study. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Remote sensing analysis of water quality and the entrapment zone in the San Francisco Bay and delta

    Science.gov (United States)

    Colwell, R. N.; Knight, A. W. (Principal Investigator); Khorram, S.

    1979-01-01

    The author has identified the following significant results. Data from an ocean color scanner flown on a U-2 aircraft at 65,000 ft and from LANDSAT MSS were enhanced to identify biologically active areas of San Francisco Bay, and to determine the salinity, turbidity, chlorophylls, and suspended solids. The best fit regression models for mapping water quality parameters were based on bands 3, 5, 7, and 10. Comparision of the results indicate that chlorophyll concentrations can best be estimated by the OCS or MSS data. Salinity can best be estimated by OCS data; turbidity can best be estimated by LANDSAT data. Neither OCS nor MSS data provide reliable basis for estimating suspended solids. Aerial photography of the highest quality taken with either conventional color or infrared-sensitive color films was unable to locate the biologically active areas.

  6. Water quality measurements in San Francisco Bay by the U.S. Geological Survey, 1969-2015.

    Science.gov (United States)

    Schraga, Tara S; Cloern, James E

    2017-08-08

    The U.S. Geological Survey (USGS) maintains a place-based research program in San Francisco Bay (USA) that began in 1969 and continues, providing one of the longest records of water-quality measurements in a North American estuary. Constituents include salinity, temperature, light extinction coefficient, and concentrations of chlorophyll-a, dissolved oxygen, suspended particulate matter, nitrate, nitrite, ammonium, silicate, and phosphate. We describe the sampling program, analytical methods, structure of the data record, and how to access all measurements made from 1969 through 2015. We provide a summary of how these data have been used by USGS and other researchers to deepen understanding of how estuaries are structured and function differently from the river and ocean ecosystems they bridge.

  7. Effects of switching to lower sulfur marine fuel oil on air quality in the San Francisco Bay area.

    Science.gov (United States)

    Tao, Ling; Fairley, David; Kleeman, Michael J; Harley, Robert A

    2013-09-17

    Ocean-going vessels burning high-sulfur heavy fuel oil are an important source of air pollutants, such as sulfur dioxide and particulate matter. Beginning in July 2009, an emission control area was put into effect at ports and along the California coastline, requiring use of lower sulfur fuels in place of heavy fuel oil in main engines of ships. To assess impacts of the fuel changes on air quality at the Port of Oakland and in the surrounding San Francisco Bay area, we analyzed speciated fine particle concentration data from four urban sites and two more remote sites. Measured changes in concentrations of vanadium, a specific marker for heavy fuel oil combustion, are related to overall changes in aerosol emissions from ships. We found a substantial reduction in vanadium concentrations after the fuel change and a 28-72% decrease in SO2 concentrations, with the SO2 decrease varying depending on proximity to shipping lanes. We estimate that the changes in ship fuel reduced ambient PM2.5 mass concentrations at urban sites in the Bay area by about 3.1 ± 0.6% or 0.28 ± 0.05 μg/m(3). The largest contributing factor to lower PM mass concentrations was reductions in particulate sulfate. Absolute sulfate reductions were fairly consistent across sites, whereas trace metal reductions were largest at a monitoring site in West Oakland near the port.

  8. Mapping Emissions that Affect Air Quality in the San Francisco Bay Area Using Adjoint Method Analysis Tools

    Science.gov (United States)

    Bastien, L. A.; Jin, L.; Brown, N. J.; Harley, R. A.

    2013-12-01

    Processes governing the fate of airborne pollutants and/or their precursors after they are emitted into the atmosphere are highly complex and, for some of them, highly non-linear. Critical gaps remain in our understanding of the detailed relationship between the spatial and temporal distributions of emissions of pollutants and how those emissions affect air quality. Another knowledge gap exists in describing the relevant emission zones of influence that affect region-wide population weighted exposure to air pollution, as opposed to focusing on air quality at specific locations. In this study, the adjoint of the Community Multiscale Air Quality model (CMAQ) is used to map areas of influence for specific pollutants and receptors of interest in the San Francisco Bay Area. Selected receptors are locations that disproportionately experience poor air quality and a population-weighted Bay Area-wide response. Studied pollutants are diesel soot and benzene for primary pollutants and ozone and formaldehyde for secondary pollutants. Emission sources that contribute the most to poor air quality for selected receptors are identified. The effectiveness of targeted versus region-wide emission control strategies is compared.

  9. Integrating terrestrial LiDAR and stereo photogrammetry to map the Tolay lakebed in northern San Francisco Bay

    Science.gov (United States)

    Woo, Isa; Storesund,; Takekawa, John Y.; Gardiner, Rachel J.; Ehret,

    2009-01-01

    The Tolay Creek Watershed drains approximately 3,520 ha along the northern edge of San Francisco Bay. Surrounded by a mosaic of open space conservation easements and public wildlife areas, it is one of the only watersheds in this urbanized estuary that is protected from its headwaters to the bay. Tolay Lake is a seasonal, spring-fed lake found in the upper watershed that historically extended over 120 ha. Although the lakebed was farmed since the early 1860s, the majority of the lakebed was recently acquired by the Sonoma County Regional Parks Department to restore its natural habitat values. As part of the restoration planning process, we produced a digital elevation model (DEM) of the historic extent of Tolay Lake by integrating terrestrial LiDAR (light detection and ranging) and stereo photogrammetry datasets, and real-time kinematic (RTK) global positioning system (GPS) surveys. We integrated the data, generated a DEM of the lakebed and upland areas, and analyzed errors. The accuracy of the composite DEM was verified using spot elevations obtained from the RTK GPS. Thus, we found that by combining photogrammetry, terrestrial LiDAR, and RTK GPS, we created an accurate baseline elevation map to use in watershed restoration planning and design.

  10. Effects of Acknowledging Uncertainty about Earthquake Risk Estimates on San Francisco Bay Area Residents' Beliefs, Attitudes, and Intentions.

    Science.gov (United States)

    Nakayachi, Kazuya; B Johnson, Branden; Koketsu, Kazuki

    2017-08-29

    We test here the risk communication proposition that explicit expert acknowledgment of uncertainty in risk estimates can enhance trust and other reactions. We manipulated such a scientific uncertainty message, accompanied by probabilities (20%, 70%, implicit ["will occur"] 100%) and time periods (10 or 30 years) in major (≥magnitude 8) earthquake risk estimates to test potential effects on residents potentially affected by seismic activity on the San Andreas fault in the San Francisco Bay Area (n = 750). The uncertainty acknowledgment increased belief that these specific experts were more honest and open, and led to statistically (but not substantively) significant increases in trust in seismic experts generally only for the 20% probability (vs. certainty) and shorter versus longer time period. The acknowledgment did not change judged risk, preparedness intentions, or mitigation policy support. Probability effects independent of the explicit admission of expert uncertainty were also insignificant except for judged risk, which rose or fell slightly depending upon the measure of judged risk used. Overall, both qualitative expressions of uncertainty and quantitative probabilities had limited effects on public reaction. These results imply that both theoretical arguments for positive effects, and practitioners' potential concerns for negative effects, of uncertainty expression may have been overblown. There may be good reasons to still acknowledge experts' uncertainties, but those merit separate justification and their own empirical tests. © 2017 Society for Risk Analysis.

  11. 78 FR 74010 - Safety Zone: Sausalito Lighted Boat Parade Fireworks Display, San Francisco Bay, Sausalito, CA

    Science.gov (United States)

    2013-12-10

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone: Sausalito Lighted Boat Parade Fireworks... Bay off of Spinnaker Point near Sausalito, CA in support of the Sausalito Lighted Boat Parade... Lighted Boat Parade Fireworks Display on December 14, 2013 off of Spinnaker Point near Sausalito, CA in...

  12. Real-time earthquake alert system for the greater San Francisco Bay Area: a prototype design to address operational issues

    Energy Technology Data Exchange (ETDEWEB)

    Harben, P.E.; Jarpe, S.; Hunter, S.

    1996-12-10

    The purpose of the earthquake alert system (EAS) is to outrun the seismic energy released in a large earthquake using a geographically distributed network of strong motion sensors that telemeter data to a rapid CPU-processing station, which then issues an area-wide warning to a region before strong motion will occur. The warning times involved are short, from 0 to 30 seconds or so; consequently, most responses must be automated. The San Francisco Bay Area is particularly well suited for an EAS because (1) large earthquakes have relatively shallow hypocenters (10- to 20-kilometer depth), giving favorable ray-path geometries for larger warning times than deeper from earthquakes, and (2) the active faults are few in number and well characterized, which means far fewer geographically distributed strong motion sensors are (about 50 in this region). An EAS prototype is being implemented in the San Francisco Bay Area. The system consists of four distinct subsystems: (1) a distributed strong motion seismic network, (2) a central processing station, (3) a warning communications system and (4) user receiver and response systems. We have designed a simple, reliable, and inexpensive strong motion monitoring station that consists of a three-component Analog Devices ADXLO5 accelerometer sensing unit, a vertical component weak motion sensor for system testing, a 16-bit digitizer with multiplexing, and communication output ports for RS232 modem or radio telemetry. The unit is battery-powered and will be sited in fire stations. The prototype central computer analysis system consists of a PC dam-acquisition platform that pipes the incoming strong motion data via Ethernet to Unix-based workstations for dam processing. Simple real-time algorithms, particularly for magnitude estimation, are implemented to give estimates of the time since the earthquake`s onset its hypocenter location, its magnitude, and the reliability of the estimate. These parameters are calculated and transmitted

  13. Geology, geochronology, and paleogeography of the southern Sonoma volcanic field and adjacent areas, northern San Francisco Bay region, California

    Science.gov (United States)

    Wagner, David L.; Saucedo, George J.; Clahan, Kevin B.; Fleck, Robert J.; Langenheim, Victoria E.; McLaughlin, Robert J.; Sarna-Wojcicki, Andrei M.; Allen, James R.; Deino, Alan L.

    2011-01-01

    Recent geologic mapping in the northern San Francisco Bay region (California, USA) supported by radiometric dating and tephrochronologic correlations, provides insights into the framework geology, stratigraphy, tectonic evolution, and geologic history of this part of the San Andreas transform plate boundary. There are 25 new and existing radiometric dates that define three temporally distinct volcanic packages along the north margin of San Pablo Bay, i.e., the Burdell Mountain Volcanics (11.1 Ma), the Tolay Volcanics (ca. 10–8 Ma), and the Sonoma Volcanics (ca. 8–2.5 Ma). The Burdell Mountain and the Tolay Volcanics are allochthonous, having been displaced from the Quien Sabe Volcanics and the Berkeley Hills Volcanics, respectively. Two samples from a core of the Tolay Volcanics taken from the Murphy #1 well in the Petaluma oilfield yielded ages of 8.99 ± 0.06 and 9.13 ± 0.06 Ma, demonstrating that volcanic rocks exposed along Tolay Creek near Sears Point previously thought to be a separate unit, the Donnell Ranch volcanics, are part of the Tolay Volcanics. Other new dates reported herein show that volcanic rocks in the Meacham Hill area and extending southwest to the Burdell Mountain fault are also part of the Tolay Volcanics. In the Sonoma volcanic field, strongly bimodal volcanic sequences are intercalated with sediments. In the Mayacmas Mountains a belt of eruptive centers youngs to the north. The youngest of these volcanic centers at Sugarloaf Ridge, which lithologically, chemically, and temporally matches the Napa Valley eruptive center, was apparently displaced 30 km to the northwest by movement along the Carneros and West Napa faults. The older parts of the Sonoma Volcanics have been displaced at least 28 km along the Rodgers Creek fault since ca. 7 Ma. The Petaluma Formation also youngs to the north along the Rodgers Creek–Hayward fault and the Bennett Valley fault. The Petaluma basin formed as part of the Contra Costa basin in the Late Miocene and

  14. Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay Coastal System

    Science.gov (United States)

    Barnard, Patrick L.; Foxgrover, Amy C.; Elias, Edwin P.L.; Erikson, Li H.; Hein, James R.; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Donald L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

  15. Ambient Greenhouse Gas (GHG) Observations in the San Francisco Bay Area of California Using a Fixed-site Monitoring Network

    Science.gov (United States)

    Martien, P. T.; Guha, A.; Bower, J.; Perkins, I.; Randall, S.; Young, A.; Hilken, H.; Stevenson, E.

    2016-12-01

    The Bay Area Air Quality Management District is the greater San Francisco Bay metropolitan area's chief air quality regulatory agency. Aligning itself with the Governor's Executive Order S-3-05, the Air District has set a goal to reduce the region's GHG emissions by 80% below 1990 levels by the year 2050. The Air District's 2016 Clean Air Plan will lay out the agency's vision and actions to put the region on a path forward towards achieving the 2050 goal while also reducing air pollution and related health impacts. The 2016 Plan has three overarching objectives: 1) develop a multi-pollutant emissions control strategy, (2) reduce population exposure to harmful air pollutants, especially in vulnerable communities, and (3) protect climate through a comprehensive Regional Climate Protection Strategy. To accomplish one of 2016 Plan's control measures (SL3 - Greenhouse Gas Monitoring and Measurement Network), the Air District has set up a long-term, ambient GHG monitoring network at four sites. The first site is located north and upwind of the urban core at Bodega Bay by the Pacific Coast. It mostly receives clean marine inflow and serves as the regional background site. The other three sites are strategically located at regional exit points for Bay Area plumes that presumably contain well-mixed GHG enhancements from local sources. CO2 and CH4are being measured continuously at the fixed-sites, along with combustion tracer CO and other air pollutants. In the longer term, the network will allow the Air District to monitor ambient concentrations of GHGs and thus evaluate the effectiveness of its policy, regulation and enforcement efforts. We present data trends from the first year of operation of the fixed-site monitoring network including monthly and seasonal patterns, diurnal variations and regional enhancements at individual sites above background concentrations. We also locate an isotopic methane instrument (Picarro, G132-i) for a short duration (a week) at each of the

  16. Final Environmental Assessment : Opening waterfowl hunting on 5,500 acres of former commercial salt ponds : Don Edwards San Francisco Bay National Wildlife Refuge : Alviso and Ravenswood Salt Ponds

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This EA for opening waterfowl hunting on salt ponds recently acquired by the Don Edwards San Francisco Bay National Wildlife Refuge proposes three alternatives....

  17. Selenium and stable isotopes of carbon and nitrogen in the benthic clam Corbula amurensis from Northern San Francisco Bay, California: May 1995-February 2010

    Science.gov (United States)

    Kleckner, Amy E.; Stewart, A. Robin; Luoma, Samuel N.

    2010-01-01

    The clam-based food webs of San Francisco Bay, California efficiently bioaccumlate selenium and thus provide pathways for exposure to predators important to the estuary. This study documents changes in monthly selenium concentrations for the clam Corbula amurensis, a keystone species of the estuary, at five locations in northern San Francisco Bay from 1995 through 2010. Samples were collected from designated U.S. Geological Survey stations and prepared and analyzed by U.S. Geological Survey methods. Stable isotopes of carbon and nitrogen in soft tissues of clams also were measured as an indicator of sources of selenium for the clams. These monitoring data indicate that clam selenium concentrations ranged from a low of 2 to a high of 22 micrograms per gram dry weight with strong spatial and seasonal variation over the period of study.

  18. Mercury concentrations and space use of pre-breeding American avocets and black-necked stilts in San Francisco Bay

    Science.gov (United States)

    Ackerman, Joshua T.; Eagles-Smith, Collin A.; Takekawa, John Y.; Demers, Scott A.; Adelsbach, Terrence L.; Bluso, J.D.; Miles, A. Keith; Warnock, Nils; Suchanek, Thomas H.; Schwarzbach, Steven E.

    2007-01-01

    We examined factors influencing mercury concentrations in pre-breeding American avocets (Recurvirostra americana) and black-necked stilts (Himantopus mexicanus), the two most abundant breeding shorebirds in San Francisco Bay, California. We tested the effects of species, site, sex, year, and date on total mercury concentrations in blood of pre-breeding adult birds and used radio telemetry to determine space use and sites of dietary mercury exposure. We collected blood from 373 avocets and 157 stilts from February to April in 2005 and 2006, radio-marked and tracked 115 avocets and 94 stilts, and obtained 2393 avocet and 1928 stilt telemetry locations. Capture site was the most important factor influencing mercury concentrations in birds, followed by species and sex. Mercury concentrations were higher in stilts (geometric mean: 1.09 μg g− 1 wet weight [ww]) than in avocets (0.25 μg g− 1 ww) and males (stilts: 1.32 μg g− 1 ww; avocets: 0.32 μg g− 1 ww) had higher levels than females (stilts: 1.15 μg g− 1 ww; avocets: 0.21 μg g− 1 ww). Mercury concentrations were highest for both species at the southern end of San Francisco Bay, especially in salt pond A8 (stilts: 3.31 μg g− 1 ww; avocets: 0.58 μg g− 1 ww). Radio telemetry data showed that birds had strong fidelity to their capture site. Avocets primarily used salt ponds, tidal marshes, tidal flats, and managed marshes, whereas stilts mainly used salt ponds, managed marshes, and tidal marshes. Our results suggest that variation in blood mercury concentrations among sites was attributed to differences in foraging areas, and species differences in habitat use and foraging strategies may increase mercury exposure in stilts more than avocets.

  19. Association of mercury and selenium with altered glutathione metabolism and oxidative stress in diving ducks from the San Francisco Bay region

    Science.gov (United States)

    Hoffman, D.J.; Ohlendorf, H.M.; Marn, C.M.; Pendleton, G.W.

    1998-01-01

    Adult male greater scaup (Aythya marila) (GS), surf scoters (Melanitta perspicillata)(SS), and ruddy ducks (Oxyura jamaicensis) (RD) were collected from Suisun Bay and coastal Tomales Bay in the greater San Francisco Bay area to assess exposure to inorganic contaminants. Hepatic selenium (Se) concentrations were highest in GS (geometric mean = 67 ppm, dw) and SS (119 ppm) in Suisun Bay, whereas hepatic mercury (Hg) was highest (19 ppm) in GS and SS from Tomales Bay. Hepatic Se and Hg were lower in RD and did not differ between locations. Hepatic supernatants were assayed for enzymes related to glutathione metabolism and antioxidant activity including: glucose-6-phosphate dehydrogenase (G-6-PDH), glutathione peroxidase (GSH-peroxidase), glutathione reductase (GSSG-reductase), and glutathione-S-transferase (GSH-transferase). GSH-peroxidase activity was higher in SS and RD, and G-6-PDH higher in GS and SS from Suisun Bay than Tomales Bay. GSSG-reductase was higher in SS from Suisun Bay. The ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH) was greater in all species from Tomales Bay. The following significant relationships were found in one or more species with increasing hepatic Hg concentration: lower body, liver and heart weights; decreased hepatic GSH concentration, G-6-PDH and GSH-peroxidase activities; increased ratio of GSSG to GSH, and increased GSSG-reductase activity. With increasing hepatic Se concentration, GSH-peroxidase increased but GSH decreased. It is concluded that measurement of associated enzymes in conjunction with thiol status may be a useful bioindicator to discriminate between Hg and Se effects. Concentrations of mercury and selenium and variable affected have been associated with adverse effects on reproduction and neurological function in experimental studies with mallards.

  20. The burden of liver cancer in Asians and Pacific Islanders in the Greater San Francisco Bay Area, 1990 through 2004.

    Science.gov (United States)

    Chang, Ellen T; Keegan, Theresa H M; Gomez, Scarlett L; Le, Gem M; Clarke, Christina A; So, Samuel K S; Glaser, Sally L

    2007-05-15

    To the authors' knowledge, no previous U.S. study has examined time trends in the incidence rate of liver cancer in the high-risk Asian/Pacific Islander population. In this study, liver cancer incidence trends were evaluated in Chinese, Filipino, Japanese, Korean, and Vietnamese men and women in the Greater San Francisco Bay Area of California between 1990 and 2004. Populations at risk were estimated by using the cohort-component demographic method. Annual percentage changes (APCs) in age-adjusted incidence rates of primary liver cancer among Asians/Pacific Islanders in the Greater Bay Area Cancer Registry were calculated by using joinpoint regression analysis. The incidence rate of liver cancer between 1990 and 2004 did not change significantly in Asian/Pacific Islander men or women overall. However, the incidence rate declined, although the decline was not statistically significant, among Chinese men (APC, -1.6%; 95% confidence interval [95% CI], -3.4-0.3%), Japanese men (APC, -4.9%; 95% CI, -10.7-1.2%), and Japanese women (APC, -3.6%; 95% CI, -8.9-2%). Incidence rates remained consistently high for Vietnamese, Korean, and Filipino men and women. Trends in the incidence rate of hepatocellular carcinoma were comparable to those for liver cancer. Although disparities in liver cancer incidence between Asians/Pacific Islanders and other racial/ethnic groups diminished between the period from 1990 through 1994 and the period from 2000 through 2004, the disparities among Asian subgroups increased. Liver cancer continues to affect Asian/Pacific Islander Americans disproportionately, with consistently high incidence rates in most subgroups. Culturally targeted prevention methods are needed to reduce the high rates of liver cancer in this growing population in the U.S. (c) 2007 American Cancer Society

  1. Impacts of representing sea-level rise uncertainty on future flood risks: An example from San Francisco Bay.

    Directory of Open Access Journals (Sweden)

    Kelsey L Ruckert

    Full Text Available Rising sea levels increase the probability of future coastal flooding. Many decision-makers use risk analyses to inform the design of sea-level rise (SLR adaptation strategies. These analyses are often silent on potentially relevant uncertainties. For example, some previous risk analyses use the expected, best, or large quantile (i.e., 90% estimate of future SLR. Here, we use a case study to quantify and illustrate how neglecting SLR uncertainties can bias risk projections. Specifically, we focus on the future 100-yr (1% annual exceedance probability coastal flood height (storm surge including SLR in the year 2100 in the San Francisco Bay area. We find that accounting for uncertainty in future SLR increases the return level (the height associated with a probability of occurrence by half a meter from roughly 2.2 to 2.7 m, compared to using the mean sea-level projection. Accounting for this uncertainty also changes the shape of the relationship between the return period (the inverse probability that an event of interest will occur and the return level. For instance, incorporating uncertainties shortens the return period associated with the 2.2 m return level from a 100-yr to roughly a 7-yr return period (∼15% probability. Additionally, accounting for this uncertainty doubles the area at risk of flooding (the area to be flooded under a certain height; e.g., the 100-yr flood height in San Francisco. These results indicate that the method of accounting for future SLR can have considerable impacts on the design of flood risk management strategies.

  2. Impacts of representing sea-level rise uncertainty on future flood risks: An example from San Francisco Bay.

    Science.gov (United States)

    Ruckert, Kelsey L; Oddo, Perry C; Keller, Klaus

    2017-01-01

    Rising sea levels increase the probability of future coastal flooding. Many decision-makers use risk analyses to inform the design of sea-level rise (SLR) adaptation strategies. These analyses are often silent on potentially relevant uncertainties. For example, some previous risk analyses use the expected, best, or large quantile (i.e., 90%) estimate of future SLR. Here, we use a case study to quantify and illustrate how neglecting SLR uncertainties can bias risk projections. Specifically, we focus on the future 100-yr (1% annual exceedance probability) coastal flood height (storm surge including SLR) in the year 2100 in the San Francisco Bay area. We find that accounting for uncertainty in future SLR increases the return level (the height associated with a probability of occurrence) by half a meter from roughly 2.2 to 2.7 m, compared to using the mean sea-level projection. Accounting for this uncertainty also changes the shape of the relationship between the return period (the inverse probability that an event of interest will occur) and the return level. For instance, incorporating uncertainties shortens the return period associated with the 2.2 m return level from a 100-yr to roughly a 7-yr return period (∼15% probability). Additionally, accounting for this uncertainty doubles the area at risk of flooding (the area to be flooded under a certain height; e.g., the 100-yr flood height) in San Francisco. These results indicate that the method of accounting for future SLR can have considerable impacts on the design of flood risk management strategies.

  3. Deep nirS amplicon sequencing of San Francisco Bay sediments enables prediction of geography and environmental conditions from denitrifying community composition.

    Science.gov (United States)

    Lee, Jessica A; Francis, Christopher A

    2017-12-01

    Denitrification is a dominant nitrogen loss process in the sediments of San Francisco Bay. In this study, we sought to understand the ecology of denitrifying bacteria by using next-generation sequencing (NGS) to survey the diversity of a denitrification functional gene, nirS (encoding cytchrome-cd 1 nitrite reductase), along the salinity gradient of San Francisco Bay over the course of a year. We compared our dataset to a library of nirS sequences obtained previously from the same samples by standard PCR cloning and Sanger sequencing, and showed that both methods similarly demonstrated geography, salinity and, to a lesser extent, nitrogen, to be strong determinants of community composition. Furthermore, the depth afforded by NGS enabled novel techniques for measuring the association between environment and community composition. We used Random Forests modelling to demonstrate that the site and salinity of a sample could be predicted from its nirS sequences, and to identify indicator taxa associated with those environmental characteristics. This work contributes significantly to our understanding of the distribution and dynamics of denitrifying communities in San Francisco Bay, and provides valuable tools for the further study of this key N-cycling guild in all estuarine systems. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Connecting Past to Present and Watersheds to Ocean: Modeling 165 Years of Incremental Changes to Flows into the San Francisco Bay Delta System

    Science.gov (United States)

    MacVean, L. J.; Thompson, S. E.; Huttom, P. H.; Sivapalan, M.

    2016-02-01

    California's Sacramento-San Joaquin Delta sits at the intersection of vast agricultural and population centers, and supplies fresh water for the diverse and often competing needs of ecosystems, farmers, and millions of Californians. Managing and allocating this resource is a complex feat of economics, politics, and engineering, made increasingly contentious by the ongoing drought. The objective of this research is to augment the scientific foundation of management decisions by addressing the question of how flows into the Delta have evolved in response to human intervention since 1850. In particular, quantifying the dynamic components of water usage through vegetative uptake and evapotranspiration, groundwater recharge, flood conveyance, and water exports at incremental levels of development is a key ambition. This approach emphasizes the built environment, which is subject to the local regulatory framework, rather than climate change, which is generally considered immovable without united global effort. This work encompasses the creation of a hydrologic model representing the watersheds of the San Francisco Bay-Delta system, and quantifies the impacts of changes in land use and the gradual construction of levees, reservoirs, and diversion infrastructure. The model is run using the same climatological forcing at each level of development, thus elucidating the effects of local anthropogenic activity on the Delta and the inflows to the San Francisco Bay estuary. Our results provide a timeline of change, giving decision-makers a scientifically established baseline to aid in the sustainable management of the Bay-Delta system.

  5. Novel analyses of long-term data provide a scientific basis for chlorophyll-a thresholds in San Francisco Bay

    Science.gov (United States)

    Sutula, Martha; Kudela, Raphael; Hagy, James D.; Harding, Lawrence W.; Senn, David; Cloern, James E.; Bricker, Suzanne B.; Beck, Marcus W.; Berg, Gry Mine

    2017-01-01

    San Francisco Bay (SFB), USA, is highly enriched in nitrogen and phosphorus, but has been resistant to the classic symptoms of eutrophication associated with over-production of phytoplankton. Observations in recent years suggest that this resistance may be weakening, shown by: significant increases of chlorophyll-a (chl-a) and decreases of dissolved oxygen (DO), common occurrences of phytoplankton taxa that can form Harmful Algal Blooms (HAB), and algal toxins in water and mussels reaching levels of concern. As a result, managers now ask: what levels of chl-a in SFB constitute tipping points of phytoplankton biomass beyond which water quality will become degraded, requiring significant nutrient reductions to avoid impairments? We analyzed data for DO, phytoplankton species composition, chl-a, and algal toxins to derive quantitative relationships between three indicators (HAB abundance, toxin concentrations, DO) and chl-a. Quantile regressions relating HAB abundance and DO to chl-a were significant, indicating SFB is at increased risk of adverse HAB and low DO levels if chl-a continues to increase. Conditional probability analysis (CPA) showed chl-a of 13 mg m−3 as a “protective” threshold below which probabilities for exceeding alert levels for HAB abundance and toxins were reduced. This threshold was similar to chl-a of 13–16 mg m−3 that would meet a SFB-wide 80% saturation Water Quality Criterion (WQC) for DO. Higher “at risk” chl-a thresholds from 25 to 40 mg m−3 corresponded to 0.5 probability of exceeding alert levels for HAB abundance, and for DO below a WQC of 5.0 mg L−1 designated for lower South Bay (LSB) and South Bay (SB). We submit these thresholds as a basis to assess eutrophication status of SFB and to inform nutrient management actions. This approach is transferrable to other estuaries to derive chl-a thresholds protective against eutrophication.

  6. Effects of the Blob on settlement of spotted sand bass, Paralabrax maculatofasciatus, to Mission Bay, San Diego, CA.

    Directory of Open Access Journals (Sweden)

    Anthony Basilio

    Full Text Available The West Coast of the United States experienced variable and sometimes highly unusual oceanographic conditions between 2012 and 2015. In particular, a warm mass of surface water known as the Pacific Warm Anomaly (popularly as "The Blob" impinged on southern California in 2014, and warm-water conditions remained during the 2015 El Niño. We examine how this oceanographic variability affected delivery and individual characteristics of larval spotted sand bass (Paralabrax maculatofasciatus to an estuarine nursery habitat in southern California. To quantify P. maculatofasciatus settlement patterns, three larval collectors were installed near the mouth of Mission Bay, San Diego CA, and retrieved weekly from June-October of 2012-2015. During 'Blob' conditions in 2014 and 2015, lower settlement rates of spotted sand bass were associated with higher sea surface temperature and lower wind speed, chlorophyll a (chl a and upwelling. Overall, the number of settlers per day peaked at intermediate chl a values across weeks. Individual characteristics of larvae that settled in 2014-2015 were consistent with a poor feeding environment. Although settlers were longer in length in 2014-15, fish in these years had slower larval otolith growth, a longer larval duration, and a trend towards lower condition, traits that are often associated with lower survival and recruitment. This study suggests that future settlement and recruitment of P. maculatofasciatus and other fishes with similar life histories may be adversely affected in southern California if ocean temperatures continue to rise in the face of climate change.

  7. Effects of the Blob on settlement of spotted sand bass, Paralabrax maculatofasciatus, to Mission Bay, San Diego, CA.

    Science.gov (United States)

    Basilio, Anthony; Searcy, Steven; Thompson, Andrew R

    2017-01-01

    The West Coast of the United States experienced variable and sometimes highly unusual oceanographic conditions between 2012 and 2015. In particular, a warm mass of surface water known as the Pacific Warm Anomaly (popularly as "The Blob") impinged on southern California in 2014, and warm-water conditions remained during the 2015 El Niño. We examine how this oceanographic variability affected delivery and individual characteristics of larval spotted sand bass (Paralabrax maculatofasciatus) to an estuarine nursery habitat in southern California. To quantify P. maculatofasciatus settlement patterns, three larval collectors were installed near the mouth of Mission Bay, San Diego CA, and retrieved weekly from June-October of 2012-2015. During 'Blob' conditions in 2014 and 2015, lower settlement rates of spotted sand bass were associated with higher sea surface temperature and lower wind speed, chlorophyll a (chl a) and upwelling. Overall, the number of settlers per day peaked at intermediate chl a values across weeks. Individual characteristics of larvae that settled in 2014-2015 were consistent with a poor feeding environment. Although settlers were longer in length in 2014-15, fish in these years had slower larval otolith growth, a longer larval duration, and a trend towards lower condition, traits that are often associated with lower survival and recruitment. This study suggests that future settlement and recruitment of P. maculatofasciatus and other fishes with similar life histories may be adversely affected in southern California if ocean temperatures continue to rise in the face of climate change.

  8. Serum biomarkers of polyfluoroalkyl compound exposure in young girls in Greater Cincinnati and the San Francisco Bay Area, USA.

    Science.gov (United States)

    Pinney, Susan M; Biro, Frank M; Windham, Gayle C; Herrick, Robert L; Yaghjyan, Lusine; Calafat, Antonia M; Succop, Paul; Sucharew, Heidi; Ball, Kathleen M; Kato, Kayoko; Kushi, Lawrence H; Bornschein, Robert

    2014-01-01

    PFC serum concentrations were measured in 6-8 year-old girls in Greater Cincinnati (GC) (N = 353) and the San Francisco Bay Area (SFBA) (N = 351). PFOA median concentration was lower in the SFBA than GC (5.8 vs. 7.3 ng/mL). In GC, 48/51 girls living in one area had PFOA concentrations above the NHANES 95th percentile for children 12-19 years (8.4 ng/mL), median 22.0 ng/mL. The duration of being breast fed was associated with higher serum PFOA at both sites and with higher PFOS, PFHxS and Me-PFOSA-AcOH concentrations in GC. Correlations of the PFC analytes with each other suggest that a source upriver from GC may have contributed to exposures through drinking water, and water treatment with granular activated carbon filtration resulted in less exposure for SWO girls compared to those in NKY. PFOA has been characterized as a drinking water contaminant, and water treatment systems effective in removing PFCs will reduce body burdens. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. The Conservation Contributions of Conservation Easements: Analysis of the San Francisco Bay Area Protected Lands Spatial Database

    Directory of Open Access Journals (Sweden)

    Adena R. Rissman

    2008-06-01

    Full Text Available Conservation easements have emerged as an important tool for land trusts and government agencies aiming to conserve private land in the United States. Despite the increase in public investment in conservation easement acquisitions, little is known about their conservation outcomes, particularly at a landscape scale. The nine-county San Francisco Bay Area exemplifies a complex conservation context: 190 organizations hold 24% of the land base in some type of protection status. Using a detailed protected lands database, we compared the contributions of conservation easements and fee-simple protected areas to ecological, agricultural, and public recreation benefits. We found that conservation easements were more likely to conserve grasslands, oak woodlands, and agricultural land, whereas fee-simple properties were more likely to conserve chaparral and scrub, redwoods, and urban areas. Conservation easements contributed to open space connectivity but were unlikely to be integrated into local land-use plans or provide public recreation. In particular, properties held by land trusts were less likely to allow for public recreation than were public lands. Conservation easements held by land trusts and special districts complemented fee-simple lands and provided greater conservation of some ecological communities and agricultural lands than fee-simple properties. Spatial databases of protected areas that include conservation easements are necessary for conservation planning and assessment.

  10. Ecosystem variability along the estuarine salinity gradient: Examples from long-term study of San Francisco Bay

    Science.gov (United States)

    Cloern, James E.; Jassby, Alan D.; Schraga, Tara; Kress, Erica S.; Martin, Charles A.

    2017-01-01

    The salinity gradient of estuaries plays a unique and fundamental role in structuring spatial patterns of physical properties, biota, and biogeochemical processes. We use variability along the salinity gradient of San Francisco Bay to illustrate some lessons about the diversity of spatial structures in estuaries and their variability over time. Spatial patterns of dissolved constituents (e.g., silicate) can be linear or nonlinear, depending on the relative importance of river-ocean mixing and internal sinks (diatom uptake). Particles have different spatial patterns because they accumulate in estuarine turbidity maxima formed by the combination of sinking and estuarine circulation. Some constituents have weak or no mean spatial structure along the salinity gradient, reflecting spatially distributed sources along the estuary (nitrate) or atmospheric exchanges that buffer spatial variability of ecosystem metabolism (dissolved oxygen). The density difference between freshwater and seawater establishes stratification in estuaries stronger than the thermal stratification of lakes and oceans. Stratification is strongest around the center of the salinity gradient and when river discharge is high. Spatial distributions of motile organisms are shaped by species-specific adaptations to different salinity ranges (shrimp) and by behavioral responses to environmental variability (northern anchovy). Estuarine spatial patterns change over time scales of events (intrusions of upwelled ocean water), seasons (river inflow), years (annual weather anomalies), and between eras separated by ecosystem disturbances (a species introduction). Each of these lessons is a piece in the puzzle of how estuarine ecosystems are structured and how they differ from the river and ocean ecosystems they bridge.

  11. Health cobenefits and transportation-related reductions in greenhouse gas emissions in the San Francisco Bay area.

    Science.gov (United States)

    Maizlish, Neil; Woodcock, James; Co, Sean; Ostro, Bart; Fanai, Amir; Fairley, David

    2013-04-01

    We quantified health benefits of transportation strategies to reduce greenhouse gas emissions (GHGE). Statistics on travel patterns and injuries, physical activity, fine particulate matter, and GHGE in the San Francisco Bay Area, California, were input to a model that calculated the health impacts of walking and bicycling short distances usually traveled by car or driving low-emission automobiles. We measured the change in disease burden in disability-adjusted life years (DALYs) based on dose-response relationships and the distributions of physical activity, particulate matter, and traffic injuries. Increasing median daily walking and bicycling from 4 to 22 minutes reduced the burden of cardiovascular disease and diabetes by 14% (32,466 DALYs), increased the traffic injury burden by 39% (5907 DALYS), and decreased GHGE by 14%. Low-carbon driving reduced GHGE by 33.5% and cardiorespiratory disease burden by less than 1%. Increased physical activity associated with active transport could generate a large net improvement in population health. Measures would be needed to minimize pedestrian and bicyclist injuries. Together, active transport and low-carbon driving could achieve GHGE reductions sufficient for California to meet legislative mandates.

  12. Sociodemographic Factors Associated With Trans*female Youth's Access to Health Care in the San Francisco Bay Area.

    Science.gov (United States)

    Johns, Elizabeth A; Jin, Harry; Auerswald, Colette L; Wilson, Erin C

    2017-08-01

    Trans*female youth (TFY) are an underserved population at risk for a variety of poor health outcomes, in part related to barriers to accessing health and mental health care. We conducted a secondary analysis of data collected with 250 TFY aged 16-24 years in the San Francisco Bay Area from 2012 to 2014. Logistic regression was used to test associations between sociodemographic variables and barriers to gender identity-based medical and mental health care. Having a history of unstable housing was associated with significantly higher odds of problems accessing both medical care (odds ratio: 2.16, 95% confidence interval: 1.12-4.13) and mental health care due to gender identity (odds ratio 2.65, 95% confidence interval: 1.08-6.45). Conversely, identifying as genderqueer/genderfluid, Latina, or living in dependent housing was associated with access to either medical or mental health care. Interventions are needed to address housing and discrimination barring access to health care among TFY. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  13. High-resolution remote sensing of water quality in the San Francisco Bay-Delta Estuary

    Science.gov (United States)

    Fichot, Cédric G.; Downing, Bryan D.; Bergamaschi, Brian; Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark C.; Thompson, David R.; Gierach, Michelle M.

    2015-01-01

    The San Francisco Bay–Delta Estuary watershed is a major source of freshwater for California and a profoundly human-impacted environment. The water quality monitoring that is critical to the management of this important water resource and ecosystem relies primarily on a system of fixed water-quality monitoring stations, but the limited spatial coverage often hinders understanding. Here, we show how the latest technology in visible/near-infrared imaging spectroscopy can facilitate water quality monitoring in this highly dynamic and heterogeneous system by enabling simultaneous depictions of several water quality indicators at very high spatial resolution. The airborne portable remote imaging spectrometer (PRISM) was used to derive high-spatial-resolution (2.6 × 2.6 m) distributions of turbidity, and dissolved organic carbon (DOC) and chlorophyll-a concentrations in a wetland-influenced region of this estuary. A filter-passing methylmercury vs DOC relationship was also developed using in situ samples and enabled the high-spatial-resolution depiction of surface methylmercury concentrations in this area. The results illustrate how high-resolution imaging spectroscopy can inform management and policy development in important inland and estuarine water bodies by facilitating the detection of point- and nonpoint-source pollution, and by providing data to help assess the complex impacts of wetland restoration and climate change on water quality and ecosystem productivity.

  14. Benthic Oxygen Demand in Three Former Salt Ponds Adjacent to South San Francisco Bay, California

    Science.gov (United States)

    Topping, Brent R.; Kuwabara, James S.; Athearn, Nicole D.; Takekawa, John Y.; Parcheso, Francis; Henderson, Kathleen D.; Piotter, Sara

    2009-01-01

    Sampling trips were coordinated in the second half of 2008 to examine the interstitial water in the sediment and the overlying bottom waters of three shallow (average depth 2 meters). The water column at all deployment sites was monitored with dataloggers for ancillary water-quality parameters (including dissolved oxygen, salinity, specific conductance, temperature, and pH) to facilitate the interpretation of benthic-flux results. Calculated diffusive benthic flux of dissolved (0.2-micron filtered) oxygen was consistently negative (that is, drawn from the water column into the sediment) and ranged between -0.5 x 10-6 and -37 x 10-6 micromoles per square centimeter per second (site averages depicted in table 2). Assuming pond areas of 1.0, 1.4, and 2.3 square kilometers for ponds A16, A14, and A3W, respectively, this converts to an oxygen mass flux into the ponds' sediment ranging from -1 to -72 kilograms per day. Diffusive oxygen flux into the benthos (listed as negative) was lowest in pond A14 (-0.5 x 10-6 to -1.8 x 10-6 micromoles per square centimeter per second) compared with diffusive flux estimates for ponds A16 and A3W (site averages -26 x 10-6 to -35 x 10-6 and -34 x 10-6 to -37 x 10-6 micromoles per square centimeter per second, respectively). These initial diffusive-flux estimates are of the order of magnitude of those measured in the South Bay using core-incubation experiments (Topping and others, 2004), which include bioturbation and bioirrigation effects. Estimates of benthic oxygen demand reported herein, based on molecular diffusion, serve as conservative estimates of benthic flux because solute transport across the sediment-water interface can be enhanced by multidisciplinary processes including bioturbation, bioirrigation, ground-water advection, and wind resuspension (Kuwabara and others, 2009).

  15. Greenhouse Gas (GHG) Source Detection and Attribution in the San Francisco Bay Area of California Using a Mobile Measurement Platform

    Science.gov (United States)

    Guha, A.; Bower, J.; Martien, P. T.; Perkins, I.; Randall, S.; Stevenson, E.; Young, A.; Hilken, H.

    2016-12-01

    The Bay Area Air Quality Management District is the greater San Francisco Bay metropolitan area's chief air quality regulatory agency. Aligning itself with the Governor's Executive Order S-3-05, the Air District has set a goal to reduce the region's GHG emissions by 80% below 1990 levels by the year 2050. The Air District's 2016 Clean Air Plan will lay out the agency's vision and actions to put the region on a path forward towards achieving the 2050 goal while also reducing air pollution and related health impacts. The 2016 Plan has three overarching objectives: 1) develop a multi-pollutant emissions control strategy, (2) reduce population exposure to harmful air pollutants, especially in vulnerable communities, and (3) protect climate through a comprehensive Regional Climate Protection Strategy. To accomplish one of 2016 Plan's control measures (SL3 - Greenhouse Gas Monitoring and Measurement Network), the Air District has fabricated a mobile measurement platform i.e. a GHG research van to perform targeted CH4 emissions hotspot detection and source attribution. The van is equipped with analyzers capable of measuring CH4, CO2 and N2O in ambient plumes at fast sampling rates. The coincident measurement of source tracers like isotopic methane (13C - CH4), CO and ethane (C2H6) provide the capability to distinguish between biogenic, combustion-based and fossil-based fugitive methane sources, respectively. The GHG research van is a comprehensive mobile tool to perform tracer-based GHG source identification and apportionment. We report observation-based source-specific tracer-to-tracer emission ratios from a region-wide survey of well-known area sources like landfills, wastewater treatment facilities and dairies, and compare those with similar ratios in the Air District's GHG inventory. We also investigate plumes from potentially under-inventoried sources like anaerobic digesters, composting operations, active and plugged oil and gas wells, and a natural gas storage

  16. Steam, solarization, and tons of prevention: the San Francisco Public Utilities Commission's fight to contain Phytophthoras in San Francisco Bay area restoration sites

    Science.gov (United States)

    Greg Lyman; Jessica Appel; Mia Ingolia; Ellen Natesan; Joe Ortiz

    2017-01-01

    To compensate for unavoidable impacts associated with critical water infrastructure capital improvement projects, the San Francisco Public Utilities Commission (SFPUC) restored over 2,050 acres of riparian, wetland, and upland habitat on watershed lands in Alameda, Santa Clara, and San Mateo Counties. Despite strict bio-sanitation protocols, plant pathogens (...

  17. High-resolution foraminiferal, isotopic, and trace element records from holocene estuarine deposits of San Francisco Bay, California

    Science.gov (United States)

    McGann, M.

    2008-01-01

    A 3.5-m gravity core (DJ6-93SF-6) from San Francisco Bay reveals a complex paleoclimatic history of the region over the last 3870 cal YBP. A polynomial equation based on 11 AMS 14C ages provides an excellent age model for the core, and environmental proxies for water temperature and salinity are derived from various foraminiferal abundances, stable carbon and oxygen isotopes, and Mg/Ca ratios. Two foraminiferal associations were identified by Q-mode cluster analysis: a colder-water Elphidium excavatum association and the warmer-water Ammonia beccarii-Elphidium gunteri association. The E. excavatum association dominates the core for all but about 600 years out of the last four millennia. At 3870 cal YBP, water temperatures were warm (13.9??C) and freshwater inflow was reduced compared with today. From 3590 to 2860 cal YBP, temperatures dropped 0.5??C and the climate remained dry. This was followed by a period of pronounced lower ??13C values, indicating that conditions became considerably wetter from 2860 to 2170 cal YBP. During this interval, the temperature oscillated frequently, peaking at 13.9??C at 2710 cal YBP, then dropping shortly thereafter to 12.8??C at 2420 cal YBP. Freshwater inflow gradually decreased between 2170 and 1950 cal YBP with a minimal rise in temperature, then changed quickly to colder and wetter conditions at 1900 cal YBP. Drier conditions then prevailed until 1480 cal YBP with water temperatures fluctuating between 13.1??C and 13.8??C, followed by wetter climate from 1480 to 1320 cal YBP. A significant faunal shift from the E. excavatum association to the A. beccarii-E. gunteri association occurred from 1250 to 650 cal YBP, possibly due to regional warming, decreased oxygen availability, and/or a change in the phyto-plankton community. Associated with this change in faunal composition were warm and dry conditions, representative of the Medieval Warm Period (Medieval Climatic Anomaly). A climatic shift coincident with the onset of the Little

  18. Sediment transport patterns in the San Francisco Bay Coastal System from cross-validation of bedform asymmetry and modeled residual flux

    Science.gov (United States)

    Barnard, Patrick L.; Erikson, Li H.; Elias, Edwin P.L.; Dartnell, Peter; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    The morphology of ~ 45,000 bedforms from 13 multibeam bathymetry surveys was used as a proxy for identifying net bedload sediment transport directions and pathways throughout the San Francisco Bay estuary and adjacent outer coast. The spatially-averaged shape asymmetry of the bedforms reveals distinct pathways of ebb and flood transport. Additionally, the region-wide, ebb-oriented asymmetry of 5% suggests net seaward-directed transport within the estuarine-coastal system, with significant seaward asymmetry at the mouth of San Francisco Bay (11%), through the northern reaches of the Bay (7–8%), and among the largest bedforms (21% for λ > 50 m). This general indication for the net transport of sand to the open coast strongly suggests that anthropogenic removal of sediment from the estuary, particularly along clearly defined seaward transport pathways, will limit the supply of sand to chronically eroding, open-coast beaches. The bedform asymmetry measurements significantly agree (up to ~ 76%) with modeled annual residual transport directions derived from a hydrodynamically-calibrated numerical model, and the orientation of adjacent, flow-sculpted seafloor features such as mega-flute structures, providing a comprehensive validation of the technique. The methods described in this paper to determine well-defined, cross-validated sediment transport pathways can be applied to estuarine-coastal systems globally where bedforms are present. The results can inform and improve regional sediment management practices to more efficiently utilize often limited sediment resources and mitigate current and future sediment supply-related impacts.

  19. How can climate change and engineered water conveyance affect sediment dynamics in the San Francisco Bay-Delta system?

    Science.gov (United States)

    Achete, Fernanda; Van der Wegen, Mick; Roelvink, Jan Adriaan; Jaffe, Bruce E.

    2017-01-01

    Suspended sediment concentration is an important estuarine health indicator. Estuarine ecosystems rely on the maintenance of habitat conditions, which are changing due to direct human impact and climate change. This study aims to evaluate the impact of climate change relative to engineering measures on estuarine fine sediment dynamics and sediment budgets. We use the highly engineered San Francisco Bay-Delta system as a case study. We apply a process-based modeling approach (Delft3D-FM) to assess the changes in hydrodynamics and sediment dynamics resulting from climate change and engineering scenarios. The scenarios consider a direct human impact (shift in water pumping location), climate change (sea level rise and suspended sediment concentration decrease), and abrupt disasters (island flooding, possibly as the results of an earthquake). Levee failure has the largest impact on the hydrodynamics of the system. Reduction in sediment input from the watershed has the greatest impact on turbidity levels, which are key to primary production and define habitat conditions for endemic species. Sea level rise leads to more sediment suspension and a net sediment export if little room for accommodation is left in the system due to continuous engineering works. Mitigation measures like levee reinforcement are effective for addressing direct human impacts, but less effective for a persistent, widespread, and increasing threat like sea level rise. Progressive adaptive mitigation measures to the changes in sediment and flow dynamics resulting from sea level rise may be a more effective strategy. Our approach shows that a validated process-based model is a useful tool to address long-term (decades to centuries) changes in sediment dynamics in highly engineered estuarine systems. In addition, our modeling approach provides a useful basis for long-term, process-based studies addressing ecosystem dynamics and health.

  20. A Trial of the Efficacy and Cost of Water Delivery Systems in San Francisco Bay Area Middle Schools, 2013.

    Science.gov (United States)

    Patel, Anisha I; Grummon, Anna H; Hampton, Karla E; Oliva, Ariana; McCulloch, Charles E; Brindis, Claire D

    2016-07-07

    US legislation requires that schools offer free drinking water where meals are served. However, little information is available about what types of water delivery systems schools should install to meet such requirements. The study objective was to examine the efficacy and cost of 2 water delivery systems (water dispensers and bottleless water coolers) in increasing students' lunchtime intake of water in low-income middle schools. In 2013, twelve middle schools in the San Francisco Bay Area participated in a cluster randomized controlled trial in which they received 6 weeks of promotional activities, received provision of cups, and were assigned to 1 of 2 cafeteria water delivery systems: water dispensers or bottleless water coolers (or schools served as a control). Student surveys (n = 595) and observations examined the interventions' effect on students' beverage intake and staff surveys and public data assessed intervention cost. Analysis occurred from 2013 through 2015. Mixed-effects logistic regression, accounting for clustering and adjustment for student sociodemographic characteristics, demonstrated a significant increase in the odds of students drinking water in schools with promotion plus water dispensers and cups (adjusted odds ratio = 3.1; 95% confidence interval, 1.4-6.7; P = .004) compared with schools with traditional drinking fountains and no cups or promotion. The cost of dispenser and bottleless water cooler programs was similar ($0.04 per student per day). Instead of relying on traditional drinking fountains, schools should consider installing water sources, such as plastic dispensers with cups, as a low-cost, effective means for increasing students' water intake.

  1. Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay

    Science.gov (United States)

    Takekawa, John Y.; Miles, A.K.; Tsao-Melcer, D. C.; Schoellhamer, D.H.; Fregien, S.; Athearn, N.D.

    2009-01-01

    Salt evaporation ponds have existed in San Francisco Bay, California, for more than a century. In the past decade, most of the salt ponds have been retired from production and purchased for resource conservation with a focus on tidal marsh restoration. However, large numbers of waterbirds are found in salt ponds, especially during migration and wintering periods. The value of these hypersaline wetlands for waterbirds is not well understood, including how different avian foraging guilds use invertebrate prey resources at different salinities and depths. The aim of this study was to investigate the dietary flexibility of waterbirds by examining the population number and diet of three feeding guilds across a salinity and depth gradient in former salt ponds of the Napa-Sonoma Marshes. Although total invertebrate biomass and species richness were greater in low than high salinity salt ponds, waterbirds fed in ponds that ranged from low (20 g l-1) to very high salinities (250 g l -1). American avocets (surface sweeper) foraged in shallow areas at pond edges and consumed a wide range of prey types (8) including seeds at low salinity, but preferred brine flies at mid salinity (40-80 g l-1). Western sandpipers (prober) focused on exposed edges and shoal habitats and consumed only a few prey types (2-4) at both low and mid salinities. Suitable depths for foraging were greatest for ruddy ducks (diving benthivore) that consumed a wide variety of invertebrate taxa (5) at low salinity, but focused on fewer prey (3) at mid salinity. We found few brine shrimp, common in higher salinity waters, in the digestive tracts of any of these species. Dietary flexibility allows different guilds to use ponds across a range of salinities, but their foraging extent is limited by available water depths. ?? 2009 USGS, US Government.

  2. Obesity and survival in population-based patients with pancreatic cancer in the San Francisco Bay Area.

    Science.gov (United States)

    Gong, Zhihong; Holly, Elizabeth A; Bracci, Paige M

    2012-12-01

    Obesity has been consistently associated with increased risk of pancreatic cancer incidence and mortality. However, studies of obesity and overall survival in patients with pancreatic cancer are notably lacking, especially in population-based studies. Active and passive follow-up were used to determine vital status and survival for 510 pancreatic cancer patients diagnosed from 1995 to 1999 in a large population-based case-control study in the San Francisco Bay Area. Survival rates were computed using Kaplan-Meier methods. Hazard ratios (HR) and 95 % confidence intervals (CI) were estimated in multivariable Cox proportional hazards models as measures of the association between pre-diagnostic obesity and pancreatic cancer survival. An elevated hazard ratio of 1.3 (95 % CI, 0.91-1.81) was observed for obese [body mass index (BMI) ≥ 30] compared with normal range BMI (patients. Associations between BMI and overall survival did not statistically significantly vary by known prognostic and risk factors (all p-interaction ≥0.18), yet elevated HRs consistently were observed for obese compared with normal BMI patients [localized disease at diagnosis (HR, 3.1), surgical resection (HR, 1.6), ever smokers (HR, 1.6), diabetics (HR, 3.3)]. Poor survival was observed among men, older patients, more recent and current smokers, whereas improved survival was observed for Asian/Pacific Islanders. Our results in general provide limited support for an association between pre-diagnostic obesity and decreased survival in patients with pancreatic cancer. Patterns of reduced survival associated with obesity in some patient subgroups could be due to chance and require assessment in larger pooled studies.

  3. Correlation Time of Ocean Ambient Noise Intensity in San Diego Bay and Target Recognition in Acoustic Daylight Images

    Science.gov (United States)

    Wadsworth, Adam J.

    A method for passively detecting and imaging underwater targets using ambient noise as the sole source of illumination (named acoustic daylight) was successfully implemented in the form of the Acoustic Daylight Ocean Noise Imaging System (ADONIS). In a series of imaging experiments conducted in San Diego Bay, where the dominant source of high-frequency ambient noise is snapping shrimp, a large quantity of ambient noise intensity data was collected with the ADONIS (Epifanio, 1997). In a subset of the experimental data sets, fluctuations of time-averaged ambient noise intensity exhibited a diurnal pattern consistent with the increase in frequency of shrimp snapping near dawn and dusk. The same subset of experimental data is revisited here and the correlation time is estimated and analysed for sequences of ambient noise data several minutes in length, with the aim of detecting possible periodicities or other trends in the fluctuation of the shrimp-dominated ambient noise field. Using videos formed from sequences of acoustic daylight images along with other experimental information, candidate segments of static-configuration ADONIS raw ambient noise data were isolated. For each segment, the normalized intensity auto-correlation closely resembled the delta function, the auto-correlation of white noise. No intensity fluctuation patterns at timescales smaller than a few minutes were discernible, suggesting that the shrimp do not communicate, synchronise, or exhibit any periodicities in their snapping. Also presented here is a ADONIS-specific target recognition algorithm based on principal component analysis, along with basic experimental results using a database of acoustic daylight images.

  4. Trajectory of early tidal marsh restoration: elevation, sedimentation and colonization of breached salt ponds in the northern San Francisco Bay

    Science.gov (United States)

    Brand, L. Arriana; Smith, Lacy M.; Takekawa, John Y.; Athearn, Nicole D.; Taylor, Karen; Shellenbarger, Gregory; Schoellhamer, David H.; Spenst, Renee

    2012-01-01

    Tidal marsh restoration projects that cover large areas are critical for maintaining target species, yet few large sites have been studied and their restoration trajectories remain uncertain. A tidal marsh restoration project in the northern San Francisco Bay consisting of three breached salt ponds (≥300 ha each; 1175 ha total) is one of the largest on the west coast of North America. These diked sites were subsided and required extensive sedimentation for vegetation colonization, yet it was unclear whether they would accrete sediment and vegetate within a reasonable timeframe. We conducted bathymetric surveys to map substrate elevations using digital elevation models and surveyed colonizing Pacific cordgrass (Spartina foliosa). The average elevation of Pond 3 was 0.96 ± 0.19 m (mean ± SD; meters NAVD88) in 2005. In 2008–2009, average pond elevations were 1.05 ± 0.25 m in Pond 3, 0.81 ± 0.26 m in Pond 4, and 0.84 ± 0.24 m in Pond 5 (means ± SD; meters NAVD88). The largest site (Pond 3; 508 ha) accreted 9.5 ± 0.2 cm (mean ± SD) over 4 years, but accretion varied spatially and ranged from sediment loss in borrow ditches and adjacent to an unplanned, early breach to sediment gains up to 33 cm in more sheltered regions. The mean elevation of colonizing S. foliosa varied by pond (F = 71.20, df = 84, P S. foliosa. Our results suggest that sedimentation to elevations that enable vegetation colonization is feasible in large sites with sufficient sediment loads although may occur more slowly compared with smaller sites.

  5. Ground-Water Quality Data in the San Francisco Bay Study Unit, 2007: Results from the California GAMA Program

    Science.gov (United States)

    Ray, Mary C.; Kulongoski, Justin T.; Belitz, Kenneth

    2009-01-01

    Ground-water quality in the approximately 620-square-mile San Francisco Bay study unit (SFBAY) was investigated from April through June 2007 as part of the Priority Basin project of the Ground-Water Ambient Monitoring and Assessment (GAMA) Program. The GAMA Priority Basin project was developed in response to the Groundwater Quality Monitoring Act of 2001, and is being conducted by the U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board (SWRCB). The study was designed to provide a spatially unbiased assessment of raw ground-water quality, as well as a statistically consistent basis for comparing water quality throughout California. Samples in SFBAY were collected from 79 wells in San Francisco, San Mateo, Santa Clara, Alameda, and Contra Costa Counties. Forty-three of the wells sampled were selected using a spatially distributed, randomized grid-based method to provide statistical representation of the study unit (grid wells). Thirty-six wells were sampled to aid in evaluation of specific water-quality issues (understanding wells). The ground-water samples were analyzed for a large number of synthetic organic constituents (volatile organic compounds [VOC], pesticides and pesticide degradates, pharmaceutical compounds, and potential wastewater-indicator compounds), constituents of special interest (perchlorate and N-nitrosodimethylamine [NDMA]), naturally occurring inorganic constituents (nutrients, major and minor ions, trace elements, chloride and bromide isotopes, and uranium and strontium isotopes), radioactive constituents, and microbial indicators. Naturally occurring isotopes (tritium, carbon-14 isotopes, and stable isotopes of hydrogen, oxygen, nitrogen, boron, and carbon), and dissolved noble gases (noble gases were analyzed in collaboration with Lawrence Livermore National Laboratory) also were measured to help identify the source and age of the sampled ground water. Quality-control samples (blank samples

  6. High resolution measurements of aseismic slip (creep) on the San Andreas fault system from Parkfield to San Francisco Bay area; 1966 to the present

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data provide measures of aseismic slip (creep) at approximately 40 sites located on the San Andreas, Hayward, and Calaveras faults in Central California from...

  7. The role of habitat-selection in restricting invasive blue mussel advancement to protect native populations in San Francisco Bay

    Science.gov (United States)

    Mittal, N.; Saarman, N. P.; Pogson, G.

    2013-12-01

    Introduced species contribute to decline of biodiversity and ecosystem services. Introduced species threaten native species by increasing competition for space and resources, changing their habitat, and disrupting species interactions. Protecting native species is crucial to preserving ecosystem services (i.e. medicinal, agricultural, ecological, and cultural benefits) for future generations. In marine communities, the number of invasive species is dramatically increasing every year, further magnifying the negative impact on native species. This research determines if habitat-specific selection can protect native species from their invasive relatives, and could allow targeted habitat restoration for native species to maintain high levels of biodiversity. Blue mussels provide an ideal system for studying the impact of an invasive species (Mytilus galloprovincialis) on native mussels (M. trossulus), because M. galloprovincialis is marked as one of the world's 100 worst invasive species. Hybridization between M. galloprovincialis and M. trossulus occurs wherever their distributions overlap (i.e. Japan, Puget Sound, and central California). In central California, hybrids form in a broad variety of habitats ever since M. galloprovincialis was introduced about 100 years ago. The current level of threat posed to native mussels in central California is unknown. When population growth rate of an invasive species is higher than the native within a hybrid zone, the invader's genes become more prominent in the hybrids than the native species' genes. This uneven mix of genes and decrease of pure native mussels threatens to drive M. trossulus to extinction. Therefore, it is important to research which environment fosters highest success of pure native species. We conducted a field experiment in San Francisco Bay where mussels were reared in different habitats. We then collected samples and extracted DNA from each treatment, and genotyped them by a next-generation sequencing

  8. Chronic sublethal effects of San Francisco Bay sediments on nereis (neanthes) arenaceodentata; effect of food ration on sediment toxicity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Moore, D.W.; Dillon, T.M.

    1993-09-01

    This report is designed to address concerns regarding the effect of food ration on toxicity during chronic sublethal sediment bioassays. To this end, a contaminated San Francisco Bay sediment and a clean control sediment were evaluated in a chronic sublethal test under a series of different food rations, with the marine polychaete worm Nereis (Neanthes) arenaceodentata. Animals were exposed from early juvenile stage through the onset of gametogenesis. Treatments were 2.OX, 1.OX, 0.5X, and 0.25X where X is the recommended food ration for laboratory cultures. Test end points were survival, growth, and reproduction. The contaminated sediment was a composite of several cores taken to project depth (38 ft (11.6 m) below mean low water mark) from an area in Oakland Inner Harbor known to be contaminated with polycyclic aromatic hydrocarbons and metals. Comparisons were made with a clean control sediment. The control sediment is used in the laboratory cultures of N. arenaceodentata and was collected from Sequim, WA. Mean percent survival of Neanthes was high (>90 percent) in both the contaminated and control sediment across all food ration treatments. Individual wet weights were significantly reduced with decreasing food ration in both contaminated and control sediments. Significant differences in wet weight between sediment types were observed at the 1.OX, 0.5X, and 0.25X rations. Reproduction (fecundity and emergent juvenile (EJ) production) was also Chronic sublethal, Neanthes, Dredged material, San Francisco Bay, Food ration, Sediment.

  9. Empirical relations to estimate underwater PAR attenuation in San Quintín Bay using Secchi depth and horizontal sighting range

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available Empirical relationships to estimate vertical attenuation coefficient of photosynthetically available radiation (KPAR using Secchi disk, vertical black disk, and horizontal sighting ranges for San Quintín Bay, Baja California, were developed. Radiometric PAR profiles were used to calculate KPAR. Vertical (ZD and horizontal (HS sighting ranges were measured with white (Secchi depth or ZSD, HSW and black (ZBD, HSB targets. The empirical power models KPAR = 1.48 ZSD –1.16, KPAR = 0.87 ZBD –1.52, KPAR = 0.54 HSW –0.65 and KPAR = 0.53 HSB –0.92 were developed for the corresponding relationships. The parameters of these models are not significantly different from those of models developed for Punta Banda Estuary, another Baja California lagoon, with the exception of the one for the KPAR-HSW relationship. Also, parameters of the KPAR-ZSD model for San Quintín Bay and Punta Banda Estuary are not significantly different from those developed for coastal waters near Santa Barbara, California. A set of general models is proposed that may apply to coastal water bodies of northwestern Baja California and southern California (KPAR = 1.45 ZSD –1.10, KPAR = 0.92 ZBD –1.45, and KPAR = 0.70 HSB –1.10. While this approach may be universal, more data are needed to explore the variability of the parameters between different water bodies.

  10. Stable hydrogen and oxygen isotopes of tap water reveal structure of the San Francisco Bay Area's water system and adjustments during a major drought.

    Science.gov (United States)

    Tipple, Brett J; Jameel, Yusuf; Chau, Thuan H; Mancuso, Christy J; Bowen, Gabriel J; Dufour, Alexis; Chesson, Lesley A; Ehleringer, James R

    2017-08-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. Water demands and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between urban centers, water transport and usage, and the impacts of climate change on water resources. To assess if stable hydrogen and oxygen isotope ratios could increase the understanding of these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters across the San Francisco Bay Area during seven collection campaigns spanning 21 months during 2013-2015. The San Francisco Bay Area was selected as it has well-characterized water management strategies and the 2012-2105 California Drought dramatically affected its water resources. Consistent with known water management strategies and previously collected isotope data, we found large spatiotemporal variations in the δ2H and δ18O values of tap waters within the Bay Area. This is indicative of complex water transport systems and varying municipality-scale management decisions. We observed δ2H and δ18O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of the isotope data collected in this study grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Various management responses to the drought, such as source

  11. Application of an unstructured 3D finite volume numerical model to flows and salinity dynamics in the San Francisco Bay-Delta

    Science.gov (United States)

    Martyr-Koller, R. C.; Kernkamp, H. W. J.; van Dam, A.; van der Wegen, M.; Lucas, L. V.; Knowles, N.; Jaffe, B.; Fregoso, T. A.

    2017-06-01

    A linked modeling approach has been undertaken to understand the impacts of climate and infrastructure on aquatic ecology and water quality in the San Francisco Bay-Delta region. The Delft3D Flexible Mesh modeling suite is used in this effort for its 3D hydrodynamics, salinity, temperature and sediment dynamics, phytoplankton and water-quality coupling infrastructure, and linkage to a habitat suitability model. The hydrodynamic model component of the suite is D-Flow FM, a new 3D unstructured finite-volume model based on the Delft3D model. In this paper, D-Flow FM is applied to the San Francisco Bay-Delta to investigate tidal, seasonal and annual dynamics of water levels, river flows and salinity under historical environmental and infrastructural conditions. The model is driven by historical winds, tides, ocean salinity, and river flows, and includes federal, state, and local freshwater withdrawals, and regional gate and barrier operations. The model is calibrated over a 9-month period, and subsequently validated for water levels, flows, and 3D salinity dynamics over a 2 year period. Model performance was quantified using several model assessment metrics and visualized through target diagrams. These metrics indicate that the model accurately estimated water levels, flows, and salinity over wide-ranging tidal and fluvial conditions, and the model can be used to investigate detailed circulation and salinity patterns throughout the Bay-Delta. The hydrodynamics produced through this effort will be used to drive affiliated sediment, phytoplankton, and contaminant hindcast efforts and habitat suitability assessments for fish and bivalves. The modeling framework applied here will serve as a baseline to ultimately shed light on potential ecosystem change over the current century.

  12. Application of an unstructured 3D finite volume numerical model to flows and salinity dynamics in the San Francisco Bay-Delta

    Science.gov (United States)

    Martyr-Koller, R.C.; Kernkamp, H.W.J.; Van Dam, Anne A.; Mick van der Wegen,; Lucas, Lisa; Knowles, N.; Jaffe, B.; Fregoso, T.A.

    2017-01-01

    A linked modeling approach has been undertaken to understand the impacts of climate and infrastructure on aquatic ecology and water quality in the San Francisco Bay-Delta region. The Delft3D Flexible Mesh modeling suite is used in this effort for its 3D hydrodynamics, salinity, temperature and sediment dynamics, phytoplankton and water-quality coupling infrastructure, and linkage to a habitat suitability model. The hydrodynamic model component of the suite is D-Flow FM, a new 3D unstructured finite-volume model based on the Delft3D model. In this paper, D-Flow FM is applied to the San Francisco Bay-Delta to investigate tidal, seasonal and annual dynamics of water levels, river flows and salinity under historical environmental and infrastructural conditions. The model is driven by historical winds, tides, ocean salinity, and river flows, and includes federal, state, and local freshwater withdrawals, and regional gate and barrier operations. The model is calibrated over a 9-month period, and subsequently validated for water levels, flows, and 3D salinity dynamics over a 2 year period.Model performance was quantified using several model assessment metrics and visualized through target diagrams. These metrics indicate that the model accurately estimated water levels, flows, and salinity over wide-ranging tidal and fluvial conditions, and the model can be used to investigate detailed circulation and salinity patterns throughout the Bay-Delta. The hydrodynamics produced through this effort will be used to drive affiliated sediment, phytoplankton, and contaminant hindcast efforts and habitat suitability assessments for fish and bivalves. The modeling framework applied here will serve as a baseline to ultimately shed light on potential ecosystem change over the current century.

  13. Agricultural Chemical Concentrations and Loads in Rivers Draining the Central Valley, California, to the San Francisco Bay-Delta Estuary: Before and During an Extended Drought

    Science.gov (United States)

    Domagalski, J. L.

    2016-12-01

    Drought or near drought conditions have occurred in California since 2012. Although some parts of the State received near normal precipitation in water year 2016, other locations were still below average. Extended drought can impact aquatic organisms in a variety of ways because of decreased flows and elevated water temperature. However, lower precipitation and availability of irrigation water may limit subsequent runoff, resulting in reduced concentrations and loads of certain environmental toxicants, such as pesticides and ammonia, thereby limiting their toxic effects. In this study, funded by the U.S. Geological Survey National Water Quality Program, the occurrence of 227 pesticides and degradation products, and nutrients was assessed before and during this current drought in the two largest rivers draining to the San Francisco Bay: the Sacramento and San Joaquin Rivers. The watersheds of both rivers include substantial agricultural and urban land use. Herbicides, insecticides, fungicides, and ammonia were detected throughout the study (2010 to 2016) and models of daily concentration using the seasonal wave model (rloadest) were formulated to assess the amount of time that concentrations may have exceeded benchmark levels known to be toxic to aquatic organisms. Frequently detected pesticides included the fungicide azoxystrobin, herbicides or their degradation products such as diuron, glyphosate, and metolachlor, and insecticides such as imidacloprid. Compounds that are transported primarily by surface runoff generally showed decreasing concentrations as the drought progressed, especially in the San Joaquin River. Compounds mainly transported by groundwater, as indicated by seasonal concentration profiles, had more stable concentrations in the rivers. Mass loads to the Bay all decreased, as expected, because of the lower river discharge. When compared to aquatic-life benchmarks, modeled concentrations indicated that individual compounds were not contributing to

  14. U.S. EPA honors San Francisco Bay Area firm Hybrid Coating Technologies with Green Chemistry Award

    Science.gov (United States)

    SAN FRANCISCO - Today the U.S. Environmental Protection Agency recognized Hybrid Coating Technologies of Daly City, Calif. with a Presidential Green Chemistry Award for developing a safer, plant-based polyurethane for use on floors, furniture and in

  15. Handbook of Techniques and Guides for the Study of the San Francisco Bay-Delta-Estuary Complex, Part 1. Monitoring Techniques for the Measurement of Physico-Chemical and Biological Parameters.

    Science.gov (United States)

    Alameda County School Dept., Hayward, CA.

    Project MER (Marine Ecology Research) is aimed at improving environmental education in the San Francisco Bay Area schools. As part of meeting this goal, it is hoped that students and teachers can see the results of their efforts being put to practical use. This guide is the first of a series produced to help the students and teachers gather data…

  16. A Global Talent Magnet: How a San Francisco/Bay Area Global Higher Education Hub Could Advance California's Comparative Advantage in Attracting International Talent and Further Build US Economic Competitiveness. Research & Occasional Paper Series: CSHE.9.11

    Science.gov (United States)

    Douglass, John; Edelstein, Richard; Hoareau, Cecile

    2011-01-01

    During the 2009-10 academic year international students generated more than $18.8 billion in net income into the US economy. California alone had nearly 100,000 international students with an economic impact of nearly $3.0 billion. In this paper, we outline a strategy for the San Francisco/Bay Area to double the number of international students…

  17. 75 FR 38412 - Safety Zone; San Diego POPS Fireworks, San Diego, CA

    Science.gov (United States)

    2010-07-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego POPS Fireworks, San Diego, CA... zone on the ] navigable waters of San Diego Bay in support of the San Diego POPS Fireworks. This safety... San Diego POPS Fireworks, which will include fireworks presentations conducted from a barge in San...

  18. Executive summary: Benefit-cost evaluation of an intra-regional air service in the Bay Area and a technology assessment of transportation system investments. [regional planning for the San Francisco Bay area of California

    Science.gov (United States)

    Haefner, L. E.

    1978-01-01

    The benefits and costs that would result from an intra-regional air service operation in the San Francisco Bay area were determined by utilizing an iterative statistical decision model to evaluate combinations of commuter airport sites and surface transportation facilities in conjunction with service by a given commuter aircraft type in light of area regional growth alternatives and peak and off-peak regional travel patterns. The model evaluates such transportation option with respect to criteria of airline profitability, public acceptance, and public and private non-user costs. In so doing, it incorporates information on modal split, peak and off-peak use of the air commuter fleet, terminal and airport costs, development costs and uses of land in proximity to the airport sites, regional population shifts, and induced zonal shifts in travel demand. The model is multimodal in its analytic capability, and performs exhaustive sensitivity analysis.

  19. Groundwater-quality data in the North San Francisco Bay Shallow Aquifer study unit, 2012: results from the California GAMA Program

    Science.gov (United States)

    Bennett, George L.; Fram, Miranda S.

    2014-01-01

    Groundwater quality in the 1,850-square-mile North San Francisco Bay Shallow Aquifer (NSF-SA) study unit was investigated by the U.S. Geological Survey (USGS) from April to August 2012, as part of the California State Water Resources Control Board (SWRCB) Groundwater Ambient Monitoring and Assessment (GAMA) Program’s Priority Basin Project (PBP). The GAMA-PBP was developed in response to the California Groundwater Quality Monitoring Act of 2001 and is being conducted in collaboration with the SWRCB and Lawrence Livermore National Laboratory (LLNL). The NSF-SA study unit was the first study unit to be sampled as part of the second phase of the GAMA-PBP, which focuses on the shallow aquifer system.

  20. Unevenness in Health at the Intersection of Gender and Sexuality: Sexual Minority Disparities in Alcohol and Drug Use Among Transwomen in the San Francisco Bay Area.

    Science.gov (United States)

    Arayasirikul, Sean; Pomart, W Andres; Raymond, H Fisher; Wilson, Erin C

    2018-01-01

    Research on the health of transwomen is largely focused on heterosexual HIV risk. Little is known about the health of sexual minority transwomen. We conducted a secondary cross-sectional analysis of data from a HIV risk and resilience study of transwomen aged 16 to 24 years in the San Francisco Bay Area (N = 259). Prevalence and demographic characteristics of sexual minority transwomen was assessed and logistic regression models were used to examine the relationship between sexual minority status and alcohol and drug use. In logistic regression models, sexual minority transwomen had greater fold odds of heavy episodic drinking and illicit prescription drug use compared to their heterosexual counterparts, controlling for race/ethnicity, age, income, nativity, hormone status, and history of feminization procedures. These results suggest that sexual minority status may be an important social determinant of health among gender minorities. Populations of transwomen are heterogeneous; effective interventions must consider sexual minority status.

  1. Swath Bathymetry Surveys of the Monterey Bay Area from Point Ano Nuevo to Moss Landing, San Mateo, Santa Cruz, and Monterey Counties, California

    Science.gov (United States)

    Ritchie, Andrew C.; Finlayson, David P.; Logan, Joshua B.

    2010-01-01

    This report describes swath bathymetry and backscatter data acquired by the U.S. Geological Survey on the continental shelf within the Monterey Bay National Marine Sanctuary between Point A?o Nuevo and Moss Landing, in San Mateo, Santa Cruz, and Monterey Counties, Calif. The survey was done for the California Seafloor Mapping Program (CSMP), in field activities S-7-09-MB and S-10-09-MB, by the Western Coastal and Marine Geology (WCMG) Team of the U.S. Geological Survey (USGS). The data were aquired in two seperate surveys: (1) between August 13, 2009 and September 3, 2009, personnel from WCMG completed field activity S-7-09-MB, from Point A?o Nuevo south to Table Rock, as well as a block west of Soquel Canyon; (2) between October 12 and December 16, 2009, WCMG conducted field activity S-10-09-MB, surveying between Table Rock and Moss Landing.

  2. Is drinking water a risk factor for endemic cryptosporidiosis? A case-control study in the immunocompetent general population of the San Francisco Bay Area

    Directory of Open Access Journals (Sweden)

    Nadle Joelle

    2003-03-01

    Full Text Available Abstract Background Cryptosporidiosis, caused by Cryptosporidium, is an enteric illness that has received much attention as an infection of immunocompromised persons as well as in community outbreaks (frequently waterborne. There are, however, no studies of the risk factors for sporadic community-acquired cryptosporidiosis in the immunocompetent US population. We undertook a case-control study in the San Francisco Bay Area as part of a national study sponsored by the Centers for Disease Control and Prevention to ascertain the major routes of transmission for endemic cryptosporidiosis, with an emphasis on evaluating risk from drinking water. Methods Cases were recruited from a population-based, active surveillance system and age-matched controls were recruited using sequential random-digit dialing. Cases (n = 26 and controls (n = 62 were interviewed by telephone using a standardized questionnaire that included information about the following exposures: drinking water, recreational water, food items, travel, animal contact, and person-to-person fecal contact, and (for adults sexual practices. Results In multivariate conditional logistic regression analyses no significant association with drinking water was detected. The major risk factor for cryptosporidiosis in the San Francisco Bay Area was travel to another country (matched odds ratio [95% confidence interval]: 24.1 [2.6, 220]. Conclusion The results of this study do not support the hypothesis that drinking water is an independent risk factor for cryptosporidiosis among the immunocompetent population. These findings should be used to design larger studies of endemic cryptosporidiosis to elucidate the precise mechanisms of transmission, whether waterborne or other.

  3. The influence of salinity and restoration on wetland soil microbial communities and carbon cycling in the San Francisco Bay-Delta Region

    Science.gov (United States)

    Theroux, S.; Hartman, W.; He, S.; Windham-Myers, L.; Tringe, S. G.

    2014-12-01

    Climate change is predicted to increase the average salinity of the San Francisco Bay-Delta watershed as sea levels rise and alpine snow volume decreases. Wetland soil microbial communities are responsible for cycling greenhouse gases and their response to climate change will heavily influence whether increasing salinity will have a negative or positive effect on the net greenhouse gas budgets of wetlands. To better understand the underlying factors determining the balance of greenhouse gas flux in wetland soils, we targeted the microbial communities along a salinity gradient ranging from freshwater to full seawater in the San Francisco Bay-Delta region. Using DNA and RNA sequencing, coupled with greenhouse gas monitoring, we sampled sixteen sites capturing a range of wetland plant types and restoration states. We determined a suite of soil biogeochemical parameters including moisture, carbon and nutrient contents, pH, sulfate, chloride, and trace metal concentrations. The results of our microbial diversity survey (16S rRNA gene Illumina tag sequencing) showed that salinity and sampling location were the primary drivers of belowground microbial community composition. Freshwater wetland soils, with lower sulfate concentrations, produced more methane than saline sites and we found a parallel increase in the relative abundance of methanogen populations in the high-methane samples. Surprisingly, wetland restoration status did not significantly alter microbial community composition, despite orders of magnitude greater methane flux in restored wetlands compared to reference sites. Deeper metagenomic and metatranscriptomic sequencing in a restored wetland allowed us to further evaluate the roles of methanogen abundance and activity in shaping soil methane production. Our study links belowground microbial communities with their greenhouse gas production, providing a mechanistic microbial framework for assessing climate change feedbacks in wetland soils resulting from sea

  4. Secular changes in the tidal constituents in San Francisco Bay originated by the California Gold Rush and major dam-building projects

    Science.gov (United States)

    Rodríguez, I.; Ortiz, M.

    2015-12-01

    Hourly sea-level records for the time period of 1901 to 2012 at Fort Point tidal station in San Francisco Bay are analyzed in an attempt to find the origin of the secular changes found in the tidal constituents. Complex demodulation implemented with a low pass filter window of 8760 hours was employed to extract the amplitude and phase of the principal tidal constituent M2 as a function of time. The 18.6 year nodal signal was removed by using the tide potential of the equilibrium tide. The results show significant trends up to 4 cm in amplitude as well as phase shifts of 17 minutes per century. Moreover, yearly amplitude variations of M2 show to be inversely correlated to river flow discharge. On the other hand, the results of a simplified two-layer numerical hydrodynamic model indicate that long-term tide variations are directly related to the morphological evolution of a sandbank located outside the bay surrounding its entrance, acting as a hydraulic control for the whole bay. According to historical results, the sandbank reached its shallowest depth during the California Gold Rush (1848-1884), when mining debris together with large amounts of sediment were deposited into the estuary. After the Central Valley Water Project was approved (1933), many dams were built decreasing significantly the sediment supply. With the passage of time, the gradual loss of sedimentation also diminished the sandbank, increasing its depth. This fact explains the observed secular long-term advance of the tidal phase, as well as the increasing trend of the M2 amplitude.

  5. MEDIA ADVISORY: EPA Administrator joins San Francisco Bay government agencies to celebrate nations largest solar energy partnership

    Science.gov (United States)

    SAN FRANCISCO - On May 13, U.S. EPA Administrator Gina McCarthy will join Alameda County to recognize the largest collaborative in the nation among government agencies to site renewable energy at their facilities. Administrator McCarthy, the federal

  6. 78 FR 34582 - Safety Zone; Fourth of July Fireworks, City of Sausalito, San Francisco Bay, Sausalito, CA

    Science.gov (United States)

    2013-06-10

    ... the Captain of the Port, San Francisco area of responsibility during the dates and times noted below. This action is necessary to protect life and property of the maritime public from the hazards... direction. The PATCOM is empowered to forbid entry into and control the regulated area. The PATCOM shall be...

  7. Monitoring the Northern San Francisco Bay Water Quality with Landsat-8. Nicholas B. Tufillaroa , and Curtiss O. Davisa. aOregon State University, Corvallis, OR, 97331, USA, nbt@coas.oregonstate.edu

    Science.gov (United States)

    Davis, C. O.; Tufillaro, N.

    2016-02-01

    Landsat-8's high spatial resolution ( 30 nm nominal), improved signal-to-noise (12bit digitizer) and expanded band set open up new applications for coastal and in-land waters. We use a recent ocean color processor for Landsat-8 created by Vanhellemont and Ruddick (RSE, 2015)to examine changes in the Northern San Francisco Bay, in particular looking for possiblechanges due to the on-going California drought. For instance, a temporary drought barrier to prevent salt water intrusion was placed during May of 2015 at West False River in the Sacramento-San Joaquin Delta. Using the new Landsat-8 ocean color products, we illustrate how to monitor changes in macro algae and plants (Sago pondweed (native), Curly pondweed (non-native)) in regions directly effected,such as the Franks Track region. Product maps using panchromatic enhancement ( 15 m resolution) andscene based atmospheric correction allow a detailed synoptic look every 16 days during theSpring, Summer, and Fall of 2015. This work is part of a larger NASA funded project aimed atimproving the modeling and predictive capabilities of the biogeochemical state for the San Francisco Bay(Davis, PI: Impacts of Population Growth on the San Francisco Bay and Delta Ecosystem, 2014-2017).

  8. Use of dissolved inorganic carbon isotopes to track photosynthesis, respiration, and nitrification along a 56 mile transect in the Sacramento River and San Francisco Bay

    Science.gov (United States)

    Silva, S. R.; Kendall, C.; Peek, S.; Young, M. B.

    2013-12-01

    A decline in phytoplankton stocks in the San Francisco Bay and Delta is thought to contribute to the pelagic organism decline observed over the past two decades. One factor controlling phytoplankton growth rate is the availability of nutrients. Although there is an excess of nutrients in the Bay and Delta, the type and relative abundance of nutrients is critical to phytoplankton growth. To evaluate the response of phytoplankton to nutrient sources and to better understand phytoplankton dynamics downstream, we tested the hypothesis that the δ13C values of dissolved inorganic carbon (DIC) along with conventional water chemistry analyses will record events such as increased nitrification (related to the Sacramento River Wastewater Treatment Plant ammonium input) and algal blooms, and reflect the balance between photosynthesis and bacterial respiration. Multiple parameters affect [DIC] and its δ13C, including DIC sources, pH, and biological processes. Consumption of CO2 by phytoplankton during photosynthesis and by autotrophic bacteria during nitrification both result in increases in δ13C-DIC. However, photosynthesis and nitrification have very different relationships to chlorophyll and nutrient concentrations. The balance between heterotrophic bacterial respiration and photosynthesis should be reflected in trends in DIC, nutrient, and chlorophyll concentration, and δ13C-DIC. The δ13C of DIC should also be reflected in the δ13C of phytoplankton with approximately a 20 per mil fractionation. Significant deviation in the fractionation factor may indicate local variations in growth rate, nutrient availability, or speciation. Combined, these parameters should provide a gauge of the relative importance of the above mentioned processes. To test this hypothesis, we collected 19 water samples per cruise between July 2012 and July 2013 along a 56 mile transect between Rio Vista on the Sacramento River and San Francisco Bay near Angel Island during 8 cruises on the USGS RV

  9. San Francisco Bay to Stockton, California Project. Environmental Impact Statement. John F. Baldwin Ship Channel. Phase II. Richmond Harbor Approach.

    Science.gov (United States)

    1984-05-01

    anadromous fish species associated with the rivers and streams of the Central Valley must swim through the project area or adjacent waters within Central...arthropods (i.e., amphipods, isopods), jellyfish , horse mussel, basket cockle, Japanese cockle, softshelled clam, Franciscan bay shrimp, black-tailed...1975) investigated the behavior of the dumped material as a function of sediment type, water type, vessel configuration, water depth, percent sediment

  10. Evaluating Tidal Marsh Sustainability in the Face of Sea-Level Rise: A Hybrid Modeling Approach Applied to San Francisco Bay

    Science.gov (United States)

    Stralberg, Diana; Brennan, Matthew; Callaway, John C.; Wood, Julian K.; Schile, Lisa M.; Jongsomjit, Dennis; Kelly, Maggi; Parker, V. Thomas; Crooks, Stephen

    2011-01-01

    Background Tidal marshes will be threatened by increasing rates of sea-level rise (SLR) over the next century. Managers seek guidance on whether existing and restored marshes will be resilient under a range of potential future conditions, and on prioritizing marsh restoration and conservation activities. Methodology Building upon established models, we developed a hybrid approach that involves a mechanistic treatment of marsh accretion dynamics and incorporates spatial variation at a scale relevant for conservation and restoration decision-making. We applied this model to San Francisco Bay, using best-available elevation data and estimates of sediment supply and organic matter accumulation developed for 15 Bay subregions. Accretion models were run over 100 years for 70 combinations of starting elevation, mineral sediment, organic matter, and SLR assumptions. Results were applied spatially to evaluate eight Bay-wide climate change scenarios. Principal Findings Model results indicated that under a high rate of SLR (1.65 m/century), short-term restoration of diked subtidal baylands to mid marsh elevations (−0.2 m MHHW) could be achieved over the next century with sediment concentrations greater than 200 mg/L. However, suspended sediment concentrations greater than 300 mg/L would be required for 100-year mid marsh sustainability (i.e., no elevation loss). Organic matter accumulation had minimal impacts on this threshold. Bay-wide projections of marsh habitat area varied substantially, depending primarily on SLR and sediment assumptions. Across all scenarios, however, the model projected a shift in the mix of intertidal habitats, with a loss of high marsh and gains in low marsh and mudflats. Conclusions/Significance Results suggest a bleak prognosis for long-term natural tidal marsh sustainability under a high-SLR scenario. To minimize marsh loss, we recommend conserving adjacent uplands for marsh migration, redistributing dredged sediment to raise elevations, and

  11. Tracing Sources and Biogeochemical Cycling of Ammonium and Nitrate in the Sacramento River and northern San Francisco Bay using Stable Isotope Techniques

    Science.gov (United States)

    Kendall, C.; Young, M. B.; Silva, S. R.; Kraus, T. E.; Parker, A. E.

    2009-12-01

    One of the potential causes of declines in several species of fish in the San Francisco Bay Estuary ecosystem is NH4-inhibition of algal productivity in the Delta and Suisun Bay, which is hypothesized to cause pelagic organism decline via cascading trophic interactions. Hence, there is considerable interest in determining the relative contributions of NH4 from waste water treatment plants (WWTPs) and from other kinds of agricultural, wetlands, and urban land uses to the ecosystem, and evaluating their effects on algal growth. N cycling within the ecosystem, including mineralization of organic N, nitrification, assimilation of NH4 and NO3, and other processes might mask the effects of specific sources and control the concentrations and speciation of N. Hence, there is a need for better understanding of N dynamics as well as sources in this ecosystem. To address these issues, we have employed a multi-isotope approach to investigate N source, fate, and transport in the Sacramento River, Delta, and northern Bay. Approximately 25 samples were collected during each of 3 transects along a 100 mile section of the ecosystem in 2008-2009, and analyzed for nutrients, chlorophyll, various physical parameters, NH4-δ15N, NO3-δ15N and δ18O, DIC-δ13C, DOC-δ13C, water-δ18O and δ2H, and seston-δ15N, δ13C, δ34S, and C:N. These data showed many distinctive downstream changes. In particular, NH4 concentrations increased sharply downstream of the Sacramento WWTP, and remained high for over 20 miles before starting a steady decline at ~20 miles upstream of the confluence. The decline in NH4 is mirrored by an increase in NO3 concentrations, and the changes in isotopic composition confirmed that the dominant N cycling process in this reach of the river was nitrification. NH4-δ15N values near the WWTP are ~ +7 permil, and increased downstream to over +20 permil. NO3-δ15N upstream of the WWTP is ~ +6 permil, and ranges between +3 and +9 permil downstream. The downstream changes

  12. One-Dimensional Convolutional Neural Network Land-Cover Classification of Multi-Seasonal Hyperspectral Imagery in the San Francisco Bay Area, California

    Directory of Open Access Journals (Sweden)

    Daniel Guidici

    2017-06-01

    Full Text Available In this study, a 1-D Convolutional Neural Network (CNN architecture was developed, trained and utilized to classify single (summer and three seasons (spring, summer, fall of hyperspectral imagery over the San Francisco Bay Area, California for the year 2015. For comparison, the Random Forests (RF and Support Vector Machine (SVM classifiers were trained and tested with the same data. In order to support space-based hyperspectral applications, all analyses were performed with simulated Hyperspectral Infrared Imager (HyspIRI imagery. Three-season data improved classifier overall accuracy by 2.0% (SVM, 1.9% (CNN to 3.5% (RF over single-season data. The three-season CNN provided an overall classification accuracy of 89.9%, which was comparable to overall accuracy of 89.5% for SVM. Both three-season CNN and SVM outperformed RF by over 7% overall accuracy. Analysis and visualization of the inner products for the CNN provided insight to distinctive features within the spectral-temporal domain. A method for CNN kernel tuning was presented to assess the importance of learned features. We concluded that CNN is a promising candidate for hyperspectral remote sensing applications because of the high classification accuracy and interpretability of its inner products.

  13. Energy-water nexus analysis of enhanced water supply scenarios: a regional comparison of Tampa Bay, Florida, and San Diego, California.

    Science.gov (United States)

    Mo, Weiwei; Wang, Ranran; Zimmerman, Julie B

    2014-05-20

    Increased water demand and scarce freshwater resources have forced communities to seek nontraditional water sources. These challenges are exacerbated in coastal communities, where population growth rates and densities in the United States are the highest. To understand the current management dilemma between constrained surface and groundwater sources and potential new water sources, Tampa Bay, Florida (TB), and San Diego, California (SD), were studied through 2030 accounting for changes in population, water demand, and electricity grid mix. These locations were chosen on the basis of their similar populations, land areas, economies, and water consumption characters as well as their coastal locations and rising contradictions between water demand and supply. Three scenarios were evaluated for each study area: (1) maximization of traditional supplies; (2) maximization of seawater desalination; and (3) maximization of nonpotable water reclamation. Three types of impacts were assessed: embodied energy, greenhouse gas (GHG) emission, and energy cost. SD was found to have higher embodied energy and energy cost but lower GHG emission than TB in most of its water infrastructure systems because of the differences between the electricity grid mixes and water resources of the two regions. Maximizing water reclamation was found to be better than increasing either traditional supplies or seawater desalination in both regions in terms of the three impact categories. The results further imply the importance of assessing the energy-water nexus when pursuing demand-side control targets or goals as well to ensure that the potentially most economical options are considered.

  14. Comparison between lead levels in dandelions grown in an ultra-clean lab environment (baseline) and those collected from the San Francisco Bay Area

    Science.gov (United States)

    Rojero, J.; Odigie, K. O.; Hibdon, S.; Flegal, A. R.

    2011-12-01

    This study is aimed at establishing the baseline (natural) levels of lead in dandelions (Taraxacum officinale) grown in an ultra-clean environment. Dandelions have been used extensively as biomonitors of environmental lead levels since their distribution is global and they can be easily collected. However, industrial lead contamination is so pervasive that even dandelions from the most remote areas in the world may be contaminated with industrial lead. Therefore, this work will test the hypothesis that "natural" lead levels in dandelions are lower than any previously published values - by growing them in a HEPA filtered air (Class 100) trace metal clean room with high purity (18 MΩ cm) water. Concentrations and isotopic compositions of lead in the clean-room grown dandelions will be compared to values in literature and to those of lead in dandelions collected from San Francisco Bay Area. Lead is a dense, ductile, and highly malleable metal that is found naturally in our environment. Due to its properties it is currently highly used in building construction, in ceramic glazes, lead chromate and in PVC plastic used to coat electrical cords. The uses of lead have included paint, leather tanning, and being used as an additive to gasoline prior to the mid 1970's, as well as others. Due to its many uses, humans are susceptible to lead regularly through various means of exposure from air, water and soil, often leading to lead toxicity.

  15. Socio-demographic factors associated with trans*female youth’s access to health care in the San Francisco Bay Area

    Science.gov (United States)

    Johns, Elizabeth A.; Jin, Harry; Auerswald, Colette L.; Wilson, Erin C.

    2017-01-01

    Purpose Trans*female youth are an underserved population at risk for a variety of poor health outcomes, in part related to barriers to accessing health and mental health care. Methods We conducted a secondary analysis of data collected with 250 TFY aged 16 to 24 years in the San Francisco Bay Area from 2012–2014. Logistic regression was used to test associations between socio-demographic variables and barriers to gender identity-based medical and mental health care. Results Having a history of unstable housing was associated with significantly higher odds of problems accessing both medical care (OR 2.16, 95% CI 1.12, 4.13) and mental health care due to gender identity (OR 2.65, 95% CI 1.08, 6.45). Conversely, identifying as genderqueer/genderfluid, Latina, or living in dependent housing was associated with access to either medical or mental health care. Conclusions Interventions are needed to address housing and discrimination barring access to health care among TFY. PMID:28438525

  16. Analysis of Salinity Intrusion in the San Francisco Bay-Delta Using a GA-Optimized Neural Net, and Application of the Model to Prediction in the Elkhorn Slough Habitat

    Science.gov (United States)

    Thompson, D. E.; Rajkumar, T.

    2002-12-01

    The San Francisco Bay Delta is a large hydrodynamic complex that incorporates the Sacramento and San Joaquin Estuaries, the Suisan Marsh, and the San Francisco Bay proper. Competition exists for the use of this extensive water system both from the fisheries industry, the agricultural industry, and from the marine and estuarine animal species within the Delta. As tidal fluctuations occur, more saline water pushes upstream allowing fish to migrate beyond the Suisan Marsh for breeding and habitat occupation. However, the agriculture industry does not want extensive salinity intrusion to impact water quality for human and plant consumption. The balance is regulated by pumping stations located along the estuaries and reservoirs whereby flushing of fresh water keeps the saline intrusion at bay. The pumping schedule is driven by data collected at various locations within the Bay Delta and by numerical models that predict the salinity intrusion as part of a larger model of the system. The Interagency Ecological Program (IEP) for the San Francisco Bay / Sacramento-San Joaquin Estuary collects, monitors, and archives the data, and the Department of Water Resources provides a numerical model simulation (DSM2) from which predictions are made that drive the pumping schedule. A problem with DSM2 is that the numerical simulation takes roughly 16 hours to complete a prediction. We have created a neural net, optimized with a genetic algorithm, that takes as input the archived data from multiple gauging stations and predicts stage, salinity, and flow at the Carquinez Straits (at the downstream end of the Suisan Marsh). This model seems to be robust in its predictions and operates much faster than the current numerical DSM2 model. Because the Bay-Delta is strongly tidally driven, we used both Principal Component Analysis and Fast Fourier Transforms to discover dominant features within the IEP data. We then filtered out the dominant tidal forcing to discover non-primary tidal effects

  17. Fish community structure in San Agustín Bay, Huatulco, Mexico Estructura comunitaria de peces en bahía San Agustín, Huatulco, México

    Directory of Open Access Journals (Sweden)

    MARTÍN RAMÍREZ-GUTIÉRREZ

    2007-12-01

    Full Text Available San Agustín bay is one of the most important bays in the Huatulco National Park because it includes the broadest coral reef surface of this park, which supports a great diversity of fish species. The importance of the present work is that describes quantitatively, for first time, the fish assemblage of this reef area. Visual censuses were realized on transects, according to the coral reef size, on coral and rocky reefs, and coral rubble environments. 64 species, 46 genus and 29 families were registered. Seasonal variation in fish assemblage was observed; reflecting the influence of pelagic shoaling species associated with the Gulf of Tehuantepec upwelling, during the dry season. Thus species were Selar crumenophthalmus, Caranx caninus, and Sardinops caeruleus. For species more closely associated to the reef habitat little seasonal variation was observed for each species, except Chromis atrilobata, which exhibited high density during the dry season. Pomacentrids exhibited more affinity for coral reef, labrids and haemulids for coral rubble environments. The highest diversity values were on coral rubble and the highest density was on the coral reef. Our study suggests that in this region, the Gulf of Tehuantepec upwelling is an important factor as well as the heterogeneity of habitats in shaping the fish assemblages, which must be protected to maintain the biodiversity of this important ecosystemLa bahía de San Agustín es una de las más importantes del Parque Nacional Huatulco debido a que incluye al arrecife coralino más grande de este parque, el cual alberga una gran diversidad de especies de peces. La importancia del presente trabajo es describir cuantitativamente, por primera vez, la comunidad de peces de este habitat de arrecifes. Para ello se realizaron censos visuales en transectos de acuerdo al tamaño de los ambientes coralino, rocoso y de escombros. 64 especies, 46 géneros y 29 familias fueron registrados. Se observaron cambios

  18. Coordinating water conservation efforts through tradable credits: A proof of concept for drought response in the San Francisco Bay area

    Science.gov (United States)

    Gonzales, Patricia; Ajami, Newsha; Sun, Yujie

    2017-09-01

    Water utilities are increasingly relying on water efficiency and conservation to extend the availability of supplies. Despite spatial and institutional interdependency of many utilities, these demand-side management initiatives have traditionally been tackled by individual utilities operating in isolation. In this study, we introduce a policy framework for water conservation credits that enables collaboration at the regional scale. Under the proposed approach, utilities have the flexibility to invest in water conservation measures that are appropriate for their specific service area. When utilities have insufficient capacity for local cost-effective measures, they may opt to purchase credits, contributing to fund subsidies for utilities that do have that capacity and can provide the credits, while the region as a whole benefits from more reliable water supplies. This work aims to provide insights on the potential impacts of a water conservation credit policy framework when utilities are given the option to collaborate in their efforts. We model utility decisions as rational cost-minimizing actors subject to different decision-making dynamics and water demand scenarios, and demonstrate the institutional characteristics needed for the proposed policy to be effective. We apply this model to a counterfactual case study of water utility members of the Bay Area Water Supply and Conservation Agency in California during the drought period of June 2015 to May 2016. Our scenario analysis indicates that when the institutional structure and incentives are appropriately defined, water agencies can achieve economic benefits from collaborating in their conservation efforts, especially if they coordinate more closely in their decision-making.

  19. Comparison Of Downscaled CMIP5 Precipitation Datasets For Projecting Changes In Extreme Precipitation In The San Francisco Bay Area.

    Science.gov (United States)

    Milesi, Cristina; Costa-Cabral, Mariza; Rath, John; Mills, William; Roy, Sujoy; Thrasher, Bridget; Wang, Weile; Chiang, Felicia; Loewenstein, Max; Podolske, James

    2014-01-01

    Water resource managers planning for the adaptation to future events of extreme precipitation now have access to high resolution downscaled daily projections derived from statistical bias correction and constructed analogs. We also show that along the Pacific Coast the Northern Oscillation Index (NOI) is a reliable predictor of storm likelihood, and therefore a predictor of seasonal precipitation totals and likelihood of extremely intense precipitation. Such time series can be used to project intensity duration curves into the future or input into stormwater models. However, few climate projection studies have explored the impact of the type of downscaling method used on the range and uncertainty of predictions for local flood protection studies. Here we present a study of the future climate flood risk at NASA Ames Research Center, located in South Bay Area, by comparing the range of predictions in extreme precipitation events calculated from three sets of time series downscaled from CMIP5 data: 1) the Bias Correction Constructed Analogs method dataset downscaled to a 1/8 degree grid (12km); 2) the Bias Correction Spatial Disaggregation method downscaled to a 1km grid; 3) a statistical model of extreme daily precipitation events and projected NOI from CMIP5 models. In addition, predicted years of extreme precipitation are used to estimate the risk of overtopping of the retention pond located on the site through simulations of the EPA SWMM hydrologic model. Preliminary results indicate that the intensity of extreme precipitation events is expected to increase and flood the NASA Ames retention pond. The results from these estimations will assist flood protection managers in planning for infrastructure adaptations.

  20. Projected evolution of California's San Francisco bay-delta-river system in a century of climate change

    Science.gov (United States)

    Cloern, J.E.; Knowles, N.; Brown, L.R.; Cayan, D.; Dettinger, M.D.; Morgan, T.L.; Schoellhamer, D.H.; Stacey, M.T.; van der Wegen, M.; Wagner, R.W.; Jassby, A.D.

    2011-01-01

    Background: Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings: We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010-2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance: Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community

  1. Projected evolution of California's San Francisco Bay-Delta-river system in a century of climate change.

    Directory of Open Access Journals (Sweden)

    James E Cloern

    Full Text Available BACKGROUND: Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. METHODOLOGY/PRINCIPAL FINDINGS: We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010-2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. CONCLUSIONS/SIGNIFICANCE: Most of these environmental indicators change substantially over the 21(st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1 an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2 varying sensitivity among environmental indicators to the uncertainty of future climates; (3 inevitability of

  2. Projected evolution of California's San Francisco Bay-Delta-river system in a century of climate change.

    Science.gov (United States)

    Cloern, James E; Knowles, Noah; Brown, Larry R; Cayan, Daniel; Dettinger, Michael D; Morgan, Tara L; Schoellhamer, David H; Stacey, Mark T; van der Wegen, Mick; Wagner, R Wayne; Jassby, Alan D

    2011-01-01

    Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010-2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Most of these environmental indicators change substantially over the 21(st) century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community changes as responses to cumulative effects of climate change and other

  3. Projected evolution of California's San Francisco Bay-Delta-River System in a century of continuing climate change

    Science.gov (United States)

    Cloern, James E.; Knowles, Noah; Brown, Larry R.; Cayan, Daniel; Dettinger, Michael D.; Morgan, Tara L.; Schoellhamer, David H.; Stacey, Mark T.; van der Wegen, Mick; Wagner, R. Wayne; Jassby, Alan D.

    2011-01-01

    Background Accumulating evidence shows that the planet is warming as a response to human emissions of greenhouse gases. Strategies of adaptation to climate change will require quantitative projections of how altered regional patterns of temperature, precipitation and sea level could cascade to provoke local impacts such as modified water supplies, increasing risks of coastal flooding, and growing challenges to sustainability of native species. Methodology/Principal Findings We linked a series of models to investigate responses of California's San Francisco Estuary-Watershed (SFEW) system to two contrasting scenarios of climate change. Model outputs for scenarios of fast and moderate warming are presented as 2010–2099 projections of nine indicators of changing climate, hydrology and habitat quality. Trends of these indicators measure rates of: increasing air and water temperatures, salinity and sea level; decreasing precipitation, runoff, snowmelt contribution to runoff, and suspended sediment concentrations; and increasing frequency of extreme environmental conditions such as water temperatures and sea level beyond the ranges of historical observations. Conclusions/Significance Most of these environmental indicators change substantially over the 21st century, and many would present challenges to natural and managed systems. Adaptations to these changes will require flexible planning to cope with growing risks to humans and the challenges of meeting demands for fresh water and sustaining native biota. Programs of ecosystem rehabilitation and biodiversity conservation in coastal landscapes will be most likely to meet their objectives if they are designed from considerations that include: (1) an integrated perspective that river-estuary systems are influenced by effects of climate change operating on both watersheds and oceans; (2) varying sensitivity among environmental indicators to the uncertainty of future climates; (3) inevitability of biological community

  4. Humboldt Bay Benthic Habitats 2009 Aquatic Setting

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  5. Humboldt Bay, California Benthic Habitats 2009 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  6. Humboldt Bay, California Benthic Habitats 2009 Biotic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  7. Humboldt Bay, California Benthic Habitats 2009 Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Humboldt Bay is the largest estuary in California north of San Francisco Bay and represents a significant resource for the north coast region. Beginning in 2007 the...

  8. Status and understanding of groundwater quality in the North San Francisco Bay Shallow Aquifer study unit, 2012; California GAMA Priority Basin Project (ver. 1.1, February 2018)

    Science.gov (United States)

    Bennett, George L.

    2017-07-20

    Groundwater quality in the North San Francisco Bay Shallow Aquifer study unit (NSF-SA) was investigated as part of the Priority Basin Project of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is in Marin, Mendocino, Napa, Solano, and Sonoma Counties and included two physiographic study areas: the Valleys and Plains area and the surrounding Highlands area. The NSF-SA focused on groundwater resources used for domestic drinking water supply, which generally correspond to shallower parts of aquifer systems than that of groundwater resources used for public drinking water supply in the same area. The assessments characterized the quality of untreated groundwater, not the quality of drinking water.This study included three components: (1) a status assessment, which characterized the status of the quality of the groundwater resources used for domestic supply for 2012; (2) an understanding assessment, which evaluated the natural and human factors potentially affecting water quality in those resources; and (3) a comparison between the groundwater resources used for domestic supply and those used for public supply.The status assessment was based on data collected from 71 sites sampled by the U.S. Geological Survey for the GAMA Priority Basin Project in 2012. To provide context, concentrations of constituents measured in groundwater were compared to U.S. Environmental Protection Agency (EPA) and California State Water Resources Control Board Division of Drinking Water regulatory and non-regulatory benchmarks for drinking-water quality. The status assessment used a grid-based method to estimate the proportion of the groundwater resources that has concentrations of water-quality constituents approaching or above benchmark concentrations. This method provides statistically unbiased results at the study-area scale and permits comparisons to other GAMA Priority Basin Project study areas.In the NSF-SA study unit as a whole, inorganic

  9. Spatiotemporal Characterization of San Francisco Bay Denitrifying Communities: a Comparison of nirK and nirS Diversity and Abundance.

    Science.gov (United States)

    Lee, Jessica A; Francis, Christopher A

    2017-02-01

    Denitrifying bacteria play a critical role in the estuarine nitrogen cycle. Through the transformation of nitrate into nitrogen gas, these organisms contribute to the loss of bioavailable (i.e., fixed) nitrogen from low-oxygen environments such as estuary sediments. Denitrifiers have been shown to vary in abundance and diversity across the spatial environmental gradients that characterize estuaries, such as salinity and nitrogen availability; however, little is known about how their communities change in response to temporal changes in those environmental properties. Here, we present a 1-year survey of sediment denitrifier communities along the estuarine salinity gradient of San Francisco Bay. We used quantitative PCR and sequencing of functional genes coding for a key denitrifying enzyme, dissimilatory nitrite reductase, to compare two groups of denitrifiers: those with nirK (encoding copper-dependent nitrite reductase) and those with nirS (encoding the cytochrome-cd 1-dependent variant). We found that nirS was consistently more abundant and more diverse than nirK in all parts of the estuary. The abundances of the two genes were tightly linked across space but differed temporally, with nirK peaking when temperature was low and nirS peaking when nitrate was high. Likewise, the diversity and composition of nirK- versus nirS-type communities differed in their responses to seasonal variations, though both were strongly determined by site. Furthermore, our sequence libraries detected deeply branching clades with no cultured isolates, evidence of enormous diversity within the denitrifiers that remains to be explored.

  10. Variation in growth rate, carbon assimilation, and photosynthetic efficiency in response to nitrogen source and concentration in phytoplankton isolated from upper San Francisco Bay.

    Science.gov (United States)

    Berg, Gry Mine; Driscoll, Sara; Hayashi, Kendra; Ross, Melissa; Kudela, Raphael

    2017-06-01

    Six species of phytoplankton recently isolated from upper San Francisco Bay were tested for their sensitivity to growth inhibition by ammonium (NH 4 + ), and for differences in growth rates according to inorganic nitrogen (N) growth source. The quantum yield of photosystem II (F v /F m ) was a sensitive indicator of NH 4 + toxicity, manifested by a suppression of F v /F m in a dose-dependent manner. Two chlorophytes were the least sensitive to NH 4 + inhibition, at concentrations of >3,000 μmoles NH 4 +  · L -1 , followed by two estuarine diatoms that were sensitive at concentrations >1,000 μmoles NH 4 +  · L -1 , followed lastly by two freshwater diatoms that were sensitive at concentrations between 200 and 500 μmoles NH 4 +  · L -1 . At non-inhibiting concentrations of NH 4 + , the freshwater diatom species grew fastest, followed by the estuarine diatoms, while the chlorophytes grew slowest. Variations in growth rates with N source did not follow taxonomic divisions. Of the two chlorophytes, one grew significantly faster on nitrate (NO 3 - ), whereas the other grew significantly faster on NH 4 + . All four diatoms tested grew faster on NH 4 + compared with NO 3 - . We showed that in cases where growth rates were faster on NH 4 + than they were on NO 3 - , the difference was not larger for chlorophytes compared with diatoms. This holds true for comparisons across a number of culture investigations suggesting that diatoms as a group will not be at a competitive disadvantage under natural conditions when NH 4 + dominates the total N pool and they will also not have a growth advantage when NO 3 - is dominant, as long as N concentrations are sufficient. © 2017 The Authors Journal of Phycology published by Wiley Periodicals, Inc. on behalf of Phycological Society of America.

  11. Simulation of climate change in San Francisco Bay Basins, California: Case studies in the Russian River Valley and Santa Cruz Mountains

    Science.gov (United States)

    Flint, Lorraine E.; Flint, Alan L.

    2012-01-01

    As a result of ongoing changes in climate, hydrologic and ecologic effects are being seen across the western United States. A regional study of how climate change affects water resources and habitats in the San Francisco Bay area relied on historical climate data and future projections of climate, which were downscaled to fine spatial scales for application to a regional water-balance model. Changes in climate, potential evapotranspiration, recharge, runoff, and climatic water deficit were modeled for the Bay Area. In addition, detailed studies in the Russian River Valley and Santa Cruz Mountains, which are on the northern and southern extremes of the Bay Area, respectively, were carried out in collaboration with local water agencies. Resource managers depend on science-based projections to inform planning exercises that result in competent adaptation to ongoing and future changes in water supply and environmental conditions. Results indicated large spatial variability in climate change and the hydrologic response across the region; although there is warming under all projections, potential change in precipitation by the end of the 21st century differed according to model. Hydrologic models predicted reduced early and late wet season runoff for the end of the century for both wetter and drier future climate projections, which could result in an extended dry season. In fact, summers are projected to be longer and drier in the future than in the past regardless of precipitation trends. While water supply could be subject to increased variability (that is, reduced reliability) due to greater variability in precipitation, water demand is likely to steadily increase because of increased evapotranspiration rates and climatic water deficit during the extended summers. Extended dry season conditions and the potential for drought, combined with unprecedented increases in precipitation, could serve as additional stressors on water quality and habitat. By focusing on the

  12. 76 FR 45693 - Safety Zone; San Diego POPS Fireworks, San Diego, CA

    Science.gov (United States)

    2011-08-01

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego POPS Fireworks, San Diego, CA... temporary safety zone on the navigable waters of San Diego Bay in support of the San Diego POPS Fireworks..., participating vessels, and other vessels and users of the waterway during scheduled fireworks events. Persons...

  13. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California; 2015

    Science.gov (United States)

    Cain, Daniel J.; Thompson, Janet K.; Crauder, Jeffrey; Parchaso, Francis; Stewart, Robin; Turner, Matthew A.; Hornberger, Michelle I.; Luoma, Samuel N.

    2016-07-22

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, California. This report includes data collected by U.S. Geological Survey (USGS) scientists for the period from January 2015 to December 2015. These data are appended to long-term datasets extending back to 1974, and serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994.

  14. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California: 2014

    Science.gov (United States)

    Cain, Daniel J.; Thompson, Janet K.; Crauder, Jeff; Parcheso, Francis; Stewart, Robin; Kleckner, Amy E.; Dyke, Jessica; Hornberger, Michelle I.; Luoma, Samuel N.

    2015-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer (km) south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2014 to December 2014. These append to long-term datasets extending back to 1974, and serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. 

  15. Non-Hodgkin's lymphoma in HIV-positive and HIV-negative homosexual men in the San Francisco Bay Area: allergies, prior medication use, and sexual practices.

    Science.gov (United States)

    Holly, E A; Lele, C

    1997-07-01

    Lifestyle, sexual history, and medical history characteristics were analyzed as risk factors for non-Hodgkin's lymphoma (NHL) in a population-based case-control study of 1593 subjects with NHL and 2515 control subjects conducted in the San Francisco Bay Area between 1988 and 1995. The results for homosexual men, 312 with NHL and 420 control subjects, showed that HIV infection was associated with a 20-fold increased risk for NHL. Among HIV-positive homosexual men, after adjustment for other factors, those that were associated with a reduced risk for NHL were frequency of receptive anal intercourse between the ages of 20 and 29 (1 to 9 times: OR = 0.63; > or = 10 times: OR = 0.37; trend: p = 0.02), allergy to grass, hay, leaves, plants and pollen (OR = 0.35, CI = 0.19 to 0.64), number of bee or wasp stings (1 to 3 times: OR = 0.65; > or =4 times: OR = 0.56; trend: p = 0.07), use of Tagamet (cimetidine) for 4 consecutive weeks or longer (OR = 0.39, CI = 0.17 to 0.89), vaccination against influenza (OR = 0.41, CI = 0.23 to 0.74), and lifetime frequency of amphetamine use (1 to 19 times: OR = 0.59; > or =20 times: OR = 0.38; trend: p = 0.003). Among HIV-negative homosexual men, after adjustment for other factors, factors that were associated with NHL status were frequency of receptive anal intercourse between the ages of 20 and 29 (1 to 9 times: OR = 0.39; > or =10 times: OR = 0.20; trend: p = 0.001), nonmedication allergies (OR = 0.43, CI = 0.21 to 0.89), vaccination against poliomyelitis at <10 years (OR = 0.41, CI = 0.17 to 0.99), and having five or more siblings (OR = 3.6, CI = 1.7 to 7.7). An increased immunosuppressive effect of seminal fluid on sensitive rectal tissue and support from earlier work suggesting that HIV-related lymphomas may be outgrowths of antigen-driven B cells provide a possible mechanism for the results of this study. The role of allergic reactions in NHL is likely to be complex and may be related to B-cell differentiation. These associations

  16. Computational Approach for Improving Three-Dimensional Sub-Surface Earth Structure for Regional Earthquake Hazard Simulations in the San Francisco Bay Area

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-25

    In our Exascale Computing Project (ECP) we seek to simulate earthquake ground motions at much higher frequency than is currently possible. Previous simulations in the SFBA were limited to 0.5-1 Hz or lower (Aagaard et al. 2008, 2010), while we have recently simulated the response to 5 Hz. In order to improve confidence in simulated ground motions, we must accurately represent the three-dimensional (3D) sub-surface material properties that govern seismic wave propagation over a broad region. We are currently focusing on the San Francisco Bay Area (SFBA) with a Cartesian domain of size 120 x 80 x 35 km, but this area will be expanded to cover a larger domain. Currently, the United States Geologic Survey (USGS) has a 3D model of the SFBA for seismic simulations. However, this model suffers from two serious shortcomings relative to our application: 1) it does not fit most of the available low frequency (< 1 Hz) seismic waveforms from moderate (magnitude M 3.5-5.0) earthquakes; and 2) it is represented with much lower resolution than necessary for the high frequency simulations (> 5 Hz) we seek to perform. The current model will serve as a starting model for full waveform tomography based on 3D sensitivity kernels. This report serves as the deliverable for our ECP FY2017 Quarter 4 milestone to FY 2018 “Computational approach to developing model updates”. We summarize the current state of 3D seismic simulations in the SFBA and demonstrate the performance of the USGS 3D model for a few selected paths. We show the available open-source waveform data sets for model updates, based on moderate earthquakes recorded in the region. We present a plan for improving the 3D model utilizing the available data and further development of our SW4 application. We project how the model could be improved and present options for further improvements focused on the shallow geotechnical layers using dense passive recordings of ambient and human-induced noise.

  17. Organochlorine and PBDE concentrations in relation to cytochrome P450 activity in livers of Forster’s Terns (Sterna forsteri) and Caspian Terns (Hydroprogne caspia), in San Francisco Bay, California

    Science.gov (United States)

    Herring, Garth; Ackerman, Joshua T.; Eagles-Smith, Collin A.; Adelsbach, Terrence L.; Melancon, Mark J.; Stebbins, Katie R.; Hoffman, David J.

    2010-01-01

    We measured halogenated organic contaminants (HOCs) [polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and dichloro-diphenyl-trichloroethane (DDT)] and P450 [e.g., ethoxyresorufin-O-dealkylase (EROD)] stress in livers from Caspian tern (Hydroprogne caspia) adults and Forster’s tern (Sterna forsteri) adults and chicks in San Francisco Bay (SFB). Penta BDEs and tetra PBDEs composed 46–66% of ∑PBDE in terns. PCB homologues di, tri, penta, hexa, and hepta composed 93–95% of ∑PCBs and p′p-DDE composed 82–98% of all ∑DDTs. We found similar concentrations of ∑PBDEs [mean micrograms per gram wet weight (ww) ± standard error = 0.4 ± 0.1], ∑PCBs (5.9 ± 1.6), and ∑DDTs (0.6 ± 0.1) among species, sexes, and regions. However, concentrations were higher in Forster’s tern adults than chicks (∑PBDEs = 0.4 ± 0.1 and 0.1 ± 0.1; ∑PCBs = 7.08 ± 2.4 and 2.4 ± 1.4; ∑DDTs = 0.5 ± 0.1 and 0.1 ± 0.1; respectively), and there was a nonsignificant trend of elevated ∑PBDEs and ∑PCBs for adult Forster’s terns in the Central South Bay and Lower South Bay portions of SFB. Combined Forster’s tern and Caspian tern ∑DDTs bioaccumulated similarly to selenium, but not mercury, and there was a nonsignificant but positive trend for ∑PBDEs and ∑PCBs bioaccumulation with mercury. P450 protein activity was higher in adult Forster’s terns than Caspian terns, higher in Central South Bay than in Lower South Bay, and higher in adult Forster’s terns than in chicks.

  18. Status and understanding of groundwater quality in the North San Francisco Bay Shallow Aquifer study unit, 2012; California GAMA Priority Basin Project

    Science.gov (United States)

    Bennett, George L.

    2017-07-20

    Groundwater quality in the North San Francisco Bay Shallow Aquifer study unit (NSF-SA) was investigated as part of the Priority Basin Project of the California Groundwater Ambient Monitoring and Assessment (GAMA) Program. The study unit is in Marin, Mendocino, Napa, Solano, and Sonoma Counties and included two physiographic study areas: the Valleys and Plains area and the surrounding Highlands area. The NSF-SA focused on groundwater resources used for domestic drinking water supply, which generally correspond to shallower parts of aquifer systems than that of groundwater resources used for public drinking water supply in the same area. The assessments characterized the quality of untreated groundwater, not the quality of drinking water.This study included three components: (1) a status assessment, which characterized the status of the quality of the groundwater resources used for domestic supply for 2012; (2) an understanding assessment, which evaluated the natural and human factors potentially affecting water quality in those resources; and (3) a comparison between the groundwater resources used for domestic supply and those used for public supply.The status assessment was based on data collected from 71 sites sampled by the U.S. Geological Survey for the GAMA Priority Basin Project in 2012. To provide context, concentrations of constituents measured in groundwater were compared to U.S. Environmental Protection Agency (EPA) and California State Water Resources Control Board Division of Drinking Water regulatory and non-regulatory benchmarks for drinking-water quality. The status assessment used a grid-based method to estimate the proportion of the groundwater resources that has concentrations of water-quality constituents approaching or above benchmark concentrations. This method provides statistically unbiased results at the study-area scale and permits comparisons to other GAMA Priority Basin Project study areas.In the NSF-SA study unit as a whole, inorganic

  19. SF Bay Water Quality Improvement Fund: Projects and Accomplishments

    Science.gov (United States)

    San Francisco Bay Water Quality Improvement Fund (SFBWQIF) projects listed here are part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  20. Foreign Language Folio. A Guide to Cultural Resources and Field Trip Opportunities in the San Francisco Bay Area for Teachers and Students of Foreign Languages, 1983-85.

    Science.gov (United States)

    Gonzales, Tony, Ed.; O'Connor, Roger, Ed.

    A listing of San Francisco area cultural resources and opportunities of use to foreign language teachers is presented. Included are the following: museums and galleries, schools, art sources, churches, clubs, cultural centers and organizations, publications and publishing companies, restaurants, food stores and markets, travel and tourism,…

  1. Seismic response of steel suspension bridge

    Energy Technology Data Exchange (ETDEWEB)

    McCallen, D.B. [Lawrence Livermore National Lab., CA (United States); Astaneh-Asl, A. [California Univ., Berkeley, CA (United States). Dept. of Civil and Environmental Engineering

    1996-11-01

    Performing accurate, realistic numerical simulations of the seismic response of long-span bridges presents a significant challenge to the fields of earthquake engineering and seismology. Suspension bridges in particular represent some of the largest and most important man-made structures and ensuring the seismic integrity of these mega-structures is contingent on accurate estimations of earthquake ground motions and accurate computational simulations of the structure/foundation system response. A cooperative, multi-year research project between the Univ. of California and LLNL was recently initiated to study engineering and seismological issues essential for simulating the response of major structures. Part of this research project is focused on the response of the long-span bridges with the San Francisco-Oakland Bay Bridge serving as a case study. This paper reports on the status of this multi-disciplinary research project with emphasis on the numerical simulation of the transient seismic response of the Bay Bridge.

  2. The Nimitz Freeway Collapse

    Science.gov (United States)

    Feldman, Bernard J.

    2004-10-01

    One of the most tragic sights created by the Loma Prieta earthquake of Oct. 17, 1989, was the collapse of the double-deck Nimitz Freeway (the Cypress Street Viaduct on Interstate 880) just south and east of the San Francisco-Oakland Bay Bridge in Oakland. Along a 1.4-km north-south stretch, the upper deck of the freeway fell on top of the lower deck of the freeway, killing 42 motorists (see Fig. 1). Even though the earthquake occurred during rush hour (5:04 p.m.), traffic was extremely light that day because the third game of the World Series between the Oakland Athletics and the San Francisco Giants was about to begin and many commuters were already at home in front of their television sets.

  3. San Pablo Avenue Green Stormwater Spine

    Science.gov (United States)

    Information about the SFBWQP San Pablo Avenue Green Stormwater Spine Project project, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

  4. Acculturation, Dietary Practices and Risk for Childhood Obesity in an Ethnically Heterogeneous Population of Latino School Children in the San Francisco Bay Area

    Science.gov (United States)

    Schwartz, Norah; Jiménez-Cruz, Arturo; Bacardi-Gascon, Montserrat; Heyman, Melvin B.

    2015-01-01

    Previous studies have found increased acculturation to the US lifestyle increases risk for obesity in Latinos. However, methodologies differ, and results in children are inconsistent. Moreover, previous studies have not evaluated risk factors within the heterogeneous US population. We recruited 144 self-identified Latino school children and their mother or father in grades 4–6 in San Francisco parochial schools and South San Francisco public schools using an information letter distributed to all students. Children and parents had weights, heights, demographic information, dietary patterns and lifestyle variables collected in English or Spanish through an interview format. A high percentage of our children were overweight [≥85th percentile body mass index (BMI)] (62.5%) and obese (≥95th percentile BMI) (45.2%). Correspondingly parents also had a high percentage of overweight (BMI ≥ 25 & obesity (BMI ≥ 30) (45.3%). Mexico was the country of origin for 62.2% of parents, and 26.6% were from Central or South America. In multivariate logistic analysis, speaking Spanish at home was an independent risk factor for obesity [odds ratio (OR) 2.97, 95% confidence interval (CI) 1.28–6.86]. Eating breakfast daily (OR 0.34, 95% CI 0.15–0.78) and consumption of tortas (a Mexican fast food sandwich) (OR 0.45, 95% CI 0.21–1.00) were associated with decreased risk. In stratified analysis, significant differences in risk factors existed between Mexican origin versus Central/South American Latino children. The processes of acculturation likely impact eating and lifestyle practices differentially among Latino groups. Interventions should focus on ensuring that all children eat a nutritious breakfast and take into consideration ethnicity when working with Latino populations. PMID:22101726

  5. Acculturation, dietary practices and risk for childhood obesity in an ethnically heterogeneous population of Latino school children in the San Francisco bay area.

    Science.gov (United States)

    Wojcicki, Janet M; Schwartz, Norah; Jiménez-Cruz, Arturo; Bacardi-Gascon, Montserrat; Heyman, Melvin B

    2012-08-01

    Previous studies have found increased acculturation to the US lifestyle increases risk for obesity in Latinos. However, methodologies differ, and results in children are inconsistent. Moreover, previous studies have not evaluated risk factors within the heterogeneous US population. We recruited 144 self-identified Latino school children and their mother or father in grades 4-6 in San Francisco parochial schools and South San Francisco public schools using an information letter distributed to all students. Children and parents had weights, heights, demographic information, dietary patterns and lifestyle variables collected in English or Spanish through an interview format. A high percentage of our children were overweight [≥85th percentile body mass index (BMI)] (62.5%) and obese (≥95th percentile BMI) (45.2%). Correspondingly parents also had a high percentage of overweight (BMI ≥ 25 & obesity (BMI ≥ 30) (45.3%). Mexico was the country of origin for 62.2% of parents, and 26.6% were from Central or South America. In multivariate logistic analysis, speaking Spanish at home was an independent risk factor for obesity [odds ratio (OR) 2.97, 95% confidence interval (CI) 1.28-6.86]. Eating breakfast daily (OR 0.34, 95% CI 0.15-0.78) and consumption of tortas (a Mexican fast food sandwich) (OR 0.45, 95% CI 0.21-1.00) were associated with decreased risk. In stratified analysis, significant differences in risk factors existed between Mexican origin versus Central/South American Latino children. The processes of acculturation likely impact eating and lifestyle practices differentially among Latino groups. Interventions should focus on ensuring that all children eat a nutritious breakfast and take into consideration ethnicity when working with Latino populations.

  6. Evaluation of Caspian tern (Hydroprogne caspia) and snowy plover (Charadrius alexandrinus nivosus) nesting on modified islands at the Don Edwards San Francisco Bay National Wildlife Refuge, California—2016 Annual Report

    Science.gov (United States)

    Hartman, C. Alex; Ackerman, Joshua T.; Herzog, Mark P.; Strong, Cheryl; Trachtenbarg, David; Shore, Crystal A.

    2017-05-08

    Executive SummaryIn order to address the 2008/10 and Supplemental 2014 NOAA Fisheries Biological Opinion for operation of the Federal Columbia River Power System, the U.S. Army Corps of Engineers (USACE) and the Bureau of Reclamation (Reclamation) developed and have begun implementation of Caspian tern (Hydroprogne caspia) management plans. This implementation includes redistribution of the Caspian terns in the Columbia River estuary and the mid-Columbia River region to reduce predation on salmonids listed under the Endangered Species Act. Key elements of the plans include (1) reducing nesting habitat for Caspian terns in the Columbia River estuary and the mid-Columbia River region, and (2) creating or modifying nesting habitat at alternative sites within the Caspian tern breeding range. USACE and Reclamation developed Caspian tern nesting habitat at the U.S. Fish and Wildlife Service Don Edwards San Francisco Bay National Wildlife Refuge (DENWR), California, prior to the 2015 nesting season. Furthermore, to reduce or eliminate potential conflicts between nesting Caspian terns and threatened western snowy plovers (Charadrius alexandrinus nivosus), nesting habitat for snowy plovers also was developed. Seven recently constructed islands within two managed ponds (Ponds A16 and SF2) of DENWR were modified to provide habitat attractive to nesting Caspian terns (5 islands) and snowy plovers (2 islands). These 7 islands were a subset of 46 islands recently constructed in Ponds A16 and SF2 to provide waterbird nesting habitat as part of the South Bay Salt Pond (SBSP) Restoration Project.We used social attraction methods (decoys and electronic call systems) to attract Caspian terns and snowy plovers to these seven modified islands, and conducted surveys between March and September of 2015 and 2016 to evaluate nest numbers, nest density, and productivity. Results from the 2015 nesting season, the first year of the study, indicated that island modifications and social

  7. California: Environmental Health Coalition Clean Ports, Healthy Communities in San Diego (A Former EPA CARE Project)

    Science.gov (United States)

    The Environmental Health Coalition (EHC) is a recipient of a CARE Level II cooperative agreement grant. The Clean Ports, Healthy Communities in San Diego targets the Barrio Logan and Old Town National City areas located along San Diego Bay.

  8. The Purisima Formation and related rocks (upper Miocene - Pliocene), greater San Francisco Bay area, central California; review of literature and USGS collection now housed at the Museum of Paleontology, University of California, Berkeley

    Science.gov (United States)

    Powell, C.L.

    1998-01-01

    Sedimentary rocks more than 1.6 kilometers thick are attributed to the upper Miocene to upper Pliocene Purisima Formation in the greater San Francisco Bay area. These rocks occur as scattered, discontinuous outcrops from Point Reyes National Seashore in the north to south of Santa Cruz. Lithologic divisions of the Formation appear to be of local extent and are of limited use in correlating over this broad area. The Purisima Formation occurs in several fault-bounded terranes which demonstrate different stratigraphic histories and may be found to represent more than a single depositional basin. The precise age and stratigraphic relationship of these scattered outcrops are unresolved and until they are put into a stratigraphic and paleogeographic context the tectonic significance of the Purisima Foramtion can only be surmised. This paper will attempt to resolve some of these problems. Mollusks and echinoderms are recorded from the literature and more than 70 USGS collections that have not previously been reported. With the exception of one locality, the faunas suggest deposition in normal marine conditions at water depths of less than 50 m and with water temperatures the same or slightly cooler than exist along the present coast of central California. The single exception is a fauna from outcrops between Seal Cove and Pillar Point, where both mollusks and foraminifers suggest water depths greater than 100 m. Three molluscan faunas, the La Honda, the Pillar Point, and the Santa Cruz, are recognized based on USGS collections and published literature for the Purisima Formation. These biostratigraphically distinct faunas aid in the correlation of the scattered Purisima Formation outcrops. The lowermost La Honda fauna suggests shallow-water depths and an age of late Miocene to early Pliocene. This age is at odds with a younger age determination from an ash bed in the lower Purisima Formation along the central San Mateo County coast. The Pillar Point fauna contains only a

  9. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California; 2016

    Science.gov (United States)

    Cain, Daniel J.; Thompson, Janet K.; Parchaso, Francis; Pearson, Sarah; Stewart, Robin; Turner, Mathew; Barasch, David; Luoma, Samuel N.

    2017-10-30

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2014 to December 2016. These append to long-term datasets extending back to 1974. A major focus of the report is an integrated description of the 2016 data within the context of the longer, multi-decadal dataset. This dataset supports the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994.Significant reductions in silver and copper concentrations in sediment and M. petalum occurred at the site in the 1980s following the implementation by PARWQCP of advanced wastewater treatment and source control measures. Since the 1990s, concentrations of these elements appear to have stabilized at concentrations somewhat above (silver) or near (copper) regional background concentrations Data for other metals, including chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn), have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2016, concentrations of silver and copper in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported previously. Seasonal patterns for other elements, including Cr, Ni, Zn, Hg, and Se, were generally similar in timing and magnitude as those for Ag and Cu. This record suggests that legacy contamination and regional-scale factors now largely control sedimentary and bioavailable concentrations of silver and copper, as well as other elements of

  10. Macroinvertebrate Prey Availability and Fish Diet Selectivity in Relation to Environmental Variables in Natural and Restoring North San Francisco Bay Tidal Marsh Channels

    Directory of Open Access Journals (Sweden)

    Emily R. Howe

    2014-03-01

    Full Text Available Tidal marsh wetlands provide important foraging habitat for a variety of estuarine fishes. Prey organisms include benthic–epibenthic macroinvertebrates, neustonic arthropods, and zooplankton. Little is known about the abundance and distribution of interior marsh macroinvertebrate communities in the San Francisco Estuary (estuary. We describe seasonal, regional, and site variation in the composition and abundance of neuston and benthic–epibenthic macroinvertebrates that inhabit tidal marsh channels, and relate these patterns to environmental conditions. We also describe spatial and temporal variation in diets of marsh-associated inland silverside, yellowfin goby, and western mosquitofish. Fish and invertebrates were sampled quarterly from October 2003 to June 2005 at six marsh sites located in three river systems of the northern estuary: Petaluma River, Napa River, and  the west Delta. Benthic/epibenthic macroinvertebrates and neuston responded to environmental variables related to seasonal changes (i.e., temperature, salinity, as well as those related to marsh structure (i.e., vegetation, channel edge. The greatest variation in abundance occurred seasonally for neuston and spatially for benthic–epibenthic organisms, suggesting that each community responds to different environmental drivers. Benthic/epibenthic invertebrate abundance and diversity was lowest in the west Delta, and increased with increasing salinity. Insect abundance increased during the spring and summer, while Collembolan (springtail abundance increased during the winter. Benthic/epibenthic macroinvertebrates dominated fish diets, supplemented by insects, with zooplankton playing a minor role. Diet compositions of the three fish species overlapped considerably, with strong selection indicated for epibenthic crustaceans—a surprising result given the typical classification of Menidia beryllina as a planktivore, Acanthogobius flavimanus as a benthic predator, and Gambusia

  11. Using SW4 for 3D Simulations of Earthquake Strong Ground Motions: Application to Near-Field Strong Motion, Building Response, Basin Edge Generated Waves and Earthquakes in the San Francisco Bay Are

    Science.gov (United States)

    Rodgers, A. J.; Pitarka, A.; Petersson, N. A.; Sjogreen, B.; McCallen, D.; Miah, M.

    2016-12-01

    Simulation of earthquake ground motions is becoming more widely used due to improvements of numerical methods, development of ever more efficient computer programs (codes), and growth in and access to High-Performance Computing (HPC). We report on how SW4 can be used for accurate and efficient simulations of earthquake strong motions. SW4 is an anelastic finite difference code based on a fourth order summation-by-parts displacement formulation. It is parallelized and can run on one or many processors. SW4 has many desirable features for seismic strong motion simulation: incorporation of surface topography; automatic mesh generation; mesh refinement; attenuation and supergrid boundary conditions. It also has several ways to introduce 3D models and sources (including Standard Rupture Format for extended sources). We are using SW4 to simulate strong ground motions for several applications. We are performing parametric studies of near-fault motions from moderate earthquakes to investigate basin edge generated waves and large earthquakes to provide motions to engineers study building response. We show that 3D propagation near basin edges can generate significant amplifications relative to 1D analysis. SW4 is also being used to model earthquakes in the San Francisco Bay Area. This includes modeling moderate (M3.5-5) events to evaluate the United States Geologic Survey's 3D model of regional structure as well as strong motions from the 2014 South Napa earthquake and possible large scenario events. Recently SW4 was built on a Commodity Technology Systems-1 (CTS-1) at LLNL, new systems for capacity computing at the DOE National Labs. We find SW4 scales well and runs faster on these systems compared to the previous generation of LINUX clusters.

  12. ASTER Flyby of San Francisco

    Science.gov (United States)

    2002-01-01

    The Advanced Spaceborne Thermal Emission and Reflection radiometer, ASTER, is an international project: the instrument was supplied by Japan's Ministry of International Trade and Industry. A joint US/Japan science team developed algorithms for science data products, and is validating instrument performance. With its 14 spectral bands, extremely high spatial resolution, and 15 meter along-track stereo capability, ASTER is the zoom lens of the Terra satellite. The primary mission goals are to characterize the Earth's surface; and to monitor dynamic events and processes that influence habitability at human scales. ASTER's monitoring and mapping capabilities are illustrated by this series of images of the San Francisco area. The visible and near infrared image reveals suspended sediment in the bays, vegetation health, and details of the urban environment. Flying over San Francisco (3.2MB) (high-res (18.3MB)), we see the downtown, and shadows of the large buildings. Past the Golden Gate Bridge and Alcatraz Island, we cross San Pablo Bay and enter Suisun Bay. Turning south, we fly over the Berkeley and Oakland Hills. Large salt evaporation ponds come into view at the south end of San Francisco Bay. We turn northward, and approach San Francisco Airport. Rather than landing and ending our flight, we see this is as only the beginning of a 6 year mission to better understand the habitability of the world on which we live. For more information: ASTER images through Visible Earth ASTER Web Site Image courtesy of MITI, ERSDAC, JAROS, and the U.S./Japan ASTER Science Team

  13. Constraining Daily-To-Annual Carbon Budgets in a Brackish Tidal Marsh in the San Francisco Bay Delta: Insights on Methane and Carbon Dioxide Fluxes from Eddy Covariance Measurements

    Science.gov (United States)

    Saraceno, J.; Anderson, F. E.; Knox, S.; Windham-Myers, L.; Bergamaschi, B. A.

    2016-12-01

    Carbon cycling in coastal wetlands is difficult to measure and model due to extremely dynamic atmospheric (vertical) and hydrologic (lateral) fluxes, as well as sensitivities to dynamic land- and ocean-based drivers. Whereas atmospheric carbon is sequestered in accreted carbon stocks over millennia to maintain balance with sea level rise, annual or seasonal carbon fluxes from tidal wetlands can become net negative or net positive, as key drivers of carbon cycling, such as inundation area, soil and air temperature and salinity change over short time periods. Few studies have documented the interannual variability in the net ecosystem carbon balance for tidal-driven ecosystems. Using the eddy covariance technique, we present 2.5 years (March 2014-September 2016) of net ecosystem exchanges (NEE) for CO2 and CH4 from a historic wetland (the National Estuarine Research Reserve's Rush Ranch) in the Suisun Marsh complex of San Francisco Bay, California, where salinity ranges from oligohaline to mesohaline. Preliminary estimates show that daily rates of CO2 NEE were approximately -15 gC m-2 d-1 during the peak growing season in the summer to +10 gC m-2 d-1 during the winter months. CH4 emissions, ranged from 0 to +30 mgC m-2 d-1, a small fraction of observed rates from neighboring freshwater marshes. We have also found that using standard parameters (e.g. temperature and radiation) in an artificial neural network approach to gap-fill missing fluxes and estimate random error uncertainty were insufficient, suggesting that daily and seasonal shifts in salinity, water levels, and plant community phenology may help to reduce uncertainty in estimated values of both CO2 and CH4 fluxes. An additional aspect of this study is to investigate the significance of carbon exported through tidal exchanges, especially considering that regional estimates of carbon accretion in the soils to be only 100 gC m-2. Here we will estimate the aquatic carbon flux using proxies for dissolved

  14. Possible effects of Bay fill on air quality

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Baylands Subcommittee is seeking background information on the effects and ramifications of developing those parts of San Francisco Bay that lie in Santa Clara...

  15. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in South San Francisco Bay, California: 2013

    Science.gov (United States)

    Dyke, Jessica; Cain, Daniel J.; Thompson, Janet K.; Kleckner, Amy E.; Parcheso, Francis; Hornberger, Michelle I.; Luoma, Samuel N.

    2014-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2013 to December 2013. These data serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. Following significant reductions in the late 1980s, silver (Ag) and copper (Cu) concentrations in sediment and M. petalum appear to have stabilized. Data for other metals, including chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn), have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2013, concentrations of Ag and Cu in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported previously. Seasonal patterns for other elements, including Cr, Ni, Zn, Hg, and Se, were generally similar in timing and magnitude as those for Ag and Cu. In M. petalum, all observed elements showed annual maxima in January–February and minima in April, except for Zn, which was lowest in December. In sediments, annual maxima also occurred in January–February, and minima were measured in June and September. In 2013, metal concentrations in both sediments and clam tissue were among the lowest concentrations on record. This record suggests that regional-scale factors now largely control sedimentary and bioavailable concentrations of Ag and Cu, as well as other elements of regulatory interest, at the Palo Alto site. Analyses of the benthic community structure of a

  16. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California, 2012

    Science.gov (United States)

    Dyke, Jessica; Thompson, Janet K.; Cain, Daniel J.; Kleckner, Amy E.; Parcheso, Francis; Luoma, Samuel N.; Hornberger, Michelle I.

    2013-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January to December 2012. These data serve as the basis for the City of Palo Alto’s Near-Field Receiving Water Monitoring Program, initiated in 1994. Following significant reductions in the late 1980s, silver (Ag) and copper (Cu) concentrations in sediment and in M. petalum appear to have stabilized. Data for other metals, including chromium (Cr), mercury (Hg), nickel (Ni), selenium (Se), and zinc (Zn), have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2012, concentrations of Ag and Cu in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported for previous time periods. Seasonal patterns for other elements, including Cr, Ni, Zn, Hg, and Se were generally similar in timing and magnitude as those for Ag and Cu. In 2012, metal concentrations in both sediments and clam tissue were among the lowest concentrations on record. This record suggests that regional-scale factors now largely control sedimentary and bioavailable concentrations of Ag and Cu, as well as other elements of regulatory interest, at the Palo Alto site. Analyses of the benthic community structure of a mudflat in South San Francisco Bay over a 39-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum, from the same area

  17. Near-field receiving water monitoring of trace metals and a benthic community near the Palo Alto Regional Water Quality Control Plant in south San Francisco Bay, California: 2011

    Science.gov (United States)

    Dyke, Jessica; Thompson, Janet K.; Cain, Daniel J.; Kleckner, Amy E.; Parcheso, Francis; Luoma, Samuel N.; Hornberger, Michelle I.

    2012-01-01

    Trace-metal concentrations in sediment and in the clam Macoma petalum (formerly reported as Macoma balthica), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in South San Francisco Bay, Calif. This report includes the data collected by U.S. Geological Survey (USGS) scientists for the period January 2011 to December 2011. These data serve as the basis for the City of Palo Alto's Near-Field Receiving Water Monitoring Program, initiated in 1994. Following significant reductions in the late 1980s, silver (Ag) and copper (Cu) concentrations in sediment and M. petalum appear to have stabilized. Data for other metals, including chromium, mercury, nickel, selenium, and zinc, have been collected since 1994. Over this period, concentrations of these elements have remained relatively constant, aside from seasonal variation that is common to all elements. In 2011, concentrations of Ag and Cu in M. petalum varied seasonally in response to a combination of site-specific metal exposures and annual growth and reproduction, as reported previously. Seasonal patterns for other elements, including Cr, Hg, Ni, Se, and Zn, were generally similar in timing and magnitude as those for Ag and Cu. In 2011, metal concentrations in both sediments and clam tissue were among the lowest concentrations on record. This record suggests that regional-scale factors now largely control sedimentary and bioavailable concentrations of Ag and Cu, as well as other elements of regulatory interest, at the Palo Alto site. Analyses of the benthic community structure of a mudflat in South San Francisco Bay over a 38-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinel clam, M. petalum, from the same area. Analysis of the M. petalum community

  18. 2004 USGS Lidar: San Francisco Bay (CA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Lidar (Light detection and ranging) discrete-return point cloud data are available in the American Society for Photogrammetry and Remote Sensing (ASPRS) LAS format....

  19. san_francisco_bay_ca_mhw.grd

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to...

  20. San Francisco District Laboratory (SAN)

    Data.gov (United States)

    Federal Laboratory Consortium — Program CapabilitiesFood Analysis SAN-DO Laboratory has an expert in elemental analysis who frequently performs field inspections of materials. A recently acquired...

  1. How Many Transgender Men Are There in San Francisco?

    Science.gov (United States)

    McFarland, Willi; Wilson, Erin; Fisher Raymond, H

    2017-05-01

    The purpose of this study was to estimate the number of transgender men (transmen) adults living in San Francisco. We integrated two population size estimation methods into a community-based health survey of transmen (n = 122) in the San Francisco Bay Area in 2014-2015: the service multiplier and wisdom of the crowds. The median estimate was 806 transmen adults in San Francisco (0.11% of adults) and 4027 in the Bay Area. Considering potential biases, we believe our estimates are conservative. Knowing the denominator of persons at risk for health conditions is necessary for public health planning, surveillance, and impact evaluation.

  2. The effect of physical and chemical parameters on the macroinfaunal community structure of San Vicente bay, Chile Efectos de parámetros físicos y químicos en la estructura comunitaria de la macroinfauna en la bahía de San Vicente, Chile

    Directory of Open Access Journals (Sweden)

    ROCÍO A. SIEMENS

    2001-06-01

    Full Text Available San Vicente bay is a heavily industrialised bay located in central Chile, which has a sand beach extending from an area of recreational use in the south to an area of industrial use and discharge in the north. A survey of the macrofauna in the intertidal zone revealed a non-homogeneous distribution; a maximum of five invertebrate species were found with all five only occurring in one of six transects down the beach. The density ranged from 0 to 188 individuals m-2, with the highest density at the recreational end. The most common species, Emerita analoga (Stimpson, was chosen to study the macrofaunal response to beach morphodynamics, physicochemical parameters and metal concentrations. The E. analoga distribution was not significantly correlated with the results of the physicochemical analyses of interstitial water (pH, temperature, salinity and oxygen concentrations. However, oxygen concentrations decreased to 3 ml O2 l-1 in the lower intertidal closest to the recreational area where the highest numbers of intertidal macrofauna were observed. Analyses of 12 metals in the sediments showed three distinct distribution patterns across the beach in which the metals could be classified: a representative metal was chosen for each distribution. The concentration of tin ranged from 3.4 to 11.58 mg g-1DW sediment, representing the `wave' pattern. The concentration of cadmium ranged from 0 to 0.23 mg g-1DW sediment, representing the `banded' pattern. The concentration of chromium ranged from 1.97 to 3.18 mg g-1DW sediment, representing the `intermediate' pattern of metal distribution. The E. analoga distribution was not significantly correlated with the concentrations of any single metal, although multivariate statistical analysis indicated that Sn and Fe had the largest negative effect and Mn had the largest positive one. The distribution of E. analoga across the sandy beach of San Vicente bay was significantly correlated with the relative tidal range

  3. San Marino.

    Science.gov (United States)

    1985-02-01

    San Marino, an independent republic located in north central Italy, in 1983 had a population of 22,206 growing at an annual rate of .9%. The literacy rate is 97% and the infant mortality rate is 9.6/1000. The terrain is mountainous and the climate is moderate. According to local tradition, San Marino was founded by a Christian stonecutter in the 4th century A.D. as a refuge against religious persecution. Its recorded history began in the 9th century, and it has survived assaults on its independence by the papacy, the Malatesta lords of Rimini, Cesare Borgia, Napoleon, and Mussolini. An 1862 treaty with the newly formed Kingdom of Italy has been periodically renewed and amended. The present government is an alliance between the socialists and communists. San Marino has had its own statutes and governmental institutions since the 11th century. Legislative authority at present is vested in a 60-member unicameral parliament. Executive authority is exercised by the 11-member Congress of State, the members of which head the various administrative departments of the goverment. The posts are divided among the parties which form the coalition government. Judicial authority is partly exercised by Italian magistrates in civil and criminal cases. San Marino's policies are tied to Italy's and political organizations and labor unions active in Italy are also active in San Marino. Since World War II, there has been intense rivalry between 2 political coalitions, the Popular Alliance composed of the Christian Democratic Party and the Independent Social Democratic Party, and the Liberty Committee, coalition of the Communist Party and the Socialist Party. San Marino's gross domestic product was $137 million and its per capita income was $6290 in 1980. The principal economic activities are farming and livestock raising, along with some light manufacturing. Foreign transactions are dominated by tourism. The government derives most of its revenue from the sale of postage stamps to

  4. Microsatellite analyses of San Franciscuito Creek rainbow trout

    Science.gov (United States)

    Nielsen, Jennifer L.

    2000-01-01

    Microsatellite genetic diversity found in San Francisquito Creek rainbow trout support a close genetic relationship with rainbow trout (Oncorhynchus mykiss) from another tributary of San Francisco Bay, Alameda Creek, and coastal trout found in Lagunitas Creek, Marin County, California. Fish collected for this study from San Francisquito Creek showed a closer genetic relationship to fish from the north-central California steelhead ESU than for any other listed group of O. mykiss. No significant genotypic or allelic frequency associations could be drawn between San Francisquito Creek trout and fish collected from the four primary rainbow trout hatchery strains in use in California, i.e. Whitney, Mount Shasta, Coleman, and Hot Creek hatchery fish. Indeed, genetic distance analyses (δµ2) supported separation between San Francisquito Creek trout and all hatchery trout with 68% bootstrap values in 1000 replicate neighbor-joining trees. Not surprisingly, California hatchery rainbow trout showed their closest evolutionary relationships with contemporary stocks derived from the Sacramento River. Wild collections of rainbow trout from the Sacramento-San Joaquin basin in the Central Valley were also clearly separable from San Francisquito Creek fish supporting separate, independent ESUs for two groups of O. mykiss (one coastal and one Central Valley) with potentially overlapping life histories in San Francisco Bay. These data support the implementation of management and conservation programs for rainbow trout in the San Francisquito Creek drainage as part of the central California coastal steelhead ESU.

  5. Quaternary geology of Alameda County, and parts of Contra Costa, Santa Clara, San Mateo, San Francisco, Stanislaus, and San Joaquin counties, California: a digital database

    Science.gov (United States)

    Helley, E.J.; Graymer, R.W.

    1997-01-01

    Alameda County is located at the northern end of the Diablo Range of Central California. It is bounded on the north by the south flank of Mount Diablo, one of the highest peaks in the Bay Area, reaching an elevation of 1173 meters (3,849 ft). San Francisco Bay forms the western boundary, the San Joaquin Valley borders it on the east and an arbitrary line from the Bay into the Diablo Range forms the southern boundary. Alameda is one of the nine Bay Area counties tributary to San Francisco Bay. Most of the country is mountainous with steep rugged topography. Alameda County is covered by twenty-eight 7.5' topographic Quadrangles which are shown on the index map. The Quaternary deposits in Alameda County comprise three distinct depositional environments. One, forming a transgressive sequence of alluvial fan and fan-delta facies, is mapped in the western one-third of the county. The second, forming only alluvial fan facies, is mapped in the Livermore Valley and San Joaquin Valley in the eastern part of the county. The third, forming a combination of Eolian dune and estuarine facies, is restricted to the Alameda Island area in the northwestern corner of the county.

  6. 78 FR 39610 - Safety Zone; Big Bay Boom, San Diego Bay; San Diego, CA

    Science.gov (United States)

    2013-07-02

    ... ``SEARCH'' box and click ``SEARCH.'' Click on Open Docket Folder on the line associated with this... positions: Shelter Island Barge: 32 42.8' N, 117 13.2' W Harbor Island Barge: 32 43.3' N, 117 12.0' W Embarcadero Barge: 32 42.9' N, 117 10.8' W Seaport Village Barge: 32 42.2' N, 117 10.0' W These temporary...

  7. Summary of California Clapper Rail winter populations in the San Francisco National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The California Clapper rail (Rallus lonqirostris obsoletus) is a seldom seen resident in some of the remaining tidal salt marshes in San Francisco Bay. The...

  8. Survival of patients with metastatic breast cancer: twenty-year data from two SEER registries

    Directory of Open Access Journals (Sweden)

    Cserni Gábor

    2004-09-01

    Full Text Available Abstract Background Many researchers are interested to know if there are any improvements in recent treatment results for metastatic breast cancer in the community, especially for 10- or 15-year survival. Methods Between 1981 and 1985, 782 and 580 female patients with metastatic breast cancer were extracted respectively from the Connecticut and San Francisco-Oakland registries of the Surveillance, Epidemiology, and End Results (SEER database. The lognormal statistical method to estimate survival was retrospectively validated since the 15-year cause-specific survival rates could be calculated using the standard life-table actuarial method. Estimated rates were compared to the actuarial data available in 2000. Between 1991 and 1995, further 752 and 632 female patients with metastatic breast cancer were extracted respectively from the Connecticut and San Francisco-Oakland registries. The data were analyzed to estimate the 15-year cause-specific survival rates before the year 2005. Results The 5-year period (1981–1985 was chosen, and patients were followed as a cohort for an additional 3 years. The estimated 15-year cause-specific survival rates were 7.1% (95% confidence interval, CI, 1.8–12.4 and 9.1% (95% CI, 3.8–14.4 by the lognormal model for the two registries of Connecticut and San Francisco-Oakland respectively. Since the SEER database provides follow-up information to the end of the year 2000, actuarial calculation can be performed to confirm (validate the estimation. The Kaplan-Meier calculation for the 15-year cause-specific survival rates were 8.3% (95% CI, 5.8–10.8 and 7.0% (95% CI, 4.3–9.7 respectively. Using the 1991–1995 5-year period cohort and followed for an additional 3 years, the 15-year cause-specific survival rates were estimated to be 9.1% (95% CI, 3.8–14.4 and 14.7% (95% CI, 9.8–19.6 for the two registries of Connecticut and San Francisco-Oakland respectively. Conclusions For the period 1981–1985, the 15

  9. Survival of patients with metastatic breast cancer: twenty-year data from two SEER registries.

    Science.gov (United States)

    Tai, Patricia; Yu, Edward; Vinh-Hung, Vincent; Cserni, Gábor; Vlastos, Georges

    2004-09-02

    Many researchers are interested to know if there are any improvements in recent treatment results for metastatic breast cancer in the community, especially for 10- or 15-year survival. Between 1981 and 1985, 782 and 580 female patients with metastatic breast cancer were extracted respectively from the Connecticut and San Francisco-Oakland registries of the Surveillance, Epidemiology, and End Results (SEER) database. The lognormal statistical method to estimate survival was retrospectively validated since the 15-year cause-specific survival rates could be calculated using the standard life-table actuarial method. Estimated rates were compared to the actuarial data available in 2000. Between 1991 and 1995, further 752 and 632 female patients with metastatic breast cancer were extracted respectively from the Connecticut and San Francisco-Oakland registries. The data were analyzed to estimate the 15-year cause-specific survival rates before the year 2005. The 5-year period (1981-1985) was chosen, and patients were followed as a cohort for an additional 3 years. The estimated 15-year cause-specific survival rates were 7.1% (95% confidence interval, CI, 1.8-12.4) and 9.1% (95% CI, 3.8-14.4) by the lognormal model for the two registries of Connecticut and San Francisco-Oakland respectively. Since the SEER database provides follow-up information to the end of the year 2000, actuarial calculation can be performed to confirm (validate) the estimation. The Kaplan-Meier calculation for the 15-year cause-specific survival rates were 8.3% (95% CI, 5.8-10.8) and 7.0% (95% CI, 4.3-9.7) respectively. Using the 1991-1995 5-year period cohort and followed for an additional 3 years, the 15-year cause-specific survival rates were estimated to be 9.1% (95% CI, 3.8-14.4) and 14.7% (95% CI, 9.8-19.6) for the two registries of Connecticut and San Francisco-Oakland respectively. For the period 1981-1985, the 15-year cause-specific survival for the Connecticut and the San Francisco-Oakland

  10. 78 FR 53243 - Safety Zone; TriRock San Diego, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2013-08-29

    ... Folder on the line associated with this rulemaking. You may also visit the Docket Management Facility in... Convention Center bound by the following coordinates including the marina: 32 42'16 N, 117 09'58'' W to 32 42'15'' N, 117 10'02'' W then south to 32 42'00'' N, 117 09'45'' W to 32 42'03'' N, 117 09'40'' W. This...

  11. 77 FR 54811 - Safety Zone; TriRock San Diego, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2012-09-06

    ... on Open Docket Folder on the line associated with this rulemaking. You may also visit the Docket... bound by the following coordinates including the marina; 32 42'16'' N, 117 09'58'' W to 32 42'15'' N, 117 10'02'' W then south to 32 42'00'' N, 117 09'45'' W to 32 42'03'' N, 117 09'40'' W. This safety...

  12. Yupingfeng San

    Science.gov (United States)

    Liu, Xue; Shen, Jiawen; Fan, Danping; Qiu, Xuemei; Guo, Qingqing; Zheng, Kang; Luo, Hui; Shu, Jun; Lu, Cheng; Zhang, Ge; Lu, Aiping; Ma, Chaoying; He, Xiaojuan

    2017-01-01

    Yupingfeng San (YPFS) is a representative Traditional Chinese Medicine (TCM) formula with accepted therapeutic effect on Asthma. However, its action mechanism is still obscure. In this study, we used network pharmacology to explore potential mechanism of YPFS on asthma. Nucleotide-binding oligomerization domain (NOD)-like receptor pathway was shown to be the top one shared signaling pathway associated with both YPFS and asthma. In addition, NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome was treated as target protein in the process of YPFS regulating asthma. Further, experimental validation was done by using LPS-stimulated U937 cells and ovalbumin (OVA)-sensitized BALB/c mice model. In vitro experiments showed that YPFS significantly decreased the production of TNF-α and IL-6, as well as both mRNA and protein levels of IL-1β, NLRP3, Caspase-1 and ASC in LPS-stimulated U937 cells. In vivo experiment indicated that YPFS treatment not only attenuated the clinical symptoms, but also reduced inflammatory cell infiltration, mucus secretion and MUC5AC production in lung tissue of asthmatic mice. Moreover, YPFS treatment remarkably decreased the mRNA and protein levels of IL-1β, NLRP3, Caspase-1 and ASC in lung tissue of asthmatic mice. In conclusion, these results demonstrated that YPFS could inhibit NLRP3 inflammasome components to attenuate the inflammatory response in asthma.

  13. Bay Area Transit Agencies Propel Fuel Cell Buses Toward Commercialization (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    This fact sheet describes the Zero Emission Bay Area (ZEBA) demonstration of the next generation of fuel cells buses. Several transit agencies in the San Francisco Bay Area are participating in demonstrating the largest single fleet of fuel cell buses in the United States.

  14. Modeling the hydrodynamic responses to land reclamation in different regions of a semi-enclosed bay

    Science.gov (United States)

    Yang, Y.; Chui, T. F. M.

    2016-12-01

    Water area in bays has been reclaimed to meet the increasing land demand for development. Numbers of studies have examined the hydrodynamic impacts induced by land reclamations in semi-enclosed bays such as San Francisco Bay in the U.S., Tokyo Bay in Japan, and Jiaozhou Bay in China. However, they have not compared the impacts of land reclamations taken place in different regions. The Deep Bay in China was selected as a case study to evaluate and compare the hydrodynamic responses to land reclamations that narrows the bay mouth and that causes water surface loss inside of the bay. A numerical model was employed to simulate the hydrodynamics throughout the bay and to examine the differences in impacts through scenario experiments. The model was validated using the observations of water elevation, currents, and salinity. To indicate the changes in hydrodynamics, tidal prism, current field, tidal energy flux, and water age were computed. Simulation results show that narrowing the bay mouth length by 30% with ??% loss of its original water surface area would increase the total energy flux entering the bay by 26 %, while 14% loss of its original water surface area in middle bay would decrease the total energy entering the bay by 23%. The two regions of reclamations have both resulted in substantial but different changes in current field, the spatial distribution of tidal energy flux and water age. For example, the reclamation at bay mouth has increased the current velocity and tidal energy flux at the bay mouth while that inside of the bay has streamlined the current field and increased the velocity in the inner bay. The water age throughout the bay has been reduced by 5.1% and 13.7% respectively in the two scenarios, increasing the water exchange ability of the bay with the adjacent sea. This study is beneficial to other semi-enclosed bays considering land reclamations, facilitating quick and preliminary estimations of hydrodynamic impacts for planning and management.

  15. A Creek to Bay Biological Assessment in Oakland, California

    Science.gov (United States)

    Ahumada, E.; Ramirez, N.; Lopez, A.; Avila, M.; Ramirez, J.; Arroyo, D.; Bracho, H.; Casanova, A.; Pierson, E.

    2011-12-01

    In 2007, the Surface Water Ambient Monitoring Program (SWAMP) assessed the impact of trash on water quality in the Peralta Creek which is located in the Fruitvale district of Oakland, CA. This 2011 follow-up study will take further steps in evaluating the physical and biological impacts of pollution and human development on Peralta Creek and in the San Leandro Bay, where the Creek empties into the larger San Francisco Bay estuary. This study will utilize two forms of biological assessment in order to determine the level of water quality and ecosystem health of Peralta Creek and San Leandro Bay in Oakland, California. A Rapid Bioassesment Protocal (RBP) will be used as the method of biological assessment for Peralta Creek. RBP uses a biotic index of benthic macroinvertebrates to provide a measure of a water body's health. Larval trematodes found in two mud snails (Ilynassa obsoleta and Cerithidea californica) will be used to evaluate the health of the San Leandro Bay. Due to the complex life cycle of trematodes, the measure of trematode diversity and richness in host species serves as an indicator of estuarine health (Huspeni 2005). We have completed the assessment of one section of Peralta Creek, located at 2465 34th Avenue, Oakland, CA 94601. Abundance results indicate a moderately healthy creek because there were high levels of pollution tolerant benthic macroinvertebrates. The tolerant group of benthic macroinvertebrates includes such organisms as flatworms, leeches, and scuds. This is possibly due to this section of the creek being pumped up to the surface from culverts impacting the macroinvertebrate's life cycle. Another contributing factor to creek health is the amount of organic debris found in the creek, which inhibits the flow and oxygenation of the water, allowing for more pollution tolerant aquatic insects to persist. Further investigation is being conducted to fully assess the Peralta Creek watershed; from the preliminary results one can surmise that

  16. The San Andreas Fault 'Supersite' (Invited)

    Science.gov (United States)

    Hudnut, K. W.

    2013-12-01

    An expanded and permanent Supersite has been proposed to the Committee on Earth Observation Satellites (CEOS) for the San Andreas Fault system, based upon the successful initial Group on Earth Observations (GEO) Geohazard Supersite for the Los Angeles region from 2009-2013. As justification for the comprehensive San Andreas Supersite, consider the earthquake history of California, in particular the devastating M 7.8 San Francisco earthquake of 1906, which occurred along the San Andreas Fault, as did an earthquake of similar magnitude in 1857 in southern California. Los Angeles was only a small town then, but now the risk exposure has increased for both of California's megacities. Between the San Francisco and Los Angeles urban areas lies a section of the San Andreas Fault known to creep continually, so it has relatively less earthquake hazard. It used to be thought of as capable of stopping earthquakes entering it from either direction. Transitional behavior at either end of the creeping section is known to display a full range of seismic to aseismic slip events and accompanying seismicity and strain transient events. Because the occurrence of creep events is well documented by instrumental networks such as CISN and PBO, the San Andreas Supersite can be expected to be especially effective. A good baseline level of geodetic data regarding past events and strain accumulation and release exists. Many prior publications regarding the occurrence of geophysical phenomena along the San Andreas Fault system mean that in order to make novel contributions, state-of-the-art science will be required within this Supersite region. In more recent years, the 1989 Loma Prieta earthquake struck adjacent to the San Andreas Fault and caused the most damage along the western side of the San Francisco Bay Area. More recently, the concern has focused on the potential for future events along the Hayward Fault along the eastern side of San Francisco Bay. In Southern California, earthquakes

  17. Naval Air Station Alameda’s Material Distribution System.

    Science.gov (United States)

    1979-12-01

    COSTS 1 October 1978 to 31 September 1979 Type Total Average Average Average Equinment 1Tumber Repair Cost Utilization Cost per Unit Per Unit...monitoring was ’one bit supervisors to ensure that material does not get ,-pigeon holed" for indefinite periods of time or that vehicles are actually...San Francisco, Oakland, California, April 1979. 19. Nanagement Control of m,[aterial Handline Equinment Ashore ’ctivity Verification and Allowance

  18. San Mateo Creek Basin

    Science.gov (United States)

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  19. 76 FR 19519 - Intent To Prepare an Environmental Impact Statement for the Downtown San Francisco Ferry Terminal...

    Science.gov (United States)

    2011-04-07

    ... Francisco Ferry Terminal Expansion Project in the City and County of San Francisco, CA AGENCY: Federal... Transportation Authority (WETA) are planning to prepare an EIS for the proposed expansion and improvements to the... Expansion Project is to support and expand ferry service on San Francisco Bay, as established by WETA in its...

  20. Forward Stagewise Naive Bayes

    OpenAIRE

    Vidaurre Henche, Diego; Bielza, Concha; Larrañaga Múgica, Pedro

    2012-01-01

    The naïve Bayes approach is a simple but often satisfactory method for supervised classification. In this paper, we focus on the naïve Bayes model and propose the application of regularization techniques to learn a naïve Bayes classifier. The main contribution of the paper is a stagewise version of the selective naïve Bayes, which can be considered a regularized version of the naïve Bayes model. We call it forward stagewise naïve Bayes. For comparison’s sake, we also introduce an explicitly r...

  1. Map showing locations of damaging landslides in San Mateo County, California, resulting from 1997-98 El Nino rainstorms

    Science.gov (United States)

    Jayko, Angela S.; De Mouthe, Jean; Lajoie, Kenneth R.; Ramsey, David W.; Godt, Jonathan W.

    1999-01-01

    Heavy rainfall associated with a strong El Nino caused over $150 million in landslide damage in the 10-county San Francisco Bay region during the winter and spring of 1998. A team of USGS scientists collected information on landslide locations and damage costs. About $55 million in damages were assessed in San Mateo County. The only fatality attributed to landsliding in the region during the period occurred in San Mateo County near Loma Mar.

  2. Thatcher Bay, Washington, Nearshore Restoration Assessment

    Science.gov (United States)

    Breems, Joel; Wyllie-Echeverria, Sandy; Grossman, Eric E.; Elliott, Joel

    2009-01-01

    The San Juan Archipelago, located at the confluence of the Puget Sound, the Straits of Juan de Fuca in Washington State, and the Straits of Georgia, British Columbia, Canada, provides essential nearshore habitat for diverse salmonid, forage fish, and bird populations. With 408 miles of coastline, the San Juan Islands provide a significant portion of the available nearshore habitat for the greater Puget Sound and are an essential part of the regional efforts to restore Puget Sound (Puget Sound Shared Strategy 2005). The nearshore areas of the San Juan Islands provide a critical link between the terrestrial and marine environments. For this reason the focus on restoration and conservation of nearshore habitat in the San Juan Islands is of paramount importance. Wood-waste was a common by-product of historical lumber-milling operations. To date, relatively little attention has been given to the impact of historical lumber-milling operations in the San Juan Archipelago. Thatcher Bay, on Blakely Island, located near the east edge of the archipelago, is presented here as a case study on the restoration potential for a wood-waste contaminated nearshore area. Case study components include (1) a brief discussion of the history of milling operations. (2) an estimate of the location and amount of the current distribution of wood-waste at the site, (3) a preliminary examination of the impacts of wood-waste on benthic flora and fauna at the site, and (4) the presentation of several restoration alternatives for the site. The history of milling activity in Thatcher Bay began in 1879 with the construction of a mill in the southeastern part of the bay. Milling activity continued for more than 60 years, until the mill closed in 1942. Currently, the primary evidence of the historical milling operations is the presence of approximately 5,000 yd3 of wood-waste contaminated sediments. The distribution and thickness of residual wood-waste at the site was determined by using sediment

  3. Chapter A. The Loma Prieta, California, Earthquake of October 17, 1989 - Lifelines

    Science.gov (United States)

    Schiff, Anshel J.

    1998-01-01

    To the general public who had their televisions tuned to watch the World Series, the 1989 Loma Prieta earthquake was a lifelines earthquake. It was the images seen around the world of the collapsed Cypress Street viaduct, with the frantic and heroic efforts to pull survivors from the structure that was billowing smoke; the collapsed section of the San Francisco-Oakland Bay Bridge and subsequent home video of a car plunging off the open span; and the spectacular fire in the Marina District of San Francisco fed by a broken gasline. To many of the residents of the San Francisco Bay region, the relation of lifelines to the earthquake was characterized by sitting in the dark because of power outage, the inability to make telephone calls because of network congestion, and the slow and snarled traffic. Had the public been aware of the actions of the engineers and tradespeople working for the utilities and other lifeline organizations on the emergency response and restoration of lifelines, the lifeline characteristics of this earthquake would have been even more significant. Unobserved by the public were the warlike devastation in several electrical-power substations, the 13 miles of gas-distribution lines that had to be replaced in several communities, and the more than 1,200 leaks and breaks in water mains and service connections that had to be excavated and repaired. Like the 1971 San Fernando, Calif., earthquake, which was a seminal event for activity to improve the earthquake performance of lifelines, the 1989 Loma Prieta earthquake demonstrated that the tasks of preparing lifelines in 'earthquake country' were incomplete-indeed, new lessons had to be learned.

  4. Bathymetry and acoustic backscatter: Estero Bay, California

    Science.gov (United States)

    Hartwell, Stephen R.; Finlayson, David P.; Dartnell, Peter; Johnson, Samuel Y.

    2013-01-01

    Between July 30 and August 9, 2012, scientists from the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), acquired bathymetry and acoustic-backscatter data from Estero Bay, San Luis Obispo, California, under PCMSC Field Activity ID S-05-12-SC. The survey was done using the R/V Parke Snavely outfitted with a multibeam sonar for swath mapping and highly accurate position and orientation equipment for georeferencing. This report provides these data in a number of different formats, as well as a summary of the mapping mission, maps of bathymetry and backscatter, and Federal Geographic Data Committee (FGDC) metadata.

  5. SAN CARLOS APACHE PAPERS.

    Science.gov (United States)

    ROESSEL, ROBERT A., JR.

    THE FIRST SECTION OF THIS BOOK COVERS THE HISTORICAL AND CULTURAL BACKGROUND OF THE SAN CARLOS APACHE INDIANS, AS WELL AS AN HISTORICAL SKETCH OF THE DEVELOPMENT OF THEIR FORMAL EDUCATIONAL SYSTEM. THE SECOND SECTION IS DEVOTED TO THE PROBLEMS OF TEACHERS OF THE INDIAN CHILDREN IN GLOBE AND SAN CARLOS, ARIZONA. IT IS DIVIDED INTO THREE PARTS--(1)…

  6. Aggregate Settling Velocities in San Francisco Estuary Margins

    Science.gov (United States)

    Allen, R. M.; Stacey, M. T.; Variano, E. A.

    2015-12-01

    One way that humans impact aquatic ecosystems is by adding nutrients and contaminants, which can propagate up the food web and cause blooms and die-offs, respectively. Often, these chemicals are attached to fine sediments, and thus where sediments go, so do these anthropogenic influences. Vertical motion of sediments is important for sinking and burial, and also for indirect effects on horizontal transport. The dynamics of sinking sediment (often in aggregates) are complex, thus we need field data to test and validate existing models. San Francisco Bay is well studied and is often used as a test case for new measurement and model techniques (Barnard et al. 2013). Settling velocities for aggregates vary between 4*10-5 to 1.6*10-2 m/s along the estuary backbone (Manning and Schoellhamer 2013). Model results from South San Francisco Bay shoals suggest two populations of settling particles, one fast (ws of 9 to 5.8*10-4 m/s) and one slow (ws of Brand et al. 2015). While the open waters of San Francisco Bay and other estuaries are well studied and modeled, sediment and contaminants often originate from the margin regions, and the margins remain poorly characterized. We conducted a 24 hour field experiment in a channel slough of South San Francisco Bay, and measured settling velocity, turbulence and flow, and suspended sediment concentration. At this margin location, we found average settling velocities of 4-5*10-5 m/s, and saw settling velocities decrease with decreasing suspended sediment concentration. These results are consistent with, though at the low end of, those seen along the estuary center, and they suggest that the two population model that has been successful along the shoals may also apply in the margins.

  7. Review of suspended sediment in lower South Bay relevant to light attenuation and phytoplankton blooms

    Science.gov (United States)

    Schoellhamer, David H.; Shellenbarger, Gregory; Downing-Kunz, Maureen; Manning, Andrew J.

    2016-01-01

    Lower South Bay (LSB), a shallow subembayment of San Francisco Bay (SFB), is situated south of the Dumbarton Bridge, and is surrounded by, and interconnected with, a network of sloughs, marshes, and former salt ponds undergoing restoration (Figure ES.1). LSB receives 120 million gallons per day of treated wastewater effluent from three publicly owned treatment works (POTWs) that service San Jose and the densely populated surrounding region. During the dry season, when flows from creeks and streams are at their minimum, POTW effluent comprises the majority of freshwater flow to Lower South Bay. Although LSB has a large tidal prism, it experiences limited net exchange with the surrounding Bay, because much of the water that leaves on ebb tides returns during the subsequent flood tides. The limited exchange leads to distinctly different biogeochemical conditions in LSB compared to other SFB subembayments, including LSB having the highest nutrient concentrations and highest phytoplankton biomass.

  8. Morphological evolution in the San Francisco Bight

    Science.gov (United States)

    Hanes, Daniel M.; Barnard, Patrick L.

    2007-01-01

    San Francisco Bight, located near the coast of San Francisco, USA, is an extremely dynamic tidal inlet environmental subject to large waves and strong currents. Wave heights coming from the Pacific Ocean commonly exceed 5 m during winter storms. During peak flow tidal currents approach 3 m/s at the Golden Gate, a 1 km wide entrance that connects San Francisco Bay to the Pacific Ocean. Flow structure in this region varies markedly spatially and temporally due to the complex interaction by wind, waves and tidal currents. A multibeam sonar survey was recently completed that mapped in high resolution, for the first time, the bottom morphology in the region of the ebb tidal delta. This data set includes a giant sand wave field covering an area of approximately 4 square kilometers. The new survey enables the calculation of seabed change that has occurred in the past 50 years, since the last comprehensive survey of the area was completed. This comparison indicates an average erosion of 60 centimeters which equates to a total volume change of approximately 9.3 x 107 m3. Morphologic change also indicates that flood channels have filled and that the entire ebb delta is contracting radially.

  9. Locally Weighted Naive Bayes

    OpenAIRE

    Frank, Eibe; Hall, Mark; Pfahringer, Bernhard

    2012-01-01

    Despite its simplicity, the naive Bayes classifier has surprised machine learning researchers by exhibiting good performance on a variety of learning problems. Encouraged by these results, researchers have looked to overcome naive Bayes primary weakness - attribute independence - and improve the performance of the algorithm. This paper presents a locally weighted version of naive Bayes that relaxes the independence assumption by learning local models at prediction time. Experimental results s...

  10. Tidal Marsh Vegetation of China Camp, San Pablo Bay, California

    OpenAIRE

    Baye, Peter R.

    2012-01-01

    China Camp (Marin County, California) preserves extensive relict stands of salt marsh vegetation developed on a prehistoric salt marsh platform with a complex sinuous tidal creek network. The low salt marsh along tidal creeks supports extensive native stands of Pacific cordgrass (Spartina foliosa). The outer salt marsh accreted following hydraulic gold mining sedimentation. It consists of a wave-scarped pickleweed-dominated (Sarcocornia pacifica) high salt marsh terrace with a broad fringing ...

  11. Shallow benthic habitats of San Francisco Bay, California CMECS Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has been developed for the National Oceanic and Atmospheric Administration's (NOAA) Office for Coastal Management (OCM) as a collaborative and...

  12. Dengue fever in the San Juan Bay Estuary: Evaluating the ...

    Science.gov (United States)

    Dengue is transmitted by Aedes aegypti, a species that thrives in cities. Here we ask which elements within the urban environment could be managed to reduce the potential for Dengue occurrence. In particular, we study the potential of wetlands in the SJBE to buffer from vector proliferation. Wetlands provide ecosystem services such as heat and water hazard mitigation, water purification and habitat for a diversity of species, all of which are factors that have been shown to affect Dengue vectors. As such, we hypothesize that within coastal neighborhoods in the SJBE wetlands, ecosystem services lead to lower Dengue occurrence. We test this hypothesis using Dengue data from 2010-2013, which includes the largest epidemic in PR history. Our analytical model includes relevant socio-economic factors and environmental controls that may also affect Dengue dynamics. Results indicated a negative effect of neighborhood mangrove cover and a positive effect of percent flood area on Dengue prevalence. Moreover, heat hazards were positively correlated with dengue prevalence and negatively correlated with neighborhood mangrove cover. Dengue prevalence did not correlate with herbaceous wetlands, or with the ecosystem services of water quality or vertebrate species richness. Mosquito borne diseases are an increasingly important health concern, which pose great challenges for safe and sustainable control and eradication. This reality calls for management approaches that consider m

  13. Marine Ecological Index Survey of San Diego Bay

    Science.gov (United States)

    2013-03-01

    Taxonomist specialties were as follows:  Tony Phillips – Dancing Coyote Environmental, Arthropods and Echinoderms  Gretchen Lambert, MS – University of...vectors for parasites and disease that can harm both native species and humans (Wilcove et al., 1998; Ruiz et al., 2000). A strain of cholera never...with arthropods making up 58%, mollusks making up 28%, nemerteans making up 12%, and one species of cnidaria at 4%. The arthropod Cirolana harfordi

  14. Coastal Bend Texas Benthic Habitat - San Antonio Bay 2007 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 2006 and 2007 the NOAA Office for Coastal Management purchased services to process existing digital multi-spectral imagery (ADS-40) and create digital benthic...

  15. Wakasa Bay Weather Forecast Maps

    Data.gov (United States)

    National Aeronautics and Space Administration — The AMSR-E Wakasa Bay Field Campaign was conducted over Wakasa Bay, Japan, in January and February, 2003. The Wakasa Bay Field Campaign includes joint research...

  16. 76 FR 70480 - Otay River Estuary Restoration Project, South San Diego Bay Unit of the San Diego Bay National...

    Science.gov (United States)

    2011-11-14

    ... restore * * * coastal wetlands * * * to benefit the native fish, wildlife, and plant species supported... restoration is being provided by the Poseidon Resources Carlsbad Desalination Project, in order to implement... requirement for the desalination project. On November 15, 2007, the California Coastal Commission approved a...

  17. Site-specific Protocol for Monitoring Marsh Birds : Don Edwards San Francisco Bay and San Pablo Bay National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This site-specific survey protocol provides standardized methods for monitoring marsh birds and was designed for use by the U.S. Fish and Wildlife Service (USFWS) on...

  18. H10080: NOS Hydrographic Survey , San Francisco Bay and San Pablo Bay, California, 1983-04-29

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  19. 75 FR 17329 - Safety Zone; Big Bay Fourth of July Fireworks, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2010-04-06

    ..., which will then become highlighted in blue. In the ``Document Type'' drop down menu select ``Proposed..., design, or operation; test methods; sampling procedures; and related management systems practices) that...

  20. F00242: NOS Hydrographic Survey , San Francisco Bay and San Pablo Bay, California, 1983-05-03

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  1. F00311: NOS Hydrographic Survey , San Francisco Bay and San Pablo Bay, California, 1987-11-16

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  2. eBay.com

    DEFF Research Database (Denmark)

    Engholm, Ida

    2014-01-01

    Celebrated as one of the leading and most valuable brands in the world, eBay has acquired iconic status on par with century-old brands such as Coca-Cola and Disney. The eBay logo is now synonymous with the world’s leading online auction website, and its design is associated with the company...

  3. Experimental enhancement of pickleweed, Suisun Bay, California

    Science.gov (United States)

    Miles, A. Keith; Van Vuren, Dirk H.; Tsao, Danika C.; Yee, Julie L.

    2015-01-01

    As mitigation for habitat impacted by the expansion of a pier on Suisun Bay, California, two vehicle parking lots (0.36 ha and 0.13 ha) were restored by being excavated, graded, and contoured using dredged sediments to the topography or elevation of nearby wetlands. We asked if pickleweed (Sarcocornia pacifica L, [Amaranthaceae]) colonization could be enhanced by experimental manipulation on these new wetlands. Pickleweed dominates ecologically important communities at adjacent San Francisco Bay, but is not typically dominant at Suisun Bay probably because of widely fluctuating water salinity and is outcompeted by other brackish water plants. Experimental treatments (1.0-m2 plots) included mulching with pickleweed cuttings in either the fall or the spring, tilling in the fall, or applying organic enrichments in the fall. Control plots received no treatment. Pickleweed colonization was most enhanced at treatment plots that were mulched with pickleweed in the fall. Since exotic vegetation can colonize bare sites within the early phases of restoration and reduce habitat quality, we concluded that mulching was most effective in the fall by reducing invasive plant cover while facilitating native plant colonization.

  4. Operational modal identification using variational Bayes

    Science.gov (United States)

    Li, Binbin; Der Kiureghian, Armen

    2017-05-01

    Operational modal analysis is the primary tool for modal parameter identification in civil engineering. Bayesian statistics offers an ideal framework for analyzing uncertainties associated with the identified modal parameters. However, the exact Bayesian formulation is usually intractable due to the high computational demand in obtaining the posterior distributions of modal parameters. In this paper, the variational Bayes method is employed to provide an approximate solution. Unlike the Laplace approximation and Monte Carlo sampling, the variational Bayes approach provides a gradient-free algorithm to analytically approximate the posterior distributions. Working with the state-space representation of a dynamical system, the variational Bayes approach for identification of modal parameters is derived by ignoring statistical correlation between latent variables and the model parameters. In this approach, the joint distribution of the state-transition and observation matrices as well as the joint distribution of the process noise and measurement error are firstly calculated analytically using conjugate priors. The distribution of modal parameters is extracted from these obtained joint distributions using a first-order Taylor series expansion. A robust implementation of the method is discussed by using square-root filtering and Cholesky decomposition. The proposed approach is illustrated by its application to an example mass-spring system and the One Rincon Hill Tower in San Francisco.

  5. 77 FR 60899 - Safety Zone; Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Science.gov (United States)

    2012-10-05

    ..., Program Manager, Docket Operations, telephone (202) 366-9826. SUPPLEMENTARY INFORMATION: Table of Acronyms... opportunity to comment pursuant to authority under section 4(a) of the Administrative Procedure Act (APA) (5 U... Subjects in 33 CFR Part 165 Harbors, Marine safety, Navigation (water), Reporting and recordkeeping...

  6. 77 FR 42638 - Safety Zone: Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Science.gov (United States)

    2012-07-20

    .... SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security FR Federal Register NPRM Notice... Administrative Procedure Act (APA) (5 U.S.C. 553(b)). This provision authorizes an agency to issue a rule without... in 33 CFR Part 165 Harbors, Marine safety, Navigation (water), Reporting and recordkeeping...

  7. 77 FR 42649 - Safety Zone: Sea World San Diego Fireworks, Mission Bay; San Diego, CA

    Science.gov (United States)

    2012-07-20

    ..., telephone (202) 366-9826. SUPPLEMENTARY INFORMATION: Table of Acronyms DHS Department of Homeland Security... authority under section 4(a) of the Administrative Procedure Act (APA) (5 U.S.C. 553(b)). This provision... Part 165 Harbors, Marine safety, Navigation (water), Reporting and recordkeeping requirements, Security...

  8. 76 FR 1386 - Safety Zone; Centennial of Naval Aviation Kickoff, San Diego Bay, San Diego, CA

    Science.gov (United States)

    2011-01-10

    ... highlighted in blue. In the ``Document Type'' drop down menu select ``Proposed Rule'' and insert ``USCG-2010... afternoon when vessel traffic is low. Before the effective period, the Coast Guard will publish a local... patrol personnel by siren, radio, flashing light, or other means, the operator of a vessel shall proceed...

  9. 75 FR 27432 - Security Zone; Golden Guardian 2010 Regional Exercise; San Francisco Bay, San Francisco, CA

    Science.gov (United States)

    2010-05-17

    ... this rule because it is impracticable since the logistical details of the operations were not presented... mariners (LNM) and broadcast notice to mariners (BNM) alerts via VHF-FM marine channel 16 before the... relationship between the Federal Government and Indian tribes, or on the distribution of power and...

  10. 77 FR 54815 - Safety Zone: America's Cup World Series Regattas, San Francisco Bay; San Francisco, CA

    Science.gov (United States)

    2012-09-06

    ... submit your comments by mail or hand delivery, submit them in an unbound format, no larger than 8\\1/2\\ by... section 4(a) of the Administrative Procedure Act (APA) (5 U.S.C. 553(b)). This provision authorizes an...

  11. 78 FR 77597 - Safety Zone; Allied PRA-Solid Works, San Diego Bay; San Diego, CA

    Science.gov (United States)

    2013-12-24

    ... Folder on the line associated with this rulemaking. You may also visit the Docket Management Facility in... position: 32 42.13'N, 117 10.01'W. The sponsor will provide a tug boat to patrol the safety zone and inform... barge in approximate position: 32 42.13'N, 117 10.01'W, located southwest of Embarcadero Park South in...

  12. Integrating naive Bayes and FOIL

    OpenAIRE

    Landwehr, Niels; Kersting, Kristian; De Raedt, Luc

    2007-01-01

    A novel relational learning approach that tightly integrates the naive Bayes learning scheme with the inductive logic programming rule-learner FOIL is presented. In contrast to previous combinations that have employed naive Bayes only for post-processing the rule sets, the presented approach employs the naive Bayes criterion to guide its search directly. The proposed technique is implemented in the NFOIL and TFOIL systems, which employ standard naive Bayes and tree augmented naive Bayes model...

  13. Networked but No System: Educational Innovation among Bay Area Jewish Organizations

    Science.gov (United States)

    Rubin Ross, Renee

    2017-01-01

    A widely read article from this journal explores innovative Jewish educational programs, initiatives, and organizations, arguing that these share a comdmitment to being "learner-centered" and recommending that a system be created to foster collaboration among them (Woocher, 2012). Using five San Francisco Bay Area-based…

  14. Discovery Along the San Andreas Fault: Relocating Photographs From the 1906 Earthquake in San Francisco and San Mateo Counties

    Science.gov (United States)

    Grove, K.; Prentice, C.; Polly, J.; Yuen, C.; Wu, K.; Zhong, S.; Lopez, J.

    2005-12-01

    general public to better understand the environment where they live, and will remind them to be prepared for the next earthquake that will certainly come to the San Francisco Bay Area.

  15. Hammond Bay Biological Station

    Data.gov (United States)

    Federal Laboratory Consortium — Hammond Bay Biological Station (HBBS), located near Millersburg, Michigan, is a field station of the USGS Great Lakes Science Center (GLSC). HBBS was established by...

  16. Humboldt Bay Orthoimages

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of 0.5-meter pixel resolution, four band orthoimages covering the Humboldt Bay area. An orthoimage is remotely sensed image data in which...

  17. Biscayne Bay Alongshore Epifauna

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Field studies to characterize the alongshore epifauna (shrimp, crabs, echinoderms, and small fishes) along the western shore of southern Biscayne Bay were started in...

  18. KEBERADAAN SAN REMO MANUAL 1994 DALAM KAITANNYA DENGAN UNCLOS 1982

    Directory of Open Access Journals (Sweden)

    Enny Narwati

    2010-07-01

    Full Text Available Setting the law of war at sea did not experience significant development since the Hague Convention of 1907. With the various developments that have forced the international community to make various adjusments relating to the conduct of the war at sea. The most important developments is the adoption of UNCLOS in 1982 inMontego Bay,Jamaica, which contains provisions concering the rights and obligations of the State in the sea. UNCLOS in 1982 became effective in 1994. All the provisions in the 1982 UNCLOS applies in peacetime, and no one rule governing the use of violence or war. 1994 San Remo Manual contains the guidelines for conduct of the war at sea. Because it needs to be studied how the link between the San Remo Manual 1994 with the UNCLOS 1982.

  19. g295sf.m77t and g295sf.h77t: MGD77T data and header files for single-beam bathymetry data for field activity G-2-95-SF in San Francisco Bay, Golden Gate from 05/30/1995 to 06/10/1995

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry data along with GPS navigation data was collected as part of the U.S. Geological Survey cruise G-2-95-SF. The cruise was conducted in San...

  20. Bayes and the Law.

    Science.gov (United States)

    Fenton, Norman; Neil, Martin; Berger, Daniel

    2016-06-01

    Although the last forty years has seen considerable growth in the use of statistics in legal proceedings, it is primarily classical statistical methods rather than Bayesian methods that have been used. Yet the Bayesian approach avoids many of the problems of classical statistics and is also well suited to a broader range of problems. This paper reviews the potential and actual use of Bayes in the law and explains the main reasons for its lack of impact on legal practice. These include misconceptions by the legal community about Bayes' theorem, over-reliance on the use of the likelihood ratio and the lack of adoption of modern computational methods. We argue that Bayesian Networks (BNs), which automatically produce the necessary Bayesian calculations, provide an opportunity to address most concerns about using Bayes in the law.

  1. Evolving extended naive Bayes classifiers

    OpenAIRE

    Klawonn, Frank; Angelov, Plamen

    2006-01-01

    Naive Bayes classifiers are a very simple, but often effective tool for classification problems, although they are based on independence assumptions that do not hold in most cases. Extended naive Bayes classifiers also rely on independence assumptions, but break them down to artificial subclasses, in this way becoming more powerful than ordinary naive Bayes classifiers. Since the involved computations for Bayes classifiers are basically generalised mean value calculations, they easily render ...

  2. Evaluation of Seismic Hazards at California Department of Transportation (CALTRANS)Structures

    Science.gov (United States)

    Merriam, M. K.

    2005-12-01

    The California Department of Transportation (CALTRANS) has responsibility for design, construction, and maintenance of approximately 12,000 state bridges. CALTRANS also provides oversight for similar activities for 12,200 bridges owned by local agencies throughout the state. California is subjected to a M6 or greater seismic event every few years. Recent earthquakes include the 1971 Mw6.6 San Fernando earthquake which struck north of Los Angeles and prompted engineers to begin retrofitting existing bridges and re-examine the way bridges are detailed to improve their response to earthquakes, the 1989 Mw6.9 Loma Prieta earthquake which destroyed the Cypress Freeway and damaged the San Francisco-Oakland Bay Bridge, and the 1994 Mw6.7 Northridge earthquake in the Los Angeles area which heavily damaged four major freeways. Since CALTRANS' seismic performance goal is to ensure life-safety needs are met for the traveling public during an earthquake, estimating earthquake magnitude, peak bedrock acceleration, and determining if special seismic considerationsare needed at specific bridge sites are critical. CALTRANS is currently developing a fourth generation seismic hazard map to be used for estimating these parameters. A deterministic approach has been used to develop this map. Late-Quaternary-age faults are defined as the expected seismic sources. Caltrans requires site-specific studies to determine potential for liquefaction, seismically induced landslides, and surface fault rupture. If potential for one of these seismic hazards exists, the hazard is mitigated by avoidance, removal, or accommodated through design. The action taken, while complying with the Department's "no collapse" requirement, depends upon many factors, including cost.

  3. Risk behaviors of Filipino methamphetamine users in San Francisco: implications for prevention and treatment of drug use and HIV.

    OpenAIRE

    Nemoto, Tooru; Operario, Don; Soma, Toho

    2002-01-01

    OBJECTIVE: This study describes the demographics, HIV risk and drug use behaviors, and psychosocial status of Filipino American methamphetamine users in the San Francisco Bay area. METHODS: Individual interviews were conducted with 83 Filipino American methamphetamine users, recruited through snowball sampling methods. A structured survey questionnaire included measures of drug use behaviors, HIV-related sexual behaviors, psychosocial factors, and demographics. RESULTS: Filipino methamphetami...

  4. Chapter A. The Loma Prieta, California, Earthquake of October 17, 1989 - Strong Ground Motion

    Science.gov (United States)

    Borcherdt, Roger D.

    1994-01-01

    Strong ground motion generated by the Loma Prieta, Calif., earthquake (MS~7.1) of October 17, 1989, resulted in at least 63 deaths, more than 3,757 injuries, and damage estimated to exceed $5.9 billion. Strong ground motion severely damaged critical lifelines (freeway overpasses, bridges, and pipelines), caused severe damage to poorly constructed buildings, and induced a significant number of ground failures associated with liquefaction and landsliding. It also caused a significant proportion of the damage and loss of life at distances as far as 100 km from the epicenter. Consequently, understanding the characteristics of the strong ground motion associated with the earthquake is fundamental to understanding the earthquake's devastating impact on society. The papers assembled in this chapter address this problem. Damage to vulnerable structures from the earthquake varied substantially with the distance from the causative fault and the type of underlying geologic deposits. Most of the damage and loss of life occurred in areas underlain by 'soft soil'. Quantifying these effects is important for understanding the tragic concentrations of damage in such areas as Santa Cruz and the Marina and Embarcadero Districts of San Francisco, and the failures of the San Francisco-Oakland Bay Bridge and the Interstate Highway 880 overpass. Most importantly, understanding these effects is a necessary prerequisite for improving mitigation measures for larger earthquakes likely to occur much closer to densely urbanized areas in the San Francisco Bay region. The earthquake generated an especially important data set for understanding variations in the severity of strong ground motion. Instrumental strong-motion recordings were obtained at 131 sites located from about 6 to 175 km from the rupture zone. This set of recordings, the largest yet collected for an event of this size, was obtained from sites on various geologic deposits, including a unique set on 'soft soil' deposits

  5. Down by the Bay

    Science.gov (United States)

    Allison, Elizabeth; Tunks, Karyn; Hardman, Kacie

    2017-01-01

    The Pelican's Nest, located near Mobile Bay in the Gulf of Mexico, is a science center supported by a local educational foundation. Programs are geared toward marine wildlife and the coastal habitat with an emphasis on hands-on learning for students in grades K-6. The director of the science center conducts daily classroom labs and discovery trips…

  6. Presa de San Esteban

    Directory of Open Access Journals (Sweden)

    Equipo Editorial

    2017-06-01

    Full Text Available En el número 73 de esta revista se publicó un artículo, que trataba sobre los aprovechamientos hidroeléctricos de la cuenca del río Sil. En este trabajo se hace referencia, únicamente, a la importante presa de San Esteban, obra que, por so altura de salto, caudales disponibles y embalse, es la de mayor producción de las de la referida cuenca. Su proyección en planta e« circular, tipo gravedad, de 115 m de altura, y su embalse, de 213 millones de metros cúbicos.

  7. The Challenge of Supporting Change: Elementary Student Achievement and the Bay Area School Reform Collaborative's Focal Strategy. Final Report

    Science.gov (United States)

    Porter, Kristin E.; Snipes, Jason C.

    2006-01-01

    This is the second and final report for MDRC's evaluation of the Bay Area School Reform Collaborative (BASRC), a grant-making and support organization in San Francisco, California. BASRC is dedicated to improving student achievement in public schools and narrowing achievement gaps among different racial, ethnic, and socioeconomic groups. BASRC…

  8. Los Angeles og San Francisco

    DEFF Research Database (Denmark)

    Ørstrup, Finn Rude

    1998-01-01

    Kompendium udarbejdet til en studierejse til Los Angeles og San Francisco april-maj 1998 Kunstakademiets Arkitektskole, Institut 3H......Kompendium udarbejdet til en studierejse til Los Angeles og San Francisco april-maj 1998 Kunstakademiets Arkitektskole, Institut 3H...

  9. Humboldt Bay Wetlands Review and Baylands Analysis. Volume I. Summary and Findings.

    Science.gov (United States)

    1980-08-01

    Michael Mix, Ph.D. - Oregon State University (P. Invertebrates) Larry Riggs, Ph.D. (M. Mammals, N. Birds, Q. Amphibians and Reptiles ) John Rogers, M.A...long and 0.5 to 4 miles wide; Humboldt Bay is the only deep water port between San Francisco and Coos Bay, Oregon . A more detailed description of the...Biological Profiles L. Habitat Types 118 M. Mammals 130 N. Birds 144 0. Fish 164 P. Invertebrates 187 Q. Reptiles and Amphibians 201 R. Productivity 206 S

  10. A Tale of Two Cities: Access to Care and Services Among African-American Transgender Women in Oakland and San Francisco

    OpenAIRE

    Nemoto, Tooru; Cruz, Taylor M.; Iwamoto, Mariko; Sakata, Maria

    2015-01-01

    Purpose: The San Francisco Bay Area attracts people from all over the country due to the perception of lesbian, gay, bisexual, and transgender (LGBT) acceptance and affirmation. African-American transgender women are severely marginalized across society and as such have many unmet health and social service needs. This study sought to quantitatively assess unmet needs among African-American transgender women with a history of sex work by comparing residents of Oakland versus San Francisco.

  11. Zero Emission Bay Area (ZEBA) Fuel Cell Bus Demonstration: First Results Report

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, K.; Eudy, L.

    2011-08-01

    This report documents the early implementation experience for the Zero Emission Bay Area (ZEBA) Demonstration, the largest fleet of fuel cell buses in the United States. The ZEBA Demonstration group includes five participating transit agencies: AC Transit (lead transit agency), Santa Clara Valley Transportation Authority (VTA), Golden Gate Transit (GGT), San Mateo County Transit District (SamTrans), and San Francisco Municipal Railway (Muni). The ZEBA partners are collaborating with the U.S. Department of Energy (DOE) and DOE's National Renewable Energy Laboratory (NREL) to evaluate the buses in revenue service.

  12. Trace Elemental Analyses of Suspended Sediments in the San Francisco Estuary and its Tidal Marshes

    Science.gov (United States)

    Malamud-Roam, F. P.; Ingram, B. L.; Yang, W.; Collins, J.

    2004-12-01

    This research evaluates the trace elemental compositions of inorganic sediments in the San Francisco Bay estuary marshes over space and time. These sediments create and maintain the tidal marshes that surround the Sand Francisco Bay, yet a thorough analysis of the sources of these sediments remains understudied. Determining the sources of sediments is of interest because current mitigation and restoration projects around the Bay must consider whether the sediment supply will be sufficient for projects, or if opening diked wetlands to tidal flow will result in salt water intrusion further up-estuary (into the Delta). Results of trace element analyses of suspended sediments that pass through the Sacramento-San Joaquin Delta (the Delta) are compared with those of local watershed tributaries. Differences in bedrock lithology can be seen in the varying trace elemental concentrations; for example, K, Nd, Sm, Rb and Sr concentrations are significantly lower in the Sacramento river sediments than those of the San Joaquin river and can be used to differentiate further the Delta input. Results from marsh surface samples throughout the North Bay and preliminary results from 4 1-m long sediment cores collected along a transect of the Novato creek marsh (NCM) reflect local versus Delta sediment source patterns. The suspended sediment samples from the Sacramento and San Joaquin rivers and from local creeks reflect the end members of the sediment supply for local marshes. The marsh surface samples represent the most recent period (last few years or so) and reflect the extent of Delta influence into the estuary. Finally, the cores collected from the Novato creek marsh provide details on the gradient of dominant source supply (i.e., are the sediments well inland predominantly from the local watershed and how far does that influence extend downstream), as well as a history of how the sediment supply conditions have changed, comparing pre-Gold Rush and agriculture era (before about

  13. Remedial Investigation Report, Presidio Main Installation, Presidio of San Francisco. Volume 1: Text

    Science.gov (United States)

    1997-01-01

    which drains to the San Francisco Bay. Stormwater runoff from developed portions of the installation is collected by a system of swales and storm drains and...and to assess the distribution of potential contaminants in the drainage pathways. Sediment samples were collected from inside storm drains or catch...Sediment that was collected from open ditches (versus storm drains ) and from the Baker Beach seep, Lobos Creek, and Mountain Lake was evaluated based

  14. Richards Bay effluent pipeline

    CSIR Research Space (South Africa)

    Lord, DA

    1986-07-01

    Full Text Available 3815 9 D A Lord Department of Oceanography University of Port Elizabeth P 0 Box 1600 PORT ELIZABETH 6000 N D Geldenhuys Department of Environment Affairs Private Bag X9005 CAPE TOWN 8000 Cover: Richards Bay from the air showing city... of major concern identified in the effluent are the large volume of byproduct calcium sulphate (phosphogypsum) which would smother marine life, high concentrations of fluoride highly toxic to marine life, heavy metals, chlorinated organic material...

  15. 78 FR 27989 - Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos, Tillamook, and...

    Science.gov (United States)

    2013-05-13

    ... Fish and Wildlife Service Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos... Assessments (EAs) for three Oregon refuges--Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife... ``Bandon Marsh, Nestucca Bay, and Siletz Bay final CCPs and FONSIs'' in the subject line of the message. U...

  16. 75 FR 73121 - Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos, Tillamook, and...

    Science.gov (United States)

    2010-11-29

    ... Fish and Wildlife Service Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos... prepare a comprehensive conservation plan (CCP) for the Bandon Marsh, Nestucca Bay, and Siletz Bay... ``Bandon Marsh, Nestucca Bay, and Siletz Bay CCP'' in the subject line of the message. Fax: Attn: Project...

  17. BCDC Bay Trail Alignment 2009

    Data.gov (United States)

    California Department of Resources — The Bay Trail provides easily accessible recreational opportunities for outdoor enthusiasts, including hikers, joggers, bicyclists and skaters. It also offers a...

  18. Paleoseismic Study on the Peninsula Section of the San Andreas Fault South of Crystal Springs Reservoir, San Mateo County, California

    Science.gov (United States)

    Zachariasen, J. A.; Prentice, C. S.; Kozaci, O.; Sickler, R. R.; Baldwin, J. N.; Sanquini, A.; Knudsen, K. L.

    2010-12-01

    The Peninsula section of the San Andreas Fault is a significant hazard for the San Francisco Bay area, but little is known about the timing of earthquakes on this section of the fault prior to the great earthquake of April 18, 1906. An earthquake in 1838 resulted in strong shaking on the San Francisco Peninsula. Estimates of the magnitude of the 1838 earthquake vary from 6.8 to 7.4, based on historical accounts, and most workers have assumed that this event occurred on the San Andreas Fault. However, paleoseismic excavations across the fault near San Andreas Lake failed to provide evidence that the 1838 earthquake was associated with surface rupture on the Peninsula section of the San Andreas Fault (Prentice et al., 2008, 2009). Earlier work at the Filoli Estate, south of Crystal Springs Reservoirs, by Hall et al. (1999) suggested that both the 1838 and 1906 earthquakes ruptured the Peninsula section, based on the projected offsets of buried stream channels that crossed the fault. While this interpretation is permissible, the data also allow alternative interpretations that do not require surface rupture in 1838. We used LiDAR images produced from data collected by the GeoEarthScope project to search for promising paleoseismic sites along the Peninsula section of the San Andreas Fault. At a site about 1.2 km southeast of Crystal Springs Reservoir, we excavated two trenches across the fault and exposed fluvial gravel and overbank deposits cut by two distinct generations of faults. The younger set of faults break nearly to the ground surface, and we interpret these to represent 1906 surface faulting that has been buried post-1906 sediments. The older faults terminate below a colluvial wedge derived from one of the fluvial gravel deposits. The scarp-derived colluvium overlies a faulted fine-grained overbank deposit that in turn rests on the channel gravel, and represents the ground surface at the time of the older earthquake. The scarp-derived colluvium is overlain by

  19. Evaluating Bay Area Methane Emission Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Marc [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Jeong, Seongeun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-03-01

    As a regulatory agency, evaluating and improving estimates of methane (CH4) emissions from the San Francisco Bay Area is an area of interest to the Bay Area Air Quality Management District (BAAQMD). Currently, regional, state, and federal agencies generally estimate methane emissions using bottom-up inventory methods that rely on a combination of activity data, emission factors, biogeochemical models and other information. Recent atmospheric top-down measurement estimates of methane emissions for the US as a whole (e.g., Miller et al., 2013) and in California (e.g., Jeong et al., 2013; Peischl et al., 2013) have shown inventories underestimate total methane emissions by ~ 50% in many areas of California, including the SF Bay Area (Fairley and Fischer, 2015). The goal of this research is to provide information to help improve methane emission estimates for the San Francisco Bay Area. The research effort builds upon our previous work that produced methane emission maps for each of the major source sectors as part of the California Greenhouse Gas Emissions Measurement (CALGEM) project (http://calgem.lbl.gov/prior_emission.html; Jeong et al., 2012; Jeong et al., 2013; Jeong et al., 2014). Working with BAAQMD, we evaluate the existing inventory in light of recently published literature and revise the CALGEM CH4 emission maps to provide better specificity for BAAQMD. We also suggest further research that will improve emission estimates. To accomplish the goals, we reviewed the current BAAQMD inventory, and compared its method with those from the state inventory from the California Air Resources Board (CARB), the CALGEM inventory, and recent published literature. We also updated activity data (e.g., livestock statistics) to reflect recent changes and to better represent spatial information. Then, we produced spatially explicit CH4 emission estimates on the 1-km modeling grid used by BAAQMD. We present the detailed activity data, methods and derived emission maps by sector

  20. Riparian Habitat - San Joaquin River

    Data.gov (United States)

    California Department of Resources — The immediate focus of this study is to identify, describe and map the extent and diversity of riparian habitats found along the main stem of the San Joaquin River,...

  1. Environmental assessment : Rodent control program : San Joaquin river levee : San Luis National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower San Joaquin Levee District (LSJLD) requires that six miles of levee situated along the San Joaquin River on San Luis National Wildlife Refuge (SLNWR) be...

  2. Characterization of the grafting copolymer EPDM-SAN; Caracterizacao do copolimero de enxertia EPDM-SAN

    Energy Technology Data Exchange (ETDEWEB)

    Turchette, Renato; Felisberti, Maria Isabel [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail: turchete@iqm.unicamp.br

    2001-07-01

    This work aims the characterization of the grafting copolymer EPDM-SAN. This copolymer presents a fraction of free SAN chains, which was extracted by solubilization in chloroform followed of precipitation of the grafting copolymer EPDM-g-SAN in acetone. The EPDM-SAN and EPDM-g-SAN were characterized by {sup 13}C NMR, DSC, TGA and SEM. EPDM-SAN contain 23 wt% of free SAN and 77 wt% of EPDM-g-SAN. Both materials are heterogeneous and the thermal and thermo-oxidative degradation are independent of the composition. (author)

  3. Arrival and expansion of the invasive foraminifera Trochammina hadai Uchio in Padilla Bay, Washington

    Science.gov (United States)

    McGann, Mary; Grossman, Eric E.; Takesue, Renee K.; Penttila, Dan; Walsh, John P.; Corbett, Reide

    2012-01-01

    Trochammina hadai Uchio, a benthic foraminifera native to Japanese estuaries, was first identified as an invasive in 1995 in San Francisco Bay and later in 16 other west coast estuaries. To investigate the timing of the arrival and expansion of this invasive species in Padilla Bay, Washington, we analyzed the distribution of foraminifera in two surface samples collected in 1971, in nine surface samples collected by Scott in 1972–1973, as well as in two cores (Padilla Flats 3 and Padilla V1/V2) obtained in 2004. Trochanimina hadai, originally identified as the native Trochammina pacifica Cushman in several early foraminiferal studies, dominates the assemblage of most of the surface samples. In the Padilla V1/V2 and Padilla Flats 3 cores, the species' abundance follows a pattern of absence, first appearance, rapid expansion commonly seen shortly after the arrival of a successful biological invasion, setback, and second expansion. Using Q-mode cluster analysis, pre-expansion and expansion assemblages were identified. Pb-210 dating of these cores proved unsuccessful. However, based on T. hadai's first appearance occurring stratigraphically well above sedimentological changes in the cores that reflect deposition of sediments in the bay due to previous diversions of the Skagit River, and its dominance in the early 1970s surface samples, we conclude that the species arrived in Padilla Bay somewhere between the late 1800s and 1971. Trochammina hadai may have been introduced into the bay in the 1930s when oyster culturing began there or, at a minimum, ten years prior to its appearance in San Francisco Bay.

  4. Bayes multiple decision functions.

    Science.gov (United States)

    Wu, Wensong; Peña, Edsel A

    2013-01-01

    This paper deals with the problem of simultaneously making many (M) binary decisions based on one realization of a random data matrix X. M is typically large and X will usually have M rows associated with each of the M decisions to make, but for each row the data may be low dimensional. Such problems arise in many practical areas such as the biological and medical sciences, where the available dataset is from microarrays or other high-throughput technology and with the goal being to decide which among of many genes are relevant with respect to some phenotype of interest; in the engineering and reliability sciences; in astronomy; in education; and in business. A Bayesian decision-theoretic approach to this problem is implemented with the overall loss function being a cost-weighted linear combination of Type I and Type II loss functions. The class of loss functions considered allows for use of the false discovery rate (FDR), false nondiscovery rate (FNR), and missed discovery rate (MDR) in assessing the quality of decision. Through this Bayesian paradigm, the Bayes multiple decision function (BMDF) is derived and an efficient algorithm to obtain the optimal Bayes action is described. In contrast to many works in the literature where the rows of the matrix X are assumed to be stochastically independent, we allow a dependent data structure with the associations obtained through a class of frailty-induced Archimedean copulas. In particular, non-Gaussian dependent data structure, which is typical with failure-time data, can be entertained. The numerical implementation of the determination of the Bayes optimal action is facilitated through sequential Monte Carlo techniques. The theory developed could also be extended to the problem of multiple hypotheses testing, multiple classification and prediction, and high-dimensional variable selection. The proposed procedure is illustrated for the simple versus simple hypotheses setting and for the composite hypotheses setting

  5. Wastewater effluent dispersal in Southern California Bays

    KAUST Repository

    Uchiyama, Yusuke

    2014-03-01

    The dispersal and dilution of urban wastewater effluents from offshore, subsurface outfalls is simulated with a comprehensive circulation model with downscaling in nested grid configurations for San Pedro and Santa Monica Bays in Southern California during Fall of 2006. The circulation is comprised of mean persistent currents, mesoscale and submesoscale eddies, and tides. Effluent volume inflow rates at Huntington Beach and Hyperion are specified, and both their present outfall locations and alternative nearshore diversion sites are assessed. The effluent tracer concentration fields are highly intermittent mainly due to eddy currents, and their probability distribution functions have long tails of high concentration. The dilution rate is controlled by submesoscale stirring and straining in tracer filaments. The dominant dispersal pattern is alongshore in both directions, approximately along isobaths, over distances of more than 10. km before dilution takes over. The current outfall locations mostly keep the effluent below the surface and away from the shore, as intended, but the nearshore diversions do not. © 2014 Elsevier Ltd.

  6. USGS Tampa Bay Pilot Study

    Science.gov (United States)

    Yates, K.K.; Cronin, T. M.; Crane, M.; Hansen, M.; Nayeghandi, A.; Swarzenski, P.; Edgar, T.; Brooks, G.R.; Suthard, B.; Hine, A.; Locker, S.; Willard, D.A.; Hastings, D.; Flower, B.; Hollander, D.; Larson, R.A.; Smith, K.

    2007-01-01

    Many of the nation's estuaries have been environmentally stressed since the turn of the 20th century and will continue to be impacted in the future. Tampa Bay, one the Gulf of Mexico's largest estuaries, exemplifies the threats that our estuaries face (EPA Report 2001, Tampa Bay Estuary Program-Comprehensive Conservation and Management Plan (TBEP-CCMP)). More than 2 million people live in the Tampa Bay watershed, and the population constitutes to grow. Demand for freshwater resources, conversion of undeveloped areas to resident and industrial uses, increases in storm-water runoff, and increased air pollution from urban and industrial sources are some of the known human activities that impact Tampa Bay. Beginning on 2001, additional anthropogenic modifications began in Tampa Bat including construction of an underwater gas pipeline and a desalinization plant, expansion of existing ports, and increased freshwater withdrawal from three major tributaries to the bay. In January of 2001, the Tampa Bay Estuary Program (TBEP) and its partners identifies a critical need for participation from the U.S. Geological Survey (USGS) in providing multidisciplinary expertise and a regional-scale, integrated science approach to address complex scientific research issue and critical scientific information gaps that are necessary for continued restoration and preservation of Tampa Bay. Tampa Bay stakeholders identified several critical science gaps for which USGS expertise was needed (Yates et al. 2001). These critical science gaps fall under four topical categories (or system components): 1) water and sediment quality, 2) hydrodynamics, 3) geology and geomorphology, and 4) ecosystem structure and function. Scientists and resource managers participating in Tampa Bay studies recognize that it is no longer sufficient to simply examine each of these estuarine system components individually, Rather, the interrelation among system components must be understood to develop conceptual and

  7. MARS: a cabled observatory testbed in Monterey Bay

    Science.gov (United States)

    McNutt, M.; Massion, G.; Raybould, K.; Bellingham, J.; Paull, C.

    2003-04-01

    With funding from the U.S. National Science Foundation and the David and Lucile Packard Foundation, the Monterey Bay Aquarium Research Institute (MBARI) will be installing a deep-sea observatory in Monterey Bay, California, that will serve as a test bed for a future regional-scale cabled observatory. Monterey Bay offers a variety of active processes for scientific inquiry, including a very productive zone of ocean upwelling, a seismically active strand of the San Andreas fault system, cold seeps, and a very dynamic submarine canyon. The MARS (Monterey Accelerated Research System) cable will extend more than 60 km offshore to an instrument node at a depth of approximately 1.2 km. Extension cords can be run by remotely operated vehicles (ROVs) from the cable node up to several kilometers away in order to provide greater flexibility in siting instruments. The observatory will be serviced using ROVs and will serve as a test bed for developing new sensors, instruments systems, experiment protocols, and mobile platforms for which submarine cables will provide power and two-way communications. In addition to serving as a test bed for instrumentation and platforms, the MARS project will demonstrate models for how to operate, service, and manage a community facility of this sort. In cooperation with our outreach partner, the Monterey Bay Aquarium, we will be examining ways to exploit the full potential of deep-sea observatories for student education and public information. We will also be preparing a proposal to the Integrated Ocean Drilling Program (IODP) to provide a nearby drill hole for connecting bore-hole experiments to the MARS cable, thereby accelerating the development of new tools for probing Earth beneath the oceans.

  8. Linking hydrodynamic complexity to delta smelt (Hypomesus transpacificus) distribution in the San Francisco Estuary, USA

    Science.gov (United States)

    Bever, Aaron J.; MacWilliams, Michael L.; Herbold, Bruce; Brown, Larry R.; Feyrer, Frederick V.

    2016-01-01

    Long-term fish sampling data from the San Francisco Estuary were combined with detailed three dimensional hydrodynamic modeling to investigate the relationship between historical fish catch and hydrodynamic complexity. Delta Smelt catch data at 45 stations from the Fall Midwater Trawl (FMWT) survey in the vicinity of Suisun Bay were used to develop a quantitative catch-based station index. This index was used to rank stations based on historical Delta Smelt catch. The correlations between historical Delta Smelt catch and 35 quantitative metrics of environmental complexity were evaluated at each station. Eight metrics of environmental conditions were derived from FMWT data and 27 metrics were derived from model predictions at each FMWT station. To relate the station index to conceptual models of Delta Smelt habitat, the metrics were used to predict the station ranking based on the quantified environmental conditions. Salinity, current speed, and turbidity metrics were used to predict the relative ranking of each station for Delta Smelt catch. Including a measure of the current speed at each station improved predictions of the historical ranking for Delta Smelt catch relative to similar predictions made using only salinity and turbidity. Current speed was also found to be a better predictor of historical Delta Smelt catch than water depth. The quantitative approach developed using the FMWT data was validated using the Delta Smelt catch data from the San Francisco Bay Study. Complexity metrics in Suisun Bay were-evaluated during 2010 and 2011. This analysis indicated that a key to historical Delta Smelt catch is the overlap of low salinity, low maximum velocity, and low Secchi depth regions. This overlap occurred in Suisun Bay during 2011, and may have contributed to higher Delta Smelt abundance in 2011 than in 2010 when the favorable ranges of the metrics did not overlap in Suisun Bay.

  9. 33 CFR 165.1195 - Regulated Navigation Area; Humboldt Bay Bar Channel and Humboldt Bay Entrance Channel, Humboldt...

    Science.gov (United States)

    2010-07-01

    ...; Humboldt Bay Bar Channel and Humboldt Bay Entrance Channel, Humboldt Bay, California. 165.1195 Section 165... Channel and Humboldt Bay Entrance Channel, Humboldt Bay, California. (a) Location. The Regulated Navigation Area (RNA) includes all navigable waters of the Humboldt Bay Bar Channel and the Humboldt Bay...

  10. Ground motion modeling of the 1906 San Francisco earthquake II: Ground motion estimates for the 1906 earthquake and scenario events

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard, B; Brocher, T; Dreger, D; Frankel, A; Graves, R; Harmsen, S; Hartzell, S; Larsen, S; McCandless, K; Nilsson, S; Petersson, N A; Rodgers, A; Sjogreen, B; Tkalcic, H; Zoback, M L

    2007-02-09

    We estimate the ground motions produced by the 1906 San Francisco earthquake making use of the recently developed Song et al. (2008) source model that combines the available geodetic and seismic observations and recently constructed 3D geologic and seismic velocity models. Our estimates of the ground motions for the 1906 earthquake are consistent across five ground-motion modeling groups employing different wave propagation codes and simulation domains. The simulations successfully reproduce the main features of the Boatwright and Bundock (2005) ShakeMap, but tend to over predict the intensity of shaking by 0.1-0.5 modified Mercalli intensity (MMI) units. Velocity waveforms at sites throughout the San Francisco Bay Area exhibit characteristics consistent with rupture directivity, local geologic conditions (e.g., sedimentary basins), and the large size of the event (e.g., durations of strong shaking lasting tens of seconds). We also compute ground motions for seven hypothetical scenarios rupturing the same extent of the northern San Andreas fault, considering three additional hypocenters and an additional, random distribution of slip. Rupture directivity exerts the strongest influence on the variations in shaking, although sedimentary basins do consistently contribute to the response in some locations, such as Santa Rosa, Livermore, and San Jose. These scenarios suggest that future large earthquakes on the northern San Andreas fault may subject the current San Francisco Bay urban area to stronger shaking than a repeat of the 1906 earthquake. Ruptures propagating southward towards San Francisco appear to expose more of the urban area to a given intensity level than do ruptures propagating northward.

  11. Eutrophication in the Chesapeake Bay

    Science.gov (United States)

    Ulanowicz, R. E.

    1978-01-01

    The advantages and limitations of using remote sensing to acquire fast reliable data on the nutrient problem in the Chesapeake Bay ecosystem are discussed. Pollution effects to phytoplankton blooms during late summer and early fall months are also considered.

  12. FL BAY SPECTROUT-DIET

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Juvenile spotted seatrout and other sportfish are being monitored annually over a 6-mo period in Florida Bay to assess their abundance over time relative to...

  13. Missisquoi Bay Phosphorus Model Addendum

    Science.gov (United States)

    This technical memorandum provides results of an extended load reduction simulation. The memorandum serves as an addendum to the main Missisquoi Bay Phosphorus Mass Balance Model report prepared for the Lake Champlain Basin Program by LimnoTech in 2012

  14. Lavaca Bay 1985-1987

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Samples were collected from October 15, 1985 through June 12, 1987 in emergent marsh and non-vegetated habitats throughout the Lavaca Bay system to characterize...

  15. Constructing Puale Bay field camp

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Puale bay is located on the Pacific side of the Alaskan Peninsula across Shelikof Strait from the southern end of Kodiak Island. The weather, although often mild, is...

  16. San Language Development for Education in South Africa: The South African San Institute and the San Language Committees

    Science.gov (United States)

    Pamo, Billies

    2011-01-01

    This article focuses on the 3 San communities in South Africa: the !Xun, the Khwe, and the [image omitted]Khomani San. The !Xun and Khwe communities are living in Platfontein, near Kimberley in the Northern Cape. The [image omitted]Khomani San community is living in Upington and in the southern Kalahari, which are also in the Northern Cape. This…

  17. San Jorge, el primer rejoneador

    OpenAIRE

    Mandianes Castro, Manuel

    2008-01-01

    Las proezas de Jorge son una réplica de las de Santiago. Este luchó y venció las serpientes que habitaban Galicia para entrar allí y convertirla al cristianismo. San Jorge venció al monstruo del lago, y el rey y los habitantes de Silca se convirtieron a Cristo. Santiago ganó el nombre de Matamoros y de soldado de Cristo por excelencia porque, montado en su caballo blanco, venció en 1.000 batallas a los moros al frente de los cristianos. San Jorge venció a los sarracenos y conquistó Jerusalén ...

  18. Vegetation - San Felipe Valley [ds172

    Data.gov (United States)

    California Department of Resources — This Vegetation Map of the San Felipe Valley Wildlife Area in San Diego County, California is based on vegetation samples collected in the field in 2002 and 2005 and...

  19. The San Bernabe power substation; La subestacion San Bernabe

    Energy Technology Data Exchange (ETDEWEB)

    Chavez Sanudo, Andres D. [Luz y Fuerza del Centro, Mexico, D. F. (Mexico)

    1997-12-31

    The first planning studies that gave rise to the San Bernabe substation go back to year 1985. The main circumstance that supports this decision is the gradual restriction for electric power generation that has been suffering the Miguel Aleman Hydro System, until its complete disappearance, to give priority to the potable water supply through the Cutzamala pumping system, that feeds in an important way Mexico City and the State of Mexico. In this document the author describes the construction project of the San Bernabe Substation; mention is made of the technological experiences obtained during the construction and its geographical location is shown, as well as the one line diagram of the same [Espanol] Los primeros estudios de planeacion que dieron origen a la subestacion San Bernabe se remontan al ano de 1985. La circunstancia principal que soporta esta decision es la restriccion paulatina para generar energia que ha venido experimentando el Sistema Hidroelectrico Miguel Aleman, hasta su desaparicion total, para dar prioridad al suministro de agua potable por medio del sistema de bombeo Cutzamala, que alimenta en forma importante a la Ciudad de Mexico y al Estado de Mexico. En este documento el autor describe el proyecto de construccion de la subestacion San Bernabe; se mencionan las experiencias tecnologicas obtenidas durante su construccion y se ilustra su ubicacion geografica, asi como un diagrama unifilar de la misma

  20. Reconnaissance of geothermal resources near US naval facilities in the San Diego area, California

    Energy Technology Data Exchange (ETDEWEB)

    Youngs, L.G.

    1984-01-01

    A reconnaissance study has found little evidence of potential geothermal resources useful at naval facilities in the greater San Diego metropolitan area. However, there is a zone of modest elevated water well temperatures and slightly elevated thermal gradients that may include the eastern portion of the Imperial Beach Naval Air Station south of San Diego Bay. An increase of 0.3/sup 0/ to 0.4/sup 0/F/100 ft over the regional thermal gradient of 1.56/sup 0/F/100 ft was conservatively calculated for this zone. The thermal gradient can be used to predict 150/sup 0/F temperatures at a depth of approximately 4000 ft. This zone of greatest potential for a viable geothermal resource lies within a negative gravity anomaly thought to be caused by a tensionally developed graben, approximately centered over the San Diego Bay. Water well production in this zone is good to high, with 300 gpm often quoted as common for wells in this area. The concentration of total dissolved solids (TDS) in the deeper wells in this zone is relatively high due to intrusion of sea water. Productive geothermal wells may have to be drilled to depths economically infeasible for development of the resource in the area of discussion.

  1. Convair Astronautics, San Diego (California

    Directory of Open Access Journals (Sweden)

    Pereira & Luckmam, Arquitectos

    1960-05-01

    Full Text Available Este brillante y espectacular complejo industrial se ha creado especialmente para la investigación y fabricación de cohetes intercontinentales y vehículos del espacio de las Fuerzas Aéreas de los EE. UU., en las proximidades de San Diego y cerca del campo de pruebas de Sycamore Canyon.

  2. Draft Environmental Impact Statement, San Francisco Bay to Stockton, California Project. John F. Baldwin Ship Channel. Phase II. Central San Francisco Bay Segment.

    Science.gov (United States)

    1983-12-01

    ONI’ EVAL.O 𔃺 1 OIIR OB. /ICR I Il. NI,. PULIC INTERST FACTOPS F XCF L I rH’!’I I X" .’ LDER EPA ’VOL. CuT.lb) "V_ W. AND CORT , RECS1 4 ’ PARI...resources. We have reviewed the report and concur in its findings. Sincerely, I Directo .4 --" ~~~~.........................’ ’i - t" ........ i -t

  3. San Francisco Bay Area Baseline Trash Loading (5000-25000 gal per yr), San Francisco Bay Area CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Marine debris degrades ocean habitats, endangers marine and coastal wildlife, causes navigation hazards, results in economic losses to industry and governments, and...

  4. San Francisco Bay Area Baseline Trash Loading (2501-5000 gal per yr), San Francisco Bay Area CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Marine debris degrades ocean habitats, endangers marine and coastal wildlife, causes navigation hazards, results in economic losses to industry and governments, and...

  5. San Francisco Bay Area Baseline Trash Loading (25001-50000 gal per yr), San Francisco Bay Area CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Marine debris degrades ocean habitats, endangers marine and coastal wildlife, causes navigation hazards, results in economic losses to industry and governments, and...

  6. San Francisco Bay Area Baseline Trash Loading (Over 50,000 gal per yr), San Francisco Bay Area CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Marine debris degrades ocean habitats, endangers marine and coastal wildlife, causes navigation hazards, results in economic losses to industry and governments, and...

  7. San Francisco Bay Area Baseline Trash Loading (0-2500 gal per yr), San Francisco Bay Area CA, 2012, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — Marine debris degrades ocean habitats, endangers marine and coastal wildlife, causes navigation hazards, results in economic losses to industry and governments, and...

  8. 78 FR 21397 - Don Edwards San Francisco Bay National Wildlife Refuge, Alameda, Santa Clara, and San Mateo...

    Science.gov (United States)

    2013-04-10

    ... by the National Wildlife Refuge System Improvement Act of 1997, requires us to develop a CCP for each... within the approved boundary, applicability of state health and safety codes in relation to mosquito... LEED-certified remodel of the Environmental Education Center, Spanish translation of materials and...

  9. 78 FR 39588 - Special Local Regulations; Revision of 2013 America's Cup Regulated Area, San Francisco Bay; San...

    Science.gov (United States)

    2013-07-02

    ... Folder on the line associated with this rulemaking. You may also visit the Docket Management Facility in... docket number (USCG-2011-0551) in the ``SEARCH'' box and click ``SEARCH.'' Click on Open Docket Folder on... the Coast Guard in complying with the National Environmental Policy Act of 1969 (NEPA) (42 U.S.C. 4321...

  10. The monterey bay broadband ocean bottom seismic observatory

    Directory of Open Access Journals (Sweden)

    R. Uhrhammer

    2006-06-01

    Full Text Available We report on the installation of a long-term buried ocean-floor broadband seismic station (MOBB in Monterey Bay, California (USA, 40km off-shore, at a water depth of 1000 m. The station was installed in April 2002 using a ship and ROV, in a collaborative effort between the Monterey Bay Aquarium Research Institute (MBARI and the Berkeley Seismological Laboratory (BSL. The station is located on the western side of the San Gregorio Fault, a major fault in the San Andreas plate boundary fault system. In addition to a 3-component CMG-1T seismometer package, the station comprises a current meter and Differential Pressure Gauge, both sampled at high-enough frequency (1 Hz to allow the study of relations between background noise on the seismometers and ocean waves and currents. The proximity of several land-based broadband seismic stations of the Berkeley Digital Seismic Network allows insightful comparisons of land/ocean background seismic noise at periods relevant to regional and teleseismic studies. The station is currently autonomous. Recording and battery packages are exchanged every 3 months during scheduled one day dives. Ultimately, this station will be linked to shore using continuous telemetry (cable and/or buoy and will contribute to the earthquake notification system in Northern California. We present examples of earthquake and noise data recorded during the first 6 months of operation of MOBB. Lessons learned from these and continued recordings will help understand the nature and character of background noise in regional off-shore environments and provide a reference for the installation of future off-shore temporary and permanent broadband seismic stations.

  11. Coastal monitoring of the May 2005 dredge disposal offshore of Ocean Beach, San Francisco, Calif.

    Science.gov (United States)

    Barnard, Patrick L.; Hanes, Daniel M.

    2006-01-01

    Ocean Beach, California, contains an erosion hot spot in the shadow of the San Francisco ebb tidal delta south of Sloat Boulevard that threatens valuable public infrastructure as well as the safe recreational use of the beach. In an effort to reduce the erosion at this location and avoid hazardous navigation conditions at the current disposal site (SF-8), a new plan for the management of sediment dredged annually from the main shipping channel at the mouth of Francisco Bay was implemented in May 2005 by the United States Army Corps of Engineers, San Francisco District (COE). The objective for COE was to perform a test dredge disposal of ~230,000 m3 (300,000 yd3) of sand just offshore of the erosion hot spot, in depths between approximately 9 and 14 m. This disposal site was chosen because it is in a location where the strong tidal currents associated with the mouth of San Francisco Bay and waves can potentially feed sediment toward the littoral zone in the reach of the beach that is experiencing critical erosion. The onshore migration of sediment from the target disposal location might feed the primary longshore bar or the nearshore zone, and provide a buffer to erosion that peaks during winter months when large waves impact the region. The U.S. Geological Survey (USGS), in collaboration with the Sea Floor Mapping Lab (SFML) of California State University, Monterey Bay, monitored the initial bathymetric evolution of the test dredge disposal site and the adjacent coastal region from May 2005 to November 2005. This paper reports on this monitoring effort and assesses the short-term coastal response.

  12. BOBMEX: The Bay of Bengal Monsoon Experiment

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, G.S.; Gadgil, S.; Kumar, P.V.H.; Kalsi, S.R.; Madhusoodanan, P.; Murty, V.S.N.; Rao, C.V.K.P.; RameshBabu, V.; Rao, L.V.G.; Rao, R.R.; Ravichandran, M.; Reddy, K.G.; Rao, P.Sanjeeva; Sengupta, D.; Sikka, D.R.; Swain, J.; Vinayachandran, P.N.

    , ocean, and their interface to gain deeper insight into some of the processes that govern the variability of organized convection over the bay. Simultaneous time series observations were carried out in the northern and southern Bay of Bengal from ships...

  13. 77 FR 57107 - Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos, Tillamook, and...

    Science.gov (United States)

    2012-09-17

    ... Fish and Wildlife Service Bandon Marsh, Nestucca Bay, and Siletz Bay National Wildlife Refuges, Coos... conservation plans and environmental assessments (Draft CCP/EAs) for three Oregon refuges-- Bandon Marsh... . Include ``Bandon Marsh, Nestucca Bay, and Siletz Bay draft CCP and EA'' in the subject line of the message...

  14. 33 CFR 100.112 - Swim the Bay, Narragansett Bay, Narragansett, RI.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Swim the Bay, Narragansett Bay, Narragansett, RI. 100.112 Section 100.112 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND..., Narragansett Bay, Narragansett, RI. (a) Regulated area. All waters of the East Passage of Narragansett Bay...

  15. Bayes linear statistics, theory & methods

    CERN Document Server

    Goldstein, Michael

    2007-01-01

    Bayesian methods combine information available from data with any prior information available from expert knowledge. The Bayes linear approach follows this path, offering a quantitative structure for expressing beliefs, and systematic methods for adjusting these beliefs, given observational data. The methodology differs from the full Bayesian methodology in that it establishes simpler approaches to belief specification and analysis based around expectation judgements. Bayes Linear Statistics presents an authoritative account of this approach, explaining the foundations, theory, methodology, and practicalities of this important field. The text provides a thorough coverage of Bayes linear analysis, from the development of the basic language to the collection of algebraic results needed for efficient implementation, with detailed practical examples. The book covers:The importance of partial prior specifications for complex problems where it is difficult to supply a meaningful full prior probability specification...

  16. Contaminant transport in Massachusetts Bay

    Science.gov (United States)

    Butman, Bradford

    Construction of a new treatment plant and outfall to clean up Boston Harbor is currently one of the world's largest public works projects, costing about $4 billion. There is concern about the long-term impact of contaminants on Massachusetts Bay and adjacent Gulf of Maine because these areas are used extensively for transportation, recreation, fishing, and tourism, as well as waste disposal. Public concern also focuses on Stellwagen Bank, located on the eastern side of Massachusetts Bay, which is an important habitat for endangered whales. Contaminants reach Massachusetts Bay not only from Boston Harbor, but from other coastal communities on the Gulf of Maine, as well as from the atmosphere. Knowledge of the pathways, mechanisms, and rates at which pollutants are transported throughout these coastal environments is needed to address a wide range of management questions.

  17. 76 FR 2085 - National Estuarine Research Reserve System; North Inlet-Winyah Bay, SC and San Francisco Bay, CA...

    Science.gov (United States)

    2011-01-12

    ... efforts on four critical issues that affect the reserve's ability to conserve ecological communities in..., Estuarine Reserves Division, 1305 East-West Highway, N/ORM5, 10th floor, Silver Spring, MD 20910. Dated...

  18. Hierarchical mixtures of naive Bayes classifiers

    OpenAIRE

    Wiering, M.A.

    2002-01-01

    Naive Bayes classifiers tend to perform very well on a large number of problem domains, although their representation power is quite limited compared to more sophisticated machine learning algorithms. In this pa- per we study combining multiple naive Bayes classifiers by using the hierar- chical mixtures of experts system. This system, which we call hierarchical mixtures of naive Bayes classifiers, is compared to a simple naive Bayes classifier and to using bagging and boosting for combining ...

  19. Arcos triunfales de San Petersburgo

    OpenAIRE

    Kurz Muñiz, Juan Albert; Gordo, Carmen María

    2001-01-01

    Se conmemora el tricentenario de la ciudad de San Petersburgo, ciudad que nos ha dejado grandiosos monumentos a lo largo de su historia. La importancia de los arcos triunfales, exponentes máximos que reglejan las victorias acaecidas, con un refinamiento y belleza occidental. Erigidos durante los reinados de Pedro I el Grande y Catalina II, monarcas ilustrados que supieron abrir a Rusia hacia la modernidad.

  20. Impact of Vehicular Traffic on Beach Habitat and Wildlife at Cape San Blas, Florida

    OpenAIRE

    Cox, Jack H.; Zupančič, Marjan; Percival, H. Franklin; Colwell, Sheila V.

    1994-01-01

    Cape San Bias is located on a barrier spit, St. Joseph peninsula, between St. Joseph Bay and the Gulf of Mexico in Gulf County, Florida (Fig. 1). Locally, the name of the cape is often used to refer to the entire peninsula. St. Joseph Peninsula State Park (SJPSP) comprises the northern 10 miles of the 22 mile-long peninsula. This section is closed to development and provides protection for representative coastal habitats, including sand dune and scrub pine. Two other parks are found on the...

  1. Dam-induced Flow Changes, Sacramento and San Joaquin Rivers, California

    Science.gov (United States)

    Kondolf, G. M.

    The Sacramento and San Joquin Rivers drain nearly 158,000 km of the Sierra_Nevada- Cascade Range, the Coast Range, and the intervening Central Valley, flowing west- ward through San Francisco Bay and Golden Gate to the Pacific. Numerous dams in the basin (for irrigation, hydroelectric power, and municipal/industry) all together im- pound 80% of the mean annual runoff in the Sacramento River basin, 120% in the San Joaquin River. I calculated the Impounded Runoff Index (IR), the reservoir stor- age capacity divided by the mean annual runoff for at least 12 sites on the channel. I analyzed changes in annual peak discharge and mean monthly flows since dam con- struction on the mainstem Sacramento San Joaquin and ten major tributaries for which suitable data were available. Ratios of post-to-pre-dam ranged from 0.72 (a 28% re- duction) to 0.006 (a 90% reduction). Reduction in peak flows was greater with higher values of IR, but the relations had scatter. Means monthly flows ranged from virtually no change pre-dam, to significant reductions in winter/spring high flows and increased the base flow.

  2. Resonance interaction between Bays and Harbors forced by tsunamis

    Science.gov (United States)

    Vela, Jordi; Pérez, Begoña.; González, Mauricio; Otero, Luis; Olabarrieta, Maitane; Canals, Miquel

    2010-05-01

    The tsunami induced by the 21 May 2003 Boumerdès-Zemmouri (Algeria) earthquake (Mw=6.9) did not generated important inundations damages or fatalities in the western Mediterranean area. However, damages and economic losses were reported in some harbors, generated by important sea level disturbances. Noticeable impacts were noted (broken mooring lines, sunken boats, displaced moorings, etc.) in some harbours in the Balearic Islands (Palma de Majorca, Ibiza and San Antoni) and also along the French border (La Figueirette and Mouré-Rouge harbours). Various authors have attempted to simulate this event finding discrepancies between the tsunami arrival time and amplitudes of waves on the tide gauges and results with numerical models. The models underestimate the amplitude of the tsunami. In some cases the underestimations have been associated to numerical limitations due to the lack of a high-resolution bathymetry and poor harbor geometry definition. Other cases, associated to a non appropriate seismic source characterization. Finally, some authors point out the occurrence of one or several submarine landslides triggered by the earthquake simultaneously with the seafloor vertical displacement, which have not been included in the numerical simulations. For a better knowledge of the response of a harbour interacting with a bay forced by a tsunami, a numerical study has been carried out for Palma Bay and Palma de Majorca Harbour. The transference of energy of the tsunami from the generation area to the continental shelf, the bay and the harbour has been studied for the Algerian tsunami (21 May 2003) and compared with the natural oscillation modes of the bay and the harbour water bodies. Furthermore, a sensibility analysis regarding the influence of the grid size of the harbour and bay bathymetries was also performed to understand the discrepancies between simulations and observations. The 2003 Zemmouri tsunami measured by the tidal gauge of Palma habour showed energy

  3. ROV observation of fluid expulsion in Monterey Bay, California

    Energy Technology Data Exchange (ETDEWEB)

    Orange, D.L.; Barry, J.; Maher, N. (Monterey Bay Aquarium Research Institute., Pacific Grove, CA (United States)) (and others)

    1996-01-01

    ROV dives in Monterey Bay have been used to examine the relationship of fluid flow to tectonic and stratigraphic conduits along an active transpressional continental margin. We used side-scan sonar to identify dive targets for the ROV, since anomalous reflectivity can be caused by the presence of biological [open quote]cold seep[close quotes] communities or authigenic carbonate. On a compressional ridge west of the San Gregorio Fault, cold seep clams are found along with extensive fields of authigenic carbonate in an elliptical region of anomalous reflectivity [approximately]400m in diameter. The reflectivity and fluid expulsion suggest that this feature is an active mud volcano. Analyses of push cores from the ridge site indicate high concentrations of both methane and sulfide and the presence of higher-order hydrocarbons. Many carbon isotopic ratios of the carbonate crusts indicate a methane carbon source; some values represent a mixture of methane carbon and normal marine carbon. Fluids charging the seeps west of the San Gregorio Fault may originate in tectonically-compacted sediments affected by residual Pacific-North America plate convergence, and may have an additional component of hydrocarbon charging from the underlying Monterey Formation. At the intersection of the Monterey Fault Zone and the Monterey Canyon a number of cold seeps occur in headless side canyons characterized by intense fracturing. This supports the hypothesis that submarine canyons act as hydrologic sinks for any overpressured fluid flowing toward the surface. On the San Gregorio Fault itself we have found in echelon ridges of carbonate. The fluids seeping out along fault zones may originate deep in the section and utilize the deformation-induced fracture permeability of the fault zone. Alternatively, aquifer-forcing from the uplifted Santa Cruz Mountains may provide a source of fluids venting along these fault zones (aquicludes ) and at seeps east of the fault zones.

  4. ROV observation of fluid expulsion in Monterey Bay, California

    Energy Technology Data Exchange (ETDEWEB)

    Orange, D.L.; Barry, J.; Maher, N. [Monterey Bay Aquarium Research Institute., Pacific Grove, CA (United States)] [and others

    1996-12-31

    ROV dives in Monterey Bay have been used to examine the relationship of fluid flow to tectonic and stratigraphic conduits along an active transpressional continental margin. We used side-scan sonar to identify dive targets for the ROV, since anomalous reflectivity can be caused by the presence of biological {open_quote}cold seep{close_quotes} communities or authigenic carbonate. On a compressional ridge west of the San Gregorio Fault, cold seep clams are found along with extensive fields of authigenic carbonate in an elliptical region of anomalous reflectivity {approximately}400m in diameter. The reflectivity and fluid expulsion suggest that this feature is an active mud volcano. Analyses of push cores from the ridge site indicate high concentrations of both methane and sulfide and the presence of higher-order hydrocarbons. Many carbon isotopic ratios of the carbonate crusts indicate a methane carbon source; some values represent a mixture of methane carbon and normal marine carbon. Fluids charging the seeps west of the San Gregorio Fault may originate in tectonically-compacted sediments affected by residual Pacific-North America plate convergence, and may have an additional component of hydrocarbon charging from the underlying Monterey Formation. At the intersection of the Monterey Fault Zone and the Monterey Canyon a number of cold seeps occur in headless side canyons characterized by intense fracturing. This supports the hypothesis that submarine canyons act as hydrologic sinks for any overpressured fluid flowing toward the surface. On the San Gregorio Fault itself we have found in echelon ridges of carbonate. The fluids seeping out along fault zones may originate deep in the section and utilize the deformation-induced fracture permeability of the fault zone. Alternatively, aquifer-forcing from the uplifted Santa Cruz Mountains may provide a source of fluids venting along these fault zones (aquicludes?) and at seeps east of the fault zones.

  5. Backscatter imagery in Jobos Bay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 1x1 meter resolution backscatter mosaic of Jobos Bay, Puerto Rico (in NAD83 UTM 19 North). The backscatter values are in relative 8-bit (0 –...

  6. Classification using Hierarchical Naive Bayes models

    DEFF Research Database (Denmark)

    Langseth, Helge; Dyhre Nielsen, Thomas

    2006-01-01

    Classification problems have a long history in the machine learning literature. One of the simplest, and yet most consistently well-performing set of classifiers is the Naïve Bayes models. However, an inherent problem with these classifiers is the assumption that all attributes used to describe......, termed Hierarchical Naïve Bayes models. Hierarchical Naïve Bayes models extend the modeling flexibility of Naïve Bayes models by introducing latent variables to relax some of the independence statements in these models. We propose a simple algorithm for learning Hierarchical Naïve Bayes models...

  7. Streamflow gains and losses along San Francisquito Creek and characterization of surface-water and ground-water quality, southern San Mateo and northern Santa Clara counties, California, 1996-97

    Science.gov (United States)

    Metzger, Loren F.

    2002-01-01

    San Francisquito Creek is an important source of recharge to the 22-square-mile San Francisquito Creek alluvial fan ground-water subbasin in the southern San Mateo and northern Santa Clara Counties of California. Ground water supplies as much as 20 percent of the water to some area communities. Local residents are concerned that infiltration and consequently ground-water recharge would be reduced if additional flood-control measures are implemented along San Francisquito Creek. To improve the understanding of the surface-water/ground-water interaction between San Francisquito Creek and the San Francisquito Creek alluvial fan, the U.S. Geological Survey (USGS) estimated streamflow gains and losses along San Francisquito Creek and determined the chemical quality and isotopic composition of surface and ground water in the study area.Streamflow was measured at 13 temporary streamflow-measurement stations to determine streamflow gains and losses along a 8.4-mile section of San Francisquito Creek. A series of five seepage runs between April 1996 and May 1997 indicate that losses in San Francisquito Creek were negligible until it crossed the Pulgas Fault at Sand Hill Road. Streamflow losses increased between Sand Hill Road and Middlefield Road where the alluvial deposits are predominantly coarse-grained and the water table is below the bottom of the channel. The greatest streamflow losses were measured along a 1.8-mile section of the creek between the San Mateo Drive bike bridge and Middlefield Road; average losses between San Mateo Drive and Alma Street and from there to Middlefield Road were 3.1 and 2.5 acre-feet per day, respectively.Downstream from Middlefield Road, streamflow gains and losses owing to seepage may be masked by urban runoff, changes in bank storage, and tidal effects from San Francisco Bay. Streamflow gains measured between Middlefield Road and the 1200 block of Woodland Avenue may be attributable to urban runoff and (or) ground-water inflow. Water

  8. Species - San Diego Co. [ds121

    Data.gov (United States)

    California Department of Resources — This is the Biological Observation Database point layer representing baseline observations of sensitive species (as defined by the MSCP) throughout San Diego County....

  9. Microplastics in tourist beaches of Huatulco Bay, Pacific coast of southern Mexico.

    Science.gov (United States)

    Retama, I; Jonathan, M P; Shruti, V C; Velumani, S; Sarkar, S K; Roy, Priyadarsi D; Rodríguez-Espinosa, P F

    2016-12-15

    The presence and impacts of plastic marine debris (PMD) have been documented in the oceans worldwide, and they deserve special attention. This study is the first to report the presence of microplastics in tourist beaches located in Huatulco Bay, southern Mexico. A total of 70 beach sediment samples (for 2 distinct seasons) were collected from Huatulco Bay in April 2013 and December 2014. The samples were subsequently extracted by scanning electron microscopy (SEM) to identify the fibrous microplastics (diametermicroplastics is present in the Conejos, Tangolunda, Santa Cruz, and San Agustin beaches. The microplastics are mainly derived from tourism-based activities and effluents discharged from the hotels and restaurants located along the beaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. 77 FR 34988 - Notice of Inventory Completion: San Diego State University, San Diego, CA

    Science.gov (United States)

    2012-06-12

    ... National Park Service Notice of Inventory Completion: San Diego State University, San Diego, CA AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: San Diego State University Archeology Collections Management Program has completed an inventory of human remains and associated funerary objects, in...

  11. 77 FR 46115 - Notice of Inventory Completion: San Diego Museum of Man, San Diego, CA

    Science.gov (United States)

    2012-08-02

    ...-1100-665] Notice of Inventory Completion: San Diego Museum of Man, San Diego, CA AGENCY: National Park Service, Interior. ACTION: Notice. SUMMARY: The San Diego Museum of Man has completed an inventory of... Diego Museum of Man. Repatriation of the human remains to the Indian tribe stated below may occur if no...

  12. 78 FR 34123 - Notice of Inventory Completion: San Francisco State University NAGPRA Program, San Francisco, CA

    Science.gov (United States)

    2013-06-06

    ... NAGPRA Program, c/o Department of Anthropology, San Francisco State University, 1600 Holloway Avenue, San... construction activities for the Middle Fork American River Project. Site materials from the Middle Fork... Jeffrey Boland Fentress, San Francisco State University NAGPRA Program, c/o Department of Anthropology...

  13. NOAA Office for Coastal Management Coastal Inundation Digital Elevation Model: San Francisco Bay/Monterey (CA) WFO - Contra Costa, San Francisco, Alameda, San Mateo, and Santa Clara Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea...

  14. Commencement Bay Study. Volume VII. Sediments, Noise, Climate, and Air Quality, Aesthetics, Birds.

    Science.gov (United States)

    1981-12-31

    Passeriformes VI. Sand-spit at mouth of Puyallup River numerous shore birds feeding Western Grede-large flocks Double Crested Cormorant-spring only...L Of S.AN3ARDSl V-0 ICOMMENCEMENT BAY STUDY ~~ Sediments Noise Climate, and Air Qualt Aesthetics Birds .. . . ... . . .......... 2..... VV.X D0O~U~T...Sediments, Noise, Climate 5. PERFORMING ORG. REPORT NUMBER and Air Quality, Birds 682-021-05 7. AUTHOR(*) S. CONTRACT OR GRANT NUMBR(s) DACW67-80-C

  15. Cuartel San Carlos. Yacimiento veterano

    Directory of Open Access Journals (Sweden)

    Mariana Flores

    2007-01-01

    Full Text Available El Cuartel San Carlos es un monumento histórico nacional (1986 de finales del siglo XVIII (1785-1790, caracterizado por sufrir diversas adversidades en su construcción y soportar los terremotos de 1812 y 1900. En el año 2006, el organismo encargado de su custodia, el Instituto de Patrimonio Cultural del Ministerio de Cultura, ejecutó tres etapas de exploración arqueológica, que abarcaron las áreas Traspatio, Patio Central y las Naves Este y Oeste de la edificación. Este trabajo reseña el análisis de la documentación arqueológica obtenida en el sitio, a partir de la realización de dicho proyecto, denominado EACUSAC (Estudio Arqueológico del Cuartel San Carlos, que representa además, la tercera campaña realizada en el sitio. La importancia de este yacimiento histórico, radica en su participación en los acontecimientos que propiciaron conflictos de poder durante el surgimiento de la República y en los sucesos políticos del siglo XX. De igual manera, se encontró en el sitio una amplia muestra de materiales arqueológicos que reseñan un estilo de vida cotidiana militar, así como las dinámicas sociales internas ocurridas en el San Carlos, como lugar estratégico para la defensa de los diferentes regímenes que atravesó el país, desde la época del imperialismo español hasta nuestros días.

  16. San Diego's High School Dropout Crisis

    Science.gov (United States)

    Wilson, James C.

    2012-01-01

    This article highlights San Diego's dropout problem and how much it's costing the city and the state. Most San Diegans do not realize the enormous impact high school dropouts on their city. The California Dropout Research Project, located at the University of California at Santa Barbara, has estimated the lifetime cost of one class or cohort of…

  17. Estimating Natural Flows into the California's Sacramento - San Joaquin Delta

    Science.gov (United States)

    Huang, G.; Kadir, T.; Chung, F. I.

    2014-12-01

    Natural flows into the California's Sacramento - San Joaquin Delta under predevelopment vegetative conditions, if and when reconstructed, can serve as a useful guide to establish minimum stream flows, restoration targets, and a basis for assessing impacts of global warming in the Bay-Delta System. Daily simulations of natural Delta flows for the period 1922-2009 were obtained using precipitation-snowmelt-runoff models for the upper watersheds that are tributaries to the California's Central Valley, and then routing the water through the Central Valley floor area using a modified version of the California Central Valley Groundwater-Surface Water Simulation Model (C2VSIM) for water years 1922 through 2009. Daily stream inflows from all major upper watersheds were simulated using 23 Soil Water Assessment Tool (SWAT) models. Historical precipitation and reference evapotranspiration data were extracted from the SIMETAW2 with the 4km gridded meteorological data. The Historical natural and riparian vegetation distributions were compiled from several pre-1900 historical vegetation maps of the Central Valley. Wetlands were dynamically simulated using interconnected lakes. Flows overtopping natural levees were simulated using flow rating curves. New estimates of potential evapotranspiration from different vegetative classes under natural conditions were also used. Sensitivity simulations demonstrate that evapotranspiration estimates, native vegetation distribution, surface-groundwater interaction parameters, extinction depth for groundwater uptake, and other physical processes play a key role in the magnitude and timing of upstream flows arriving at the Delta. Findings contradict a common misconception that the magnitude of inflows to the Delta under natural vegetative conditions is greater than those under the historical agricultural and urban land use development. The developed models also enable to study the impacts of global warming by modifying meteorological and

  18. The Chesapeake Bay impact structure

    Science.gov (United States)

    Powars, David S.; Edwards, Lucy E.; Gohn, Gregory S.; Horton, J. Wright

    2015-10-28

    About 35 million years ago, during late Eocene time, a 2-mile-wide asteroid or comet smashed into Earth in what is now the lower Chesapeake Bay in Virginia. The oceanic impact vaporized, melted, fractured, and (or) displaced the target rocks and sediments and sent billions of tons of water, sediments, and rocks into the air. Glassy particles of solidified melt rock rained down as far away as Texas and the Caribbean. Models suggest that even up to 50 miles away the velocity of the intensely hot air blast was greater than 1,500 miles per hour, and ground shaking was equivalent to an earthquake greater than magnitude 8.0 on the Richter scale. Large tsunamis affected most of the North Atlantic basin. The Chesapeake Bay impact structure is among the 20 largest known impact structures on Earth.

  19. Bayes reconstruction of missing teeth

    DEFF Research Database (Denmark)

    Sporring, Jon; Jensen, Katrine Hommelhoff

    2008-01-01

     We propose a method for restoring the surface of tooth crowns in a 3D model of a human denture, so that the pose and anatomical features of the tooth will work well for chewing. This is achieved by including information about the position and anatomy of the other teeth in the mouth. Our system...... contains two major parts: A statistical model of a selection of tooth shapes and a reconstruction of missing data. We use a training set consisting of 3D scans of dental cast models obtained with a laser scanner, and we have build a model of the shape variability of the teeth, their neighbors...... regularization of the log-likelihood estimate based on differential geometrical properties of teeth surfaces, and we show general conditions under which this may be considered a Bayes prior.Finally we use Bayes method to propose the reconstruction of missing data, for e.g. finding the most probable shape...

  20. Influenza in Bristol Bay, 1919

    OpenAIRE

    Maria Gilson deValpine

    2015-01-01

    The 1918 influenza pandemic has been blamed for as many as 50 million deaths worldwide. Like all major disasters, the full story of the pandemic includes smaller, less noted episodes that have not attracted historical attention. The story of the 1919 wave of the influenza pandemic in Bristol Bay Alaska is one such lost episode. It is an important story because the most accessible accounts—the Congressional Record and t...

  1. Zooplankton Biomass Data from Prince William Sound, Icy Bay and Yakutat Bay, Alaska 2010-2011

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset includes zooplankton biomass from Prince William Sound, Icy Bay and Yakutat Bay, Alaska. Zooplankton were sampled with a ring net (0.6 m diameter with...

  2. [Characteristics of Pahs pollution in sediments from Leizhou coastal marine area, Liusha Bay and Shenzhen Bay].

    Science.gov (United States)

    Zhao, Li-Rong; Sun, Sheng-Li; Ke, Sheng

    2012-04-01

    Leizhou coastal marine area, Liusha Bay and Shenzhen Bay represented open coastal area and half-closed bay, respectively. This study discussed the differences of PAHs concentration levels, spatial distribution and sources in sediments from these three marine areas. The results showed that detected ratios of 15 PAHs were 100%, and major compounds were 3-ring and 4-ring PAHs, especialy Phe, Fla, Pry and Bbf; Sigma PAHs concentration was Leizhou the outside, and the aquaculture > the non-aquaculture in Liusha Bay and Shenzhen Bay. It suggested that large-scale mariculture inside bay played an important role in PAHs pollution and might make it serious. Oil, fossil fuels and biomass burning were the dominant sources of PAHs in sediments from Leizhou coastal area, Liusha Bay and Shenzhen Bay.

  3. Linear dimension reduction and Bayes classification

    Science.gov (United States)

    Decell, H. P., Jr.; Odell, P. L.; Coberly, W. A.

    1978-01-01

    An explicit expression for a compression matrix T of smallest possible left dimension K consistent with preserving the n variate normal Bayes assignment of X to a given one of a finite number of populations and the K variate Bayes assignment of TX to that population was developed. The Bayes population assignment of X and TX were shown to be equivalent for a compression matrix T explicitly calculated as a function of the means and covariances of the given populations.

  4. Investigation of Tidal Power, Cobscook Bay, Maine.

    Science.gov (United States)

    1980-08-01

    include Perry, Pembrook, Edmunds, Dennyville, Whiting and Trescott (See Figure 1). Located entirely in the United States at the mouth of the Bay of Fundy ...Quoddy Region because of the softer sediments in that area. Some are harvested within the bay itself, although to a much lesser extent. Lobsters are...earthquake of an intensity VIII occurring in the Bay of Fundy approximately 35 miles west of the site. Closer to the site an earthquake of intensity VII

  5. 78 FR 45061 - Safety Zone; Sister Bay Marina Fest Fireworks and Ski Show, Sister Bay, WI

    Science.gov (United States)

    2013-07-26

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Sister Bay Marina Fest Fireworks and Ski... intended to restrict vessels from a portion of Sister Bay due to a fireworks display and ski show. This... with the fireworks display and ski show in Sister Bay on August 31, 2013. DATES: This rule is effective...

  6. 78 FR 46813 - Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay, WI

    Science.gov (United States)

    2013-08-02

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Evening on the Bay Fireworks; Sturgeon Bay... of Sturgeon Bay due to a fireworks display. This temporary safety zone is necessary to protect the surrounding public and vessels from the hazards associated with the fireworks display. DATES: This rule is...

  7. Suicides in San Mateo County.

    Science.gov (United States)

    Krieger, G

    1967-08-01

    The usual surveys of completed suicides, encompassing, as they do, large geographical areas, are of limited value to physicians of a particular community. The unique and differentiating characteristics of the suicides in his locale may be "washed out" in these large surveys.San Mateo County has an annual suicide rate of 17 per 100,000 and a disproportionately high incidence in persons over 65 years old. In this particular county females, widows and Orientals are more prone to suicide than has usually been reported elsewhere. Alcohol was directly or indirectly involved in a significant number of instances. Many of the persons who killed themselves were under a physician's care at the time of self-destruction. There are probably important ecological and sociological variables as well as personal factors involved in the suicidal process that are of significance to any suicide prevention program. It is urged that there be more extensive and comparative research in this important public health problem.

  8. Distribution and Invasion Potential of Limonium ramosissimum subsp. provinciale in San Francisco Estuary Salt Marshes

    Directory of Open Access Journals (Sweden)

    Gavin Archbald

    2014-06-01

    Full Text Available Non-native sea lavenders (Limonium spp. are invasive in salt marshes of southern California and were first documented in the San Francisco Estuary (the estuary in 2007. In this study, we mapped distributions of L. ramosissimum subsp. provinciale (LIRA and L. duriusculum within the estuary and investigated how the invasion potential of the more common species, LIRA, varies with elevation and edaphic conditions. We contacted colleagues and conducted field searches to find and then map sea lavender populations. In addition, we measured LIRA’s elevational range at three salt marshes. Across this range we measured (1 soil properties: salinity, moisture, bulk density, and texture; and (2 indicators of invasion potential: LIRA size, seed production, percent cover, spread (over 1 year, recruitment, and competition with native halophytes (over 6 months. We found LIRA in 15,144 m2 of upper salt marsh habitat in central and south San Francisco bays and L. duriusculum in 511 m2 in Richardson and San Pablo bays. LIRA was distributed from mean high water (MHW to 0.42 m above mean higher high water (MHHW. In both spring and summer, soil moisture and salinity were lowest at higher elevations within LIRA’s range, which corresponded with greater rosette size, inflorescence and seed production (up to 17,400 seeds per plant, percent cover, and recruitment. LIRA cover increased on average by 11% in 1 year across marshes and elevations. Cover of the native halophytes Salicornia pacifica, Jaumea carnosa, and Distichlis spicata declined significantly at all elevations if LIRA were present in plots (over a 6-month, fall–winter period. Results suggest LIRA’s invasion potential is highest above MHHW where salinity and moisture are lower, but that LIRA competes with native plants from MHW to above MHHW. We recommend removal efforts with emphasis on the salt marsh-terrestrial ecotone where LIRA seed output is highest.

  9. Phytoplankton in the Upper San Francisco Estuary: Recent Biomass Trends, Their Causes, and Their Trophic Significance

    Directory of Open Access Journals (Sweden)

    Alan Jassby

    2008-02-01

    Full Text Available Several pelagic fish populations in the upper San Francisco Estuary have recently declined to historically low abundances, prompting an interest in the status of their food supply. Previous studies have indicated that the primary food supply for metazoans in the Delta is phytoplankton productivity, and the long-term decrease in phytoplankton over the last few decades may very well play a role in the long-term decline of pelagic fish abundance. Regional phytoplankton biomass trends during 1996–2005, however, are positive in the Delta and neutral in Suisun Bay, the two major sub-regions of the upper estuary. The trend in Delta primary productivity is also positive. Changes in phytoplankton biomass and production during the last decade are therefore unlikely to be the cause of these more recent metazoan declines. The main source of interannual phytoplankton variability in the Delta during 1996–2005, including the upward trend, appears to have been freshwater flow variability and its effect on particle residence time. This conclusion is supported by trend analyses; the concurrence of these time trends at widely-separated stations; empirical models at the annual and monthly time scales; particle residence time estimates; and experience from other estuaries. A significant temperature increase was also noticed, at least partially independent of flow changes, but its net effect on the phytoplankton community is unknown because of differential effects on growth and loss processes. Phytoplankton biomass in Suisun Bay, in contrast to the Delta, did not increase during 1996–2005. Consistent with this observation, Suisun Bay phytoplankton exhibited relatively low responsiveness to flow variability. This behavior differs from earlier chlorophyll-flow relationships reported in the literature. The reason appears to be the invasion of Suisun Bay by a clam—Corbula amurensis—in 1986, which has since maintained the phytoplankton community mostly at low

  10. Testing cosmic dose rate models for ESR: Dating corals and molluscs on San Salvador, Bahamas

    Energy Technology Data Exchange (ETDEWEB)

    Deely, A.E. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Blackwell, B.A.B., E-mail: bonnie.a.b.blackwell@williams.edu [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Dept. of Chemistry, Williams College, Williamstown MA, 01267-2692 (United States); Mylroie, J.E. [Dept. of Geosciences, Mississippi State University, MS, 39762-5448 (United States); Carew, J.L. [Dept. of Geology and Environmental Geosciences, College of Charleston, Charleston, SC 29424 (United States); Blickstein, J.I.B. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Skinner, A.R. [RFK Science Research Institute, Glenwood Landing, NY, 11547-0866 (United States); Dept. of Chemistry, Williams College, Williamstown MA, 01267-2692 (United States)

    2011-09-15

    Sealevel curves are best developed on tectonically stable coastlines, like San Salvador, where eolianites preserve transgressive and regressive phases associated with Quaternary high seastands, while reef facies mark the highstands. At 11 locations around San Salvador, terrestrial molluscs (Cerion) from the eolianites, lagoonal bivalves (Codakia), and corals from the highstand deposits were dated by ESR. Volumetrically averaged sedimentary dose rates were calculated from sedimentary geochemistry and time-averaged cosmic dose rates from each sample's current and past geologic contexts. Rice Bay Formation corals dated at 3.9 {+-} 0.3 to 7.1 {+-} 0.4 ka (OIS 1). Minimum ages for the Cockburn Town Member's regressive phase ranged from 49 {+-} 6 to 75 {+-} 8 ka, correlating with OIS 3-4. Codakia dates showed that an OIS 5a sealevel approached modern levels at 91-78 ka. In situ corals from the Cockburn Town Reef averaged from 127 {+-} 6 to 138 {+-} 10 ka, correlating well with OIS 5e. Ages from the Reef's rubble zones hint that some coral reefs grew as early as OIS 7, but were likely reworked during OIS 5. San Salvador preserves deposits from three mid to late Quaternary highstands above, and as many as three that closely approach, modern sealevel.

  11. Assessing Climate Variability Effects on Dengue Incidence in San Juan, Puerto Rico

    Directory of Open Access Journals (Sweden)

    Pablo Méndez-Lázaro

    2014-09-01

    Full Text Available We test the hypothesis that climate and environmental conditions are becoming favorable for dengue transmission in San Juan, Puerto Rico. Sea Level Pressure (SLP, Mean Sea Level (MSL, Wind, Sea Surface Temperature (SST, Air Surface Temperature (AST, Rainfall, and confirmed dengue cases were analyzed. We evaluated the dengue incidence and environmental data with Principal Component Analysis, Pearson correlation coefficient, Mann-Kendall trend test and logistic regressions. Results indicated that dry days are increasing and wet days are decreasing. MSL is increasing, posing higher risk of dengue as the perimeter of the San Juan Bay estuary expands and shorelines move inland. Warming is evident with both SST and AST. Maximum and minimum air surface temperature extremes have increased. Between 1992 and 2011, dengue transmission increased by a factor of 3.4 (95% CI: 1.9–6.1 for each 1 °C increase in SST. For the period 2007–2011 alone, dengue incidence reached a factor of 5.2 (95% CI: 1.9–13.9 for each 1 °C increase in SST. Teenagers are consistently the age group that suffers the most infections in San Juan. Results help understand possible impacts of different climate change scenarios in planning for social adaptation and public health interventions.

  12. Assessing Climate Variability Effects on Dengue Incidence in San Juan, Puerto Rico

    Science.gov (United States)

    Méndez-Lázaro, Pablo; Muller-Karger, Frank E.; Otis, Daniel; McCarthy, Matthew J.; Peña-Orellana, Marisol

    2014-01-01

    We test the hypothesis that climate and environmental conditions are becoming favorable for dengue transmission in San Juan, Puerto Rico. Sea Level Pressure (SLP), Mean Sea Level (MSL), Wind, Sea Surface Temperature (SST), Air Surface Temperature (AST), Rainfall, and confirmed dengue cases were analyzed. We evaluated the dengue incidence and environmental data with Principal Component Analysis, Pearson correlation coefficient, Mann-Kendall trend test and logistic regressions. Results indicated that dry days are increasing and wet days are decreasing. MSL is increasing, posing higher risk of dengue as the perimeter of the San Juan Bay estuary expands and shorelines move inland. Warming is evident with both SST and AST. Maximum and minimum air surface temperature extremes have increased. Between 1992 and 2011, dengue transmission increased by a factor of 3.4 (95% CI: 1.9–6.1) for each 1 °C increase in SST. For the period 2007–2011 alone, dengue incidence reached a factor of 5.2 (95% CI: 1.9–13.9) for each 1 °C increase in SST. Teenagers are consistently the age group that suffers the most infections in San Juan. Results help understand possible impacts of different climate change scenarios in planning for social adaptation and public health interventions. PMID:25216253

  13. Hybridization between invasive Spartina Densiflora (Poaceae) and native S. Foliosa in San Francisco Bay, California, USA

    Science.gov (United States)

    Rapid evolution in contemporary time can result when related species, brought together through human-aided introduction, hybridize. The evolutionary consequences of post introduction hybridization range from allopolyploid speciation to extinction of species through genetic amalg...

  14. F00590: NOS Hydrographic Survey , Enterance to San Diego Bay, California, 2010-10-25

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data in support of nautical chart compilation for safe...

  15. Chronic Sublethal Effects of San Francisco Bay Sediments on Nereis (Neanthes) arenaceodentata; Bioaccumulation from Bedded Sediments

    Science.gov (United States)

    1993-09-01

    of their own. Juvenile worms grow and eggs become visible in the coelom of females about 6 weeks postemergence, F, gg deposition follows 3 to 7 weeks...the fighting response (Reish and Alosi 1968) and the presence or absence (if eggs in the coelom . Unpaired worms were discarded. Pairs were placed in

  16. San Francisco Bay Area Base Line Trash Loading (0-2500 gal/yr)

    Science.gov (United States)

    Marine debris degrades ocean habitats, endangers marine and coastal wildlife, causes navigation hazards, results in economic losses to industry and governments, and threatens human health and safety. EPA Pacific Southwest (Region 9) is tapping existing programs and resources to advance the prevention, reduction and clean-up of marine debris in the North Pacific Ocean. EPA Pacific Southwest activities build upon specific recommendations of the Interagency Marine Debris Coordinating Committee by targeting threats and sources of debris and responding to debris impacts. EPA is initiating a three-pronged effort to reduce sources of marine debris, prevent trash from entering the oceans, and assess the human and ecosystem impacts and potential for cleanup.

  17. San Francisco Bay Area Base Line Trash Loading (5000 - 25000 gal/yr)

    Science.gov (United States)

    Marine debris degrades ocean habitats, endangers marine and coastal wildlife, causes navigation hazards, results in economic losses to industry and governments, and threatens human health and safety. EPA Pacific Southwest (Region 9) is tapping existing programs and resources to advance the prevention, reduction and clean-up of marine debris in the North Pacific Ocean. EPA Pacific Southwest activities build upon specific recommendations of the Interagency Marine Debris Coordinating Committee by targeting threats and sources of debris and responding to debris impacts. EPA is initiating a three-pronged effort to reduce sources of marine debris, prevent trash from entering the oceans, and assess the human and ecosystem impacts and potential for cleanup.

  18. San Francisco Bay Area Base Line Trash Loading (2501 - 5000 gal/yr)

    Science.gov (United States)

    Marine debris degrades ocean habitats, endangers marine and coastal wildlife, causes navigation hazards, results in economic losses to industry and governments, and threatens human health and safety. EPA Pacific Southwest (Region 9) is tapping existing programs and resources to advance the prevention, reduction and clean-up of marine debris in the North Pacific Ocean. EPA Pacific Southwest activities build upon specific recommendations of the Interagency Marine Debris Coordinating Committee by targeting threats and sources of debris and responding to debris impacts. EPA is initiating a three-pronged effort to reduce sources of marine debris, prevent trash from entering the oceans, and assess the human and ecosystem impacts and potential for cleanup.

  19. Two examples of seismic zonation in the San Francisco Bay region

    Science.gov (United States)

    Kockelman, W.J.; Brabb, E.E.

    1981-01-01

    The science of earthquakes in complex, requiring data and research in seismology, geology, soil mechanics, geophysics, hydrology, and engineering. Nevertheless, if earthquake hazards are to be reduced, earth science information must be translated from scientific and technical language into a form that can be effectively used by planners and decisionmakers.

  20. Effectiveness of a San Francisco Bay area community education program on reducing home energy use

    Science.gov (United States)

    Wilkinson, Ellen M.

    In order to promote the adoption of home energy reduction practices and mitigate the climate impact of the collective greenhouse gas emissions generated by consumers, it is critical to identify an effective educational approach. A community-based educational intervention model that employs norms, information, commitment, feedback, and face-to-face communication strategies was examined for its ability to motivate changes in everyday energy-use behavior in two communities compared to a control group. A follow up study was also conducted to evaluate whether behaviors adopted as a result of the intervention were long lasting, and whether the community-focused features of the intervention were motivating to participants. Results showed that a greater number of individuals participated in the intervention over its five-month duration, reported significantly higher numbers of adopted behaviors, and maintained more adopted behaviors post-intervention than did people in the control group. In addition, intervention participants reported that some of the community-based features of the intervention motivated their behavior changes. These findings lend support to a number of social and community psychology theories about how to design effective interventions by leveraging social awareness and support.