Publications
For more than a century, USGS scientists have conducted research in California’s Bay-Delta region. Informing natural-resource management decisions on the region’s issues, this research has been published in thousands of documents, some highlighted below.
Filter Total Items: 307
A perspective on modern pesticides, pelagic fish declines, and unknown ecological resilience in highly managed ecosystems A perspective on modern pesticides, pelagic fish declines, and unknown ecological resilience in highly managed ecosystems
Pesticides applied on land are commonly transported by runoff or spray drift to aquatic ecosystems, where they are potentially toxic to fishes and other nontarget organisms. Pesticides add to and interact with other stressors of ecosystem processes, including surface-water diversions, losses of spawning and rearing habitats, nonnative species, and harmful algal blooms. Assessing the...
Authors
Nathaniel L. Scholz, Erica Fleishman, Larry Brown, Inge Werner, Michael L. Johnson, Marjorie L. Brooks, Carys L. Mitchelmore, Daniel Schlenk
Downscaling future climate projections to the watershed scale: A north San Francisco Bay estuary case study Downscaling future climate projections to the watershed scale: A north San Francisco Bay estuary case study
We modeled the hydrology of basins draining into the northern portion of the San Francisco Bay Estuary (North San Pablo Bay) using a regional water balance model (Basin Characterization Model; BCM) to estimate potential effects of climate change at the watershed scale. The BCM calculates water balance components, including runoff, recharge, evapotranspiration, soil moisture, and stream...
Authors
Elisabeth Micheli, Lorraine Flint, Alan Flint, Stuart Weiss, Morgan Kennedy
Mercury exposure may suppress baseline corticosterone levels in juvenile birds Mercury exposure may suppress baseline corticosterone levels in juvenile birds
Mercury exposure has been associated with a wide variety of negative reproductive responses in birds, however few studies have examined the potential for chick impairment via the hypothalamic-pituitary-adrenal (HPA) axis. The HPA axis regulates corticosterone levels during periods of stress. We examined the relationship between baseline fecal corticosterone metabolite concentrations and...
Authors
Garth Herring, Joshua T. Ackerman, Mark P. Herzog
Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta
Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward exchange, and local sedimentation in open...
Authors
David H. Schoellhamer, Scott Wright, Judith Z. Drexler
Sources of mercury to San Francisco Bay surface sediment as revealed by mercury stable isotopes Sources of mercury to San Francisco Bay surface sediment as revealed by mercury stable isotopes
Mercury (Hg) concentrations and isotopic compositions were examined in shallow-water surface sediment (0–2 cm) from San Francisco (SF) Bay to determine the extent to which historic Hg mining contributes to current Hg contamination in SF Bay, and to assess the use of Hg isotopes to trace sources of contamination in estuaries. Inter-tidal and wetland sediment had total Hg (HgT)...
Authors
Gretchen E. Gehrke, Joel D. Blum, Mark Marvin-DePasquale
Projected evolution of California's San Francisco Bay-Delta-River System in a century of continuing climate change Projected evolution of California's San Francisco Bay-Delta-River System in a century of continuing climate change
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...
Authors
James E. Cloern, Noah Knowles, Larry R. Brown, Daniel Cayan, Michael D. Dettinger, Tara L. Morgan, David H. Schoellhamer, Mark T. Stacey, Mick van der Wegen, R. Wayne Wagner, Alan D. Jassby
PCB-induced changes of a benthic community and expected ecosystem recovery following in situ sorbent amendment PCB-induced changes of a benthic community and expected ecosystem recovery following in situ sorbent amendment
The benthic community was analyzed to evaluate pollution-induced changes for the polychlorinated biphenyl (PCB)-contaminated site at Hunters Point (HP) relative to 30 reference sites in San Francisco Bay, California, USA. An analysis based on functional traits of feeding, reproduction, and position in the sediment shows that HP is depauperate in deposit feeders, subsurface carnivores...
Authors
Elisabeth M.-L. Janssen, Janet K. Thompson, Samuel N. Luoma, Richard G. Luthy
Oxidative stress response of Forster's terns (Sterna forsteri) and Caspian terns (Hydroprogne caspia) to mercury and selenium bioaccumulation in liver, kidney, and brain Oxidative stress response of Forster's terns (Sterna forsteri) and Caspian terns (Hydroprogne caspia) to mercury and selenium bioaccumulation in liver, kidney, and brain
Bioindicators of oxidative stress were examined in prebreeding and breeding adult and chick Forster's terns (Sterna forsteri) and in prebreeding adult Caspian terns (Hydroprogne caspia) in San Francisco Bay, California. Highest total mercury (THg) concentrations (mean±standard error;μg/g dry wt) in liver (17.7±1.7), kidney (20.5±1.9), and brain (3.0±0.3) occurred in breeding adult...
Authors
David J. Hoffman, Collin A. Eagles-Smith, Joshua T. Ackerman, Terrence L. Adelsbach, Katherine R. Stebbins
Small-scale sediment transport patterns and bedform morphodynamics: New insights from high resolution multibeam bathymetry Small-scale sediment transport patterns and bedform morphodynamics: New insights from high resolution multibeam bathymetry
New multibeam echosounder and processing technologies yield sub-meter-scale bathymetric resolution, revealing striking details of bedform morphology that are shaped by complex boundary-layer flow dynamics at a range of spatial and temporal scales. An inertially aided post processed kinematic (IAPPK) technique generates a smoothed best estimate trajectory (SBET) solution to tie the vessel...
Authors
Patrick L. Barnard, Li H. Erikson, Rikk G. Kvitek
Bird mercury concentrations change rapidly as chicks age: Toxicological risk is highest at hatching and fledging Bird mercury concentrations change rapidly as chicks age: Toxicological risk is highest at hatching and fledging
Toxicological risk of methylmercury exposure to juvenile birds is complex due to the highly transient nature of mercury concentrations as chicks age. We examined total mercury and methylmercury concentrations in blood, liver, kidney, muscle, and feathers of 111 Forster's tern (Sterna forsteri), 69 black-necked stilt (Himantopus mexicanus), and 43 American avocet (Recurvirostra americana)...
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith, Mark P. Herzog
Recent scientific advances and their implications for sand management near San Francisco, California: The influences of the ebb tidal delta Recent scientific advances and their implications for sand management near San Francisco, California: The influences of the ebb tidal delta
Recent research in the San Francisco, California, U.S.A., coastal region has identified the importance of the ebb tidal delta to coastal processes. A process-based numerical model is found to qualitatively reproduce the equilibrium size and shape of the delta. The ebb tidal delta itself has been contracting over the past century, and the numerical model is applied to investigate the...
Authors
Daniel M. Hanes, Patrick L. Barnard, Kate Dallas, Edwin Elias, Li H. Erikson, Jodi Eshleman, Jeff Hansen, Tian Jian Hsu, Fengyan Shi
Overview of the ARkStorm scenario Overview of the ARkStorm scenario
The U.S. Geological Survey, Multi Hazards Demonstration Project (MHDP) uses hazards science to improve resiliency of communities to natural disasters including earthquakes, tsunamis, wildfires, landslides, floods and coastal erosion. The project engages emergency planners, businesses, universities, government agencies, and others in preparing for major natural disasters. The project also...
Authors
Keith Porter, Anne Wein, Charles N. Alpers, Allan Baez, Patrick L. Barnard, James Carter, Alessandra Corsi, James Costner, Dale Cox, Tapash Das, Mike Dettinger, James Done, Charles Eadie, Marcia Eymann, Justin Ferris, Prasad Gunturi, Mimi Hughes, Robert Jarrett, Laurie Johnson, Hanh Dam Le-Griffin, David Mitchell, Suzette Morman, Paul Neiman, Anna Olsen, Suzanne Perry, Geoffrey Plumlee, Martin Ralph, David Reynolds, Adam Rose, Kathleen Schaefer, Julie Serakos, William Siembieda, Jonathan D. Stock, David Strong, Ian Sue Wing, Alex Tang, Pete Thomas, Ken Topping, Chris Wills, Lucile Jones
By
Natural Hazards Mission Area, Coastal and Marine Hazards and Resources Program, Earthquake Hazards Program, Science Application for Risk Reduction, Geologic Hazards Science Center, Pacific Coastal and Marine Science Center, Big Sur Landslides, Reducing Risk, San Francisco Bay and Sacramento-San Joaquin Delta Estuary