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
Probabilistic estimation of numbers and costs of future landslides in the San Francisco Bay region Probabilistic estimation of numbers and costs of future landslides in the San Francisco Bay region
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...
Authors
R. A. Crovelli, J. A. Coe
Avian response to early tidal salt marsh restoration at former commercial salt evaporation ponds in San Francisco Bay, California, USA Avian response to early tidal salt marsh restoration at former commercial salt evaporation ponds in San Francisco Bay, California, USA
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...
Authors
Nicole D. Athearn, John Y. Takekawa, Joel Shinn
Postfledging Forster's Tern movements, habitat selection, and colony attendance in San Francisco Bay Postfledging Forster's Tern movements, habitat selection, and colony attendance in San Francisco Bay
Relatively little is known about birds during the postfledging period when flighted chicks have left the nest and must learn to forage independently. We examined postfledging movements, habitat selection, and colony attendance of Forster's Terns (Sterna forsteri) radio-marked just before they fledged in San Francisco Bay, California. The proportion of the day spent at their natal colony...
Authors
Joshua T. Ackerman, Jill D. Bluso-Demers, John Y. Takekawa
Sexing California Clapper Rails using morphological measurements Sexing California Clapper Rails using morphological measurements
California Clapper Rails (Rallus longirostris obsoletus) have monomorphic plumage, a trait that makes identification of sex difficult without extensive behavioral observation or genetic testing. Using 31 Clapper Rails (22 females, 9 males), caught in south San Francisco Bay, CA, and using easily measurable morphological characteristics, we developed a discriminant function to distinguish...
Authors
Cory T. Overton, Michael L. Casazza, John Y. Takekawa, Tobias M. Rohmer
Integrating toxicity risk in bird eggs and chicks: Using chick down feathers to estimate mercury concentrations in eggs Integrating toxicity risk in bird eggs and chicks: Using chick down feathers to estimate mercury concentrations in eggs
The concentration of mercury (Hg) in eggs that causes reduced hatching success is regarded as a critical end point for Hg toxicity in birds. However, incorporating effects of in ovo mercury exposure on chick health and survival could improve risk assessment. We developed equations to predict Hg in eggs using Hg in chick down feathers, and vice versa, by assessing the relationship between...
Authors
Joshua T. Ackerman, Collin A. Eagles-Smith
Potential Inundation due to Rising Sea Levels in the San Francisco Bay Region Potential Inundation due to Rising Sea Levels in the San Francisco Bay Region
An increase in the rate of sea level rise is one of the primary impacts of projected global climate change. To assess potential inundation associated with a continued acceleration of sea level rise, the highest resolution elevation data available were assembled from various sources and mosaicked to cover the land surfaces of the San Francisco Bay region. Next, to quantify high water...
Authors
Noah Knowles
Home range, habitat selection, and movements of California Black Rails at tidal marshes at San Francisco Bay, California Home range, habitat selection, and movements of California Black Rails at tidal marshes at San Francisco Bay, California
Little is known about the movements and habitat selection of California Black Rails (Laterallus jamaicensis coturniculus) in coastal California. We captured 130 Black Rails, of which we radio-marked 48, in tidal marshes in San Francisco Bay during 2005 and 2006. Our objective was to examine their home ranges, movements, and habitat selection to improve the species' conservation. The mean...
Authors
Danika C. Tsao, John Y. Takekawa, Isa Woo, Julie L. Yee, Jules G. Evens
Utilization by fishes of the Alviso Island ponds and adjacent waters in south san francisco bay following restoration to tidal influence Utilization by fishes of the Alviso Island ponds and adjacent waters in south san francisco bay following restoration to tidal influence
Earthen levees of three isolated salt ponds known locally as the Alviso Island Ponds were intentionally breached in March 2006 to allow tidal exchange of the ponds with water from Coyote Creek. The water exchange transformed the previously fishless hypersaline ponds into lower salinity habitats suitable for fish life. This study documented fish utilization of the ponds, adjacent reaches...
Authors
M. K. Saiki, F.H. Mejia
Benthic flux of nutrients and trace metals in the northern component of San Francisco Bay, California Benthic flux of nutrients and trace metals in the northern component of San Francisco Bay, California
Two sets of sampling trips were coordinated in late summer 2008 (weeks of July 8 and August 6) to sample the interstitial and overlying bottom waters at 10 shallow locations (9 sites
Authors
James S. Kuwabara, Brent R. Topping, Francis Parcheso, Anita C. Engelstad, Valerie E. Greene
Earthquake stress drops and inferred fault strength on the Hayward Fault, east San Francisco Bay, California Earthquake stress drops and inferred fault strength on the Hayward Fault, east San Francisco Bay, California
We study variations in earthquake stress drop with respect to depth, faulting regime, creeping versus locked fault behavior, and wall-rock geology. We use the P-wave displacement spectra from borehole seismic recordings of M 1.0-4.2 earthquakes in the east San Francisco Bay to estimate stress drop using a stack-and-invert empirical Green's function method. The median stress drop is 8.7...
Authors
J.L. Hardebeck, A. Aron
A Viscoelastic earthquake simulator with application to the San Francisco Bay region A Viscoelastic earthquake simulator with application to the San Francisco Bay region
Earthquake simulation on synthetic fault networks carries great potential for characterizing the statistical patterns of earthquake occurrence. I present an earthquake simulator based on elastic dislocation theory. It accounts for the effects of interseismic tectonic loading, static stress steps at the time of earthquakes, and postearthquake stress readjustment through viscoelastic...
Authors
Fred F. Pollitz
Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay Dietary flexibility in three representative waterbirds across salinity and depth gradients in salt ponds of San Francisco Bay
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...
Authors
John Y. Takekawa, A.K. Miles, D. C. Tsao-Melcer, D. H. Schoellhamer, S. Fregien, N.D. Athearn