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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: 308

Effect of tides, river flow, and gate operations on entrainment of juvenile salmon into the interior Sacramento–San Joaquin River Delta

Juvenile Chinook Salmon Oncorhynchus tshawytscha emigrating from natal tributaries of the Sacramento River, California, must negotiate the Sacramento-San Joaquin River Delta (hereafter, the Delta), a complex network of natural and man-made channels linking the Sacramento River with San Francisco Bay. Fish that enter the interior and southern Delta—the region to the south of the Sacramento River wh
Authors
Russell W. Perry, Patricia L. Brandes, Jon R. Burau, Philip T. Sandstrom, John R. Skalski

Targeting climate diversity in conservation planning to build resilience to climate change

Climate change is raising challenging concerns for systematic conservation planning. Are methods based on the current spatial patterns of biodiversity effective given long-term climate change? Some conservation scientists argue that planning should focus on protecting the abiotic diversity in the landscape, which drives patterns of biological diversity, rather than focusing on the distribution of
Authors
Nicole E. Heller, Jason R. Kreitler, David Ackerly, Stuart Weiss, Amanda Recinos, Ryan Branciforte, Lorraine E. Flint, Alan L. Flint, Elisabeth Micheli

Diel activity patterns of juvenile late fall-run Chinook salmon with implications for operation of a gated water diversion in the Sacramento–San Joaquin River Delta

In the Sacramento-San Joaquin River Delta, California, tidal forces that reverse river flows increase the proportion of water and juvenile late fall-run Chinook salmon diverted into a network of channels that were constructed to support agriculture and human consumption. This area is known as the interior delta, and it has been associated with poor fish survival. Under the rationale that the fish
Authors
John M. Plumb, Noah S. Adams, Russell W. Perry, Christopher Holbrook, Jason G. Romine, Aaron R. Blake, Jon R. Burau

Collaborative decision-analytic framework to maximize resilience of tidal marshes to climate change

Decision makers that are responsible for stewardship of natural resources face many challenges, which are complicated by uncertainty about impacts from climate change, expanding human development, and intensifying land uses. A systematic process for evaluating the social and ecological risks, trade-offs, and cobenefits associated with future changes is critical to maximize resilience and conserve
Authors
Karen M. Thorne, Brady J. Mattsson, John Y. Takekawa, Jonathan Cummings, Debby Crouse, Giselle Block, Valary Bloom, Matt Gerhart, Steve Goldbeck, Beth Huning, Christina Sloop, Mendel Stewart, Karen Taylor, Laura Valoppi

Ground motion observations of the 2014 South Napa earthquake

Ground motions of the South Napa earthquake (24 August 2014; M 6.0) were recorded at 19 stations within 20 km and 292 stations within 100 km of the rupture surface trace, generating peak ground motions in excess of 50%g and 50  cm/s in and near Napa Valley. This large dataset allows us to compare the ground motion from the earthquake to existing ground‐motion prediction equations (GMPEs) in consid
Authors
Annemarie S. Baltay, John Boatwright

Experimental enhancement of pickleweed, Suisun Bay, California

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
Authors
A. Keith Miles, Dirk H. Van Vuren, Danika C. Tsao, Julie L. Yee

Estimation of historic flows and sediment loads to San Francisco Bay,1849–2011

River flow and sediment transport in estuaries influence morphological development over decadal and century time scales, but hydrological and sedimentological records are typically too short to adequately characterize long-term trends. In this study, we recover archival records and apply a rating curve approach to develop the first instrumental estimates of daily delta inflow and sediment loads to
Authors
H.R. Moftakhari, D.A. Jay, S.A. Talke, David H. Schoellhamer

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

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

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

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

The role of tidal marsh restoration in fish management in the San Francisco Estuary

Tidal marsh restoration is an important management issue in the San Francisco Estuary (estuary). Restoration of large areas of tidal marsh is ongoing or planned in the lower estuary (up to 6,000 ha, Callaway et al. 2011). Large areas are proposed for restoration in the upper estuary under the Endangered Species Act biological opinions (3,237 ha) and the Bay Delta Conservation Plan (26,305 ha). In
Authors
Bruce Herbold, Donald Baltz, Larry R. Brown, Robin Grossinger, Wim J. Kimmerer, Peggy W. Lehman, Charles A. Simenstad, Carl Wilcox, Matthew L. Nobriga

Surveillance for zoonotic and selected pathogens in harbor seals Phoca vitulina from central California

The infection status of harbor seals Phoca vitulina in central California, USA, was evaluated through broad surveillance for pathogens in stranded and wild-caught animals from 2001 to 2008, with most samples collected in 2007 and 2008. Stranded animals from Mendocino County to San Luis Obispo County were sampled at a rehabilitation facility: The Marine Mammal Center (TMMC, n = 175); wild-caught an
Authors
Denise J. Greig, Hon S. Ip, Frances M. D. Gulland, Woutrina A. Miller, Patricia A. Conrad, Cara L. Field, Michelle Fleetwood, James T. Harvey, Spencer Jang, Andrea Packham, Elizabeth Wheeler, Ailsa J. Hall

Digital database of microfossil localities in Alameda and Contra Costa Counties, California

The eastern San Francisco Bay region (Contra Costa and Alameda Counties, California) is a geologically complex area divided by faults into a suite of tectonic blocks. Each block contains a unique stratigraphic sequence of Tertiary sediments that in most blocks unconformably overlie Mesozoic sediments. Age and environmental interpretations based on analysis of microfossil assemblages are key factor
Authors
Kristin McDougall, Debra L. Block