Gut Contents Analysis of Four Fish Species Collected in the San Leandro Bay RMP PCB Study in August 2016

San Francisco Estuary Institute (SFEI) | November 7th, 2018

In support of PCB modeling for San Leandro Bay, a Priority Margin Unit (PMU) for PCB load reduction in the estuary, fish samples of four species (topsmelt, shiner perch,

In support of PCB modeling for San Leandro Bay, a Priority Margin Unit (PMU) for PCB load reduction in the estuary, fish samples of four species (topsmelt, shiner perch, white croaker, and northern anchovy ) were obtained in August 2016 for both tissue analysis and examination of gut contents. The bay was sampled at eight locations, with a repeated sampling at one location (Airport Lagoon) for one species (topsmelt). Fish were measured, weighed, and dissected, and their gut contents examined microscopically. Topsmelt (9 samples, 188 specimens) had the greatest variety of food items, with gammarid amphipods and chain diatoms predominating. Some topsmelt, especially larger individuals, consumed macroalgae as a major dietary component. Two samples at two sites for shiner perch (20 fish each) had contents composed of close to 50% gammarids at both sites, but differed in proportions of bivalves and polychaetes among the important food items. The one sample of white croaker had consumed mostly gammarids, with fish and polychaetes ranking next in importance. A single sample of northern anchovy (20 fish analyzed) differed radically from the other species in consuming mainly a diatom that appears to have been filtered from the water column. Trace amounts of plastic fiber were seen in all species except shiner perch. All exposure to sediment appeared to have occurred in the top 2 cm of the sediment column, or as contact with flocculent material on plants or hard substrates, or even in the water column, as some fine sand grains were seen in all fish, even anchovy. There was no conclusive evidence of site-specific foraging (site fidelity). The best spatial coverage was for topsmelt, and these fish appear to have fed opportunistically, with some evidence for having fed outside San Leandro Bay.

Habitat Restoration in the Sacramento-San Joaquin Delta and Suisun Marsh: A Review of Science Programs

Delta Stewardship Council (Delta Council) | April 25th, 2013

Current plans call for the restoration of tens of thousands of acres of mainly intertidal habitat in the Sacramento-San Joaquin Delta and Suisun Marsh. Restoration on thi

Current plans call for the restoration of tens of thousands of acres of mainly intertidal habitat in the Sacramento-San Joaquin Delta and Suisun Marsh. Restoration on this scale presents both formidable challenges and tremendous opportunities. As part of its legislatively mandated oversight of Delta science programs, the Delta Independent Science Board reviewed these habitat restoration efforts. We held discussions with individuals from state and federal agencies, NGOs, consulting firms, and universities. We were impressed by their dedication, enthusiasm, and knowledge, as well as by the scientific and institutional challenges they face. Our findings and observations about the restoration efforts are grouped under a series of criteria for a successful restoration program. In such a program: the goals are clearly articulated; the design incorporates spatial and temporal context, adaptive management and flexibility, and monitoring; modeling is used in design and evaluation; planning and implementation are coordinated among projects; the necessary scientific expertise is available; and stakeholders are involved early and often. Our findings and recommendations agree with those reached independently by National Research Council (NRC) panels. For convenience, as in the Delta Plan, we use "the Delta" to encompass both the statutory Delta and Suisun Marsh.

Habitat-Specific Foraging by Striped Bass (Morone saxatilis) in the San Francisco Estuary, California: Implications for Tidal Restoration

University of California, Davis (UC Davis) | December 1st, 2022

Non-native predatory fish strongly affect aquatic communities, and anthropogenic habitat alterations can exacerbate their effects. Loss of natural habitat, and restorati

Non-native predatory fish strongly affect aquatic communities, and anthropogenic habitat alterations can exacerbate their effects. Loss of natural habitat, and restoration actions that reverse habitat loss, can modify relationships between non-native predators and prey. Predicting how these relationships will change is often difficult because insufficient information exists on the habitat-specific feeding ecology of non-native predators. To address this information gap, we examined diets of non-native Striped Bass (Morone saxatilis; 63 to 671 mm standard length; estimated age 1 to 5 yrs) in the San Francisco Estuary during spring and summer in three habitat types—marsh, shoal, and channel—with the marsh habitat type serving as a model for ongoing and future restoration. Based on a preyspecific index of relative importance, Striped Bass diets were dominated by macroinvertebrates in spring and summer (amphipods in spring, decapods and isopods in summer). In spring, diets were relatively consistent across habitats. In summer, marsh diets were dominated by sphaeromatid isopods and shoal/channel diets by idoteid amphipods and decapods. Striped Bass consumed a variety of native and non-native fishes, primarily Prickly Sculpin (Cottus asper) and Gobiidae. The highest importance of fish prey was in the marsh in spring (~ 40% prey weight), and fish prey comprised less than 25% prey weight in all other season/habitat combinations. Linear discriminant analyses suggested that marsh foraging was prevalent in Striped Bass collected in other habitats, mostly because of the predominance of marsh-associated invertebrates found in the stomachs of individual Striped Bass collected outside the marsh. Striped Bass diets differ across habitats, with marsh foraging important to Striped Bass regardless of collection location. This information can be used to forecast the potential utilization of restored habitats by this non-native piscivore.

Hacienda Avenue Bio-Infiltration Basins

San Francisco Estuary Institute (SFEI) | July 1st, 2016

Hadley cell widening: Model simulations versus observations

American Meteorological Society (AMS) | May 15th, 2009

Observations show that the Hadley cell has widened by about 28–58 since 1979. This widening and the concomitant poleward displacement of the subtropical dry zones may

Observations show that the Hadley cell has widened by about 28–58 since 1979. This widening and the concomitant poleward displacement of the subtropical dry zones may be accompanied by large-scale drying near 308N and 308S. Such drying poses a risk to inhabitants of these regions who are accustomed to established rainfall patterns. Simple and comprehensive general circulation models (GCMs) indicate that the Hadley cell may widen in response to global warming, warming of the west Pacific, or polar stratospheric cooling. The combination of these factors may be responsible for the recent observations. But there is no study so far that has compared the observed widening to GCM simulations of twentieth-century climate integrated with historical changes in forcings. Here the Hadley cell widening is assessed in current GCMs from historical simulations of the twentieth century as well as future climate projections and preindustrial control runs. The authors find that observed widening cannot be explained by natural variability.This observed widening is also significantly larger than in simulations of the twentieth and twenty-first centuries. These results illustrate the need for further investigation into the discrepancy between the observed and simulated widening of the Hadley cell.

Handbook for Assessing Value of State Flood Management Investments

California Department of Water Resources (DWR) | June 1st, 2014

Millions of people and over half a trillion dollars in assets are exposed to flood risk in California (DWR 2013a). This remains the case even as State, federal, a

Millions of people and over half a trillion dollars in assets are exposed to flood risk in California (DWR 2013a). This remains the case even as State, federal, and local flood management agencies have worked for decades to reduce the risk and consequences of flooding in the State. The people of California have shown that they understand the increasing flood risk due to population growth, environmental concerns, climate change, and land use practices, and they are willing to invest in flood risk management projects. This requires the public agencies responsible for California’s flood risk management to demonstrate the value of those investments both before and after they are implemented. This Handbook for Assessing Value of State Flood Management Investments (HAV) supports that effort.

Handbook for Assessing Value of State Flood Management Investments

California Department of Water Resources (DWR) | June 8th, 2014

Millions of people and over half a trillion dollars in assets are exposed to flood risk in California (DWR 2013a). This remains the case even as State, federal, and local

Millions of people and over half a trillion dollars in assets are exposed to flood risk in California (DWR 2013a). This remains the case even as State, federal, and local flood management agencies have worked for decades to reduce the risk and consequences of flooding in the State. The people of California have shown that they understand the increasing flood risk due to population growth, environmental concerns, climate change, and land use practices, and they are willing to invest in flood risk management projects. This requires the public agencies responsible for California’s flood risk management to demonstrate the value of those investments both before and after they are implemented. This Handbook for Assessing Value of State Flood Management Investments (HAV) supports that effort. The California Department of Water Resources (DWR) has identified foundational goals that shape the State’s water management investment strategy. Those goals are: Improving public safety Fostering environmental stewardship Supporting economic stability

Handbook for Developing Watershed Plans to Restore and Protect Our Waters

U.S. Environmental Protection Agency (EPA) | March 20th, 2008

This handbook provides information on developing and implementing watershed management plans that help to restore and protect water quality. A watershed is the area of la

This handbook provides information on developing and implementing watershed management plans that help to restore and protect water quality. A watershed is the area of land that contributes runoff to a lake, river, stream, wetland, estuary, or bay. A watershed management plan defines and addresses existing or future water quality problems from both point sources and nonpoint sources of pollutants. Experience over the past decade has shown that effective watershed management includes active participation from stakeholders, analysis and quantification of the specific causes and sources of water quality problems, identification of measurable water quality goals, and implementation of specific actions needed to  solve those problems. This handbook is intended to serve as the basis for developing and implementing watershed plans to meet water quality standards and protect water resources. Although watershed plans are useful for all watersheds to protect and restore water resources, as well as to meet other community resource goals, they are critical for impaired or threatened waterbodies. The most recent national water quality assessment reported that 40 to 50 percent of the nation’s assessed waterbodies are impaired or threatened. 3/20This handbook is designed to provide a framework to help you develop a scientifically defensible plan that will lead to measurable results and an overall improvement in the water quality and watershed conditions that are important to your community.

Harnessing California's Waters: The Completion of the First Stage of the Pit River Power Project

Scientific American | April 1st, 1923

California is now the greatest hydro-electric power State in the Union. Over one-fifth of all the electric power generated by American water is produced in Californi

California is now the greatest hydro-electric power State in the Union. Over one-fifth of all the electric power generated by American water is produced in California. Last year, according to figures announced by Engineer H. D. McGlashan of the water resources branch of the United States Geological Survey, 3,227,262,000 kilowatt-hours were produced by water power in California. New York, which comes next with 14.72 per cent of the total. made 2,203,564,000 kilowatthours. On Saturday, September 30, 1922, an important step in California's electrification was carried out. On this date the constantly flowing waters of the Fall River were diverted through a tunnel and dropped 454 feet through steel penstocks to the Pit River Power Plant No. 1 .

Harnessing the Power of Geophysical Imaging to Recharge California's Groundwater

American Geophysical Union (AGU) | April 17th, 2025

Motivated by the availability of 20,000 line-km of airborne electromagnetic (AEM) data covering the Central Valley of California, we developed a workflow that uses resist

Motivated by the availability of 20,000 line-km of airborne electromagnetic (AEM) data covering the Central Valley of California, we developed a workflow that uses resistivity profiles from electromagnetic (EM) data to assess the suitability of areas for groundwater recharge. We defined a suitable area as one where “fastpaths” of coarse-grained material could efficiently move water from the ground surface to the water table. We defined recharge metrics and generated the corresponding maps by integrating resistivity profiles from AEM data, sediment type (from driller's logs), water level measurements, and water quality measurements. The workflow is publicly available through a web-based application, fastpath. We produced maps displaying recharge metrics on a 400 m × 400 m grid covering the Central Valley, with 80% of the cells sufficiently close to an AEM resistivity profile (within ∼3 km) to be assessed for recharge. Various decisions are made in the workflow that result in a range of values for determined metrics at any given location. The maps summarizing all metrics show that between 19% (2,000,000 acres) and 56% (7,000,000 acres) of the total area in the valley is land suitable for recharge. The landcover with the largest total area of land classified as suitable is cultivated crops. We estimated the total space available for recharge water to be ∼170 km3 which is two orders of magnitude greater than an estimate of the total volume of water likely to be available for recharge.