Aquatic Ecosystems
Aquatic Ecosystems
Aquatic ecosystems information and data is neccessary for many California water management decisions including preservation of California's natural resources. The California Water Science Center conducts interdisciplinary research from aquatic species behavioral, population and community ecology, to the effects hydrologic extremes and climage change on ecosystems.
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Continuous Monitoring of Water Quality and Suspended-Sediment Transport in the San Francisco Bay and Delta
Our group at the USGS continuously monitors suspended-sediment concentration (SSC), turbidity, dissolved oxygen, temperature, salinity, and water level at many sites throughout the San Francisco Bay (Bay) and the Sacramento-San Joaquin Rivers Delta (Delta). Our work began in 1988 to explore the spatial and temporal variability of water quality and sediment transport and to provide decision makers...
Sedimentation in the Lower Laguna-Mark West Drainage
The Sonoma County Water Agency (SCWA) and the San Francisco District office of the U.S. Army Corps of Engineers (CORPS) have identified issues associated with sedimentation in the lower Laguna de Santa Rosa and Mark West Creek in Sonoma County. Human activities in the watershed over the last 200 years have accelerated erosion and sediment delivery to the Laguna reducing the water storage capacity...
Subsidence in the Sacramento-San Joaquin Delta
The Sacramento-San Joaquin Delta is part of the San Francisco Estuary, home to a diverse flora and fauna, including several threatened and endangered species, has a large area of prime farmland, and serves as the hub of California's freshwater-delivery system that moves water from the wet north to the dry southern part of the State.
Ecosystem Engineers: Impacts of Invasive Aquatic Vegetation on the Delta’s Critical Ecosystems
The Sacramento-San Joaquin Delta (Delta) is home to a diverse community of plants and animals and is the hub of California’s freshwater delivery system. The Delta supplies water for over 25 million Californians and supports millions of acres of farming, commercial and sport fishing, shipping and ports, and recreational boating.
Mercury and Dissolved Organic Matter in Delta Wetlands
Between 1860 and 1914, hydraulic mining activities sent more than 800,000,000 cubic yards of mercury-laden sediment into the Delta altering the landscape, water flows, and contributing to the leveeing and reclamation of the Delta's marshes. Transport of mercury from historic mining areas continues today. The sedimentary supply of mercury to the Delta and in Delta sediments (cinnabar, metacinnabar...
Sources of Disinfection Byproduct-forming Material in the State Water Project
Water from the Sacramento-San Joaquin Delta contains high concentrations of disinfection byproduct-forming (DBP-forming) materials when treated for potable use. DBPs form when dissolved organic compounds (DOC) in water react with disinfectants such as chlorine and ozone during the water-treatment process. The amount of DBPs that form is a function of the amount and source of the DOC, both of which...
Scoping Study of Los Angeles River-Arroyo Seco Confluence Park
The Mountains Recreation and Conservation Authority (MRCA) is considering plans for developing a new park at the confluence of the Los Angeles River and the Arroyo Seco. These plans include removing channel lining and creating a temporary lake using an inflatable rubber dam. Before implementing the plan, a wide array of scientific and engineering issues must be addressed. The U.S. Geological...
A Non-Point Source Of Contaminants To The Estuarine Food Web: Mobilized Particles From The Intertidal Zone
The San Francisco Bay and Sacramento-San Joaquin Delta (Bay-Delta) region is a highly urbanized and contaminated estuary with a valuable commercial and recreational fishery (Nichlos et al., 1986; SFEI, 2004). Many fish and birds in the San Francisco Estuary exhibit high levels of contaminants (metals and organic pollutants), which have been shown to affect their behavior and reproductive success...
Mercury
Mercury is a rare, dense metal, slightly more common than gold in the earth's crust. Mercury occurs in several different forms, the most important of which is methylmercury. Methylmercury is the form most readily incorporated into biological tissues and most toxic to humans. Methylmercury accumulates and biomagnifies in the food chain, reaching highest concentrations in predatory fish such as bass...
Assessing the role of winter flooding on baseline greenhouse gas fluxes from corn fields in the Sacramento – San Joaquin Bay Delta
Understanding the magnitude and variability of baseline greenhouse gas (GHG) emissions from the Sacramento – San Joaquin Bay Delta is critical for current and future land management. For example, strategies that maximize carbon sequestration in soils and plants while minimizing unintended consequences such as GHG emissions are likely to produce both economic and environmental benefits for the...
Pesticide Occurrence in California – Yolo Bypass Pesticide Analyses
The project is part of an overarching Interagency Ecological Program (IEP)/Department of Water Resources (DWR) study that is focused on understanding the processes by which the Yolo Bypass may provide a fall food web supply for the Cache Slough Complex and downstream regions of the Sacramento/San Joaquin Delta. Several studies conducted since 2011 have shown that phytoplankton blooms can be...
Spatially Explicit Mapping of Hydrologic Residence Time Paired with Water Quality Measurements to Determine the Effects of the Emergency Drought Barrier
The purpose of this study is to assess the distribution of water residence times across the central Delta using rapid water isotope measurements (δ2H, δ18O) made with a boat-based flow-through instrument.