Aquatic Ecology
Aquatic Ecology
Acquatic Ecology research at the California Water Science Center includes the study of interacting populations of plants, animals, and microorganisms that occupy areas throughout the state. A particular focus of these efforts is to gain better understanding of the effects human activity, hydrologic extremes, and climate change have on these ecosystems.
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Evaluation of Exposure and Vulnerability of Selected Inland National Wildlife Refuges in the Pacific Southwest to Water Resources Constraints in the Face of Climate Change using Downscaled Climate Change Modeling
As competition for water is growing, a major challenge is to ensure that sufficient quantities of good quality water are available for fish, wildlife, and plants. Competition for a limited supply of water with adequate water quality to support National Wildlife Refuges are a dominant threat for many National Wildlife Refuges across the U.S. and is only heightened during times of drought and in the...
Mapping Sturgeon Spawning Habitat in the Lower San Joaquin River
The spawning of adult white sturgeon ( Acipenser transmontanus ) in the lower San Joaquin River was documented recently by the United States Fish and Wildlife Service (USFWS) (Gruber and others, 2012; Jackson and Eenennaam, 2013). Streamflow on the San Joaquin River has been modified by State and Federal water project operations, and there are a variety of questions regarding the effects on fish...
Pesticide Studies in the Sacramento/San Joaquin Delta and San Francisco Bay Estuary
The objectives of this specific study are to characterize the mixtures of current-use pesticides and pesticide degradates entering the Sacramento/San Joaquin Delta from its two main river sources over a period of 12 consecutive months.
Understanding Juvenile Salmon Entrainment and Survival in the South Sacramento/San Joaquin Delta Through the Use of Acoustic Telemetry and Hydrodynamic Measurements
This study will use the release-recapture information derived from the 2012 receiver array to populate a mark-recapture model based on a Cormack-Jolly-Seber model in combination with a route-specific survival model of Skalski et al. (2002) to derive maximum likelihood estimates and standard errors of reach specific survival and entrainment rates at important junctions, similar to what was used in...
Modeling in support of development of biocriteria for wadeable California streams and rivers
The State Water Resources Control Board (SWRCB) of California has initiated a process to develop biological objectives for wadeable freshwater streams and rivers for the entire state.
San Francisco Bay Wetlands Priority Ecosystem Studies
The U.S. Fish & Wildlife Service's (USFWS) San Francisco Bay National Wildlife Refuge manages wildlife at a number of salt ponds that the Cargill Corporation currently operates for salt production. A number of these ponds probably will be purchased by the USFWS. With acquisition, the USFWS will be responsible for maintenance or restoration of thousands of hectares of wetlands, an extremely complex...
The role of the alien clam Corbicula fluminea in the regulation of organic carbon in the San Joaquin River watershed
Sources and fate of various forms of organic carbon in the Sacramento-San Joaquin Delta (Delta) and San Joaquin River watershed are of concern because of the importance of identifying the sources of carbon contributing to the oxygen depletion zone on the San Joaquin River near the city of Stockton, the need to understand the causes of the low primary and secondary production in the Delta, and the...
Processes Controlling Riverbank Filtration of Pathogens in the Russian River Basin, Sonoma County, California
The Sonoma County Water Agency (SCWA) supplies drinking water to municipalities and water districts in Sonoma and Marin Counties by diverting water from the alluvial aquifer underlying and adjacent to the Russian River. The U.S. Geological Survey, in cooperation with SCWA, is conducting an ongoing research program on water quality conditions in the Russian River and the physical and geochemical...
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...
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...