California Water Science Center

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.  

Filter Total Items: 70
Date published: January 20, 2021
Status: Active

Assessing Sediment Nutrient Storage and Release in California's Sacramento-San Joaquin Delta

Sediments represent an important pool of nutrients in the Sacramento-San Joaquin Delta (Delta). The exchange of nutrients between the water column and the benthos impacts water quality and effects phytoplankton, harmful algal blooms, aquatic vegetation, and drinking water quality. To date, there is very limited information about nutrient pools in Delta sediments, nor how these nutrients are...

Date published: November 20, 2020
Status: Active

Ecosystem Engineering Impacts of Water Primrose in the Sacramento-San Joaquin Delta

Many non-native fish, invertebrates, and plants have colonized the Sacramento-San Joaquin Delta (Delta), the landward most region of the San Francisco Estuary. Included among these invasive species is the water primrose (Ludwigia grandiflora ssp. hexapetala and Ludwigia peploides), an aggressive floating aquatic plant that is native to South and Central America and parts of the US, but...

Date published: November 2, 2020
Status: Active

Selenium Hazard in the Salton Sea Environment, Summary of Current Knowledge to Inform Future Science

The effect of selenium (Se) toxicity on wildlife has been known for more than 50 years. The threat of Se contamination gained greater attention from federal agencies in the 1980s due to the observation of embryo deformity and mortality in birds at a National Wildlife Refuge in California. Harmful effects from Se were determined to be connected to irrigation drainage water.

As a result,...

Date published: August 5, 2020
Status: Active

Evaluating the effects of wastewater-derived nutrients on phytoplankton abundance and community structure in the San Francisco Estuary and Delta

Planned upgrades to the Sacramento Regional wastewater treatment plant (SRWTP) will substantially reduce nutrient discharge and also alter the types and amounts of nutrients being distributed across the San Francisco Delta and Estuary (Delta).

One highly anticipated outcome of lower nutrients is improved productivity in the phytoplankton communities that supply aquatic food webs, which...

Date published: July 15, 2020
Status: Active

Modeling Nitrogen Reduction Benefit to Invasive Aquatic Vegetation vs. Native Phytoplankton

Phytoplankton comprise the bottom of the aquatic food web and the abundance of phytoplankton serves as an indicator of healthy aquatic habitats. In the Sacramento-San Joaquin River Delta (Delta), competing with phytoplankton for required nitrogen, invasive aquatic vegetation (IAV) has increased exponentially in recent years. Once established, IAV can negatively impact local ecosystems and...

Date published: June 26, 2020
Status: Active

Monitoring Cyanotoxins in California's Sacramento-San Joaquin Delta: Fixed Stations and High-Resolution Mapping Surveys

California’s Sacramento-San Joaquin River Delta (Delta) provides drinking water to about 30 million people and irrigation water to the agriculturally rich Central Valley. The Delta is also home to numerous threatened and endangered native species. The health of the Delta's aquatic ecosystems, and fish in particular, have long been in a state of decline. This is associated with decreasing...

Date published: August 27, 2019
Status: Active

Mercury studies at Sulphur Bank Mercury Mine and Clear Lake, California

The abandoned Sulphur Bank Mercury Mine on the shores of Clear Lake in Northern California has been designated as a "Superfund Site" by the U.S. Environmental Protection Agency (EPA). This means that the EPA has determined that the area is contaminated by hazardous waste and requires cleanup...

Date published: July 24, 2019
Status: Active

Organic Matter Research Laboratory

The USGS California Water Science Center's Organic Matter Research Laboratory provides laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy along with standard measurement of total dissolved organic carbon and nitrogen concentration.

Date published: March 13, 2019
Status: Active

Neonicotinoid Seed Treatment Study

Neonicotinoids are a new class of insecticides chemically related to nicotine. Like nicotine, they act on receptors in the nerves and are generally much more toxic to insects, than they are to mammals and other higher organisms. Their use has increased rapidly over the last decade, driven in large part by their use for seed coating. Seed coating is when a seed is treated with an insecticide...

Contacts: James Orlando
Date published: February 27, 2019
Status: Active

SGMApy: An open source platform for computing sustainability metrics and visualizing MODFLOW data

Climate change and demographic changes have underscored the need to improve effectiveness of managing valuable water resources for sustainability. In 2014, the Sustainable Groundwater Management Act (SGMA) established a framework for sustainable, local groundwater management. SGMA requires groundwater-dependent regions to halt overdraft and bring basins into balanced levels of pumping and...

Date published: December 20, 2018
Status: Active

California's Central Valley

Competition for water resources is growing throughout California, particularly in the Central Valley. The Central Valley's population is expected to increase to 6 million by 2020. This population growth, along with anticipated reductions in Colorado River water deliveries, drought, and the ecological crisis in the Sacramento-San Joaquin Delta, have created an intense demand for water. The...

Contacts: Claudia C Faunt
Date published: December 19, 2018
Status: Completed

Occurrence of Current-use Pesticides in Suisun Bay and Potential Effects on Phytoplankton

Suisun Bay is an area identified as critical habitat for the threatened Delta Smelt. Several important changes in the pelagic food web of this area have been documented over the last two decades indicating that food for Delta Smelt and other threatened fishes is in short. 

Contacts: James Orlando