Emergency Drought Barrier’s Impacts on cyanoHABs and Water Quality
Cyanobacterial Harmful Algal Blooms (cyanoHABs)
Scientists gather data on cyanoHABs associated with a drought salinity barrier in the Sacramento-San Joaquin Delta
Drought is making the Delta Saltier. Less freshwater coming from watershed runoff and reservoir releases means that more salty water flows into the Sacramento San Joaquin Delta (Delta) from the Pacific Ocean. Changes in Delta salinity have far-reaching impacts, affecting the water supply for agriculture, drinking, wildlife, and Delta ecosystems.
In response, the California Department of Water Resources (CADWR) has installed an emergency drought salinity barrier in the Delta. The West False River Barrier is a temporary rock barrier designed to reduce the intrusion of high salinity water into the central and south Delta.
The Delta is a transition zone between freshwater and saltwater and has complex flow patterns driven by daily tides and freshwater flowing down from the Sierra Nevada. Because barriers block the flow through channels, monitoring their associated effects is important to understanding possible impacts to water quality in the Delta transition zone. One area of study is the abundance and distribution of toxic cyanobacterial harmful algal blooms (cyanoHABs). Since 1999, cyanoHABs have posed a threat to people, animals, and water quality in the Delta.
To assist the CADWR quantify levels of cyanoHABs in the areas associated with the barriers, USGS scientists will conduct high-resolution, boat-based mapping surveys, both in the vicinity of the West False River Barrier Scientists will also gather data at a fixed stations equipped with in situ sensors that monitor flow and water. Data will be validated, undergo lab analysis, and then reported on. In addition to gathering data on site, the USGS will also make use of satellite remote-sensing (RS) technology.
The study will address the following research questions:
- What is the spatial distribution of HABs in the Delta in relation to the Drought Barriers?
- What is the impact of water residence time on HABs?
- Could HABs cause problems for human or animal health?
Research tasks include:
High-resolution mapping surveys around Franks Tract and Mildred Island
One concern is that the drought barrier in the West False River will reduce flows into Franks Tract and therefore decrease how quickly water flows through Franks Tract. This can give cyanobacteria more time to grow and could promote denser cyanoHABs in Franks Tract when the barrier is installed. To describe the phytoplankton species composition and potential bloom density around the False River Barrier, USGS scientists will conduct high-resolution boat mapping in and around Franks Tract. Scientists will also conduct mapping in and around nearby Mildred Island. Mildred Island has no drought barrier and will serve as a control site.
During the course of the study, cyanotoxin samples will be collected through a partnership between CADWR and USGS. Monthly or biweekly samples will be collected in Franks Tract and will be analyzed by the Lumigen Instrument Center at Wayne State University and by BSA Environmental Services.
Field-validation of remote sensing cyanoHAB algorithm
Data remotely gathered from satellite sensors is useful for tracking bloom dynamics on large water bodies that would be costly to sample frequently with field visits. For this task, the USGS will use satellite algorithms developed by the National Oceanographic and Atmospheric Administration (NOAA) to estimate cyanobacterial density in surface water. While such remote sensed data provides high spatial and temporal coverage, certain water conditions can affect the algorithm, resulting in inaccurate data. Fortunately, remote-sensed data can be validated by comparison with sampling using handheld field measurements.
In this phase of the project USGS scientists will collect handheld measurements to validate satellite algorithms against factors that may influence results.
Reporting and Deliverables
During the course of the study, the USGS will deliver monthly progress reports on the status of all aspects of each task described above. In addition, the USGS will inform the CADWR of updates to the sampling strategy and any anomalies including equipment failure, analytical issues, or other changes/concerns as the study progresses. Provisional data will be made available to the CADWR upon request. Each task described above will also generate a USGS-approved data release.
USGS will contribute to data analysis projects coordinated or led by the CADWR and will help plan future data collection or analysis efforts. This may include participating in future data analysis and interpretation projects relating to water quality, phytoplankton, and food-webs in the Delta.
Below are other related USGS science projects.
Biogeochemistry Group
Flow and Water Quality Data in the San Francisco Estuary
Assessing Sediment Nutrient Storage and Release in California's Sacramento-San Joaquin Delta
Monitoring Cyanotoxins in California's Sacramento-San Joaquin Delta: Fixed Stations and High-Resolution Mapping Surveys
Drought is making the Delta Saltier. Less freshwater coming from watershed runoff and reservoir releases means that more salty water flows into the Sacramento San Joaquin Delta (Delta) from the Pacific Ocean. Changes in Delta salinity have far-reaching impacts, affecting the water supply for agriculture, drinking, wildlife, and Delta ecosystems.
In response, the California Department of Water Resources (CADWR) has installed an emergency drought salinity barrier in the Delta. The West False River Barrier is a temporary rock barrier designed to reduce the intrusion of high salinity water into the central and south Delta.
The Delta is a transition zone between freshwater and saltwater and has complex flow patterns driven by daily tides and freshwater flowing down from the Sierra Nevada. Because barriers block the flow through channels, monitoring their associated effects is important to understanding possible impacts to water quality in the Delta transition zone. One area of study is the abundance and distribution of toxic cyanobacterial harmful algal blooms (cyanoHABs). Since 1999, cyanoHABs have posed a threat to people, animals, and water quality in the Delta.
To assist the CADWR quantify levels of cyanoHABs in the areas associated with the barriers, USGS scientists will conduct high-resolution, boat-based mapping surveys, both in the vicinity of the West False River Barrier Scientists will also gather data at a fixed stations equipped with in situ sensors that monitor flow and water. Data will be validated, undergo lab analysis, and then reported on. In addition to gathering data on site, the USGS will also make use of satellite remote-sensing (RS) technology.
The study will address the following research questions:
- What is the spatial distribution of HABs in the Delta in relation to the Drought Barriers?
- What is the impact of water residence time on HABs?
- Could HABs cause problems for human or animal health?
Research tasks include:
High-resolution mapping surveys around Franks Tract and Mildred Island
One concern is that the drought barrier in the West False River will reduce flows into Franks Tract and therefore decrease how quickly water flows through Franks Tract. This can give cyanobacteria more time to grow and could promote denser cyanoHABs in Franks Tract when the barrier is installed. To describe the phytoplankton species composition and potential bloom density around the False River Barrier, USGS scientists will conduct high-resolution boat mapping in and around Franks Tract. Scientists will also conduct mapping in and around nearby Mildred Island. Mildred Island has no drought barrier and will serve as a control site.
During the course of the study, cyanotoxin samples will be collected through a partnership between CADWR and USGS. Monthly or biweekly samples will be collected in Franks Tract and will be analyzed by the Lumigen Instrument Center at Wayne State University and by BSA Environmental Services.
Field-validation of remote sensing cyanoHAB algorithm
Data remotely gathered from satellite sensors is useful for tracking bloom dynamics on large water bodies that would be costly to sample frequently with field visits. For this task, the USGS will use satellite algorithms developed by the National Oceanographic and Atmospheric Administration (NOAA) to estimate cyanobacterial density in surface water. While such remote sensed data provides high spatial and temporal coverage, certain water conditions can affect the algorithm, resulting in inaccurate data. Fortunately, remote-sensed data can be validated by comparison with sampling using handheld field measurements.
In this phase of the project USGS scientists will collect handheld measurements to validate satellite algorithms against factors that may influence results.
Reporting and Deliverables
During the course of the study, the USGS will deliver monthly progress reports on the status of all aspects of each task described above. In addition, the USGS will inform the CADWR of updates to the sampling strategy and any anomalies including equipment failure, analytical issues, or other changes/concerns as the study progresses. Provisional data will be made available to the CADWR upon request. Each task described above will also generate a USGS-approved data release.
USGS will contribute to data analysis projects coordinated or led by the CADWR and will help plan future data collection or analysis efforts. This may include participating in future data analysis and interpretation projects relating to water quality, phytoplankton, and food-webs in the Delta.
Below are other related USGS science projects.