Central Valley Water Board Harmful Algal Bloom Projects

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The Delta near Stockton

HAB monitoring partnership with Restore the Delta


Kaweah Lake and River

HAB monitoring partnership with Tulare County


San Francisco Estuary

NOAA Monitoring and Event Response for Harmful Algal Blooms (MERHAB) project


Hensley and Eastman Lakes

Water Board special study of HAB patterns and drivers


The Delta - Research Projects

Collaborative monitoring and special studies.


Biointegrity and Biostimulatory Science

Eutrophication research and applications


Clear Lake

TMDL program and other efforts


The Delta near Stockton - HAB Monitoring Partnership with Restore the Delta

Photo of a person in an orange vest holding a yellow extendable pole sampler with bottle attachment near rocky water’s edge.
Photo Credit: Spencer Fern, RTD, 2023

The Central Valley Water Board began a partnership with Restore the Delta (RTD) in 2022 to monitor Delta waters near Stockton for HABs.

HAB monitoring typically runs May through September, when HABs are most likely to occur and recreators spend the most time in the water. RTD staff visit seven sites weekly to conduct a visual inspection, record water quality parameters using a sonde, and conduct a field test to screen the water for the presence of microcystins. Additional water samples are collected for laboratory analysis of microcystins using the ELISA method 1-2 times per month, depending on conditions observed during the field visit.

Visit the Restore the Delta webpage to learn more about their organization and their Water Quality and HAB Monitoring efforts.

View the latest HAB advisories:

Kaweah Lake and River - HAB Monitoring Partnership with Tulare County

Photo from a wide, clear river where cobbles are visible on the riverbed, various green trees line the riverbanks, and brown mountains can be seen in the distance.
Photo Credit: Dana Shultz, CVWB, 2024

The Central Valley Water Board is partnering with Tulare County Environmental Health to monitor Kaweah Lake and River for HABs after a series of bloom reports were submitted by members of the public in 2022. Due to extremely high flows in 2023, a full season of monitoring began in 2024.

HAB monitoring during 2024 occurred every two weeks from late June through early October. Tulare County collected water grabs and benthic algal mat material (when present), and deployed solid phase adsorption toxin trackers (SPATT). Samples were analyzed for microcystins, anatoxin-a, cylindrospermopsin, and saxitoxins.

View the latest HAB advisories:

San Francisco Estuary - NOAA Monitoring and Event Response (MERHAB)

Digital picture of a Sentinel-2 satellite over earth with a beam of light stretching from the earth to the satellite.
Online image, ESA-Sentinel 2

Project title: New technologies and a coordination framework for an integrated HAB detection and monitoring system across the San Francisco Estuary.

Central Valley Water Board staff will serve on a team of co-investigators to advance an integrated HAB detection and monitoring system across the San Francisco Estuary. The project is led by scientists at the San Francisco Estuary Institute (SFEI), US Geological Survey (USGS), and CA Department of Water Resources (DWR). This work is funded by the NOAA MERHAB Program through 2028.

Learn more about this project:

Learn more about the NOAA MERHAB Program:

Hensley and Eastman Lakes

Map of H.V. Eastman Lake with light grey basemap and cyanobacteria abundance represented as colored pixels across the lake.
Online Image, HAB Satellite Tool

Popular recreational lakes H.V. Eastman and Hensley are located within 15 miles of each other in the Sierra Nevada foothills and each have experienced annual HAB events. This study took a multifaceted approach to investigate the patterns and drivers of HABs at these lakes. In situ sampling from the lakes and upstream tributaries was conducted between May 2021 and December 2022.

Products:

  • Manuscript in prep
  • Presentation at 30th Annual California Aquatic Bioassessment Workgroup (CABW) 2023 Meeting (Video will open in YouTube)

The Delta - Research Projects

Photograph of two people on a boat preparing a sonde for deployment.
Photo Credit: Matt Krause, CVWB, 2024

Comprehensive information about the CVWB's work in the Delta can be found on the Delta Water Quality webpage.

The highest priority information gap identified in the CVWB's Delta Nutrient Research Plan is to improve understanding of causes, trends and potential for management of HABs in the Delta. Staff are involved in several collaborative projects advancing HAB monitoring and research.

A select list of CVWB HAB-related projects and efforts in the Delta are highlighted below. HAB-related publications from CVWB work in the Delta can be found on the Central Valley Water Board HAB Documents webpage.

Current Projects:

Biointegrity and Biostimulatory Science

Photograph of a frog on a pier above water covered with aquatic vegetation.
Photo Credit: Daniel Killam, 2018

The State Water Resource Control Board (State Water Board) is developing a statewide plan for biostimulatory substances and cyanotoxins under the Biostimulation, Cyanotoxins, and Biological Condition Provisions.

In an effort to provide additional information, the Central Valley Water Board contracted with the Southern California Coastal Water Research Project (SCCWRP) to complete additional analysis focused in the Central Valley.

Products:

Clear Lake

Collage of microscope photos from Clear Lake water samples depicting algae and cyanobacteria around a large center photo of Mount Konocti as seen from the lake.
Photo Credit: Jerry Bruns, CVWB, 2024/2025

Clear Lake is the largest natural freshwater lake in California. HABs have been observed in Clear Lake throughout the 20th century with blooms well documented and described since the early 1970s.

Links:

Contact Us

FHAB Program Coordinator:

Dana Shultz
(916)464-4638

Dana.Shultz@waterboards.ca.gov


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Webmaster5@waterboards.ca.gov

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