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Blue-Green Algae (Cyanobacteria): Health Facts & Information

Updated October 11, 2016

Algae, including blue-green algae (aka cyanobacteria), is a normal inhabitant of many water environments. Certain conditions, such as high temperatures and elevated nutrient concentrations allow algae to grow more rapidly than usual creating mats or blooms. Most algae is harmless; however, some species of blue-green algae can produce toxins which create health effects for humans and animals.

Throughout the summer of 2016, the Environmental Health & Safety Section (EHS) of the Sonoma County Department of Health Services (DHS) and the North Coast Regional Water Quality Control Board (NCRWQCB) has been monitoring conditions along the Russian River.

On October 11, 2016, DHS removed all “Caution” signs along the Russian River. The “Caution” signs are no longer necessary because the weather and water conditions on the river are no longer favorable for blue-green algal growth.

Water Testing Results

The Russian River is a moving body of water. The conditions detected from our water testing at any of the beaches listed below may be present at all beaches throughout the river. We are concerned about conditions along the entire Russian River.

Anatoxin
Cloverdale River Park Del Rio Woods Beach Camp Rose Beach Healdsburg Veterans Steelhead Beach Forestville Access Beach Sunset Beach Johnson's Beach Monte Rio Beach Patterson Point
August 1, 2016 ND ND ND ND 0.167 0.153 ND ND 0.237 0.193
August 8, 2016 ND ND ND ND ND ND ND ND ND ND
August 15, 2016 ND ND ND ND ND ND ND ND ND ND
August 22, 2016 ND ND ND ND ND ND .35 ND ND ND
August 29, 2016 ND ND ND ND ND ND ND ND ND ND
September 6, 2016 ND ND ND ND ND ND ND ND ND .17*
September 12, 2016 ND ND ND ND ND ND ND ND ND ND
September 19, 2016 ND ND ND ND ND ND ND ND ND ND

All results are in µg/L. ND indicates that no toxins were detected.

*Final results were inconclusive.

Microcystin
Cloverdale River Park Del Rio Woods Beach Camp Rose Beach Healdsburg Veterans Steelhead Beach Forestville Access Beach Sunset Beach Johnson's Beach Monte Rio Beach Patterson Point
August 1, 2016 ND ND ND ND ND ND ND ND ND ND
August 8, 2016 ND ND ND ND ND ND ND ND ND ND
August 15, 2016 ND ND ND ND ND ND ND 0.68 ND ND
August 22, 2016 ND ND ND ND ND ND ND ND ND ND
August 29, 2016 ND ND ND ND ND ND ND ND ND ND
September 6, 2016 ND ND ND >5* ND >5* >5* >5* 3* >5*
September 12, 2016 ND ND ND ND ND ND ND ND ND ND
September 19, 2016 ND ND ND ND ND ND ND ND ND ND

All results are in µg/L. ND indicates that no toxins were detected.

*Final results were inconclusive.

Cylindrospermopsin
Cloverdale River Park Del Rio Woods Beach Camp Rose Beach Healdsburg Veterans Steelhead Beach Forestville Access Beach Sunset Beach Johnson's Beach Monte Rio Beach Patterson Point
August 1, 2016 ND ND ND ND ND ND ND ND ND ND
August 8, 2016 ND ND ND ND ND ND ND ND ND ND
August 15, 2016 ND ND ND ND ND ND ND ND ND ND
August 22, 2016 ND ND ND ND ND ND ND ND ND ND
August 29, 2016 ND ND ND ND ND ND ND ND ND ND
September 6, 2016 ND ND ND >2* ND ND ND >2* ND >2*
September 12, 2016 ND ND ND ND ND ND ND ND ND ND
September 19, 2016 ND ND ND ND ND ND ND ND ND ND

All results are in µg/L. ND indicates that no toxins were detected.

*Final results were inconclusive.

State Trigger Levels
Level Anatoxin Microcystin Cylindrospermopsin
Caution Any Detected 0.8 1
Warning 20 6 4
Danger 90 20 17

Source: State Water Resources Control Board.

Related Links

Blue-Green Algae (Cyanobacteria) Blooms
Source: California Department of Public Health.

California CyanoHAB Network (CCHAB)
Source: State Water Resources Control Board.

Harmful Algal Blooms
Source: The Centers for Disease Control and Prevention.

My Water Quality
Source: California Water Quality Monitoring Council.

Contact

Environmental Health and Safety Programs
625 5th Street
Santa Rosa, CA 95404
(707) 565-6565
eh@sonoma-county.org

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