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Department of Health Services

Environmental Health

Harmful Algae Blooms (HABs)

The California State Water Resources Control Board has announced that the occurrence of HABs appears to be increasing. This has led to an increase in the public’s concern regarding potential health impacts to humans and animals, particularly dogs. Please review this fact sheet.

What are Harmful Algae Blooms (HABs)?

Algae are tiny, harmless organisms that live naturally in water. A harmful algae bloom (HAB) is actually made of cyanobacteria, sometimes called blue-green algae. Some cyanobacteria species create toxins that can make people and pets sick.

Blue-Green Algae (Cyanobacteria)

Blue-green algae poisoning is most common in pets. Symptoms, including death, can be more severe in pets because they tend to drink the water from affected lakes and reservoirs. Children and adults can experience serious injury to the liver, kidney, and nervous system if affected water is swallowed. Medical treatment should be sought immediately if a person or pet is suspected to have blue-green algae poisoning.

Cyanobacteria can be found in waterbodies throughout the United States as well as California. Common recreational water purification techniques, including camping filters, tablets, and boiling, do not remove toxins from affected water.

The following signs may be posted at designated Sonoma County public beaches:

  • Gualala River: "Check for Algae"
  • Russian River:
    • Cloverdale River Park: "Check for Algae"
    • Del Rio Woods Beach: "Check for Algae"
    • Camp Rose Beach: "Check for Algae"
    • Healdsburg Veterans Beach: "Check for Algae"
    • Steelhead Beach: "Check for Algae"
    • Forestville Access Beach: "Check for Algae"
    • Sunset Beach: "Check for Algae"
    • Johnson’s Beach: "Check for Algae"
    • Monte Rio Beach: "Check for Algae"
    • Patterson Point: "Check for Algae"
  • Salmon Creek: "Check for Algae"
  • Spring Lake: "Check for Algae"

When In Doubt Stay Out

Know the signs of an algae bloom. Don’t go in water that is foamy, scummy, thick like paint, pea-green, blue-green or brownish red.

Healthy Water Habits

At all times, DHS encourages individuals to follow healthy water habits for recreational river use:

  • Do not drink river water. Do not cook or wash dishes with river water
  • Wash yourself and your family with clean water after river play
  • Consume fish only after removing guts and liver, and rinsing fillets in clean water. Mercury has been detected in fish from the Russian River. Check here for additional guidance regarding mercury in fish:
  • Bring your life jacket, but leave the alcohol at home. The side effects of alcohol – impaired judgment, reduced balance, poor coordination – can be magnified by the boating environment. For additional safety tips please visit the State Parks Division of Boating and Waterways:
  • Follow safe practice for Harmful Algae Blooms: To learn more about Harmful Algae Blooms read Algal mats brochure

Reporting an Algae Bloom

More Information

Find more information about Harmful Algae Blooms (HABs) at this HABs Frequently Asked Questions page from the California State Water Resources Control Board.

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