Killer algae on the Van Duzen



The Humboldt County Department of Health and Human Services today issued the following warning:


Due to its potential health risks, the Humboldt County Department of Health and Human Services, Division of Environmental Health and the North Coast Regional Water Quality Control Board, are urging swimmers, boaters, and recreational users to avoid contact with the blue-green algae now blooming on the Van Duzen River in Northern California. Residents and recreational users of the Van Duzen River should use caution or avoid contact with water with visible blooms until further notice.

"A blue-green algae bloom can present a health hazard for those swimming or playing in the river, especially children and pets. We recommend that people stay out of the water where significant algae are present, and keep their dogs out of the river at this time," said Kevin Metcalfe, Consumer Protection Unit Supervisor of the Humboldt County Division of Environmental Health.

A dog that recently died after swimming in the Van Duzen River just below Pamplin Grove Campground was likely poisoned by blue green algae toxins.

We are aware of nine other dog deaths that occurred shortly after contact with fresh water bodies in Humboldt and Mendocino Counties which may have been caused by blue-green algae poisoning since 2001. Five dogs died after swimming in Big Lagoon in 2001, while four dogs died after swimming in the South Fork Eel River in 2002 and 2004. A toxin associated with a type of blue-green algae was found in the stomachs of two of the dogs who swam in the South Fork Eel River. The algae that produce this toxin have been found in water samples taken from the Van Duzen River in the area where the dog swam. The dog died approximately one hour after leaving the water on Sunday, July 26, 2009.

The algal blooms look like green, blue-green, white, or brown foam, scum or mats floating on the water. Recreational exposure to toxic blue-green algae can cause eye irritation, allergic skin rash, mouth ulcers, vomiting, diarrhea, and cold and flu-like symptoms. Accidentally drinking or swallowing large amounts of contaminated water can be extremely dangerous.

The Statewide Guidance on Harmful Algal Blooms recommends the following:

• Avoid wading and swimming in water containing visible blooms or water containing algal scums or mats, which are most often present on the shoreline;

• Take care that pets and livestock do not drink the water or swim through heavy scums or mats, nor lick their fur after going in the water;

• If no algal scums or mats are visible, you should still carefully watch young children and warn them not to swallow the water;

• Do not drink, cook or wash dishes with untreated river water;

• Consume fish only after removing guts and liver, and rinsing fillets in clean drinking water;

• Get medical treatment right away if you think that you, your pet, or your livestock might have been poisoned by blue green algae toxins. Be sure to alert the medical professional to the possible contact with blue green algae.

With proper precautions to avoid water contact, people can still visit the Van Duzen River and enjoy activities such as camping, hiking, biking, canoeing, picnicking or other recreational activities excluding direct contact with the algae bloom scum.


Contact the Humboldt County Division of Environmental Health at (707) 445-6215 or 1-800-963-9241 for more information.

If you have questions about medical treatment, call your doctor. For further information on animal health, contact the State Animal Health Branch at (707) 826-1658.

The following websites provide more detail on blue green algae:

California Department of Public Health:

State Water Resources Control Board:

National Center for Disease Control:

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