Health officials in Mendocino County are warning the public about potentially toxic algal mats recently discovered in two local rivers, advising caution for anyone who boats, fishes, or swims in the affected areas.
The North Coast Regional Water Quality Control Board and Mendocino County issued advisories for the Navarro River in Philo and the East Fork of the Russian River, where the algal mats were found. Children and dogs, who are most susceptible to serious health impacts, should avoid touching any suspicious-looking algal material in the water or along the riverbanks.
The Navarro River advisory follows an August 9, 2024, report of a bloom, which led to testing that confirmed the presence of potentially toxic algal mats growing on the riverbed. These mats, which may detach and become stranded on the banks, were found to contain low levels of toxins (~5 ug/L anatoxins), but still pose health risks.
Similarly, during a field training session on August 9, 2024, Water Board staff sampled benthic mats in the East Fork of the Russian River near Elledge Ranch Road. Testing confirmed the presence of potentially toxic algal mats on the river’s bottom.
The North Coast Regional Water Quality Control Board has posted “Toxic Algae Alert” signs at recreational areas along both rivers, urging users to be vigilant. The public is advised not to touch or ingest any algal mat material and to prevent dogs from drinking river water. If contact occurs, officials recommend washing exposed areas immediately.
The Water Board is monitoring the situation and will provide updates on the California Harmful Algal Blooms (HABs) Reports Web Map. The advisories emphasize practicing “Healthy Water Habits,” such as avoiding algae in the water, keeping an eye on children and pets, and following any posted warnings.
Anyone who suspects a harmful algal bloom or encounters toxic algal mats is encouraged to report it through the California HABs portal, by emailing CyanoHAB.Reports@waterboards.ca.gov, or calling the HABs hotline at 1-844-729-6466.
For more information on harmful algal blooms, visit the California Harmful Algal Blooms Portal.
https://www.cnn.com/2024/09/01/climate/klamath-dam-salmon/index.html