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Stay Away From Bodies of Water With Blue-Green Algae

Some Algae May Be Toxic in Large Quantities

Department of Health and Human Services
Sherri Z. Heller

10/8/2015 10:00 PM

Media Contact:

Laura McCasland    (916) 875-2008


Sacramento, CA –Health officials are advising the public and their pets in Sacramento County to stay away from rivers, lakes, ponds and any bodies of water that have scum layers, large mats or other visible blooms of blue-green algae.

Sacramento County Public Health was notified this week by a local veterinarian that a dog had died after swimming in the Sacramento River at Sand Cove Park.  UCD Veterinary Lab will test the dog to determine if blue-green algae contributed to the cause of death. 

Sacramento County Environmental Management Department and the California State Department of Fish and Wildlife took samples of water from the Sacramento River on Wednesday, October 7, to test for blue-green algae toxins and are awaiting results. 

Meanwhile, the City and County of Sacramento are constructing signs to post at parks along the river advising the public and pet owners to stay away from water with foam, scum or mats.

Blue-green algae are a type of bacteria and are naturally found in fresh and marine water bodies. It's only when they are present in large quantities that they present a problem.

Warm, slow-moving waters that are rich in nutrients such as phosphorous and nitrogen can cause algae growth. Blooms can occur at any time, but are most common in late summer or early fall.  The bloom can be green, blue green, white or brown, and may look like a floating layer of scum. 

If toxic algae touches a person's skin or is accidentally inhaled or swallowed, he/she could get a rash or an allergic reaction, or develop gastrointestinal problems, including nausea, vomiting, and diarrhea. In large quantities, the toxins can also cause neurological or liver damage and lead to death.  Reactions can occur anywhere from a few hours to days after exposure. 

People and pets should not swim, nor wade, in water that contains algae.  People should not drink or cook with this water. Even if the water is boiled or filtered, the toxins can persist. Livestock should not swim, nor drink, from areas where there is foam, scum or mats.  Medical treatment should be sought if any person, pet or livestock is suspected of having been poisoned by blue green algae toxins.