PROVO — State health officials have extended an algal bloom warning to include all of Utah Lake, and are urging people and pets to stay out of the water.
The blue-green algae, or cyanobacteria, poses serious health risks.
The Utah Department of Environmental Quality collected water samples and found algal species in several areas of the lake with the potential to produce toxins and cell concentrations "significantly over the recommended warning threshold level," according to a press release Wednesday from the Utah County Health Department.
"To protect the health of people and animals that use the lake, it is important for the public to be aware of the warning on the lake," said Eric Edwards, deputy director of the Utah County Health Department.
The recreational danger threshold for toxin cell concentrations is between 20,000 and 10 million cells per milliliter. Recent samples from Lincoln Beach and its marina measured at more than 6 million cells per milliliter, and those at Sandy Beach measured at about 2.5 million cells per milliliter.
Health officials encouraged anyone visiting the lake to "take caution and avoid areas of scum. Recreationists are advised to be mindful of conditions, as they may change over the course of the day," the release states.
Blue-green algae belong to many freshwater ecosystems, according to health officials, but can grow quickly under certain conditions including high levels of nutrients in the water, warm temperatures, sunlight and calm water. Those conditions can result in "extensive blooms," health officials said.
Cyanobacteria within the blooms is harmful to people, animals and fish, according to the release.
Visitors at all areas of the lake are cautioned to stay out of the water and keep their animals away from it. Anglers at the lake should clean fish well and discard the guts, officials said.
"Symptoms of exposure include headache, fever, diarrhea, abdominal pain, nausea and vomiting, and sometimes allergic-like reactions from skin contact," officials warned.
Scofield Reservoir also remains under a warning advisory for cyanobacteria levels, but officials noted levels in the water have decreased since July.
More information on harmful algal blooms is available at the Utah Department of Environmental Quality's website.
For concerns about possible exposure, call the Utah Poison Control Center at 800-222-1222 or your local doctor.