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SALT LAKE CITY – As the summer heat continues in Utah, harmful algae is becoming more of a problem with several county health departments issuing watches and warnings.
In addition to algal blooms, monitoring teams have also detected benthic algal mats in several bodies of water, which can be especially dangerous to children and animals.
"The problem with harmful algal mats is dogs really like how they smell," said Hannah Bonner, an environmental scientist with the Utah Division of Water Quality. "So they'll actually find them and eat them, which if toxins are present means the animal is going to get a really high load of toxins."
Unlike algal blooms, which are dispersed through the water, mats grow on the bottom and then wash to the shore in clumps.
"The same thing with kids," Bonner said. "Maybe they'll grab some accidentally, or they're playing on top of one and then drink the water — that's where the risk occurs."
Utah scientists are still learning about algal mats since they were first discovered in the state in 2020, Bonner said. The recent discovery of the mats in the pond at Liberty Park marks the first them they've been found in the Salt Lake City area.
The mats are being looked into after approximately 30 wild ducks died at Liberty Park earlier this month. However, tests are still pending and veterinarians suspect other possible causes of death.
Algal mats have also been detected in the water near Calf Creek Campground and Lower Calf Creek trail in southern Utah, prompting these guidelines from the Division of Water Quality for the area:
- Avoid touching or disturbing benthic algal mats.
- Do not dunk your head in the water.
- Do not drink water or get it in your mouth.
- Do not let pets drink water or eat algae.
Harmful algal mats are also suspected to be present in the Virgin River in Washington County, including near St. George.
"We had another dog illness, very suspicious, that seems like it could be caused by eating one of these harmful algal mats right in the St. George area," Bonner said.
Recent water monitoring on Utah Lake revealed two new areas that are now under a health watch for harmful algae blooms: American Fork Marina and Lindon Marina, where teams saw visible signs of algae.
That's in addition to the warning advisories that were already in place for Lincoln Beach and Provo Bay, which included these restrictions from the Utah County Health Department:
- Do not swim or water ski.
- Avoid areas of algae when boating.
- Clean fish well and discard guts.
- Keep animals away.
- Don't drink the water.
Blooms have also been detected in other bodies of water around the state, including Otter Creek Reservoir, Yuba Lake, Panguitch Lake, Steinaker Reservoir and Deer Creek.
"Historically, we haven't started having blooms at Deer Creek until a little bit later in the summer, August or September, so this is sooner than we'd hoped for this year," Bonner said.
The hot weather combined with nutrient pollution from spring flooding is fueling the algae growth.










