Recreationists planning to spend Labor Day weekend at Weber County’s Pineview Reservoir should be careful to avoid a harmful blue-green algal bloom, according to health department officials.

Weber-Morgan Health Department officials said in a news release Saturday that while Pineview Reservoir wasn’t closed, people and pets should avoid touching the scum produced by the bloom or ingesting the water.

The bloom is the latest issue at the lake, which only reopened to the public Friday after being closed to accommodate fire crews scooping water from it to extinguish the nearby Avon Fire.

The health department’s environmental health director Michela Harris said in the release that those visiting the lake should stay away from areas with algae scum and be aware that wind and changing temperatures can cause the bloom to move to other parts of the lake.

Blue-green algae occurs naturally in freshwater ecosystems, according to the health department, but becomes problematic when it proliferates, which typically happens when there are warm temperatures and high levels of nutrients in calm water.

Those exposed to blue-green algae could experience headaches, fever, diarrhea, abdominal pain, nausea and vomiting. Some people have an allergic-like reaction to touching the bloom, according to the release.

Utah Lake has also had problems with harmful algal blooms over the summer. The Utah Department of Environmental Quality has closed the Lindon marina and Lincoln beach and marina to the public. It warns against swimming or skiing in the rest of the lake.

The department has also issued warnings about algal blooms in the Jordan River and canals, Piute County’s Otter Creek, Panguitch Lake in the Dixie National Forest and the Matt Warner, Mill Meadow and Scofield reservoirs.

Those concerned about possible exposure can contact the Utah Poison Control Center at 800-222-1222.

Correction: Sept. 2, 2018, 8 p.m. • A previous version of the story's headline included an incorrect location.