Utah Lake Authority hosts explain what causes harmful algal blooms and how visitors can stay safe

Sam, a host of the Utah Lake Authority podcast, and Courtney, the program co-host, explained how harmful algal blooms (HABs) form on Utah Lake and offered guidance for people who recreate there.

Harmful algal bloom season generally runs in summer — roughly June through September — though the hosts said blooms can appear earlier or later depending on conditions. "HABs happen," Courtney said, underscoring that blooms are a natural phenomenon that increase during warm months and under high nutrient loads.

The hosts described causes and why Utah Lake is particularly vulnerable. Courtney said Utah Lake is "super shallow and it's very nutrient rich," and noted that the lake's bottom sediments store nutrients that can fuel cyanobacteria (commonly called blue-green algae) that sometimes produce toxins harmful to dogs and, rarely, to humans. Sam added that most nutrient pollution in Utah Lake comes from nonpoint sources such as agriculture, road runoff and pet waste, while point sources like wastewater treatment plants are often unfairly blamed; Sam said those plants "are one of the heroes" because they treat sewage that formerly flowed raw to water bodies.

The podcast offered practical identification tips for nonexperts. Sam walked listeners through visual cues posted on the statewide site habs.utah.gov: "pea soup," "spilled paint," green scum or mats, globules and grass-clipping–like material, plus larger benthic mats along shorelines. They emphasized that visual checks are a useful rule of thumb but that professional testing is required to determine whether a bloom is harmful.

Hosts urged people to check the statewide HABs site for maps and advisories before heading to the water. Sam said the site is updated frequently and can show whether an advisory applies to the entire lake or only a bay or marina; Courtney said that on a large water body such as Utah Lake (about 97,000 acres when full), a bloom may affect only a specific section.

On management, Sam described the Authority's ongoing research and interventions, including carp removal: "We're getting rid of carp, which is helping with algae blooms," he said, noting studies that link carp presence to a shift from underwater vegetation to algae domination. The hosts cautioned that HAB management is complex, that different interventions carry trade-offs, and that the Authority is testing multiple approaches.

For recreation, the presenters advised common-sense measures: avoid entering areas with visible algae, move to another location on the lake if a localized bloom is present, and if you fish in an area under an advisory, clean the fish before eating it. They also encouraged residents to reduce runoff — pick up pet waste, avoid overfertilizing lawns and do not dump yard waste into storm drains — as simple actions that collectively reduce nutrients entering the lake.

The episode closed with the hosts reiterating the central public-safety message: check advisories, learn the visual signs, and modify activities during blooms. The Utah Lake Authority podcast provides links and photos at habs.utah.gov for people who want more information.