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Utah Lake’s algal bloom heading into third month and may last a few more

Scott Sommerdorf | The Salt Lake Tribune A boat heads out onto Utah Lake from the marina near Utah Lake State Park, Friday, July 14, 2017.

Typically, this is the time of year when algae strike the state’s waterways and yet the persistent toxic bloom in Utah Lake has been going strong since June with no end in sight.

Most of the lake and portions of the Jordan River remain under a warning that advises against coming into direct contact with the water through swimming, wading, water skiing or other activities.

Low levels of anatoxin, a potent neurotoxin that can be fatal in even small doses, were still present in samples collected from Utah Lake last week. State policy recommends an advisory remain in place so long as any amount of anatoxin is present.

Utah Lake isn’t the only body of water to have experienced an algal bloom this summer. Blooms have also taken place on Mantua Reservoir, Matt Warner Reservoir, Rockport Reservoir and the Upper Box Creek Reservoir.

None of these other blooms has warranted a health advisory, though the Matt Warner Reservoir bloom was tied to the death of at least 800 fish. The state Division of Wildlife Resources believes the fish died because the bloom used up too much of the oxygen

Utah Lake has not yet experienced a similar fish kill this summer, but businesses tied to the lake have taken a hit. Eric Ellis, executive director of the Utah Lake Commission, told state lawmakers last week that the lake’s recreation community has lost some $1 million as a result of the bloom.

“Even with last year’s negative press and perception, this year started out positive,” he said. “We were on track to have a really banner year… after the Fourth of July when that bloom was announced, a typically pretty packed lake dropped to no more than 10 boats per day, which is nothing.”

Earlier this month, a series of storms had the lake’s managers feeling hopeful that the bloom’s end was near. But the return of hot, sunny weather allowed the bloom to return, said Jodi Gardberg, who manages technical services, including algal bloom monitoring, for the state Division of Water Quality.

This year’s bloom has behaved differently than last year’s dramatic events on Utah Lake, said Erin Jones, one of the Brigham Young University graduate students helping the state study the lake this summer. Populations of cyanobacteria — the organisms more commonly known as toxic algae — exploded on the lake in 2016, she said, and then died just as quickly, leaving high levels of toxins in their wake.

This year’s bloom, she said, has maintained a more steady population over time, producing a lower amount of toxins.

It’s not unusual to have algal blooms on bodies of still water this time of year, Gardberg said. August and September are usually peak algae season.

This year’s long-lasting bloom will likely continue until temperature drop low enough to stop the spread of the algae, but Jones said it’s not clear how long that will take. Right now BYU researchers plan to continue sampling the lake on a weekly basis through October, but it’s possible the bloom could last longer than that.

“That’s one of the problems with climate change,” she said. “As we extend the period of time that water bodies don’t have ice on them, it increases the number of days that the cyanobacteria are able to persist.”

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