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UVU professor outlines algae‑harvesting boat, says single craft reduced surface algae but a fleet is needed
Summary
Dr. Kevin Sherloft of Utah Valley University described a mobile algae‑harvesting boat funded by a state grant that removed an average ~60% of surface algae per pass at hotspot marinas; he said one boat is insufficient after a late‑summer bloom and the team seeks to scale to multiple vessels.
Dr. Kevin Sherloft, a chemistry professor at Utah Valley University, described a mobile algae‑harvesting boat his team built with roughly $400,000 in state grant funding to remove harmful surface algal blooms at Utah Lake marinas and beaches.
Sherloft said the boat uses a front intake boom to collect surface water, adds a filter aid (diatomaceous earth or powdered cellulose) and passes water through two large filter presses mounted on a boat. "We can filter 400 gallons per minute," he said, and reported that, across sites in 2022, one pass through the presses reduced apparent algae concentration by about 60 percent on average.
The approach grew from work after a severe 2016 harmful algal bloom, when state monitoring showed cell counts can spike rapidly in a matter of days. Sherloft said the team reviewed some 20 separation and filtration techniques, tested seven in the lab and scaled the method that worked best. He said the lab press began at 1.23 square feet of filter area and the field system now uses two large presses providing about 291 square feet of filter area.
Field operations began after the boat was built in 2021 and students have been operating the system on Utah Lake since 2022. Sherloft said two students staff the boat — one drives, one monitors and operates equipment — typically five hours a day on weekdays from May through August. Based on those schedules, he estimated the boat filters roughly 96,000 gallons per day and yields about 90 kilograms of dry algae per day after dewatering.
Sherloft described the harvest as a spot‑treatment strategy: "The algal blooms don't cover the entire lake," he said, explaining the team focuses on marinas and beaches where people interact with the water. The boat cannot treat the whole lake quickly; during a late‑summer bloom at Linden Marina, mechanical problems and rapid bloom growth outpaced the single craft. "We need more boats, and we would like to build a fleet of boats," he said.
The team patented two elements of the method: the use of a filter aid to prevent press clogging and the mobile platform to treat hotspot areas. Sherloft described the batch process for the presses: once full, presses are opened and the dried "filter cake" is discharged into bins and taken to Utah Valley University's compost pile as a soil amendment; he noted cellulose‑based cake could be used as a biomass fuel in principle but said that application has not been demonstrated.
Sherloft cited Utah Department of Environmental Quality monitoring data from a multi‑day 2016 event to illustrate how quickly blooms can escalate and to justify early, targeted intervention. He framed the current system as a mitigation tool for public‑use areas rather than a substitute for watershed‑scale nutrient reductions.
The presentation did not record any formal funding decision or policy vote. Sherloft said the program has operated at Linden Marina and rotates to Utah Lake State Park, Saratoga Springs and American Fork marinas, and that program leaders aim to scale the approach to multiple boats to better cover recurring hotspots.
