Three lakes in central Wisconsin’s Adams County have been plagued with unsightly, mucky algae blooms for years, some of which have produced harmful toxins. The lakes, which eventually drain to the Wisconsin River, are known as the Tri-Lakes.
A few years ago, Tri-Lakes Management District chairman Carl Hasdal found a potential solution he wanted to try: nanobubbles.
Here’s what to know about the technology and what it could mean for algae in Wisconsin lakes.
More: Toxic algae threatens Wisconsin waters. Could microscopic bubbles save the day?
What are nanobubbles?
As their name indicates, nanobubbles are bubbles — really, really tiny ones. They’re 2,500 times smaller than a grain of salt.
Why is algae a problem for Wisconsin lakes?
Increased nutrients, warm temperatures and lots of sunlight in a body of water can produce an algae bloom.
Not all algae are harmful, but too much of it can hamper recreational activity on a lake. Blue-green algae, also known as cyanobacteria, can produce toxins that make humans and animals sick.
Algae blooms are a huge and growing problem for Wisconsin’s beloved waters. More than one in 10 water bodies in the state listed as impaired in 2024 by the U.S. Environmental Protection Agency were on the list because of excess algae growth.
How can nanobubbles fix a lake’s algae problem?
Moleaer, the California-based company that installed nanobubble technology in the Tri-Lakes, uses a three-part system: gas that concentrates oxygen from the air, the nanobubble generator itself and a pipe that draws water out of the lake and sends it back in.
Once the water is drawn into the unit, it gets infused with oxygen, creating the nanobubbles. Then that water is sent back into the lake, where the bubbles will settle throughout the water, bringing oxygen with them.
It’s meant to stop a vicious cycle: Phosphorus and nitrogen in the water create algae blooms, and then the blooms die, sucking up oxygen from the lake. With less oxygen, aquatic life suffers and more phosphorus is released from the lake bottom in a process called internal loading, feeding more algae blooms.
Adding oxygen to the lake bottom through nanobubbles stops more phosphorus from being released, cutting off a key ingredient for the algae.
Moleaer has installed more than 650 nanobubble units in water bodies worldwide.
How is the DNR monitoring nanobubble use in Wisconsin?
Madi Johansen, aquatic plant management coordinator in the DNR’s water quality bureau, said nanobubble technology for lake restoration is still considered an emerging area of research.
There’s limited peer-reviewed scientific literature to support Moleaer’s claims of improved water quality, she said, and none assessing the technology’s effects on other aspects of lake ecology. For now, the department will consider each request to use nanobubbles individually, and permits must be obtained for the work.
Researchers from UW-Stevens Point are on the Tri-Lakes weekly assessing oxygen and nutrient levels, as well as any impacts to phytoplankton, zooplankton and plants. They’ll compare that data with baseline monitoring done on the lakes last year and will share all their information with the state Department of Natural Resources.
Madeline Heim covers health and the environment for the Milwaukee Journal Sentinel. Contact her at 920-996-7266 or mheim@gannett.com.
This article originally appeared on Milwaukee Journal Sentinel: What to know about the invisible bubbles that help get rid of algae