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Tampa launches buoys aimed at reducing blue-green algae in Hillsborough River

City of Tampa launches ultrasonic buoys to deal with blue-green algae
Posted at 5:21 PM, Mar 27, 2023

TAMPA, Fla. — If you're planning on traveling the Hillsborough River, you may notice a new addition in one part.

The City of Tampa installed two new buoys Monday, but they're not your average buoys. These buoys are equipped with technology to reduce blue-green algae in the water.

Algae moves to the water surface for photosynthesis to grow and to the bottom of the water column for nutrients. The LG Sonic buoy uses ultrasonic sound waves to block algae's access to sunlight & nutrients. Algae sinks to the bottom and die off without releasing toxins.

"This is going to reduce that. And it's going to help us maintain the algae growth that we usually see at this time of the year in the river," said John Ring, the City of Tampa Water Production Manager.

Each buoy is capable of producing sound waves within a 500 feet radius to help maintain algae growth common this time of year.

"These buoys will project that sound right up to the banks. And that'll prevent the algae from growing and proliferating. That's gonna be the way we're able to control a bloom from taking place. This is gonna help us keep this and manage it and keep it under control, rather than using an algaecide," Ring said.

Hillsborough Algae Control Activities notice
A notice on the Hillsborough River about work being done to take control of blue-green algae.

Although new to Tampa, the buoys aren't a new piece of technology, according to Barry Rosen, a professor with the Water School at Florida Gulf Coast University.

"I hear from colleagues that it does work in smaller confined areas where the ultrasound can interfere with the gas vesicles and keep blue-green algae, cyanobacterial, to the lower part of the water column," Rosen said.

However, Rosen said the technology isn't as sound in some bodies of water.

"If it's a moving water body like the Hillsborough River, it's a little bit more problematic because those organisms can escape the influence," he said.

The effects on the Hillsborough River will be under a microscope for the next two years. The buoys are part of a pilot program funded by the Florida Department of Environmental Protection. Over the next two years, the city will test the two locations. The team will collect data and samples, then compare how the ultrasonic works compared to the original method, copper sulfate.

"It's a non-invasive way of controlling the algae, rather than applying an algaecide through the river. And typically with that, we're going out in our boats and applying it sometimes day or, or every other day basis," Ring added.

The technology can monitor multiple things worth studying in the water, even fine-tuning ways to adapt to existing algae.

Blue-green algae ultrasonic monitor from LG
An ultrasonic monitor like this will work to control blue-green algae in the Hillsborough River

"The ultrasonic buoys allow us to change frequency of the ultrasonics. So depending on the type of bloom or algae species, we may be encountering, we can adjust the ultrasonics to help keep that under control. So it will be something that we'll be continuously monitoring," Ring explained.

The ultimate goal is to keep algal blooms away and quality water flowing through the city.

"Water quality wise, this allows us to maintain a nice steady quality of water entering into the facility. And typically, with algae, algae blooms, we have systems inside the facility that will eliminate the taste and odor that is a residual from algae being present. This will be kind of a belt and suspenders approach to us. So it'll help us always maintain a good quality of taste and odor in the water," he continued.