Florida researchers test floating filters to stop red tide before it starts

SANIBEL, Fla. (WINK)—Researchers at Florida Polytechnic University are working on a new system to stop harmful algae blooms before they start by targeting the nutrients that fuel them.

The last major red tide bloom hit Southwest Florida's Gulf Coast in February 2025. Blue-green algae showed up earlier this year in the upper Caloosahatchee River.

The blooms don't follow a schedule. They show up fast, spread quickly, and can shut down a day by the water in no time.

Adam Jalberd, a Punta Gorda neighbor who fishes on the Sanibel Causeway, knows the impact firsthand.

"As a chef, you can't cook any of the clams, oysters, or anything. It's not very good," Jalberd said. "It definitely takes away from business, especially in seafood restaurants."

The memory of the red tide is hard to shake.

"Oh, yeah, make the hair on my arm stand up," Jalberd said. "It just looks like there's trash everywhere. The smell is the worst thing you've ever smelled."

He compared the stench to forgetting bait in a car trunk for two weeks in the sun.

Toxic algae like red tide and blue-green algae are fueled by nutrients like nitrogen and phosphorus. The more nutrients in the water, the bigger the bloom.

That's why Florida Polytechnic University is trying something different by going straight to the source.

"What we have been trying to do is we try to remove the nutrients from the water body, and the way we try to target is we design a floating column," said Dr. Yudi Wu, Florida Polytechnic University assistant professor in civil and environmental engineering.

Dr. Wu said the system uses microorganisms, limestone, and biochar to target algae hotspots and clean the water as it flows through.

"We can absorb most of the nutrients from the water and let the clean water come out from this column again," Dr. Wu said.

Think of it as a floating filter moving through trouble spots before red tide or blue-green algae can take over.

Jalberd, out fishing, has only one wish.

"I hope it works," Jalberd said.

The project is still in early testing. Dr. Wu said the floating columns are expected to be deployed in Polk County next year.

If successful, researchers hope to scale them across Florida from inland canals to the Gulf Coast.