Why are we seeing so much blue-green algae lately?

LAKE WORTH BEACH, Fla. (CBS12) — Blue-green algae is again forcing health officials to issue warnings on the Treasure Coast and Palm Beach County.

Algae has been making headlines a lot lately: you might remember, a toxin associated with the algae that recently showed up in the drinking water in West Palm Beach.

This latest warning in Palm Beach County comes from the C-51 canal, which does not supply any drinking water.

READ MORE: Why West Palm Beach's water issue is unique

Officials say the water in the C-51 canal near Southern Boulevard and Military Trail, Pine Tree Park in Lake Clarke Shores, and the spillway in Lake Worth Beach all tested positive from a test earlier this month.

When CBS12 News visited each area, we did not see any blue-green algae, but experts say it comes to the surface when it needs sunlight and might not always be visible.

The C-51 is part a network of waterways, connected to Lake Okeechobee, intended for flood control. It starts at 20 Mile Bend, runs parallel to Southern Boulevard for much of it, and eventually dumps into the Intracoastal.

“I’m not surprised at all, C-51 is a very large canal and there’s all sorts of backwaters where cyanobacteria can grow,” said Barry Rosen, a professor at The Water School at Florida Gulf Coast University, in a Zoom interview with CBS12 News.

Cyanobacteria the scientific term for blue-green algae. It needs backwater, also known as stagnant water, heat, sunlight and nutrients to thrive.

It’s the second report of algae this season on the C-51. In May, it was discovered in Lake Clarke Shores.

“A lot of times, when we’re talking algae, it’s Lake Okeechobee and the Treasure Coast, you’re not necessarily used to hearing about it down in Palm Beach County. What can you say about algae in Palm Beach County?” CBS12 News asked Rosen.

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“I can tell you this: cyanobacteria are always present in these canal systems, the conditions have to be right for them to take off and become a dominant organism,” Rosen said. “And the conditions are right.”

Keep your dogs out of this water especially, it’s dangerous for them. You can still fish, but it must be gutted and cooked thoroughly.