FGCU expert says smelly algae in Cape Coral canal is normal

Thick algae are blanketing a Cape Coral canal on Skyline Boulevard and Gleason Parkway. Neighbors worry the algae might be toxic.

WINK News met with Dr. Barry Rosen from The Water School at Florida Gulf Coast University to find out if their concerns are warranted.

“These are cyanobacteria, which means they’re blue-green algae. So it’s fairly common. But don’t worry about it as blue-green algae because it’s not a toxin producer,” said Dr. Rosen.

To put it simply, all of this gunk is natural. To prove it, Dr. Rosen showed WINK News the algae under a microscope.

Filled with chlorophyll, the bacteria photosynthesize using oxygen from the warm water. “That’s what we have a lot of globular mucilage, or slime, that builds up, and the colony gets bigger and bigger, and then those, when that oxygen gets trapped, those bubbles, those mucilage balls can be lifted off the bottom,” Dr. Rosen said.

That process turns into all the gunk found in the canal and can be expected as we continue warming up into the summer season.

The good news is even though it is unsightly, it’s not harmful to your health.

Dr. Rosen said the worst part is the smell. The only thing he suggests you should look out for is keeping your furry friends away from it. “Bottom line is because, even though this is the dominant organism, there are some other algae in here too. And there’s protozoa, there’s other things to worry about. So, I would say generally do not drink the water.”

The City of Cape Coral told WINK News it would send samples of this water to another private lab for further identification.

The city believes the algae is a continuation of a bloom from three weeks ago near the Palmetto Pines Golf Course. Dr. Rosen said that’s possible.

“When the rains start to come, and you change the nutrient conditions out there, and it starts to flush, these will get moved out, and especially if they’re floating, they’ll still be some on the bottom,” Dr. Rosen said.

In the last few weeks, the city has observed some downstream movement from the golf course to the area where the area the gunk is now. Given our recent warm weather, coupled with more nutrients from neighbors’ fertilizer, the conditions are ripe for blooms like this.

Dr. Rosen said this is healthy for the canals, so he sees no reason for Cape Coral to interfere. “You can’t remove it all. So what you’re doing is perpetuating it, not letting it get to the end of where it’s depleted everything it needs so it can’t grow anymore.”

The biggest indication it’s done growing is when the color changes from green to brown. After sampling some of the algae Thursday, Dr. Rosen noticed most of it is already at that stage.

So while it may be frustrating to look at, he recommends neighbors keep their patience and let nature run its course. “It’s not a swimming pool, so you can’t just kill it. And if you did kill it, the wrong organism could start to grow. One that does produce toxins. So it’s a nuisance, but it will pass.”