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Blue Green Algae Blooms continue to threaten Lake O and the Caloosahatchee

Posted at 7:02 PM, Jun 15, 2023
and last updated 2023-06-15 19:02:01-04

For the last several weeks, Fox 4 has been tracking the blue-green algae blooms on Lake Okeechobee and the Caloosahatchee. On Thursday, Fox 4 learned that the Army Corps is not releasing water into the Caloosahatchee, despite increasing target flows this past weekend.

FGCU Professor Dr. Barry Rosen told Fox 4 a few weeks ago that algae season was right around the corner. Dr. Rosen now gives an update on the current bloom on Lake O, and smaller blooms we have been seeing on the Caloosahatchee.

“There are a lot of nutrients in the water,” said Dr. Rosen. “There is plenty of blue green algae. They like this warmer temperature. They are very happy right now.”

The current bloom on Lake Okeechobee covers 380 square miles according NOAA’s Sentinel Satellite. With the current bloom and local watershed flows already damaging levels from rain runoff, the Army Corps is not releasing water into the Caloosahatchee. That means water levels in the lake are rising.

“The major outflow right now is from evaporation and that's all we can do,” said Dr. Rosen.

And that watershed runoff is feeding the blooms in the Caloosahatchee.

“The watershed we know is pretty enriched,” said Dr. Rosen. “So, any cyanobacteria that are already in the canal system, and there is plenty, they are going to be stimulated by having that extra nutrient load from the watershed.”

Those blooms on the Caloosahatchee have led to numerous health alerts this week for possible harmful algal toxins. Dr. Rosen says those alerts are for ingesting that water in any way.

“So, most of those protections are about recreational exposure,” said Dr. Rosen. “People aren’t going to drink that water, but their pets might.”

And while the Army Corps pauses releases into the Caloosahatchee, water levels of Lake Okeechobee are rising. As water rises, the risk of a damaging water release later this summer increases.

The Sanibel Captiva Conservation Foundation says the Army Corps is going to have get creative in how they lower those levels.

“As the rainy season continues and we are still getting that basin runoff, and we get to point where we need to make Lake releases, then that’s only going to exasperate the situation,” said SCCF Environmental Policy Director Matt DePolis.

A large release of Lake O water would increase nutrient loading in the river, feeding more blooms, damaging oyster beds and possibly feeding new algal blooms in the Gulf.

With the current blooms, DePolis and Dr. Rosen both think it will be a busy summer of blooms.

“We have seen it at some of the boat launches down the river. We are getting anecdotal reports that it is showing up in some of the canals in Cape Coral and some of the other areas too,” said DePolis. “So, I think we are in place where the huge toxin algae blooms haven’t started yet, but they are well on their way.”

Lake O is currently just over 14 feet deep. After the recent improvements to the Herbert Hoover Dike, the lake can hold nearly 20 feet of water. But a deeper lake means an unhealthy lake. That said Dr. Rosen says for the Lake to drop a foot would take months of releases.