Fort Myers News

October 18, 2017

 

Fluctuating Blue, Brown Water on Fort Myers Beach the Norm for Coming Months

By Jessica Salmond

 

http://www.fort-myers-beach-observer.com/page/content.detail/id/632383/Fluctuating-blue--brown-water-on-Fort-Myers-Beach-the-norm-for-coming-months.html?nav=5000

 

There are freshwater catfish near Sanibel and the Causeway.

 

Rae Ann Wessel, Director of Policy for the Sanibel-Captiva Conservation Foundation, said it's a side effect from the freshwater releases from Lake Okeechobee following the heavy rainfalls of the past two months.

 

"Normally they're 30 miles away up river," Wessel said. "We wouldn't even see them at the 41 bridges. But they're finding new homes because they can."

 

As bottom feeders, the catfish could have been washed out to sea by the releases, but they're staying alive in an environment that should be too salty for them.

 

Lake Okeechobee was measuring at 17 feet last week, the highest it's been since 2005. Typically, the lake should be between 12.5 and 15.5 feet deep, according to the U.S. Army Corps of Engineer's policy. But the copious influx of rain and runoff into the lake has had it on the rise.

 

The water has to go somewhere - so the Corps has been releasing freshwater down the St. Lucie and Caloosahatchee. Southern releases have been restricted to avoid flooding the communities there, and much of the southern storage areas are already full, Wessel said. On Monday, Oct. 9, the Caloosahatchee was receiving an average of 13,800 cubic feet per second at the Franklin lock that is 33 miles upstream - five times the recommended harm threshold of 2,800 cubic feet per second.Wessel said it could take years to fully understand the detrimental effects the sheer amount of releases has had on the local ecology.

 

But some of its effects are already becoming known, including the presence of these surviving catfish.

 

Such a rush-in of fresh water is detrimental to the estuary area where the salt water meets the river mouth, Wessel said.

 

"This area is very productive for fish and wildlife. It's really important because they depend on that mixing zone as a nursery," she said.

 

The mixing zone is being pushed further out toward the Gulf, which doesn't have the right "infrastructure" to support the fish hatcheries and other habitats of creatures like oysters.

 

"You're pushing all the fry, spat, seeds out into the Gulf where it can't thrive. It's too salty there," she said.

 

The sea grasses are also struggling. They need light to photosynthesize, and the water coming from the Caloosahatchee is dark. The river water is always a tea-color, caused by the tannins released from decomposing plant matter, but this water is dark and turbid for an additional reason, Wessel said. Besides tannins, it holds colored dissolved organic matter (CDOM) in copious amounts, as well as excessive nitrogen and phosphorous nutrients.The darkness is prohibiting photosynthesis, which in turn prevents the grasses from producing oxygen that other species need. The lack of oxygen in water is called hypoxia, and it will start to kill those species that can't move somewhere else.

 

Wessel said the estuary is losing out on part of the reproductive cycle of the bottom food-chain species, which depend on the delicate balance of water temperature, salinity, and length of the day and clarity of the water to reproduce.

 

But, the releases aren't likely to stop, and Wessel said the estuary and the Gulf are better off to get them now rather than later.

 

Species are already not reproducing now; it would be better to get rid of the freshwater now before the spring season begins, she said.

 

"With the options we have, the best scenario is to get the (freshwater) now before the really critical and reproductive periods in the spring," she said.

 

Fort Myers Beach's Gulf water seems to change color at will, one moment muddy brown, the next an inviting aqua.

 

That flux between beautiful blue and icky brown will be a regular phenomena for a while, said Rae Burns, environmental technician for the Town of Fort Myers Beach.

 

At high tide, when water is flowing in from the ocean, it should look more normal. But during low tide, water is sucked back out into the ocean - and the tide is also sucking the Caloosahatchee's tannin-filled waters and Lake Okeechobee releases out into the Gulf, which is why the water will look cloudy and dark.

 

But despite the change in colors, Burns said the water's safety levels are normal right now.

 

"It's really not dangerous to people at this time," she said.

 

There is no strong presence of red tide, no fish kills and the wash-up of red drift algae onto the beach has subsided, she said.

 

When it's out in the Gulf, the algae exist as a large mat floating near the surface of the water. Weather conditions such as strong winds or vigorous waves can break off chucks of the mat, which may then drift to shore.

 

Red drift algae are not harmful to humans and are not the same thing as red tide. The algae often wash up in big clumps that smell rather poorly, but Burns said it's actually good for the environment and provides snacks for birds.

 

But the mat has been growing offshore due to the availability of nutrients carried down from the Caloosahatchee, Burns said.

 

Wessel said it's important for people to check with the Department of Health for updates and not to get in with any health concerns or open wounds, a warning issued any time of the year.

 

"Is it safe? That implies so much. Anybody who has a concern when the water doesn't look good, don't go in with open cuts or ingest any water," Wessel said. "It doesn't mean the water is dangerous, but there is no real-time monitoring of bacteria levels."

 

The Department of Health tests the water weekly, but the results take several days to come back. Visit lee.floridahealth.gov and visitbeaches.org to check on local water quality results.

 

"(Releases are) probably going to continue, and we'll see high flows through the end of the year," Wessel said.

 

That's best case, and only if it stops raining so much.

 

January 2016 through June 2016 was the wettest season on record; then October 2016 it stopped raining. November 2016 was the driest of record, and Florida was put into drought, Wessel said. Now, the state got a record amount of rainfall from the August rains and September storms.

 

"It's not an El Nino or La Nina year, it's just an example of extreme climate variability. This is what climate change looks like," Wessel said. "If it stops raining, we'll see dark water through the end of the year. I'd love to be wrong."