by SC Reporter Reese Holiday
Recent Lake Okeechobee releases into the Gulf of Mexico could increase harmful algae blooms and threaten the environment surrounding Sanibel, according to Sanibel Captiva Conservation Foundation Environmental Policy Director James Evans.
Evans and SCCF have been monitoring a recent release of freshwater from the lake. And Evans said releases into the Gulf can come from Lake Okeechobee, or run-off from the Caloosahatchee River watershed. However, this isn’t the first-time releases were reported.
“We’ve been experiencing these high flow discharges for a long time,” Evans said. “It’s just that some years are worse than others, and it’s really dependent on rain fall.”
This year’s rainy season has seen high amounts of rainfall, especially in October. This, according to Evans, is what caused some of the freshwater releases into the Gulf.
“In early October, there were a number of storms that increased the volume of water in the lake,” Evans said. “That really was what kind of kicked off the releases from Lake Okeechobee into the estuaries.”
As for the recent storm, Tropical Storm Eta, the Army Corps of Engineers predicted that Lake Okeechobee could rise by 10 inches. However, the storm’s trajectory didn’t cause as much rain fall around the lake as predicted, resulting in decreased freshwater releases.
“Because it went out into the Gulf of Mexico and curved back, it didn’t result in the amount of rainfall that was forecast to fall on the lake,” Evans said.
Evans explained that freshwater can disrupt the salinity of the Gulf and bring unwanted nutrients. The most common are phosphorus and nitrogen, which can come from urban areas and cause damaging algae blooms.
“Those nutrients can actually be harmful because they can feed algae, in particular harmful algae blooms, like red tide or blue green algae that can produce toxins that are harmful to people and to organisms,” Evans said.
Harm can be caused in the opposite way as well with not enough freshwater released into the Gulf. According to Evans, too little freshwater will cause the salinity to increase, damaging the ecosystem.
“It’s not just the high flow releases to the estuary, it’s also if we don’t get enough during the dry season because then our salinity would get too high,” Evans said. “It’s that delicate balance between too much and too little and getting it just right.”
To solve these problems, the National Park Service has implemented the Comprehensive Everglades Restoration Plan. According to the website of the NPS, the plan will “restore, preserve, and protect the south Florida ecosystem.” This means reducing freshwater releases into the Gulf, preserving the surrounding environment.
“What we need to solve it is water storage,” Evans said. “The roadmap to do that is really the Comprehensive Everglades Restoration Plan. That’s a huge capital improvement project plan to create storage and treatment all around Lake Okeechobee.”
As it stands, the Gulf of Mexico will continue to experience freshwater releases from Lake Okeechobee. However, with the SCCF monitoring the problem, and the NPS working on a solution, we could see these releases decrease, returning Sanibel’s ecosystem back to a pristine state.