Seagrass die off due to hyper salinity

Seagrass die off due to hyper salinity - A close up of a map - Florida Bay

Officials say conservation projects need to move faster

By Gabriel Sanchez

It started last summer during the drought and was only exacerbated by the continued blockage of freshwater flowing southward through the Everglades. A large section of seagrass (between 30,000 and 50,0000 acres affected) has died off in the Florida Bay, and things could be getting worse. “The expansion of algae overgrowth needs to be stopped,” says Steve Davis, staff ecologist with the Everglades Foundation.

On a recent tour of Florida Bay, and its affected basins, the Weekly observed firsthand the effects of the recent algae bloom prior to a public meeting on June 21 on the issue. Members of The U.S. Army Corps of Engineers, South Florida Water Management District, the Florida House of Representatives, the Everglades Foundation, local officials, and Florida Bay Forever (a Monroe County based conservation group) were present to learn and discuss solutions.

The hypersalinity in the Florida Bay is a result of fresh water not being able to flow south through the Everglades. But the problem actually originates further north: dating back to the 1940s, a system of levees, dykes, and waterways have been constructed to redirect the overflowing waters of Lake Okeechobee’s south end for agricultural and construction projects. The draining of the Everglades started then and has continued, the only change being Floridians’ regained appreciation for our unique ecosystem.

Florida Bay is irrigated naturally by fresh water through two primary locations: Taylor slough and Shark River slough. Shark River slough has more volume, and dischargers into the western basin. The eastern basin, home to various mangrove regions, has seen a third of its usual freshwater flow, resulting in stagnant and salty water. “The die off originally began north of Whipray basin, but in the last two months has extended south,” says Xavier Figueredo, local captain and co-founder of Florida Bay Forever.

The result has been what experts are calling a “near catastrophic” seagrass die off, with the Rankin basin being the epicenter. Since the passing of the Comprehensive Everglades Restoration Plan of 2000, which allocated more than $8 billion to project restoring the Everglades, less than a third of the 68 scheduled projects have been completed, according to Florida Bay Forever.

“Right now there’s is a lot of attention, effort, and energy surrounding water storage, flow, and Lake Okeechobee. From my perspective, continuing the bridging of Tamiami trail (U.S. 41) is important and finishing the projects we’ve started,” said state Rep. Holly Raschein. “In the words of Adam Putnam, we need to have more ribbon cuttings and less ground breakings.”

The Army Corps of Engineers have finished construction on one of five bridges on the Tamiami trail designed to increase the flow of freshwater, and say the second bridge will be completed in three years. “The passing of the Florida Legacy Act during the last session was a step in the right direction,” said Raschein. “Over the next 10 years it devotes a minimum of $200 million just for Everglades restoration. It has goals in water management and land acquisitions, all of which work towards the number one goal −being restoration.”

There are things we can be doing right now to help the problem, however, says Bill Horn, former assistant secretary of the federal Fish and Wildlife (Department of Interior), and board member of Bonefish and Tarpon Trust. He said if the government is willing to relax the phosphorus standards, water flow from Lake Okeechobee could increase, thus helping salinity levels in the Everglades and also the Keys backcountry.

“One thing we can do short term is build more STAs (Stormwater Treatments Areas). They take water, store it, and work like sponges and get rid of the high levels of phosphorus. Water in Lake Okeechobee is loaded with phosphorus, causing the levels to be roughly 100 parts per billion. To be able to move that water south, it needs to be brought down to 10 parts per billion. With that being said, if the State and Federal government agreed to lower the standard, knowing it might have some adverse effects on Conservation area 1, I believe they could get some water down there to avoid the looming catastrophe.”


The hypersalinity problem in Rankin Basin is critical. How bad is it? Steve Davis, wetland ecologist, recently tested the water and discovered the levels were at 83 parts part thousand. To compare, he said, “So going back to the ’40s we don’t have records of salinity above 70 to 80 parts per thousands. So, in that regard, it’s a record. But then when we look at the paleo-record and try to piece together what salinity was like in the natural pre-drainage Florida Bay, it was nowhere near that level of hyper-salinity.”

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