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SCCF Documents Decrease in Salinity Due to Lake O Discharges

March 19, 2024
chiquita lock

Researchers from SCCF’s Marine Laboratory collected samples surrounding the Chiquita Lock on Feb. 28 as part of an ongoing monthly survey monitoring the quality of the water coming from Cape Coral’s canal system.

The sampling was done 11 days after the U.S. Army Corps of Engineers started making damaging releases to the Caloosahatchee River from Lake Okeechobee.

“We noticed there was already an effect on the lower estuary where the Chiquita Lock is located,” said Research Associate Leah Reidenbach. “The salinity was significantly lower than it had been during the previous four months of sampling which is unusual during the dry season.”

Researchers also observed that the salinity in the river was lower than in the canals.

“Usually, the canals are a freshwater source to the lower estuary, as the water mainly comes from runoff whereas the Caloosahatchee estuary experiences tidal inflows of saltwater,” said Reidenbach.

SCCF has been monitoring the damaging releases from Lake Okeechobee, which began on Feb. 17.

“In addition to impacting seagrass growth and oyster spawning, the release of nutrient-rich freshwater fuels potential harmful algal blooms,” she added.

When researchers from the Marine Laboratory sampled the lower estuary on Feb. 28, it showed that the releases from the Lake are dramatically changing the salinity regime of the lower river and the Caloosahatchee Estuary.

Aside from collecting water samples, the Marine Lab also does remote monitoring with real-time data from its RECON (River, Estuary, and Coastal Observing Network).

RECON data helps the lab understand the magnitude and severity of lake-lowering discharge events. Parameters like salinity are used to evaluate stress to species like seagrass and oysters.

“So far, dissolved oxygen levels have been normal and not dipping to lethal values for living creatures,” said Reidenbach.

RECON also provides data on the amount of microscopic algae in the system throughout the freshwater and estuary system from Moorehaven to the Gulf of Mexico. 

Researchers are also continuing monthly sampling of the Caloosahatchee and its tributaries to document and study harmful algal blooms (HABs). SCCF is working in partnership with the Center for Coastal Solutions at the University of Florida (Phlips Lab) and the Florida Department of Environmental Protection to see if tributaries such as Popash Creek, Orange River, Hancock Creek, and Whiskey Creek are facilitating conditions that are favorable to HABs.

With HABs blooming in the tributaries, excess nutrients from Lake Okeechobee could provide the fuel necessary to intensify the bloom throughout the estuary. 

Stay up to date with the impacts of these releases by subscribing to SCCF’s Weekly Water Conditions Tracker and Caloosahatchee Conditions Reports.

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