Freshwater discharges impacting oyster beds, seagrass

Freshwater discharges impacting oyster beds, seagrass

Freshwater discharges from Lake Okeechobee are playing havoc with the salinity needed for oyster beds and seagrass.

SPECIAL COVERAGE: Protecting Paradise

WPTV spoke with Mark Perry, the longtime executive director of the Florida Oceanographic Society, at the St. Lucie River Estuary just off downtown Stuart.

Perry was checking oyster beds, and WPTV NewsChannel 5 anchor Michael Williams waded along to see him at work.

Perry found live oysters, but also plenty of dead or stunted ones. Too many, he said.

Mark Perry (right) says oyster beds once covered 470 acres of the St. Lucie Estuary. That figure is now only 20 acres.
Mark Perry (right) says oyster beds once covered 470 acres of the St. Lucie Estuary. That figure is now only 20 acres.

"These oysters filter algae. They filter algae out of the water and feed on it. They're the sentinel species of the estuary. It means if they are going down, the estuary is going down," Perry said.

Perry said the oyster beds in the 1940s and 1950s once covered 470 acres of the estuary.

Now, those oyster beds cover about 20 acres, victimized by pollution and freshwater.

The freshwater is not salty enough and the estuary needs a natural balance of saltwater and freshwater for oyster beds and the crab, shrimp and larval fish that depend on them right up the food chain.

"They probably had too much freshwater for too long, especially back in October and November at the end of rainy season," Perry said.

The freshwater keeps coming. A prime source -- as it has been for decades -- is Lake Okeechobee.

Mark Perry shows how part of the oyster is dead due to fresh water discharges.
Mark Perry shows how part of the oyster is dead due to fresh water discharges.

Water, billions of gallons worth when it is released, keep pouring through the St. Lucie River lock system and into an estuary. Nature did not design for such inflows.

Most recently, the Army Corps of Engineers opened the gates in early March, worried about high lake levels.

"We should be putting that water south to the Everglades and Florida Bay, rather than dumping it into the northern estuaries. These estuaries need to be left alone and naturally have their own watersheds, and naturally mix that fresh(water) and saltwater from the ocean together, and create this beautiful nursery ground for oysters, seagrass, fish," Perry said.

That plaintive cry has been made for years, but a planned reservoir south of Lake Okeechobee is years away from being finished.

Meanwhile, the Army Corps of Engineers always juggles competing concerns and interests: coastal, inland, storm season, flood control, agricultural demands for water.

Perry remains hopeful that ongoing discussions might drastically reduce freshwater inflows in the estuary system. Also, environmentalists hope oyster spawning season this spring will yield good news.

"If the water quality drops off and the oysters die off, and the fish go away, nobody would want to come here and live here if the water is polluted," Perry warned.

Nature is in the balance, and it's a sobering reminder about the tipping point that has consequences for all of us.

Scripps Only Content 2021