The Flow Beneath Us

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The following article appeared in the March, 2019 issue of Florida Sportsman.

Comments by OSFR historian Jim Tatum.
-A river is like a life: once taken, it cannot be brought back-

March 1st, 2019 The Flow Beneath Us

David Conway

From the March 2019 print issue, on newsstands now. Click here to subscribe.

A checkup on the pumping heart of all Florida waters.

When we talk about the health of Florida’s springs, we’re talking about a lot more than a chance for a great day swimming and diving in a clear, freshwater pool. We’re actually talking about the health of all Florida waters (including our drinking water) and the quality of fishing in our estuaries and along our coasts. As Lisa Rinaman, St. Johns Riverkeeper says, all Florida waters are connected. The springs are their pumping heart.

Though a lot of people—15 to 20 million a year in fact—visit Florida springs, generating as much as 1 billion dollars in direct annual revenue—it’s much harder to see the connection between springs and the rich river and coastal fishing that we have unless you speak with the scientists who study these ecosystems and the anglers who live on them.

First, a few facts for people like me who don’t know as much about Florida’s amazing network of springs as they might like. Bob Knight, founder and director of the Howard T. Odum Florida Springs Institute in High Springs filled me in:

Florida’s got the largest number of springs of any region in the world and they’re artesian springs. These are powered by the pressure of the underground aquifer, called the Floridan aquifer, which stretches 100,000 square miles wide across all Florida, portions of Georgia and other Southeastern states. It’s formed of ancient limestone beneath the ocean, a giant water storage tank of fresh water, riddled with caves, some with openings up to the surface, which creates a spring. In the Southeastern U.S., about 12 to 15 billion gallons of rainwater a day recharges these springs, which so many species, and many of our rivers depend upon for their life.


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Divers marvel at the striped bass and hybrids at Silver Glen Springs.

The state’s three largest rivers by size, the Apalachicola, St. Johns and Suwannee all receive a large fraction of their flows and all their base flow in the dry season from springs. As these rivers go, so do our coastal fisheries.

Dr. Bob Knight is an environmental scientist/systems ecologist with four decades of experience as an aquatic and wetland ecologist in Florida. His doctoral work included an ecological assessment of Silver Springs and Silver River, and in 2010, he founded the Howard T. Odum Florida Springs Institute for research, education and advocacy on Florida’s springs.

“Freshwater flows into coastal systems produce the estuaries, and these are our critical nurseries for a variety of gamefish species, as well as forage fish,” says Knight. “Just as we’ve seen reduction in fresh water in the Apalachicola River has been devastating to the oyster populations, the Lower Suwannee is way more salty and this may affect the scalloping. In fact there are scallop declines in the Steinhatchee area. Some fishermen are telling me that there are areas with no live bottom and they’re seeing fewer scallops. Now saltwater intrusion is also a threat, and some of the springs are putting out saltwater, such as those around Kings Bay. This disrupts water clarity and affects fishing. These are impacts from groundwater pumping, directly. All of our springs are getting saltier, and saltwater intrusion is marching inland all around North Florida due to our increasing consumption of water from the Florida aquifer.”

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Weeki Weeki Wachee Springs has been a popular Florida destination for generations.

What’s happening is, more and more water is being pumped out of our aquifer for new human developments around the state and other states. The groundwater pumping amounts to about 3 billion gallons a day (include other states and it adds up to about 4 billion), says Knight.

“So we’re pumping out about a third of what’s going in, a significant amount, and the aquifer levels are declining,” Knight says. “That’s why we’ll see a decline in spring flow. As the spring flows slow, this allows the saltwater to push in. Some springs have even stopped flowing altogether and reversed flow, so that they’re sucking out river water.

“Combined with increasing nutrient pollution that we’re seeing in our springs, it’s like a one-two punch to our estuaries. We’ll kill our estuaries.”

For example, Knight explains, a third or a half less freshwater is flowing into the Suwannee River estuary. In addition, there’s so much nitrogen in the river, averaging 5,000 tons a year whereas historically it would be about 1,000 tons. “The contamination of these springs by nitrates also means that our aquifer’s drinking water is contaminated, and that’s something that we should all be concerned about. The springs are giving us early warning, and these warnings can’t be ignored,” Knight says.

Additionally, Knight and his teams at the Florida Springs Institute have been quantifying fish populations in the springs for decades. In the ’70s they were down about 50 percent from the ’50s, and in the 2000s they were down about 90 percent.

“There’s over a 50 percent decline at Silver Springs, the biggest spring in the state, and similar populations declines in other springs statewide,” he says.


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Dr. Robert Knight

“What we’re seeing is that the fish are disappearing because the habitat is worsening. Some springs are dominated by algae whereas before they were dominated by grasses. That filamentous algae that’s growing has little or no nutritious value for the invertebrates and if they’re not there, there’s nothing for the other fish to eat, and so they do not go there.”


Each watershed in Florida has its own lifestory, and those in north Florida are profoundly interlinked to the springs and aquifer. The St. Johns has been facing, for many years, too much nutrient pollution runoff, fertilizers in urban and agricultural runoff, sewage from faulty septic systems and overdevelopment, says Lisa Rinaman, the Riverkeeper in the St. Johns Riverkeeper organization.

“Our wetlands are the kidneys of the St. Johns, and as we overdevelop in them, they lose their ability to filter out pollutants going into our river. And as we grow, we get more pollution, and as we cut regulations on pollution, we get even more.



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Recreation is hugely popular at Florida springs. Here, paddlers enjoy Silver Springs in Ocala.

“Additionally, on the northern end, there’s saltwater intrusion due to sea level rise and dredging in that area that creates a direct conduit to let saltwater into our 100-mile long estuary. The grass beds—eelgrass—suffer, and that estuary itself needs the right balance of fresh and salt for habitat for all the species that live there.

“The springs play a role in providing freshwater to hold off that saltwater intrusion and to keep our estuaries brackish, so our river is only as healthy as our springs,” Rinaman says.

Yes, the St. Johns is undergoing some major changes, agrees Florida Sportsman Northeast Field Editor Rick Ryals, a longtime resident of Jacksonville. “Salt water has made the grassy areas that I grew up wading for largemouth bass, now redfish and speckled trout habitat. The biggest problem I see with this is the loss of the massive grassbeds that served as nurseries for some fish, and hunting grounds for others.

“There was a time when riverside community Green Cove Springs was nationally noted for its giant black bass, but it is now a much better area for croakers and redfish,” Ryals says.

Lifetime bass angler Patrick Mullarkey says, “Saltwater intrusion has certainly impacted the grassbeds, and consequently the bass fishing. What the saltwater didn’t kill, the last two hurricanes have.”

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Anhinga also at Silver Springs.

“We are now catching trout and reds under the same docks where we used to catch largemouths.”

In addition to the springs’ deep cultural and historic value to Florida and its people, says Rinaman, “The economies that drive Florida—tourism, agriculture, growth, real estate—all depend on clean water, so we need to have a balanced and comprehensive system for protecting the aquifer.”

I spoke to Rinaman in January, just after she’d attended an Everglades restoration conference in the Florida Keys, and after Gov. DeSantis announced some significant initiatives in the fight for Florida’s waters. Rinaman said that she was feeling optimistic about the number of people who were now at the table in discussions.

“The last couple years have been a disaster with toxic algae outbreaks, and recently our governor has voiced some changes that have us optimistic,” she said. “Though we are concerned that his executive order prioritizes South Florida over North Florida waters. For us to truly make a difference for all Florida we have to have a holistic approach, so we’ll be working with other concerned people and organizations to protect all Florida waters, not only the Everglades, but our springs, rivers and estuaries. It’s that important to our future. I think that the future of Florida— everything that is real to us, and everything that gives us a competitive advantage to our state in tourism—is at stake.”

Bob Knight, of the Florida Springs Institute, echoes her view:

“What’s happening to our springs, the increasing algae, nutrients and the flow changes, are exactly analogous to what’s happening in South Florida rivers and estuaries,” he said. “There’s some hope in the springs community with new leadership in the state of Florida and in the direction of Everglades restoration that the same attention will be paid to North Florida and its springs that are so important in this state.”


St. Johns Riverkeeper (904) 256-7591
The Howard T. Odum Florida Springs Institute (386) 454-9369

First Published Florida Sportsman Magazine March 2019, available on newsstands now

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