10 minute read
Restoring Rookery Bay
By Michael Adno
Restoring tidal flow in Florida is much like returning a chicken to an egg, but in some cases, mimicking those flows presents the opportunity to ensure a vital habitat and fishery for centuries.
As fresh water poured down North America 100,000 years back, the coast of southwest Florida flooded as the sea-level rose 100 feet. At the northern edge of the Ten Thousand Islands where the Everglades meet the Gulf, mangroves walked across the coast as currents began to carve paths into the heart of Florida as far as Big Cypress. Some of the first visitors to those byways were tarpon, slipping in and out of Rookery Bay, making their way west and tracing the edge of the continent in a mysterious rhythm that we’re still trying to understand today. This little corner of the world, like much of the state’s coast, was their resting place, the nursery where juvenile fish came of age, where they wintered, and where later they would capture the imagination of anglers everywhere.
Today, that’s still the case. The difference is that the habitat so central to their life cycle has been reduced by more than 50 percent in Florida. It’s the same habitat inextricably tied to the snook fishery that draws so many to this stretch of coast, and whether it’s due to destruction wrought by development, degradation due to a lack of freshwater flows, or erosion, it’s a part of our environment that we can’t afford to lose—not even a single stand of mangroves.
For twenty-five years, that sentiment has driven Bonefish & Tarpon Trust’s work, and this year BTT will work collaboratively with the Florida Department of Environmental Protection (FDEP) to restore tidal flow to two sites in Rookery Bay. With a matching grant of $250,000 from the National Fish and Wildlife Foundation, the project will be shovel ready.
In turn, the reward is to retain a fishery and set of habitats that are intimately tied to the character of the state, rescue critical habitat not just for tarpon or snook but gopher tortoises and the indigo snake, and ultimately provide a blueprint for the rest of the country.
The 110,000 acres that fall within the borders of the Rookery Bay National Estuarine Research Reserve, the provenance of Florida from Timucua to Calusa to colonial settlers, including the Americans who arrived here after the Civil War, tell the story of how the hands of time altered this place. Shell mounds tell the story of a sophisticated society that existed here until colonists pushed them off the continent. Roads seemingly leading nowhere tell the story of early developments that would foreshadow the immense growth of southwest Florida, and it’s the latter that molded this part of the state, because the infrastructure that grew up in Collier County would later cut off the estuary’s historic flow of fresh water from the state’s corridor.
It’s where the flatwoods that march down the west coast fell into the Gulf of Mexico just south of Naples; where a finger of the Everglades drew the Gulf into a nexus of backcountry, and where men and women would look onto mangrove forests and see promise. In 1886, 3712 acres in Naples garnered $11,136 or $3 per acre. Three years later, a hotel followed. By the time Baron Collier arrived, the concept of growth set his mind on fire. In 1923, he promised to finish the vein of asphalt that would connect Miami to Tampa, the Tamiami Trail, and five years later he made good on the promise.
For his faith, the state split Lee County in two, and the bulk of his land became Collier County. In 1969, 35,000 people called this corner of America home. In the past five decades, the population grew to nearly 400,000 or 1000 percent, dwarfing growth in the rest of the state by four times. That exponential push coupled with development, including roads, heavily altered the landscape of Rookery Bay, cutting off freshwater flows from this once vital estuary.
On the eastern edge of Henderson Creek, Shell Island Road cuts across a ridge, serving as a dike, and further east across Collier Boulevard, Marco Shores Island stretches into the mangroves before a former road spur falls off into the woods. These two impediments operate as dams, and breaching these effective dams is the core feature of FDEP and BTT’s project. A series of new culverts will punch through and under the roads enabling water to flow once again into the presently marooned portions of the estuary. Of course, restoring historic flow in much of Florida is like returning an omelet to an egg, but in the best cases, the focus remains on preservation rather than complete restoration.
“It’s really important to us that we are able to restore these systems so that they can provide the highest number of ecological and human benefits that they possibly can,” said Keith Laakkonen, Director of the Rookery Bay Research Reserve. Game fish are of course central to the equation, first forming the draw for anglers who hire guides, rent hotels, and bolster the economies tied to the areas where they fish, but it extends far beyond that, Laakkonen noted, impacting the commercial fisheries as well as the myriad types of recreational tourism tied to these areas. Moreover, the value runs much deeper than its relationship to the economy but more broadly to the cultural resource the fishery provides to residents.
For JoEllen Wilson, BTT’s Juvenile Tarpon Habitat Program Manager, this project serves as a sort of litmus test, both in how it can be applied statewide by BTT and FDEP as well as in damaged juvenile tarpon habitats throughout the Caribbean and Central America. “We want to provide proof that this is an effective means of restoring the hydrologic connection to these mangrove swamps and salt marshes that have been cut off from their natural tidal flow,” Wilson said. “With minimal alterations, we can provide so much more habitat for fisheries.”
Along the Gulf Coast, especially in Charlotte Harbor, there’s a semblance of hope that the same sort of management could be applied throughout the Burnt Store Corridor along the eastern rim of the upper harbor, but it holds true all throughout Florida. With mangrove habitat, which are tarpon and snook nurseries, Wilson pointed to the loss of more than 50 percent of that lifeblood throughout the state, noting how that ultimately will have a legacy effect on the fisheries so many hold dear. Recreational anglers are most familiar with mature tarpon when they reach 20 to 30 years old, and as Wilson said, “They don’t realize the development in hydrological changes that Florida has undergone in the past 20 or 30 years.”
The enormous, and at times volatile, shift in water management is something that’s hard to even articulate let alone form a record of, but as mangroves degrade, estuaries disintegrate, and water flows are altered, Wilson said, “You’re impacting the fishery that your kids are going to have.” In the short term, it’s red tides and fish kills that turn heads, but over the course of decades, it’s the loss of habitats like those strewn throughout Rookery Bay that will irrevocably impact tarpon and snook fisheries in South Florida.
In two similar mangrove habitats, it’s often hard to visibly see the indicators of a degraded or poorly functioning habitat as compared to a healthy one, Wilson said, noting that, “You won’t know that until you start studying the fish.” In regions where there’s an abundance of freshwater flow and a flush of new growth, tarpon grow much faster than those in stagnant mangrove zones. The difference can be as much as seven inches per year, with healthy nurseries garnering growth rates between eight and ten inches and sickly ones only leading to one inch annually.
From 10,000 feet up, the FDEP looks to aerial photography, satellite imagery, and a whole host of factors to determine whether a stand of mangroves might be on a poor trajectory. “We’re not seeing a cohort of young trees growing up. We’re not seeing flushing,” Laakkonen explained of the troubling signs before adding, “Unfortunately, that’s an indicator that may not show itself until those mangrove forests hit a tipping point.” To call mangroves resilient might be an understatement, so in many cases, the stands of old growth will hang in there until their health is dire, and then rapidly, they’ll decompensate just as cruelly as the human body might. “It’s a phenomenon that folks have called a mangrove heart attack,” Laakkonen said. “We think it’s part of our mission as stewards of these to work with partner organizations such as BTT to do a preemptive restoration.”
And for both the FDEP and BTT, there are case studies to draw from, namely Fruit Farm Creek and Coral Creek, where both agencies have studied the resilience of habitats as well as how flows, depths, and access affect the juvenile fish that come of age there. For most anglers, laid up snook, rolling tarpon, and verdant mangroves intuitively signal a vital pocket, but as Wilson said, it’s truly about how quickly those fish grow and what size they reach when they leave the system that reveals a productive habitat. Here in Rookery Bay, the return of freshwater flows to parts of the estuary will in turn show just how effective this application of science to management can be on a larger scale. “It’s very easy to show proof of concept here,” Wilson said before putting it plainly. “Any time that we increase the amount of tarpon nursery habitat, we’re enhancing the fishery.”
The nursery nestled in Rookery Bay is an especially ripe case considering that it lies less than 60 miles from the tarpon fishing capital of Boca Grande, from Sanibel where tarpon angling began 140 years ago, and from the serpentine rivers where tarpon winter in the western Everglades. Back in 2016, an adult tarpon tagged by BTT in Charlotte Harbor headed south once summer ran out, charting a course through the Everglades, as others have for centuries, before appearing off the coast of Cape Canaveral. After reaching South Carolina, that fish returned south, finding its way to wintering grounds in the rivers north of Whitewater Bay. The following year, it took the same path, slipping past Rookery Bay and returning to South Carolina. This project, like others, not only restores the habitat but our hope that this mysterious migration will continue for centuries if not millennia.
Michael Adno writes for The New York Times, National Geographic, and The Bitter Southerner, where he won a James Beard Award for profile writing in 2019. He lives in his hometown, Sarasota, Florida, along the Gulf of Mexico.
