An American Original
The Okefenokee Swamp's reputation as a forbidding place hasn't deterred stalwart scientists from probing the secrets of this national treasure
Being desk-bound might seem like purgatory for a freshly minted wetlands ecologist. But Cyndy Loftin admits that after five years of field work in one of the wildest and soggiest landscapes in the lower 48 states--southeastern Georgia's Okefenokee Swamp--she was "ready to get back on dry land" and face the chore of writing her Ph.D. dissertation and articles about her research for various scientific journals.
An American original, the Okefenokee is one of the world's great primitive wilderness areas and wildlife preserves. For decades, people have used words like "dark" and "forbidding" to describe it--and not without justification. Perhaps that's why a lot of secrets about the swamp's ecology remain hidden. Told that one of her colleagues had called the swamp an "inhospitable and dangerous" place to work, Loftin, a research associate with the Florida Cooperative Fish And Wildlife Research Unit, laughs and says, "It depends on how badly you want to do a study."
Was Loftin worried about getting lost in a virtually trackless world of prairies, lakes, cypress stands and piney islands where alligators stare back at every glance? "I carried a compass and knew that I could go north, south, east or west and eventually hit a canoe trail," she says. But Loftin also vividly remembers the time when a helicopter pilot forgot where he had dropped her off. "I knew where I was," she recalls, "and I had a radio, so I could hear the helicopter crew arguing about where to go." From the air, the pieces of the Okefenokee mosaic have few hard edges.
"You know," Loftin reflects with a touch of wistfulness, "I really miss the place." The Okefenokee Swamp, it seems, can get under your skin in more ways than one.
There may be larger wetlands in North America and the world, but none are quite like the Okefenokee. An immense bog covering 770 square miles of the Atlantic coastal plain, the swamp sits 75 miles inland from the present Georgia shore. However, prevailing wisdom asserts that the saucer-shaped depression, which is tilted from the northwest to the southwest, was a salty lagoon behind a 40-mile-long sandbar until the ocean receded 250,000 years ago.
Today, the Okefenokee lies about 100 feet above sea level and the ancient sandbar on its eastern rim is now known as Trail Ridge. The ridge is a natural dam that confines rainfall--the source of 70 percent of the swamp's water--to the basin. There the water moves ever so slowly to the headwaters of both the Suwannee River, which drains into the Gulf of Mexico, and the St. Mary's River, which empties into the Atlantic. Trail Ridge also is a rich source of titanium minerals, deposited by ocean waves and winds. Those minerals were the reason for a proposed, controversial mining operation that became the latest threat to the swamp's integrity.
Peat deposits as thick as 15 feet cover the Okefenokee's sand bottom, and methane gas produced by the decay of sunken vegetation periodically propels large chunks of this compressed organic matter to the surface of open water areas. Most of these peat mats, some as long as 100 feet, will sink back to the bottom. However, a few of these "floating islands" rapidly undergo succession to shrubby greenbrier tangles and then to swamp forests populated with bald cypress, loblolly bay and black gum trees.
But walking on one of these peat rafts, where you might sink to your waist without warning, is an unsettling experience. This accounts for an Indian word for the place ("Ekanfinada" on a map from 1790) that means "trembling earth." European families that settled on the upland islands and lived off the swamp in the mid-1800s pronounced it "Oak-fin-oak" rather than the more euphonious "Oaky-fen-oaky" one usually hears today.
The swampers, as these pioneers were known, also left their names on such places as Mixon's Hammock, Minnie's Lake, Craven's Island and Chesser Prairie. Note, though, that the Okefenokee's so-called prairies are covered with a foot or more of warm tannic tea and aquatic vegetation such as water lilies and bladderworts rather than windblown fields of bluestem grass and purple coneflowers. A high-and-dry Dakotan would call them marshes. They cover about 8 percent of the swamp, most of which lies within the boundaries of the largest national wildlife refuge east of the Mississippi River. In turn, most of Okefenokee Refuge, created in 1937 by President Franklin D. Roosevelt, is designated as a wilderness area.
No surprise: Animal and plant life abound in the Okefenokee. By latest count, the swamp hosts 234 species of birds, 49 mammals, 64 reptiles, 37 amphibians, 39 fishes and at least 621 plants. The number of insect species is any entomologist's guess, but clearly it is huge. "The Okefenokee is reputed to be a place of mystery and terror," observed nature writer Franklin Russell, "yet it is a world of millions of singing creatures and a garden of spectacular flower displays."
The swamp's loudest voice is the basso profundo of the American alligator. According to tales told over jars of moonshine, gators once were so abundant that people supposedly could walk across the swamp, 25 miles east to west, 38 miles north to south, by stepping on the great reptiles' armored backs. "No true Okefenokee man would have traveled anywhere in the swamp without carrying his gun and a pole shod with iron that he could use to beat back attacks on his boat by alligators seeking to seize his dogs," Russell related.
By the early 1970s, when Russell's classic book on the swamp was published, alligator populations throughout the Okefenokee and across the southeastern United States had been decimated by hide hunters to make fashionable handbags and shoes. Howard Hunt, curator of herpetology at Zoo Atlanta, remembers that when he first visited the swamp in 1965, he saw piles of bleached gator bones along the only road into the interior. A federal-government clampdown put the poachers out of business, and today the refuge has a healthy number of alligators--as many as 12,000--though presumably a lot fewer than in historic times.
The swamp's other formidable creature is the black bear, and Hunt's research, which includes the use of surveillance cameras, revealed that Ursus americanus is the primary predator of Okefenokee alligator nests. A female alligator typically deposits around 30 eggs in the middle of a four-foot-high mound of vegetation, which she scrapes together with her feet while backing in a circle around the nest site. But her work often goes for naught.
Hunt monitored 129 nestsover a 13-year period and found that 69 percent of them were lost to all predators during the six-week crucial incubation period. In one of his study areas, the figure was 93 percent, the highest ever reported. In contrast, the predation rate on alligator nests in one Florida Everglades survey was only about 7 percent.
"The Okefenokee is one of the few places where you get lots of bears and alligators in the same place," says Hunt. He suggests that while nest-guarding female gators will rout marauding raccoons or otters and sometimes bluster at human intruders without attacking, they're "reluctant to do all-out battle with a bigger predator. Otherwise we would find alligators ripped to shreds or bears with serious injuries."
When the intrepid scientist donned a black bear costume and approached one alligator nest on all fours, the female lurking nearby submerged and swam away for a considerable distance. "They do what's the least hazardous to their health," Hunt adds. "They can always make another nest." Cyndy Loftin has never prowled the prairies in a rented fur suit. Among other things, she was always busy monitoring two dozen water-level recorders. However, her study of the swamp's hydrology, vegetation and related refuge-management issues was not as ho-hum as it might sound. In fact, her findings will lead to the correction of a serious mistake that was once ordained by the U.S. Congress.
The Okefenokee is one of the best-preserved wetlands in America, but humans have left more than footprints. In the 1890s, a scheme to drain, log and then farm the swamp was aborted when the money ran out after steam shovels had dug 12 miles of the Suwannee Canal. In 1909, loggers built a railroad trestle deep into the swamp and took out 430 million board feet of cypress before the easily accessible timber ran out.
And after wildfires in 1954-55 burned 80 percent of the refuge along with thousands of acres of the high-value pine plantations that surround it, Congress attempted to solve future fire problems by ordering construction of an earthen levee--the Suwannee River Sill--"to prevent drainage of the Okefenokee Swamp during periods of drought." At the time no one understood that only 20 percent of the water leaves as stream flow and 80 percent as plant evapotranspiration. Indeed, most of the area has no perceptible water movement like the sheet flow of the Everglades to the south.
Loftin found that in dry periods, the sill floods only 4,000 acres, or less than 1 percent of the swamp. Moreover, she noted, as many fires occurred after construction of the levee as before. After all, the Okefenokee is located in one of the country's highest lightning-strike zones. In high-water times, however, the sill impoundment covers as much as 60,000 acres and has altered plant successional patterns on about half that area, Loftin reports. The U.S. Fish and Wildlife Service now plans to remove water-control structures and breach the levee in order to restore the affected area's original hydrology and vegetation.
But as Loftin emphasizes, wildfire is an essential part of the landscape dynamic. Peat corings show that intense fires occur every few hundred years during extended droughts, playing a major role in reshaping the character of the swamp. For example, many present-day prairie/marsh and open-water areas were created when fire raged through swamp forest and burned deep into the peat. Surface fires like those of the mid-1950s set back plant succession to a lesser degree. Refuge policy calls for extinguishing fires of less than one acre, containing larger ones in the interior and vigorously suppressing all wildfires on the swamp perimeter that threaten private timberlands.
The interruption of the Okefenokee's natural fire regime, Loftin says, will have significant short-term impact on the swamp by allowing more areas to fill in and become forest. But she predicts that a fire intense enough to significantly change the landscape will occur within 50 years. "Weather patterns will change, and when the peat dries out a lightning hit will cause the whole place to burn," she says. "But that doesn't mean all the wet forest, which accounts for almost 60 percent of the swamp, will revert to prairie."
Meantime, conservationists can relax a bit about the DuPont company's controversial plan to expand its titanium mining operations on Trail Ridge. DuPont is the world's largest maker of titanium dioxide, a white pigment used in the paper, plastics and paint industries, and the chemical giant owns or leases 38,000 acres along the ridge. The firm's proposal to open a 30-mile-long, 3-mile-wide surface mine along- side the Okefenokee wilderness area was denounced by Secretary of the Interior Bruce Babbitt, the National Wildlife Federation, the Georgia Wildlife Federation and other conservation groups feared that the 50-year project would adversely affect the swamp's hydrology.
Earlier this year, faced with an onslaught of criticism, DuPont's embattled shareholders signed off on a different scenario: In place of a huge strip mine, a consortium of conservationists would build a world-class research and education facility focusing on the rare and complex Okefenokee ecosystem and on the Native Americans who lived near the swamp or on its islands for at least 5,000 years. The success of the pact depends on finding funds to acquire land and mineral rights from DuPont, local governments and another landowner with a financial stake in the titanium mine.
Without that, the threat of mining could again loom on the horizon. But for the moment, the dark waters of the Okefenokee, which hide many secrets, are no longer rippled with trouble.
Field Editor Les Line wrote about
roseate spoonbills in the April/May issue.
WF Priority: Protecting A Southern Gem
The Okefenokee Swamp is the heart of the Greater Okefenokee Ecosystem, a 10-million-acre mosaic of riparian wetlands, estuaries and uplands straddling the Georgia-Florida state line.
Because of the region's importance to wildlife, NWF and its affiliates, the Georgia Wildlife Federation and the Florida Wildlife Federation, are seeking to protect part of the ecosystem by creating the North Florida Wildlife Corridor. The goal: to secure one million acres of wilderness, connecting the Okefenokee with Florida's Osceola National Forest. "The wildlife corridor will benefit from environmentally compatible economic development in the surrounding ecosystem," says NWF biologist Andrew Schock.
For more information, write: NWF Southeastern Natural Resource Center, 1330 West Peachtree Street, Atlanta, Georgia 30309.