AQUATIC CAVES AND CAVERNS

MAIN INDEX | Cave formation | Cave life | Cave diving | Cave scenics

Part of our watery limestone labyrinth

MORE FRESHWATER CAVERNS AND CAVES are found in Florida than anywhere else in the world. Beneath our feet, a complex network of underground channels and basins penetrates thousands of feet into the subsurface aquifer and conducts groundwater throughout the water-bearing limestone bedrock. Each day, these conduits transport more than eight billion gallons of fresh water to the surface at more than 600 natural springs throughout the state.

CAVE FORMATION
Springs are merely the surface portals to a limestone labyrinth that lies beneath. Over thousands of years, erosion from moving groundwater along joints and fractures in the bedrock has created a subsurface system of interconnected caverns and caves. The cave system conducts groundwater downward along a hydraulic gradient, when it intersects the surface, a spring forms.

Inside the spring, the walls of the maze-like cave system are sculpted into an unlimited variety of contoured geologic formations. The size and shape of the caves vary from vertical or horizontal cracks in the limestone, to immense chambers hundreds of feet in diameter. Within the limestone walls, ancient strata display a fossil record of millions of years of skeletal remains of sea creatures such as seabiscuits, crabs and whales. Thus, cave walls reveal Florida's ancient history beneath the sea.

Along the cave floor, confining beds of sand, clay, and silt are layered into a multicolored parfait of siliciclastic sediment. These deposits create an impermeable layer. Yet, water flow sculpts and molds the clay beds into an assortment of formations, from miniature dunes to enormous hills. Undisturbed, the clay banks appear as piles of fluffy powder until miniature cave creatures carve trails into the seemingly lifeless bottom.

Troglobites are true cave-dwellers that cannot survive on the surface. Twenty-six of the 27 aquatic troglobites in Florida are arthropods. Arthropods are characterized by segmented bodies, jointed legs and exoskeletons made of chitin (ki-tn). Aquatic troglobite arthropods in Florida include decapods, amphipods and isopods - they are types of, mainly scavenger, crustaceans. The ten-legged decapods include the albino crayfish. Nestled deep within the dark underwater cave system, these aquatic cave creatures generally lack eyes and have little to no pigment. They sense their enemies and hunt prey by detecting odors, chemical changes, and movement. Due to the lack of sunlight, photosynthesis cannot take place within the cave system. As a result, nutrient material must come in through visiting animals, percolate through the limestone ceiling, or siphon in through sinkhole recharge. Troglobites have adapted to the limited food supply and are extremely energy efficient. Still, environmental stressors can be detrimental to troglobitic species.

Troglobites rely on consistent water temperature and quality for survival. Slight changes in the environment, such as contaminants or decreased water flow, can decimate an entire population. Today, over one quarter of all known aquatic troglobite species in Florida are "threatened" or of "special concern."

Blind albino cave crayfish, Procambarus spp., represent over half of Florida's aquatic troglobites. They have been spotted by cavedivers more than 4,000 feet within the caves. Measuring approximately four inches long, they are the largest aquatic troglobites in Florida. Cave crayfish generally crawl on the cave floor, although they can be found climbing up the walls and across the cave ceiling. The crayfish feed by scavenging and preying on other troglobites.

One common genus of cave amphipods, Crangonyx spp., have laterally compressed bodies measuring about 3/16-7/16 inch long. They swim or crawl on the bottom, residing in cracks or under debris. Amphipods scavenge organic matter along the bottom, but will also enter the water column to feed on suspended particles.

Isopods such as those of the genus Remasellus, are one of the largest orders of crustaceans. The flattened creatures are 3/16-7/16 inches long and crawl on ceilings and floors. Like other troglobites, cave isopods lack pigmentation and eyes. Similar to amphipods, they scavenge along the bottom feeding on plant and animal remains.

Other aquatic troglobites in Florida include the Georgia blind salamander, one species of blind cave snail and one species of cave shrimp.

Troglophiles reside both in and out of caves. Bull catfish that feed on rotting leaves, insects, and crayfish have been spotted hundreds of feet within cave systems. The American eel frequents cave openings. Its diet primarily consists of larval insects. The red eye, or spring chub, is a two-inch fish that eats insects, crustaceans and smaller fishes.

Trogloxenes visit the cave system, but must return to the surface to breed or feed. They include salamanders, minnows, sunfish, some crayfish, and cavedivers.

Cave diving requires training

CAVEDIVING
Until recently, little was known about Florida's dark and mysterious aquatic caves. Now, through the collaborative efforts of cavedivers and scientists, Florida's caves have become a new frontier in exploration. Advanced cavediving teams and individuals are continuously exploring and mapping the maze-like systems. On a single dive, the world record holding Woodville Karst Plains Project cavediving team ventured 300 below the surface and surveyed nearly 20 thousand feet within North Florida's Wakulla Spring. A team of explorers recently connected the Old Bellamy cave system to Sweetwater Lake, providing significant data about the Santa Fe River and groundwater patterns. Exploration and research conducted by teams and individuals have provided invaluable information about Florida's subterranean geology, groundwater quality, cave biology, and drainage patterns.

Cavediving is a highly dangerous sport that requires a tremendous amount of specialized skill and training. Advanced teams draw on the experiences of early cavediving pioneers such as Sheck Exley, Woody Jasper, Mary Ellen Eckhoff, and numerous scubadivers who have lost their lives while diving in Florida's aquatic caves.