AMERICA'S SUBTROPICAL WONDERLAND
Florida Bay and the Coastal Prairie
When you reach Flamingo, a former fishing village and
now a center for visitor services and accommodations, you will be on the
shore of Florida Bay. Here is an environment rich in variety of animal
life, where porpoises play, the American crocodile makes its last stand,
and the great white heron, once feared doomed to extinction, holds its
own. The abundance of game fish in the bay has given it a reputation as
one of the best sport-fishing grounds on the east coast.
The bay's approximately 100 keys (low-lying islets)
were built up by mangroves and provide foothold for other plants hardy
enough to withstand the salty environment and the sometimes violent
winds. The keys are also a breeding ground for water birds, ospreys, and
bald eagles.
Florida Bay, larger than some of our States, is so
shallow that at low tide much of it is out of water. (Its greatest depth
is about 9 feet.) The shallows and mudflats attract great numbers of
wading birds, which feed upon the abundant life sheltered in the
seaweedsin a plant-and-animal community nourished by nutrients
carried in the waters flowing from the glades and mangroves.
To the west beyond Flamingo is Cape Sable. This
near-island includes the finest of the park's beaches (Shell Beach) and
much of the coastal prairie ecosystem. A fringe of coconut palms along
the beach could be the remnants of early attempts at a plantation on the
cape that did not survive the hurricanes; or it could be the result of
the sprouting of coconuts carried by currents from Caribbean plantations
and washed up on the cape. For a time, casuarina trees (called
"Australian pines"), which became established on Cape Sable after
Hurricane Donna, seemed to threaten the ecology of the beach. But these
invaders were mostly removed in 1971, and now appear to be under
control.
FLORIDAY BAY AND THE COASTAL PRAIRIE. (elevation:
sea level to 2 feet above sea level) 1) Red mangrove; 2) Black-mangrove;
3) White-mangrove; 4) Buttonwood; 5) Cabbage palmetto; 6) Hurrican-killed black-mangroves;
7) Fig; 8) Poisonwood. (click on image for an enlargement in a new window)
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Examine the "sand" of this beach. You will discover
that it is not quartz grainsbut mostly minute shell fragments.
Entire shells of the warm-water molluscs that live offshore also wash up
on the beach. There are also artifacts that speak of Indian activity in
this area in past centuries, curled centers of conch shells from which
the pre-Columbian Indians fashioned tools, and numerous pieces of
pottery (potsherds). Both shells and potsherds tempt the collector.
Shellingthat is, the collecting of dead shells, for non-commercial
purposesis permitted. But Federal law prohibits the removal of
even a fragment of potteryfor these are invaluable Indian relics,
essential to continuing scientific investigation of the human history of
the region.
Back from the narrow beach is a drier zone of grasses
and other low-growing vegetation. Some of the plants of this zone, such
as the railroad vine, are so salt-tolerant that in places they grow
almost to the water's edge. (No plant that is extremely sensitive to
salty soil could survive on Cape Sable.) Beyond the grassy zone is a
zone of hardwoods (buttonwood, gumbo-limbo, Jamaica dogwood), cactuses,
yucca, and other plants forming a transition from beach to coastal
prairie.
Birds provide much of the visual excitement of the
beach community, just as they do in other parts of the park. Sandpipers,
pelicans, gulls, egrets, ospreys, and bald eagles use it and the
bordering waters for feeding, nesting, and resting. Mammals, notably
raccoons, stalk the beach in search of food. And the big loggerhead
turtle depends on it for nesting. In late spring and early summer the
female loggerhead hauls herself up on the beach and digs a hole above
hightide mark. There she deposits about 100 ping-pong ballswhich
should hatch out into baby loggerheads. Unfortunately for this marine
reptile, however, most of them meet another fate. Hardly has the female
turtle covered the eggs with sand and started back toward the water,
than they are dug up and devoured by raccoons and other predators. These
conditions created such high mortality of the turtles that the National
Park Service has adopted special protective measuresremoving some
of the raccoons and erecting wire barriers around turtle nests. These
measures have been effective, but continued surveillance is required if
the loggerhead is not to disappear from Florida (as have several other
species of sea turtles that formerly thrived here but have fallen victim
to man's greed and carelessness).
THE FLAMINGO AREA. (click on image for an enlargement in a new window)
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An abundance of raccoons and other predators is not
the only threat to survival of the loggerhead turtle. A major factor in
its decline is the serious depletion of its nesting habitat. Park
visitors are, of course, prohibited from interfering in any way with
these dwindling reptiles.
Cape Sable beach is today virtually the only wild
beach in South Florida (thanks to its inclusion in Everglades National
Park). At present, visitors can reach it only by boat. But it would be
foolhardy to take it for granted that the beach will remain unspoiled.
Its potential as an attraction is such that someone not ecologically
aware might believe that access for motorists would be an improvement.
Roads, however, would bring increased pressure on the ecosystem by large
numbers of visitors, and demands for further developmentfor
lodging, meals, and other services seem always to go with automobiles.
With continued protection from such encroachments, Cape Sable Beach will
remain a unique wilderness resource, and will not become just another
recreational facility.
Merging with the beach is the coastal prairie, an
ecosystem supporting red and black mangroves, grasses, and other plants
tolerant of the very salty environment. Hardwood hammocks have developed
here on Indian shell mounds, but the trees are stunted by the saline
soils. Though there is no lack of water on the cape, much of the region
appears arid because the hurricane-lashed tides have deposited soils of
marl and debris so salt-laden that only sparse vegetation develops.
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