A guide for planners and managers - IUCN

PART III
Case Histories of Marine Protected Areas
2. Boca Grande Key: Management
of a Wilderness Island
Boca Grande Key is an isolated 90-ha island in the Key West National Wildlife Refuge
in Florida, USA. It is a federally designated wilderness area in the Florida Keys,
situated some 14 miles west of Key West, a heavily populated international tourist
mecca. Boca Grande Key harbors rare and endangered wildlife, including 3 nesting
sea turtle species (Wilmers, 1994), and contains an important sand dunes tract (Kruer,
1992). Visitation to Boca Grande Key increased concurrently with burgeoning
population growth in the Florida Keys, and the advent of large commercial tours from
Key West.
Boca Grande Key’s 1.2-km beach is narrow and bordered by extensive shallow
seagrass flats. Public use is concentrated along 215m of the beach where a deep-water
channel facilitates boater access to the beach and adjacent low-lying dune. In northern
part of the beach, native vegetation has been damaged or destroyed by illegal campers
and /or careless visitors, resulting in increased erosion and/or invasion of exotic
grasses. This beach section has essentially no accretion (T.Kana, pers, comm.). Plant
roots are exposed on scattered scarps of up to 1.5m high, with the dune highly
unstable in such areas.
Because of the island’s rare wildlife, significant plant communities, and increasing
public use problems (crowding, loss of biodiversity), the southern half of the beach
was closed to public entry in 1993. The north part remained open to provide boat
access.
Dune erosion has impacted nesting sea turtles. Only two endangered green turtles
(Chelonia mydas) nest on Boca Grande Key (Wilmers, 1994), and both nest only
there. They dig deep body pits and clutch cavities, with most nests dug on the dune,
not the beach. But the narrow dunes have eroded so much that some nests are laid
beyond the dune crest, in salt marsh habitant where they are flooded at spring high
tides.
Attempts to post regulatory signs had been futile because of vandalism. In
1991, a vandal deterrent signage system was implemented. Thick-wall steel signposts
were placed in one-m 2 holes into which 300 pounds of concrete was poured. Steel
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