Times of the Islands Summer 2016

green pages newsletter of the department of environment & maritime affairs
stalactites, and flowstone, which can only originate
inside caves. The morphology of the cave walls is also
a clue; intricate rock erosion occurs by rock dissolution,
wave energy tends to make smooth walls by brute force.
Juniper Hole, on Middle Caicos, has been described as
the largest sea cave in the TCI, but it is actually a flank
margin cave that has been over-printed by wave action in
the last few thousand years.
The very young eolianites found from Little Water
Cay north to Parrot Cay have numerous small sea caves
formed right at current tide level. These eolianites, as
noted earlier, are very young, too young to contain flank
margin caves from a past interglacial.
Flank margin caves that have opened naturally often
contain colonies of bats. Thick piles of bat excretement,
called guano, cover the floor of many caves. This guano
is a powerful fertilizer, as it contains nitrates and phosphates
needed by plants. Throughout the TCI, these
deposits were mined for both local use, and for export
to neighboring countries, primarily the USA in the late
1800s. The industry collapsed after World War I because
the Haber process, a way to make nitrate fertilizer from
the nitrogen gas in the atmosphere, was commercially
Vandalism has marred Conch Bar Cave (top and bottom left) and Indian Cave (bottom right) in
Middle Caicos.
developed. Bats are critically important in the ecology as
they eat insects, and transfer pollen between plants, both
important to people.
Why are caves important?
Caves contain an unusual collection of animals that have
adapted to life underground. Some of these animals lack
eyes and pigment, unnecessary energy expenditures in
a lightless environment (the human eye has the highest
metabolic rate of any organ in the body). The food chain
is based on the organic material that enters the cave.
Sometimes that food is very fine particulate matter that
flows into the cave with the drip water, other times it is
larger pieces of vegetation that fall down a hole in the
ceiling, but most of the organic energy comes from the
bat guano and the molds, fungi, and invertebrates that
live on that bat waste. While invertebrate cave life is abundant
in the TCI, the only vertebrates are cave fish and
bats.
Throughout the history of humans, caves have been
sites for living and for conducting ceremony. Cave paintings
from the Pyrenees of Europe have been dated to
30,000 years ago. Archeological materials indicate that
the Lucayan-Taino culture first
emerged in the TCI after AD
700. Some caves were used as
shelters, burial sites or ceremonial
spaces by native Lucayans
well before Columbus reached
the Islands. Even today, caves
are used as hurricane shelters,
and in the case of Conch Bar
Cave, as a tourist destination.
The caves are also very
important sites for instruction
about how the natural environment
works, and how geological
and biological processes function
in concert to create an
important ecosystem. Conch
Bar Cave is one example of how
carefully selected cave sites can
serve as ecotourism destinations
with a delicate balance of
access and resource preservation.
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