Coral Reefs
Coral reefs are arguably the world’s most beautiful habitats. Coral reefs
have
been called the rainforests of the oceans, because of the rich diversity
of life
they support. Scientists have not yet finished counting the thousands
of
different species of plants and animals that use or live in the coral
reef.
There are three types of coral reefs: fringing reefs, barrier
reefs, and atolls.
Fringing reefs are located close to shore, separated
from land by only shallow
water. Barrier reefs lie farther offshore,
separated from land by lagoons more
than ten meters deep. Atolls, on the
other hand, are formed far offshore and
they make a ring-shaped reef that
close a circular lagoon. Coral reefs are the
largest biological structures on
the planet, with the largest being the Great
Barrier Reef covering over
2000 kilometers along the east coast of Australia
(Focus, 1995). The reef is
said to be 500,000 to 2,500,000 years old and is said
to be visible from the
moon.(Scientif! ic, 1987). There is only one problem with
this beautiful
structure and that is the carelessness of man. Silt from
deforested lands and
pollution from crowded coastlines choke them, and overuse
by coal miners,
fisheries, and even tourists deplete and destroy coral reefs.
There are
many more factors which add to the destruction of the coral reefs,
which if
not stopped it will destroy all coral reefs. Corals are animals, not
plants,
sunlight is the key to their survival. They need it to power the
millions of
microscopic algae, called zooxanthellae, that live in their tissues.
The
algae provides the corals with food and oxygen in return for raw
materials
and a secure place to live. This teamwork is what allows the reef
to survive in
nutrient-poor tropical seas. This relationship is sensitive to
such changes in
the environment as cloudy waters or extreme temperatures. The
stress on the
corals can cause them to expel their algae, a phenomenon known
as
bleaching(Futurists, 1993). With the algae gone, the coral skeleton is
visible
and eventually it dies. Died corals lead further on to the death of
the reef.
There are four environmental factors that effect their growth:
temperature,
salinity, water depth, and wave action. These factors exposes
the reef to
changes in the environment very easily especially since it is
located so close
to shore. This also makes it hard for all of the species
which use the coral
reef to survive. Coral reefs are home to perhaps
one-fourth of all marine
species. This in turns effects the entire ecosystem
of the ocean. Pollution by
humans have directly or indirectly caused the
death of 5%-10% of the world’s
living reefs, according to marine biologist
Clive Wilkinson of the Australian
Institute of Marine Science. This
estimate didn’t take in global warming and
ozone depletion as a factor. The
pollution is caused by fisheries, oil spills,
deforestation, tourists, and
even reckless divers. The problems which are
getting even bigger is the
problem of deforestation and reckless divers. In the
watershed of Bacuit Bay
in the Philippines, deforestation inc! reased erosion
into the bay by more
that 200 times.(Futurists, 1995) One of the biggest threats
to coral reefs
are tourists. Last year alone over 1.2 million tourists visited
the Great
Barrier Reef. (Star-Bulletin, 1995) The tourists are not only
fisherman and
devoted divers they are also scientists who wanted to see the
enormous reef.
Every year the numbers of visitors increase by 10%. It has
brought many
resorts to the area who also want to get into fun and making a
little money
in the $1 billion business. Even the hotels and the motels pollute
the reefs
by their drainage and sewage pipes. This is causing a huge problem in
coastal
tourism which is the world’s fastest growing industry, worth over $7
billion
annually in the Caribbean.(Star-Bulletin, 1995) Marine Scientists are
really
worried of how much longer the reef can survive with all these visitors
to
the reefs. Global warming and ozone depletion are major contributors
to
destruction of the earth’s coral reefs. Global warming is said to cause
the
effect of bleaching, as mentioned earlier. This bleaching has just
started in
the islands of Hawaii. The temperature of the water in Hawaii has
said to have
rose over a two degrees in just one decade which the scientists
think soon will
show the effects in their reefs (Star-Bulletin, 1995).
Another example during
1982-83 El Nino event, during which unusually warm
water flowed from South
America’s Pacific Coast, up to 70%-90% of the
corals off the Pacific coasts of
Costa Rica, Panama ,and Columbia died.
Also, coral mortality was more than 95%
off Ecuador’s Galapagos
Islands(Futurists, 1993). Scientists have found that
temperatures more than 4
degrees Celsius above normal, even for a few hours,
will result in greater
that 90% coral mortality. The coral reefs can provide
great things to mankind
if they are taken from the corals with care and
responsibility. Coral reefs
yield approximately one-tenth of all fish caught for
human consumption, or
around 4 to 8 billion tons annually (Futurists, 1993).
Healthy reefs are
thought to be among the most productive fisheries in the
ocean, 10 to 100
times higher per unit area that of the deep ocean ( Scientific,
1987). If
the fisheries are regulated than the reefs can be used as a food
source
without hurting the reefs or the ecosystem. For example,
Pacific
Islanders obtain up to 90% of their animal protein from reef fish
without
affecting the reefs and without depleting the fish and effecting the
ecosystem
(Star-Bulletin, 1995). Surprisingly, some of the world’s largest
oil and gas
fields are ancient reefs. Like the rain forests, the reefs also
hold
considerable untapped potential in the science of medicine. Japan’s
coast is
one of the most studied coral coast in the world. In Japan’s reefs
there is a
chemical called kainic acid, which is used as a diagnostic
chemical to
investigate Huntington’s chorea, a rare but fatal disease of the
nervous
system (Focus, 1995). Coral also produces a natural sunscreen which
is now being
marketed to sell as a sunscreen to humans in America. Also, the
porous limestone
skeletons of coral is now being tested as bone grafts in
humans(Focus, 1995).
More promising testing is being done on other reef
organisms to generate
chemicals for cancer and AIDS research. If used
properly, the reefs of the
entire world can better serve humans with medicine
rather than with food. There
have been many studies on how long the coral
reefs will last, and they all agree
that within fifty years, coral reefs
existence will be cut in half . The studies
also say that within one hundred
years they could be completely destroyed. This
should be a wakeup call to
humans that we as a whole group have to do something
about saving these coral
reefs. If these reefs are destroyed it is thought that
it might destroy the
entire ecosystem of the ocean. There are over sixty-five
countries that have
designated some 300 parks that include coral reefs as
natural habitats in the
world (Futurists, 1993). The problem is that less that
30% of the
designated areas are fully protected. The fight is economical not
ecological.
Such as Australia and the Caribbean who are making billions of
dollars on
their coral reefs. Everyone must work together to stop the pollution
and the
destruction of our coral reefs and our environment. it is not just one
thing
that is destroying the reefs! it is many factors together that are
destroying
it. Ultimately, it is as much a question of whether we save or
destroy the
planet as it is a question of whether we save or destroy the
world’s
reef.
Bibliography
Aldridge, Susan (April, 1995) "Coral:
Replacement for Human Bones" Focus.
Goreau, Thomas (August, 1987) "Coral
and Coral Parks" Scientific American.
TenBruggencats, Jan (May, 1995)
"Coral in Hot Waters" Star-Bulletin &
Advertiser. Weber, Peter (July,
1993) "Saving the Coral Reefs"
Futurists.