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