Corals are in fact animals, even
though they may exhibit some of the characteristics of plants and are often
mistaken for rocks. In scientific classification, corals fall under the phylum
Cnidaria and the class Anthozoa. They are relatives of jellyfish and anemones.
Coral reefs are the most diverse
and beautiful of all marine habitats. Coral
are the "Rainforests" of the ocean. Reefs are ecologically important
ecosystems and have a high biodiversity that serves as a storage bank of rich
genetic resources. They are a source of food and medicine, and they protect the
coast from wave erosion.
Home to more than 1 million diverse aquatic species, including
thousands of fish species
Income: Billions of dollars and millions of jobs in more than 100
countries around the world Food: For commercial fishing enterprises and for people living
near coral reefs, especially on small islands Protection: A natural barrier protecting coastal cities,
communities, and beaches Medicine: Potential treatments for many of the world's most
prevalent and dangerous illnesses and diseases
Corals are marine animals related
to jellyfish and anemones. Both colonial and solitary corals catch plankton
(microscopic plants and animals) and other suspended food particles with
arm-like tentacles, which feed a centrally located mouth. Most hard corals also
host symbiotic algae, a long-standing and successful partnership. These algae
provide them with an additional food source through photosynthesis. Coral reefs
are formed by corals that secrete hard calcareous (aragonite) exoskeletons,
giving them structural rigidity. These colonial “hard corals” form elaborate
finger-shaped, branching, or moundshaped structures and can create masses of
limestone that stretch for tens or even hundreds of miles.
Clean, clear water is essential to their
health. Once coral larvae settle on a hard substrate and become established,
colonies can arise if conditions are suitable for growth. Given enough time,
coral colonies become thickets. As coral thickets build upward on the skeletal
remains of older colonies, a reef is established. Today, richly diverse coral
reefs are found in the tropics along coastlines, on the margins of volcanic
islands, and as isolated coral atolls.
Tropical coral reefs can be
found in a zone between 30° north and 30° south of the equator. They
don't grow deeper than 50 meters and the optimum water temperature is
25-27°C degrees, with some species able to live in colder waters up to
Cold water corals live in
higher latitudes as deep as 2000 meters and with water temperatures
4°C. These corals are stony corals but they don't necessary host a
zooxanthella. Deep water corals don't form reefs but they form
aggregation called banks or bioherms. Deep sea corals also referred to
as mounds, which describes the calcium carbonate skeleton which left
behind as the coral grows.
water corals live in nutrient rich water and feed on zooplankton. They
are also form a diverse ecosystem hosting fish species and
invertebrates. These corals are much more vulnerable as they grow slower
and takes more time to recover. They mainly threatened by human activity
such as trawling and long line fishing. Also laying of submarine
communication cables can cause huge damage.
There are two distinct regions in
which tropical coral reefs are primarily distributed: the Wider Caribbean
(Atlantic Ocean) and the Indo-Pacific (from East Africa and the Red Sea to the
Central Pacific Ocean).
The diversity of coral is far
greater in the Indo-Pacific, particularly around Indonesia, the Philippines,
and Papua New Guinea. Many other groups of marine fauna show similar
patterns, with a much greater diversity in the Indo-Pacific region.
Although they possess a
smaller number of species the corals of the Atlantic are still unique, with
few common species between the two regions .
majority of reef building corals are found within tropical and subtropical
waters. These typically occur between 300 north and 300
south latitudes. The red dots on this map show the location of major stony coral
reefs of the world. Credit:NOAA
Science from Outer Space to Inner Space
Coral reefs are found in about 100 countries. Coral
Reefs are home to
over 25 percent of all marine life and are among the world's most fragile and
endangered ecosystems. In the last few decades over 35 million acres of Coral
Reefs have been
Reefs off of 93
countries have been damaged . When corals are stressed by high temperature,
ultraviolet light or other environmental changes, they lose their symbiotic
algal cells, and appear white (the white skeleton is actually visible through
the transparent tissue). Depending on the intensity and duration of the stress,
the corals may recover or die.
If the present rate of destruction continues, 70% of the world's coral reefs will be destroyed within the
next few decades.
Climate change will destroy the
world's great coral reefs within a century, according to a report by German and
Australian marine scientists.Researchers say
governments must take action now to reduce the emissions of gases such as carbon
dioxide, which are thought to be behind a rise in average global temperatures.
rise in temperature can bleach coral like this
The scientists combined their
coral expertise with the latest climate models to project what is likely to
happen to the world's greatest reefs if global warming remains unchecked. Their
study suggests the unique marine environments will increasingly become victim to
a process known as coral bleaching.
A slight rise in maximum water
temperatures - only one to two degrees - can stress the corals. This causes them
to expel the microscopic organisms, known as zooxanthellae, which color their
tissues and provide them with essential nutrients.
If the zooxanthellae do not
return, the corals will die. In 1998 every reef
system in the world's tropical oceans were affected by some degree of bleaching.
The report says the frequency and intensity of bleaching is set to rise.
The report's lead author is
Professor Ove Hoegh-Guldberg, an expert on coral bleaching at Sydney University.
reefs could be eliminated from most areas of the world by 2100, Even the
world's largest reef - the Great Barrier Reef off Australia - could be dead
within 30 years unless measures are taken now to slow climate change.
Coral reefs are among the oldest ecosystems on Earth.
Coral reefs are the largest living structure on the planet.
Although coral reefs cover less than 1% of the Earth’s surface, they are
home to 25% of all marine fish species.
500 million people rely on coral reefs for their food and livelihoods.
Coral reefs form natural barriers that protect nearby shorelines from the
eroding forces of the sea, thereby protecting coastal dwellings,
agricultural land and beaches.
Without the existence of coral reefs, parts of Florida would be under water.
Coral reefs have been used in the treatment of cancer, HIV, cardiovascular
diseases and ulcers.
Corals' porous limestone skeletons have been used for human bone grafts.
It is estimated that coral reefs provide $375 billion per year around the
world in goods and services.
If the present rate of destruction continues, 70% of the world's coral reefs
will be destroyed by the year 2050.
Reef Relief founders Craig and DeeVon Quirolo retired from the grassroots organization last July, only to begin an effort to provide an online resource on coral reefs. Their new website provides all the award-winning educational tools, grassroots strategies, project reports and images of coral reefs assembled during their work over the past 23 years in the Florida Keys and throughout the Caribbean protecting coral reefs. You can find it
NOAA, NASA, Reef Check, UNEP, Reef Relief, Australian Government, University of
Texas, Great Barrier Reef Marine Park Authority, Coral Reef Alliance
compiled from The British Antarctic Study, NASA, Environment Canada,
UNEP, EPA and other sources as stated and credited Researched by Charles
Welch-Updated daily This Website is a project of the The Ozone Hole Inc.
a 501(c)(3) Nonprofit Organization http://www.theozonehole.com