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"Coral Bleaching" |
By: LeRoy French Undersea Adventures 16 January 2009 |
(Image shows healthy and threatened corals)
One of the many affects of 'Global Warming' is 'Coral Bleaching'. This
is one of the most devastating threats our coral reefs face. Coral
bleaching is exactly what it sounds like, the coral turns white and
subsequently dies. Coral reefs are the most sensitive ecosystems on
earth. If the reef is subjected to long term temperature change
(increase) this creates enormous physiological stress and the critical
balance is then disrupted. Corals and small animals live in immense
colonies harvesting nourishement and energy from microscopic algae
which inhabit their cells by the thousands. The algae is a golden brown
and combined with other pigments is responsible for the corals
spectacular appearance.
Fragments of coral sand and limestone make up the reef. Over
hundreds of years in the making a framework is constructed, hence the
coral reef is born. During its time hundreds of animals and plants attach
themselves to the structure creating an incredible eco-community.
These reefs are very dependent on temperate sea surface conditions.
64 degrees F or more. As global warming has increased dramatically in
the past decade the rise in ocean temperature is taking its toll on the
coral reefs. This physiological stress upsets the critical balance and the
symbiotic relationship with the algae is lost. As mentioned algae is one
the sources of the corals color and when it is lost the condition is known
as coral bleaching. Scientists have reported coral bleaching in at least
60 countries and island nations worldwide. This also includes the
Caribbean.
Coral Reefs have a tremendous value. Substantial income is derived
from tourism and about half of the potential pharmaceuticals being
explored are from the oceans.
Aside from global warming, coral bleaching is also caused by pollution,
coastal runoff, silt and sand. With silt smothering the reef and blocking
sunlight, coral polyps will get rid of their plant partners. Without the
plants the polyps lose their color, and more importantly, their ability to
build more reef.
I have just recently finished my inspection of St. Maarten's reefs and
my analysis is anything but encouraging. Over 85% are covered in silt
and sand. Most all of the reefs have one form or another of coral
bleaching. These are the rainforests of the ocean, and slowly but surely
they are vansihing before our eyes.
Remember, when a reef is lost it means a higher probability of
extinction of marine life!
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