One third of world’s corals face extinction

By Henrylito D. Tacio
 
Fort Lauderdale, Florida – Next to frogs, coral reefs are the most threatened species on this planet, according to the International Union for Conservation of Nature (IUCN). 
 
In fact, one third of the reef-building corals around the world are facing extinction.  This was the conclusion of the first-ever comprehensive global assessment to determine their conservation status. 
 
“The results are very disconcerting,” said Dr. Kent Carpenter, who headed the study.  “When corals die off, so do the other plans and animals that depend for food and shelter, and this can lead to the collapse of entire ecosystems.”
 
The global assessment is a collaborative effort of IUCN and the Conservation International (CI).  Thirty-nine experts applied the IUCN Red List Categories and Criteria to determine the status of the species in the sea.
 
Coral reefs, hailed as the “rainforests of the sea,” are among the largest and oldest living communities of plants and animals on earth, having evolved between 200 and 450 million years ago.   Today, most established coral reefs are between 5,000 and 10,000 years old.
 
Coral reefs occupy only 0.1 percent of the ocean’s surface, yet they are the world’s richest repository of marine biodiversity.  “They are home to more than 25 percent of marine species,” IUCN and CI said in a joint statement.  A single reef can support as many as 3,000 species of marine life.
 
Corals reefs can be found in most parts of the world.  But the diversity 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.
 
Of the 109 countries with significant coral reef communities, over 93 are experiencing damage to them.  Many coral reefs have reached a state of decline that they can no longer be considered as coral reefs, while others are under increasing threat from local human disturbances and impacts from a changing global climate.
 
Climate change causes rising water temperatures and more intense solar radiation, which leads to coral bleaching and disease often resulting in mass coral mortality.  In 2005, sixty-eight percent of the coral colonies in the south coast of Jamaica and the Dominican Republic were affected when coral bleaching hit them.
 
Leading researchers predict that ocean acidification will be another serious threat facing coral reefs.  As oceans absorb increasing amounts of carbon dioxide from the atmosphere, water acidity increases and pH decreases, severely impacting corals’ ability to build their skeletons that form the foundation of reefs.
 
The experts who assessed the global status of coral reefs agree that if rising sea surface temperatures continue to cause increased frequency of bleaching and disease events, many corals may not have enough time to replenish themselves and this could lead to extinction.
 
“The loss of the corals will have profound implications for millions of people who depend on coral reefs for their livelihoods,” said Roger McManus, CI’s vice president for marine programs.
 
Coral reefs also generate millions of dollars in tourism and employment.  According to the Washington-based World Resources Institute (WRI), the total economic value of reefs in the Philippines is estimated at US$1.1 billion annually.  In Indonesia, the reefs generate an annual income of US$1.6 billion.
 
Unfortunately, coral reefs are threatened with extinction.   The IUCN/CI assessment considered staghorn (Acroporid) corals as having the “highest risk of extinction,” with 52 percent of species listed in a threatened category.  Corals from the genera Favia and Porites were found to be “the least threatened” due to their relatively higher resistance to bleaching and disease.
 
The Caribbean region has been identified as having the highest number of “highly threatened corals (endangered and critically endangered).  The high biodiversity of the Indo-Pacific region has “the highest proportions of vulnerable and near-threatened species.”  The growing populations living in these areas were cited as the culprit. — ###

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One response to “One third of world’s corals face extinction

  1. Great post. FYI – World Resources Institute just released another report highlighting the economic value of coral reef ecosystems in Tobago and St. Lucia. On these two small islands, coral reef tourism alone accounted for direct and indirect economic impact totaling US$101–130 million in Tobago and US$ 160–194 million in St. Lucia. For more information, see http://www.wri.org/stories/2008/06/coastal-capital-putting-a-value-the-caribbeans-coral-reefs.

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