The Great Barrier Reef

Known as one of the few living structures visible from space, the Great Barrier Reef is in danger of losing some of that visibility.

The Great Barrier Reef is an ecological system that stretches almost 1,800 miles across the Australian coast, according to greatbarrierreef.org.

The GBR is home to thousands of living organisms, including some endangered species such as the  large green sea turtle and the dugong or sea cow.

    A satellite image of the Great Barrier reef from outer space. The GBR is one of the only living             structures visible from space.  

As we have discussed in previous entries this natural wonder is at odds with current human and economic development, which may have been triggered by the rapid speed of global warming. This seems to be a continuing theme throughout the investigation of disappearing wonders on earth.

The dangers that face the reef are many. Coral bleaching is a main concern facing this historic natural wonder.

Before we understand coral bleaching, we must take a look at corals.

A coral is actually classified as an animal and not a plant. The only reason why this animal, which holds many characteristics of a plant, is classified as such is because it cannot produce its own food. Instead the coral has tiny, tentacle like arms that capture microorganisms for food.

Beside the act of hunting, a coral looks and acts like a plant. It takes root on a rock or hard surface much like a plant does. It lacks the physical features of an animal however.

Most coral contain algae called zooxanthellae. This algae plays a critical role in the survival of the coral. While the coral provides the algae with food from its waste, the algae provides the coral with oxygen and waste removal.

Because of rising sea levels and temperatures, zooxanthellae find it more difficult to survive, thus interrupting the relationship. Coral bleaching occurs when the algae inside the corals are killed, and the coral begins to turn white. This death is often caused by an extreme rise in temperature.

Sources:

http://www.usatoday.com/story/travel/destinations/2013/05/16/disappearing-wonders-10-world-heritage-sites-in-danger/2163883/

http://www.gbrmpa.gov.au/

http://www.greatbarrierreef.org/

http://www.wwf.org.au/our_work/saving_the_natural_world/oceans_and_marine/priority_ocean_places/great_barrier_reef/

http://whc.unesco.org/en/list/154

http://www.scientificamerican.com/article/explorer-pleads-to-save-the-great-barrier-reef/

http://oceanservice.noaa.gov/facts/coral.html