Coral bleaching may be one of the greatest threats to the Great Barrier Reef. Coral bleaching is a stress response that often occurs when the surrounding waters become too warm for the corals. In the stressful situation, the corals expel their brownish zooxanthellae and lose their color. Zooxanthellae are unicellular yellow-brown algae that make it possible for the corals to grow and reproduce quickly enough to create reefs. Without the zooxanthellae, the coral cannot obtain sufficient nourishment. If conditions remain difficult, the corals may die. Major coral bleaching incidents on the Great Barrier Reef in 1998 and 2002 led to widespread death of corals in some areas. Researchers in the Barrier reef of Australia are using NASA's resources to help identify troubled coral.
Herron Island is in the southern Great Barrier Reef and is part of the Capricorn Group of Islands, just off of the Capricorn Coast. South of the Capricorn Group of islands is the Bunker Group of Islands also shown here.
The Great Barrier Reef is located on the eastern coast of Australia. This intricate network of coral formations has an area of about 14,300 sq miles, encompassing about 13 percent of the world's total coral reef.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 188.8.131.52.0