An international team of scientists are working at a rapid pace to study environmental conditions behind the fast-acting and widespread coral bleaching plaguing Australia’s Great Barrier Reef. Data from NASA observation satellites has provided scientists with near-real-time sea surface temperature and ocean color data to give them faster insight into the impact coral bleaching can have on global ecology.

Australia’s Great Barrier Reef is a massive marine habitat system made up of 2,900 reefs spanning more than 600 continental islands. Though coral reefs exist around the globe, researchers consider this network of reefs to be the center of the world’s marine biodiversity, playing a critical role in human welfare, climate, and economics. Coral reefs also are multimillion dollar recreational destinations, and the Great Barrier Reef is an important part of Australia’s economy.

Scientists use ocean temperatures and ocean color as indicators of what is happening with coral, which is very temperature sensitive. Ocean color, a measure of the concentration of chlorophyll in ocean plants, is important because it informs scientists about changes in the ocean’s biological productivity. Bleaching occurs when warmer than normal temperatures force corals to cast out the tiny algae that help the coral thrive and give them their color. Without these algae, the corals turn white and eventually die.

"Australia’s Great Barrier Reef is the largest and most complex system of reefs in the world, and like so many of the coral reefs in the world’s oceans, it’s in trouble," Gene Carl Feldman, an oceanographer with the Ocean Biology Processing Group at NASA’s Goddard Space Flight Center, said in a statement. "Coral, which can only live within a very narrow range of environmental conditions, are extremely sensitive to small shifts in the environment. Like the ‘canary in the coal mine,’ coral can provide an early warning of potentially dangerous things to come."

In 2004, NASA scientists developed an Internet-based data distribution system that enables researchers around the globe to customize requests and receive ocean color data and sea surface temperature data captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA’s Terra and Aqua satellites, generally within three hours after the satellites pass over the particular region of interest. NASA processes and distributes this data to hundreds of scientists, educators and public officials globally on a daily basis.

"The Great Barrier Reef is an icon, and we just want to know what we can do to save it," Scarla Weeks, of the University of Queensland in Australia, said. "Sea surface temperatures over the last five months are actually higher in certain locations now than they were in 2002 when we witnessed the worst bleaching incident to date."

Weeks regularly downloads MODIS data that shows her the extent of and where the coral bleaching is expanding. "We’re not able to do this kind of broad-reaching work without NASA," she said. "With this satellite data delivery service, we’re able to observe what’s happening in the ocean in ways we’ve never been able to before."