April 8th, 2006 05:01 EST
NASA Helps Find Great Barrier Reef Coral Bleaching
Washington – An international team of scientists is studying environmental conditions behind the fast-acting and widespread coral bleaching now plaguing Australia's Great Barrier Reef.
NASA's satellite data provides the scientists near-real-time sea surface
temperature and ocean color data to give them faster-than-ever insight
into the effect 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, according to an April 5 NASA press release.
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.
"Australia’s Great Barrier Reef is the largest and most complex system
of reefs in the world,” said oceanographer Gene Carl Feldman of NASA's
Goddard Space Flight Center in Maryland, “and like so many of the coral reefs in the world’s oceans, it's in trouble.”
In 2004, NASA scientists developed a free, Internet-based data
distribution system that lets researchers around the globe 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.
Coral reefs are a 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.
Coral is very temperature sensitive. Ocean color – the concentration of
chlorophyll in ocean plants – is important because it informs scientists
about changes in the ocean's biological productivity.
NASA satellites capture temperature and color data from their
space-based view of the coral reefs.
Bleaching occurs when warmer-than-tolerable 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, if
the condition persists for too long.
“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 coalmine,’” he added, “coral can provide an
early warning of potentially dangerous things to come.”
Researchers, including Scarla Weeks at the University of Queensland,
Australia, are using satellite monitoring to observe changes in sea
surface temperatures and ocean primary productivity along the Great
Barrier Reef and surrounding waters.
Recent dramatic increases in sea surface temperatures are causing a rift in the relationship between corals and the algae that live within their
Weeks regularly downloads NASA MODIS data that shows her the extent and location of coral bleaching expansion.
“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.”
“Rising ocean temperatures are just one of the ever-increasing number of environmental stresses faced by coral reefs in general and the Great
Barrier Reef in particular,” Feldman said.
The data distribution service shares NASA's unique ability to monitor
Earth from the vantage point of space, he added, and gives scientists the best and most timely information.
Source: U.S. State Department