Sydney: Clear evidence of major changes taking place in the Great Barrier Reef, off Australia, have emerged, based on satellite measurements of sea surface temperatures.
The changes have big implications for the future management of the Great Barrier Reef (GBR) and its marine protected areas, say Natalie Ban and Bob Pressey, professors at the ARC Centre of Excellence for Coral Reef Studies and James Cook University, respectively.
"When we looked back at satellite data collected since 1985, we found evidence that most of the regions of the GBR are changing significantly, in terms of sea surface temperature - especially in the southern part of the reef," says Ban, who led the study with Scarla Weeks from the University of Queensland.
"Risk of coral bleaching increases with higher water temperatures. Across the whole reef we found water temperatures increasing by an average of 0.2 of a degree over a quarter of a century - but the increase was significantly more in some areas," says Ban.
"For example, off Rockhampton the water has warmed by about half a degree over the last 25 years," adds Ban, according to an ARC Centre statement.
The changes were also altering the seasonal patterns of water temperature at particular places along the reef, Ban says.
"In some areas summer is coming earlier and lasting longer; in others, both summers and winters are warmer than in the past. This all affects the sea life."
"Some people think we ought to have the highest levels of protection for areas that are changing the least, so they remain as refugia to recharge the surrounding reef areas. Others argue the opposite - that the greatest protection should be afforded to the most vulnerable areas," says Ban.