Cool coral refuges found amid global warming waters
Wednesday 2 May 2012 9:05 a.m.
An aerial view of Christmas Island, Kiribati (AAP)
By 3 News online staff
Global warming is expected to have devastating effects on coral reefs. However, recent research has identified a few possible exceptions in the equatorial Pacific.
"These little islands in the middle of the ocean can counteract global trends and have a big impact on their own future, which I think is a beautiful concept," said study researcher Kristopher Karnauskas, a Woods Hole Oceanographic Institution scientist.
Corals are animals that host tiny plants, or algae, that feed them using photosynthesis.
Warming ocean water can cause the algae to be expelled, a change known as bleaching, turning the corals white. It indicates that the coral is under great stress and at risk of death.
Global climate models predict the central tropical Pacific will warm by about 2.8 degrees Celsius by the end of the century.
However, the research by Mr Karnauskas and Anne Cohen predicts the deep equatorial undercurrent (EUC), an eastward flowing current at the equator, will strengthen by 14 percent - bringing cooler water and nutrients to the surface.
As a result, the corals and their algae in these areas will be in a kind of refuge with a better chance to adapt as the conditions change at a slower pace.
"Our model suggests that the amount of upwelling will actually increase by about 50 percent around these islands and reduce the rate of warming waters around them by about 1.25 degrees F (0.7 degrees C) per century," said Mr Karnauskas.
There is a possibility that these areas could even become a source of new corals and other species that could re-colonise reefs damaged by warming, said Mr Karnauskas.