Worldwide bleaching of coral would be only third such event in recent history, driven by high ocean temperatures caused by global warming, RTCC reports.
2015 could see coral bleaching on a global scale for the third time in history – and the first in the absence of an El Niño.
That is the latest prediction from the National Oceanic and Atmospheric Administration (Noaa), which has just launched a model to forecast threats facing the colourful reefs.
“It started in 2014 – we had severe bleaching from July to October in the northern Marianas, bad bleaching in Guam, really severe bleaching in the north western Hawaiian Islands, and the first ever mass bleaching in the main Hawaiian Islands,” said said Mark Eakin, Noaa’s Coral Reef Watch coordinator.
“It then moved south, with severe bleaching in the Marshall Islands and it has moved south into many of the areas in the western south Pacific.
“Bleaching just now is starting in American Samoa. In Fiji we’re starting to see some, the Solomon Islands have seen some. We’ve already seen a big event.”
Bleaching takes place when corals are stressed due to changes in light, nutrients or temperature – though only the latter can cause events of this magnitude. This causes them to release algae, lose their colour and in some cases die off.
It is a relatively rare occurrence. Large-scale bleaching was recorded in 1983, followed by the first global scale event in 1998. A second global wave came in 2010.
The latest global event appears to be following the path of the earlier two, with bleaching starting in the Pacific and expected to sweep through the Indian Ocean, south east Asia and the Caribbean.
