More GBR Bleaching Ahead In Coming Months, Though Likely Not As Severe As 16-17 Cycle
The Great Barrier Reef could face more bleaching in the coming months, following unprecedented mass bleaching events in 2016 and 2017, which are believed to have killed half the coral.
Forecasts stretching to February are pushing the science to its limits, leaving significant uncertainty. But scientists say there is reason to be concerned, and some bleaching is very likely, although it won’t be anything like what happened during the past two years. The most recent forecasts of the Coral Watch program of the US National Oceanographic and Atmospheric Administration (Noaa) puts much of the reef, especially the southern parts, on “Alert Level 1” in late February. At that level, bleaching is considered likely although it is not expected to continue long enough to cause much coral to die.
The head of Noaa’s Coral Watch program, Mark Eakin, said predicting the heat stress on the Great Barrier Reef in February was complicated because of the uncertain state of the El Niño/La Niña cycle.
“Unfortunately, that’s four months away and at the bitter end of our forecast skill,” Eakin said. “The farther away the forecast, the lower the skill. We don’t have an El Niño and the La Niña isn’t looking very strong. That lowers skill.”
EDIT
https://www.theguardian.com/environment/2017/nov/03/more-coral-bleaching-feared-for-great-barrier-reef-in-coming-months