Prioritizing Select Reefs for Restoration Agenda
High-resolution predictions of annual coral bleaching can help prioritize reefs for conservation.
If current trends continue, severe bleaching will occur every year on 99% of the world's coral reefs within this century
More ambitious emissions reductions may give reefs an average of 11 extra years before annual bleaching strikes
January 5, 2017 - New climate model projections of the world's coral reefs reveal which reefs will be hit first by annual coral bleaching, an event that poses the gravest threat to one of the Earth's most important ecosystems.
These high-resolution projections, based on global climate models, predict when and where annual coral bleaching will occur. The projections show that reefs in Taiwan and around the Turks and Caicos archipelago will be among the world's first to experience annual bleaching. Other reefs, like those off the coast of Bahrain, in Chile and in French Polynesia, will be hit decades later, according to research recently published in the journal Scientific Reports.
"These predictions are a treasure trove for those who are fighting to protect one of the world's most magnificent and important ecosystems from the ravages of climate change," said Erik Solheim, head of UN Environment. "They allow conservationists and governments to prioritize the protection of reefs that may still have time to acclimatize to our warming seas. The projections show us where we still have time to act before it's too late."
Since it takes a reef five years to recover from any one bleaching event, the consequences for some of the world's richest ecosystems could be catastrophic. But catastrophe could be delayed. Drastic cuts in emissions reductions could give reefs an average of another 11 years before they start bleaching every year, according to new research.
Right now, the world's reefs are caught up in the longest global coral bleaching event ever recorded. It began in 2014, and could go on well into 2017, according to the journal Scientific Reports.
Corals are acutely sensitive to ocean temperatures and when the thermometer rises, their symbiotic relationship with a mutual beneficiary, the zooxanthellae, breaks down. Some 90 percent of the Great Barrier Reef off Australia has been affected by the latest episode, and 20 percent of the coral killed.
"Bleaching that takes place every year will invariably cause major changes in the ecological function of coral reef ecosystems," said Ruben van Hooidonk of the U.S. National Oceanic and Atmospheric Administration and the University of Miami.
"Further, annual bleaching will greatly reduce the capacity of coral reefs to provide goods and services, such as fisheries and coastal protection, to human communities."
UNIVERSITY OF MIAMI ROSENSTIEL SCHOOL OF MARINE & ATMOSPHERIC SCIENCE