WASHINGTON Teams of snorkel-wearing scientists could be warriors against the ravages of climate change on coral reefs, the International Union for Conservation of Nature reported on Wednesday.
Small teams of observers, wearing snorkels, swim fins and masks and carrying underwater note paper or slates and measuring tape, could make rapid assessments of how coral formations are faring as the world's oceans get warmer, the group said at a briefing.
Warmer waters can contribute to the bleaching of coral reefs, a process in which microscopic plants that live on and nourish the coral are lost; without these plants, coral can die in a matter of weeks.
Coral reefs are also under threat from ocean acidification as a result of long-term emissions of the greenhouse gas carbon dioxide.
Oceans have absorbed some 525 billion tons of this gas over the last 200 years, about a third of all the carbon dioxide humans have generated; when carbon dioxide combines with sea water, it forms the corrosive carbonic acid.
Coral reefs are considered sentinel ecosystems, one of several on Earth that are now showing the impact of climate change. They also furnish food and medicines to coastal communities worldwide and act as protection for coastlines.
"It's probably one of the first ecosystems, together with maybe mountain systems, that show a global change in response to climate change," said Jerker Tamelander, a specialist in the conservation group's Indian Ocean Marine Program.
"It warns us of future change. ... It also gives us an opportunity, it gives us a testing ground and methods for ensuring adaptation, for ensuring that the systems don't degrade any further," Tamelander said at the briefing.
Global climate change causes much of the damage to coral reefs, but human activities on a local scale -- including overfishing and pollution from agriculture and other land-based sources -- are the main drivers of damage, said the group's Gabriel Grimsditch.
Fast assessments of the coral's condition can help guide policy and ease protection, Grimsditch said.
There are 40 variables that can indicate whether the coral is resilient, but three of the main ones are the size of the coral population, how many plant-eating fish and how big the algae populations are around the reef, Grimsditch said.
Sea level rise, which is projected to occur this century as the world's glaciers melt, would not necessarily kill coral reefs, Tamelander said, since the reefs can grow as waters get higher.
"A healthy reef should be able to keep up," Tamelander said.