Image courtesy of gruntzooki via flickr
As oceans become more acidic, corals - subject to the pressures of a low pH environment - will continue their long, inevitable downward spiral into oblivion: That has been - and remains - the general consensus among the scientific community. A team of Australian researchers may have found the first known exception to this rule; a recent Australian Institute of Marine Science (AIMS) field expedition revealed the existence of a coral community near Miall Island on the southern Great Barrier Reef that has shown signs of adjusting to the higher sea surface temperatures. The corals there have managed to do so by switching out their old zooxanthellae, symbiotic algae that provide them with a constant source of nutrition, in favor of newer, more heat-resistant ones. This phenomenon, observed in coral communities that underwent mass bleaching events in 2006, has been dubbed "symbiont shuffling"; the researchers found that the corals now were much more likely to have two strains of thermally-resistant zooxanthellae than they were prior to the bleaching events.
While good news, the study's lead scientists advise against generalizing from this community to the rest of the Great Barrier Reef, let alone other reefs around the world; the two strains of thermally-resistant zooxanthellae that were observed, while commonly found near Miall Island, are rarely seen anywhere else on the Great Barrier Reef. This study does open the door to more such encouraging findings though, in the long run, these will likely only prove to be positive vignettes in an otherwise bleak picture.