Super corals can sustain in warm and acidic weather

Washington: Hawaiian "super corals" that have recovered despite living in warm and acidic water offer a glimmer of hope that dying reefs across the world could be saved, a new study says. The research suggests that the gloomiest climate change picture of a world without the kaleidoscope underwater habitats could still be avoided, according to lead author Christopher Jury.

"It's unfortunately but inevitably true that things are going to get worse for reefs over the next 20-30 years, but that doesn't mean it's unstoppable," said Jury, a postdoctoral researcher at the Hawaii Institute of Marine Biology.

"We can still turn this thing around and end up getting back to better than what we have today within a reasonable timeframe," he told AFP. Coral reefs cover less than one per cent of the ocean bed but support around 30 per cent of all known marine life.

But they are suffering, with stressors including the warmer and more acidic oceans caused by climate change, as well as other human-made pressures including pollution and overfishing. The UN's intergovernmental panel on climate change warned last year that just 1.5 Celsius (2.7 Fahrenheit) of global warming could see 70-90 per cent of Earth's coral reefs vanish.

But Jury's research shows that it is possible for coral to survive and even thrive in waters that are warmer and more acidic than where coral usually lives. He studied coral reefs in Hawaii's Kane'ohe Bay that were devastated between the 1930s and 1970s by urbanisation, dredging, coastal development and the discharge of sewage.

By the early 1970s, shallow coral cover across the bay had decreased by more than 70 per cent on average and by more than 95 per cent in the southern bay, nearest the sewage output. But in the late 1970s, the sewage was diverted and the coral began to recover rapidly.