Scientists found that ocean deoxygenation is the biggest threat to coral reef survival.
Oxygen in the world’s oceans has decreased by 2% since the middle of the last century, due largely to climate change, agricultural runoff and human waste. Little research has been done until now on the effects of decreased oxygen on coastal coral reefs systems. In March, Australia’s Great Barrier Reef suffered its most widespread bleaching event to date. Some corals may never recover. The climate change brought unusually warm waters to the Great Barrier Reef in February and disrupted the symbiotic relationship between the corals and their lifesustaining algae. “We know that the stresses of warming and the deoxygenation are likely to interact with each other,” a research associate at the University of Technology explained.
Scientists have carried out a trial of prototype cloud brightening equipment – a modiﬁed turbine with 100 high-pressure nozzles to spray trillions of nano-sized ocean salt crystals into the air from the back of a barge – to shade and cool corals and protect them from bleaching. The system worked. The tiny salt crystals are able to mix with low-altitude clouds, making them brighter and reﬂecting more sunlight away from the ocean surface. Scientists are racing to ﬁnd measures to save corals.