BRISBANE, 04 NOV – The bleaching of Australia’s Great Barrier Reef has reached 98%, saving only a fraction of the largest set of corals in the world, a UNESCO World Heritage Site since 1981, according to a study published in the journal Current Biology , according to which only 2% of this immense underwater ecosystem has escaped the phenomenon since the first major bleaching episode in 1998. It is a deterioration phenomenon, which results in a discoloration of the corals, due to the rise in temperature of the water that causes the expulsion of symbiotic algae that usually give the coral its color and its nutrients. The frequency, intensity and amplitude of marine heat waves that cause it continue to increase, points out study lead author Terry Hughes, of the Australian Research Council (Arc) Center of Excellence based at James University. Cook. The Great Barrier Reef has undergone three other major bleaching episodes since 1998, in 2016, 2017 and 2020. Researchers assured last July that the corals had shown signs of healing since the last bleaching, but warned that the long outlook term of this 2,300 km long ecosystem are “very negative”. The reef is also threatened by cyclones, increasingly frequent due to global warming, and by a starfish (purple acanthaster) which devours corals and which has proliferated due to pollution and agricultural runoff. (HANDLE).