Marine heat waves causing ‘almost unprecedented’ damage to Australia corals – ‘To see them badly damaged, or completely dead, as a result of bleachings that happened over previous years, and likely the one in 2013, was surprising’

By Katie Valentine
13 February 2014 (Climate Progress) – The Earth’s oceans are warming rapidly, absorbing about 90 percent of the heat created by anthropogenic climate change. Now, new research shows that this heat has caused “almost unprecedented” damage to ancient corals of the coast of Western Australia. The research, which has yet to be published but is part of a five-year study out of the University of Western Australia, found that, in the summer of 2012-2013, a marine heat wave killed off 400-year-old porites corals, which had previously been thought to be some of the more resistant to the effects of climate change. The coral’s survival depends on algae, but that algae was destroyed by the marine heatwave, causing the coral to become bleached and more susceptible to death. The study’s researchers told the Guardian that the damage these ancient corals suffered was a major shock. “To see them badly damaged, or completely dead, as a result of bleachings that happened over previous years, and likely the one in 2013, was surprising,” lead scientist Russ Babcock said. This isn’t the first time extreme heat has damaged ocean coral. The scientists said bleaching has been occurring for about 20 years, and that records show it has become more common in recent years. In 2010, corals across the world’s oceans became bleached — shedding the algae that provide them much of their food and color — due to heat stress, just the second known global bleaching of coral in history. “It is a lot easier for oceans to heat up above the corals’ thresholds for bleaching when climate change is warming the baseline temperatures,” C. Mark Eakin of the the National Oceanic and Atmospheric Administration told the New York Times in 2010. “If you get an event like El Niño or you just get a hot summer, it’s going to be on top of the warmest temperatures we’ve ever seen.” [more]

Marine Heat Waves Have Caused ‘Almost Unprecedented’ Damage To Australian Coral