Great Barrier Reef faces worst bleaching event caused by El Nino

By @iamkarlatecson on
Great Barrier Reef under threat
Oliver Lanyon, Senior Ranger in the Great Barrier Reef region for the Queenlsand Parks and Wildlife Service, takes photographs and notes during an inspection of the reef's condition in an area called the 'Coral Gardens' located at Lady Elliot Island and 80 kilometers north-east from the town of Bundaberg in Queensland, Australia, June 11, 2015. UNESCO World Heritage delegates recently snorkeled on Australia's Great Barrier Reef, thousands of coral reefs, which stretch over 2,000 km off the northeast coast. Surrounded by manta rays, dolphins and reef sharks, their mission was to check the health of the world's largest living ecosystem, which brings in billions of dollars a year in tourism. Some coral has been badly damaged and animal species, including dugong and large green turtles, are threatened. UNESCO will say on Wednesday whether it will place the reef on a list of endangered World Heritage sites, a move the Australian government wants to avoid at all costs, having lobbied hard overseas. Earlier this year, UNESCO said the reef's outlook was "poor". Picture taken June 11, 2015. Reuters

Scientists from the University of Queensland warned that the Great Barrier Reef is in danger of being damaged in early 2016 due to widespread bleaching, which is a result of the El Nino event.

This will be the third recorded global bleaching event in history, according to the results of a study published by the University of Queensland and the US National Oceanic Atmospheric Administration, or NOAA. 

“If conditions continue to worsen, the Great Barrier Reef is set to suffer from widespread coral bleaching and subsequent mortality, the most common effect of rising sea temperatures,” said Ove Hoegh-Guldberg, the university’s global change institute director, in a statement.

According to Hoegh-Guldberg, more than half the Great Barrier Reef experienced bleaching in the first major global event in 1998, with about five to 10 per cent of the corals dying. The reef was spared during this second global event in 2010 due to storm activity which alleviated the heat stress, but it may not be so lucky in 2016, Hoegh-Guldberg said. 

Bleaching occurs as a result of warmer ocean temperatures, NOAA explains in its website. When water is too warm, corals will expel the algae living in their tissues, causing the coral to turn completely white. While corals can survive a bleaching event, they are under more stress and are subject to mortality.

The El Nino weather pattern in 1988 caused one of the world’s worst cases of coral bleaching. It was characterised by the weakening of trade winds over the Pacific Ocean that caused sea temperatures to rise, affecting the reefs of 60 tropical countries. 

Predictions made by Hoegh-Guldberg and his colleagues support an earlier announcement of the United Nations’ World Meteorological Organisation, which warned that the present El Nino event could be among the strongest in 65 years. Climate experts expect that the weather phenomenon will reach its peak between October 2015 and January 2016.

Hoegh-Guldberg, in a research he conducted in 1999, predicted that mass coral bleaching events would become successively worse over time if the world failed to deal with rising atmospheric gases. 

In the study, he analysed how the frequency and intensity of bleaching events will change over the next 100 years. The results suggested that the thermal tolerances of reef-building corals are likely to be exceeded every year within the next few decades. Events as severe as the 1998 event, the worst on record, are likely to become commonplace within 20 years, Hoegh-Guldberg noted in the study. 

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