A new study on the effects of climate change and rising ocean temperatures on coral reefs was published in the scientific journal Nature Wednesday, with researchers reporting that the Great Barrier Reef (GBR) in Australia suffered “unprecedented” damage in 2016.
The paper, titled “Global warming and recurrent mass bleaching of coral”, said that 85 percent of 171 individual reefs surveyed off the coast of Australia were found to be “bleached” and more than 90 percent of GBR was at least partially in the first stages of death.
Abnormally high water temperatures particularly in the northeast Coral Sea were the main culprit for the damage, according to the study’s scientists. Bleaching refers to the decoloration of reefs after algae is ejected from the surface in reaction to the warm sea water, causing the coral to eventually die and collapse.
Coral reefs serve as a natural habitat to about 25 percent of the world’s fish, which 275 million people depend on for their livelihood and as part of their daily diet, according to UN data. In Australia, the fishing and tourism trade accounts for $3.7 billion of the country’s annual economy and provides approximately 70,000 jobs.
While 2016 saw the third significant bleaching event over the past 20 years in Australia, last year’s heat wave was the most damaging to the Great Barrier Reef and included potential destruction of other reefs in Japanese and Caribbean waters.
“We didn’t expect to see this level of destruction of the Great Barrier Reef for another 30 years,” said the study’s co-author, Terry Hughes.
New bleaching was also found earlier in 2017 off the coast of northern Queensland by Australia’s Great Barrier Reef Marine Park Authority, the first “back-to-back” bleaching events ever recorded in the region. According to University of Melbourne climate scientist Dr. Andrew King, a 1.5 degree Fahrenheit increase in global temperature would cause a coral bleaching event every other year on average.
While coral reefs that perish in extreme heat often take decades to regenerate, given that colder conditions return, much of the Great Barrier Reef was saved in 2016 when a storm created ocean churn. The freshly cooled water in its central and southern region saved 94 percent of the reef in those areas from possible destruction.
Despite the potential disaster that was staved off, coral reefs are at their greatest risk of not surviving in the southern Pacific Ocean since at least the 19th century — a sentiment borne-out by an Australian government funded study released earlier in March showing that 2016 had the “highest sea surface temperatures across the Great Barrier Reef on record.”
In the wake of the studies, Australian scientists have issued a call-to-action for national and provincial governments to take additional steps and curtail the effects of climate change, mainly by reducing the country’s carbon dioxide emissions.
“I and others would like to see stronger targets, we’d like to see a systemic intervention in the economy to reduce greenhouse gas emissions,” said Karen Hussey, professor at the Global Change Institute at the University of Queensland, who also emphasized that clean air is more critical for saving marine life than even water quality control.
[CNN] [ABC.net.au] [New York Times] [Photo courtesy Salon]