Friday, 2 June 2017

Australia's Great Barrier Reef is the largest living structure on the planet and it is dying before our very eyes

“The breathtaking array of marine creatures includes 600 types of soft and hard corals, more than 100 species of jellyfish, 3000 varieties of molluscs, 500 species of worms, 1625 types of fish, 133 varieties of sharks and rays, and more than 30 species of whales and dolphins” [Great Barrier Reef Marine Authority, 2017]

The Great Barrier Reef - stretching 2,300 kilometres along Australia’s east coast - is the largest living structure on the planet and it is dying right before our very eyes.

Winter sea surface temperatures in 2016 remained above average and, by the beginning of the 2016-17 summer, the accumulated heat stress on the Reef resulted in a second wave of mass bleaching.

Staff from the Marine Park Authority took part in aerial surveys conducted by the ARC Centre of Excellence for Coral Reef Studies, and the results confirmed the extent and severity of the 2017 bleaching event…..

In addition to severe bleaching affecting over half the Reef since 2016, large portions of the Reef have also been subjected to other simultaneous impacts during the 2016-17 summer.

Severe tropical cyclone Debbie crossed the coast at Airlie Beach on 28 March 2017.
It is estimated approximately 28 per cent of the total reef area in the Marine Park was within the ‘catastrophic damage zone’ of the cyclone’s path.

Surveys conducted by the Great Barrier Reef Marine Park Authority and Queensland Parks and Wildlife Service have revealed that some sites have suffered significant damage (up to 97 percent coral loss) and are down to very low coral cover, while others received less damage and still have moderate coral cover…..

Outbreaks of coral disease and crown-of-thorns starfish have also been ongoing.

The cumulative impact of these disturbances are affecting most of the Great Barrier Reef Marine Park, and it is likely the resilience of the majority of reefs north of Mackay has been severely diminished.

Although some disturbances are considered natural processes that have shaped coral reef communities over time, impacts such as climate change are leading to more widespread and frequent disturbances.

New Atlas, 29 May 2017:

Prior to 2017, the Great Barrier Reef had suffered through three major bleaching events in modern history – 1998, 2002 and 2016 – and underwater and aerial surveys earlier this year indicated that 2017 would offer little reprieve, with scientists confirming back-to-back bleaching events were taking place. They had maintained hope that things would cool off quickly, but further surveys have now revealed that seems unlikely, along with the true extent of the current damage. 
Scientists from the Great Barrier Reef Marine Park Authority have confirmed that 29 percent of shallow water corals died from the bleaching in 2016, an increase on the 22 percent they had predicted midway through that year. Deeper coral was also affected, but divers are unable to systematically assess mortality rates at those depths.

Science Alert, 30 May 2017:

The Great Barrier Reef can no longer be saved by existing plans to protect the ecological site, experts have warned, saying that efforts should shift to a lesser, backup plan of maintaining the reef's "ecological function" instead.

Scientists have told an Australian government committee that the current strategy to protect the reef – the Reef 2050 Long-Term Sustainability Plan – is unachievable in light of recent mass bleaching events, especially since the plan doesn't include steps to counter climate change.

The AU$2 billion Reef 2050 plan was launched in March 2015, with an aim of improving the "universal value" of the world's largest coral reef every decade leading up to 2050.

But in a meeting last week, scientists warned the advisory committee that oversees the plan that the goal of improving the reef environment is unrealistic after back-to-back bleaching events in 2016 and 2017, contributing to the worst coral die-off ever recorded…..

According to Panel Chairman and former Chief Scientist of Australia, Ian Chubb, the Reef 2050 Plan needs a significant overhaul to directly address the elephant in the room: warming oceans, the main contributor behind coral bleaching.

"We can't be passive bystanders in this. We're the custodians of the reef and its ecosystem for the world," he told Adam Morton at The Sydney Morning Herald.

"We don't say toss out the plan and start from scratch – action on water quality, sediment, and fertiliser remain important – but events mean it needs to be shifted."

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