From John Ray's shorter notes




April 22, 2018

Great Barrier grief: Coral 'cooked to death' in scorching summer heatwave

This is just an academic republication of some claims made in 2016, which were shown at the time to be greatly exaggerated.  And note below that global sea surface temperatures actually FELL during late 2016.



So if there was a big warming event in North Queensland waters at the time it was a LOCAL event, not a global one.  So any coral damage was not caused by global warming.

The BOM does record high temperatures in the reef area in 2016 but admits that there were several factors contributing to that.  I quote:

"The 2015–16 El Niņo suppressed and delayed the monsoon, leading to reduced cloud cover and weakened winds this summer. Additionally, a relatively low number of summer storms occurred over the Reef. These factors led to increased surface heating and reduced mixing, resulting in substantially warmer ocean temperatures around northern Australia from December to March 2016."

And note that the BOM places the warming in early 2016, not late 2016.  Pesky!

Something else that happened in 2016 was a regional sea-level fall --which really is detrimental to coral and could alone explain any damage.

And note the announcement from late last year that bleached corals are already recovering nicely.  So no fear is warranted.

It's just propaganda below -- propaganda in a scholarly disguise.  I actually wonder whether they did all the surveys they claim to have done? A little bit of interpolation here and there, perhaps?  JCU has a record of dubious integrity.  Ask Peter Ridd about that


Millions of corals on the Great Barrier Reef were 'cooked' during a scorching summer in the northern region, according to scientists.

The underwater heatwave eliminated a huge number of different species of coral during a process which expelled algae after the polyps were stressed.

'When corals bleach from a heatwave, they can either survive and regain their colour slowly as the temperature drops, or they can die.

'Averaged across the whole Great Barrier Reef, we lost 30 per cent of the corals in the nine-month period between March and November 2016,' said Professor Terry Hughes from James Cook University said.

Prof Hughes who acts as the Director of the ARC Centre of Excellence for Coral Reef Studies at JCU said his team was very surprised to see a quarter of the corals die in just two to three weeks during the March heatwave.

Scientists researched the entire reef by analysing water surveys at various locations along its 2,300-kilometre distance, and combined insight with aerial data and satellite monitoring.

Results showed 29 per cent of the 3,863 reefs which make up the world's largest reef system lost 'two-thirds or more of their corals', which dramatically impacts the ability of the reefs to maintain full ecological abilities.

'The Great Barrier Reef is certainly threatened by climate change, but it is not doomed if we deal very quickly with greenhouse gas emissions.

'Our study shows that coral reefs are already shifting radically in response to unprecedented heatwaves,' said Prof Hughes.

The team warn that if changes are not made to consider climate change it will have a huge effect on tropical reef ecosystems and, therefore, a detrimental impact on the benefits those environments provide to populations of poor nations.

SOURCE






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