Friday, August 26, 2016
Lying Greenie alarmists found out: Reef tourism operators find less than five per cent of coral dead under ‘extreme’ bleaching
REEF tourism operators have found less than five per cent of coral has died off — compared to the 50 to 60 per cent estimated by scientists — under "extreme" mass coral bleaching on the northern Great Barrier Reef.
Latest findings exclusively obtained by The Courier-Mail show coral mortality in the outer shelf reefs north of Lizard Island was between one and five per cent with "spectacular" fish life and coral coverage.
Teams of divers in a joint two-week expedition sponsored by Mike Ball Dive and Spirit of Freedom surveyed 28 sites on 24 outer shelf reefs along a 300km section of the hardest-hit part of the reef from Bathurst Head to Raine Island.
Spirit of Freedom owner Chris Eade said reports of 93 per cent bleaching on the 2300km long Great Barrier Reef had made global headlines and damaged the reputation of the $5 billion reef tourism industry.
"Scientists had written off that entire northern section as a complete white-out," Mr Eade said. "We expected the worst. But it is tremendous condition, most of it is pristine, the rest is in full recovery. "It shows the resilience of the reef."
Mike Ball Dive Expeditions operations manager Craig Stephen, who conducted a similar survey on the remote reefs 20 years ago, said there had been almost no change in two decades despite the latest coral bleaching event.
"It wasn’t until we got underwater that we could get a true picture of what percentage of reef was bleached," Mr Stephen said. "The discrepancy is phenomenal. It is so wrong. Everywhere we have been we have found healthy reefs. "There has been a great disservice to the Great Barrier Reef and tourism and it has not been good for our industry."
The Great Barrier Reef Marine Park Authority estimated a mass coral white-out of between 50 to 60 per cent, on average, for reefs off Cape York under the world’s biggest-ever mass coral bleaching event.
Scientists with the Townsville-based ARC Centre of Excellence for Coral Reef Studies reported about 35 per cent mortality but warned "the final death toll" on some reefs may exceed 90 per cent.
In April, aerial and underwater surveys of 522 reefs in the northern sector showed 81 per cent had been severely bleached and one per cent not bleached.
Professor Terry Hughes, convener of the National Coral Bleaching Taskforce, at the time said "it’s like 10 cyclones have come ashore all at once."
Professor Hughes yesterday welcomed the positive news but had not yet seen the latest survey findings. "We won’t know the true coral mortality until we can get back up there in October and compare before and after impacts from our March survey," Prof Hughes said.
"Those coral will either survive or more will die."
A GBRMPA spokeswoman said they would closely examine the findings of the first independent expedition into the isolated region. "Obviously if they’ve found reefs with a lower than expected mortality rate that is fabulous news," she said.
"Our initial findings noted that the level of bleaching and mortality was expected to be very variable across the entire reef system."
Tuesday, August 23, 2016
Rising sea levels caused by global warming could be GOOD news for coral reefs
It all depends on your modelling
Global warming could do at least as much to protect the world’s coral reefs as it will to damage them, new research from Australia suggests.
Climate change has long been believed to be disastrous for the fragile marine environments, but fresh modelling has predicted that oceanic changes caused by the phenomenon will also work to the reefs’ advantage.
Rising sea levels, caused by melting polar ice caps, could help moderate the extreme and often damaging conditions found in many reef habitats, according to scientists at the University of Western Australia.
By studying reef systems off the coast of north-western Australia, they showed how rapid sea level rise could substantially reduce the volatile daily extremes of water temperatures in the shallow reef habitats over the next century.
The resulting changes, they say, may potentially ameliorate the other effects of global ocean warming.
Mounting levels of atmospheric carbon dioxide are predicted to cause substantial changes to ocean temperature over the next 100 years, increasing the frequency and severity of mass bleaching, where corals expel the symbiotic algae living in their tissues, turning them completely white.
In April scientists announced that 93 per cent of the famous 1,500 mile Great Barrier Reef, on Australia’s East Coast, had now been bleached as a result of an underwater heatwave caused by global warming.
The situation caused some scientists to urge the Australian government to decide which parts of the reef it wanted to save.
Reefs in the Caribbean and in other regions such as the Maldives have also been badly affected by bleaching.
Warming seas are part of a "triple punch" said to be hitting coral reefs as a result of global warming, along with ocean acidification, which makes it more difficult for corals to build and maintain their skeletons, and more frequent and powerful reef-wrecking storms.
The new research by Professor Ryan Lowe and his team is the first to attempt to predict in detail the positive effects rising surface levels on reef environments.
Temperatures within shallow reefs often differ substantially from the surrounding ocean, so predicting future patterns of bleaching and other stresses is difficult.
However, recent science has focused on trying to improve predictions of regional ocean warming patterns driven by long-term climate change, as well as by the intensification of short-term climate patterns such as El Nino.
Using a collection of detailed field measurements, Prof Lowe and his team developed a modelling framework for predicting how local temperature extremes in shallow reefs will change in the future as a result of rising sea levels.
They found that even a modest sea level rise could substantially reduce local reef water temperatures in the future, meaning the change may partially contribute to limiting reef heat extremes in an overall warming ocean.
Despite the international carbon emissions caps agreed at the Paris climate talks last year, atmospheric warming is still expected to rise to between 2.7 and 3C above pre-industrial levels, breaching the 2C threshold beyond which many scientists say heatwaves and significant sea level rises are inevitable.
In 2015 the United Nations World Heritage Committee agreed not to list the Great Barrier Reef as an "in danger" site, providing Australia reports back to the committee in December this year with an adequate account of what is being done to preserve the reef.