Coral Bleaching Revisited

[westwall]

Just wanted to get your attention. Florida just had the first coral bleaching event in 30 years...due to cold! Bet you never knew corals could die from the cold did you?

NOAA and partners from 12 organizations surveyed sites in the Florida Keys to determine the extent of coral bleaching, and death, in the wake of record low-water temperatures. Scientists assessed coral health at more than 78 sites from January 25 to February 12 to determine the severity of coral bleaching and reefs most affected.

During the first two weeks of January 2010, water temperatures in some parts of the Keys dropped into the upper 40s and lower 50s, which is about
20 degrees Fahrenheit lower than the typical temperatures of the upper 60s and lower 70s. The lethal lower limit for corals is 60 degrees Fahrenheit.


First Florida Cold-water Bleaching Event in 30 Years

 

[Old Rocks]

I think a comparison of the scope of warm water induced bleaching, and that created by the influx of cold water experiance by some corals this winter. According to your article, most corals were not affected.

» 80 Percent of Caribbean Corals Suffer Bleaching Due to Heat Stress Ecology Today: Ecology News, Information & Commentary Blog

Coral reefs suffered record losses as a consequence of high ocean temperatures in the tropical Atlantic and Caribbean in 2005 according to the most comprehensive documentation of basin-scale bleaching to date. Collaborators from 22 countries report that more than 80 percent of surveyed corals bleached and over 40 percent of the total surveyed died, making this the most severe bleaching event ever recorded in the basin. The study appears in PLoS ONE, an international, peer-reviewed, open-access, online publication.

“Heat stress during the 2005 event exceeded any observed in the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in at least 150 years,” said C. Mark Eakin, Ph.D., coordinator of NOAA’s Coral Reef Watch Program. “This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems, and events like this are likely to become more common as the climate warms.”

First Florida Cold-water Bleaching Event in 30 Years

This survey data will support greater understanding about coral reefs and guide efforts to protect these critical habitats. Researchers are still exploring whether this cold-stress event will make corals more susceptible to disease. Following warm-water stress events, the bacterial makeup of corals changes, increasing the prevalence of coral disease. This winter’s event allows scientists to collect data to compare and contrast coral health following both cold- and warm-water events.
Florida Keys National Marine Sanctuary, the manager of most Florida Keys coral reef resources, is working with the science community and limiting certain consumptive activities in the hardest hit areas until stressful conditions subside. The Sanctuary is also asking SCUBA divers to enjoy the many reefs not affected by January’s cold weather

 

[wirebender]

Back in 1997, alarmists told us that by 2010 40% of the worlds coral would be gone.

ABC News Watch: Past Alarm. World's Coral: 40% gone by 2010

Back then, the world's coral was estimated to be something like two hundred and fifty five thousand square kilometers.

SpringerLink - Coral Reefs, Volume 16, Number 4

Today, the world's coral is estimated to be over 249,700 square kilometers.

http://pdf.wri.org/factsheets/factsheet_reefs_main.pdf

How long do you think it will be before alarmists try to flush that failed prediction down the same hole they tried to flush the 50 million climate refugees?

It simply amazes me that anyone still places creedence in the alarmist side of the argument considering that nothing they predict ever seems to materialize.

 

[Old Rocks]

http://www.princeton.edu/step/people/faculty/michael-oppenheimer/research/Donner2.pdf

Abstract
Elevated ocean temperatures can cause coral bleaching, the loss of colour from reefbuilding
corals because of a breakdown of the symbiosis with the dinoflagellate
Symbiodinium. Recent studies have warned that global climate change could increase
the frequency of coral bleaching and threaten the long-term viability of coral reefs. These
assertions are based on projecting the coarse output from atmosphere–ocean general
circulation models (GCMs) to the local conditions around representative coral reefs.
Here, we conduct the first comprehensive global assessment of coral bleaching under
climate change by adapting the NOAA Coral ReefWatch bleaching prediction method to
the output of a low- and high-climate sensitivity GCM. First, we develop and test
algorithms for predicting mass coral bleaching with GCM-resolution sea surface temperatures
for thousands of coral reefs, using a global coral reef map and 1985–2002
bleaching prediction data. We then use the algorithms to determine the frequency of
coral bleaching and required thermal adaptation by corals and their endosymbionts
under two different emissions scenarios.
The results indicate that bleaching could become an annual or biannual event for the
vast majority of the world’s coral reefs in the next 30–50 years without an increase in
thermal tolerance of 0.2–1.0 1C per decade. The geographic variability in required thermal
adaptation found in each model and emissions scenario suggests that coral reefs in some
regions, like Micronesia and western Polynesia, may be particularly vulnerable to
climate change. Advances in modelling and monitoring will refine the forecast for
individual reefs, but this assessment concludes that the global prognosis is unlikely to
change without an accelerated effort to stabilize atmospheric greenhouse gas concentrations.

 

[Old Rocks]

Two good studies with somewhat differant approaches and conclusions.

Disturbance and the Dynamics of Coral Cover on the Great Barrier Reef (1995

Coral reef ecosystems worldwide are under pressure from chronic and acute stressors that threaten their continued existence. Most obvious among changes to reefs is loss of hard coral cover, but a precise multi-scale estimate of coral cover dynamics for the Great Barrier Reef (GBR) is currently lacking. Monitoring data collected annually from fixed sites at 47 reefs across 1300 km of the GBR indicate that overall regional coral cover was stable (averaging 29% and ranging from 23% to 33% cover across years) with no net decline between 1995 and 2009. Subregional trends (10–100 km) in hard coral were diverse with some being very dynamic and others changing little. Coral cover increased in six subregions and decreased in seven subregions. Persistent decline of corals occurred in one subregion for hard coral and Acroporidae and in four subregions in non-Acroporidae families. Change in Acroporidae accounted for 68% of change in hard coral. Crown-of-thorns starfish (Acanthaster planci) outbreaks and storm damage were responsible for more coral loss during this period than either bleaching or disease despite two mass bleaching events and an increase in the incidence of coral disease. While the limited data for the GBR prior to the 1980's suggests that coral cover was higher than in our survey, we found no evidence of consistent, system-wide decline in coral cover since 1995. Instead, fluctuations in coral cover at subregional scales (10–100 km), driven mostly by changes in fast-growing Acroporidae, occurred as a result of localized disturbance events and subsequent recovery.

 

[waltky]

Sunscreen ingredient linked to coral damage...

Study: Oxybenzone in Sunscreen Linked to Coral Damage
October 20, 2015 - Using sunscreen can cut your risk of developing some of the most dangerous forms of skin cancer by 50 percent. Unfortunately, a new study suggests it also may be doing severe damage to already threatened coral reefs around the world.

The research was done by the University of Central Florida and published in Tuesday's Archives of Environmental Contamination and Toxicology. The study tested the water around coral reefs in Hawaii and the Caribbean, and found a high concentration of Oxybenzone in the water. Oxybenzone is one of the most common ingredients in sunscreen, but it can do severe damage to fragile Coral Reefs. According to the research, the chemical not only kills coral, but it also causes DNA damage in adult coral, and deforms the larvae.

Coral is seen at the Great Barrier Reef in Australia.​

One member of the research team, John Fauth said damaging coral reefs doesn't just harm the coral, but it can affect humans, as well. “Coral reefs are the world’s most productive marine ecosystems and support commercial and recreational fisheries and tourism,” Fauth said. “In addition, reefs protect coastlines from storm surge. Worldwide, the total value of coral reefs is tremendous. And they are in danger.” So how can we still protect ourselves from the sun, and enjoy the water? Fauth recommends "rash guards, or scuba wetsuits." There also is a whole new generation of swimwear that has built-in sun protection.

Study: Oxybenzone in Sunscreen Linked to Coral Damage

 

[Billy_Bob]

http://www.princeton.edu/step/people/faculty/michael-oppenheimer/research/Donner2.pdf

Abstract
Elevated ocean temperatures can cause coral bleaching, the loss of colour from reefbuilding
corals because of a breakdown of the symbiosis with the dinoflagellate
Symbiodinium. Recent studies have warned that global climate change could increase
the frequency of coral bleaching and threaten the long-term viability of coral reefs. These
assertions are based on projecting the coarse output from atmosphere–ocean general
circulation models (GCMs) to the local conditions around representative coral reefs.
Here, we conduct the first comprehensive global assessment of coral bleaching under
climate change by adapting the NOAA Coral ReefWatch bleaching prediction method to
the output of a low- and high-climate sensitivity GCM. First, we develop and test
algorithms for predicting mass coral bleaching with GCM-resolution sea surface temperatures
for thousands of coral reefs, using a global coral reef map and 1985–2002
bleaching prediction data. We then use the algorithms to determine the frequency of
coral bleaching and required thermal adaptation by corals and their endosymbionts
under two different emissions scenarios.
The results indicate that bleaching could become an annual or biannual event for the
vast majority of the world’s coral reefs in the next 30–50 years without an increase in
thermal tolerance of 0.2–1.0 1C per decade. The geographic variability in required thermal
adaptation found in each model and emissions scenario suggests that coral reefs in some
regions, like Micronesia and western Polynesia, may be particularly vulnerable to
climate change. Advances in modelling and monitoring will refine the forecast for
individual reefs, but this assessment concludes that the global prognosis is unlikely to
change without an accelerated effort to stabilize atmospheric greenhouse gas concentrations.

So which is the greater danger there old fraud? The heat that doesn't exist or the cold that does?

 

[waltky]

Great Barrier Reef suffered worst bleaching on record in 2016...

Great Barrier Reef suffered worst bleaching on record in 2016, report finds
Mon, 28 Nov 2016 - This year saw the worst-ever destruction of coral on the Great Barrier Reef, a new study finds.

Some 67% of corals died in the reef's worst-hit northern section, the ARC Centre of Excellence for Coral Reef Studies report said. The situation was better in the central section, where 6% perished, while the southern reef is in good health. But scientists warn recovery could be difficult if climate change continues. Coral bleaching happens when water temperatures rise for a sustained period of time. In February, March and April, sea surface temperatures across the Great Barrier Reef were the hottest on record, at least 1C higher than the monthly average. "Some of the initial mortality was down to heat stress," said study leader Professor Terry Hughes. "The coral was cooked."

How bleaching occurs

Far more has been lost through gradual starvation, after the coral expelled the colourful algae zooxanthella, which turns sunlight into food. This is what leads to the white, skeletal appearance of the coral, which is left without its main source of energy. The study also found that the coral which survived the bleaching have now come under greater threat from predators such as snails and crown of thorns starfish. This year's mass bleaching was the worst-ever recorded on the Great Barrier Reef, following two previous events in 1998 and 2002.

Scientists assess coral mortality on Zenith Reef following the bleaching event, Northern Great Barrier Reef​

Professor Hughes is certain that the increased water temperature is the result of carbon emissions, and warns that climate change could bring annual bleaching within 20 years. "Most of the losses in 2016 have occurred in the northern, most pristine part of the Great Barrier Reef," he said. "This region escaped with minor damage in two earlier bleaching events in 1998 and 2002, but this time around it has been badly affected."

Where is the damage?

One of the worst-hit areas is around Lizard Island in Far North Queensland, where around 90% of the coral has died. Dr Andrew Hoey, whose team charted the area, said the impact was far worse than feared after an initial survey in April. "It's devastating to get in the water somewhere you've been coming for almost 20 years, and it's just knocked it on its head," he said. "There's very little coral cover left there. It was dominated by the acropora - the branching corals - but we lost most of them." Lizard Island is home to a research station, where scientists from across the world have come for decades to study marine life

One of its directors, Dr Anne Hogget, said this was by far the worst event to hit the Great Barrier Reef since she started working there in 1990. "We had bleaching here in 2002," she said. "We thought this was bad at the time, but this has blown it completely out of the water." She is hopeful that the reef is capable of recovery, but fears it may not be give an opportunity, as sea temperatures continue to rise. "The trajectory is not good," Dr Hogget explained. "We keep pumping carbon dioxide into the atmosphere, and this happened absolutely because of that."

What happens next?

 

[Old Rocks]

And once again, we see what an idiot that Mr. Westwall is.

Bleaching Hits 93 Percent of the Great Barrier Reef
Aerial surveys reveal that the giant coral reef is suffering under global warming

We knew coral bleaching was a serious issue in the Great Barrier Reef, but the scope of just how widespread it was has been unclear—until now.

Extensive aerial surveys and dives have revealed that 93 percent of the world’s largest reef has been devastated by coral bleaching. The culprit has been record-warm water driven by El Niño and climate change that has cooked the life out of corals.

The unprecedented destruction brought leading reef scientist Terry Hughes, who runs the ARC Center of Excellence for Coral Reef Studies, to tears.

We’ve never seen anything like this scale of bleaching before. In the northern Great Barrier Reef, it’s like 10 cyclones have come ashore all at once,” Hughes said in a press release.

The Center conducted aerial surveys and dives at 911 sites spanning the full 1,430-mile length of the reef. They show the hardest hit areas are in the northern part of the reefs, which have also endured some of the hottest water temperatures for prolonged periods.

More than 80 percent of reefs surveyed there showed signs of severe bleaching. The southern end of the reef fared better, but overall the bleaching represents a massive blow to biodiversity at the UNESCO World Heritage Site.

Bleaching Hits 93 Percent of the Great Barrier Reef

 

[waltky]

Coral reefs dying off...

Scientists race to prevent wipeout of world's coral reefs
Mar 12, 2017 - There were startling colors here just a year ago, a dazzling array of life beneath the waves. Now this Maldivian reef is dead, killed by the stress of rising ocean temperatures. What's left is a haunting expanse of gray, a scene repeated in reefs across the globe in what has fast become a full-blown ecological catastrophe.

The world has lost roughly half its coral reefs in the last 30 years. Scientists are now scrambling to ensure that at least a fraction of these unique ecosystems survives beyond the next three decades. The health of the planet depends on it: Coral reefs support a quarter of all marine species, as well as half a billion people around the world. "This isn't something that's going to happen 100 years from now. We're losing them right now," said marine biologist Julia Baum of Canada's University of Victoria. "We're losing them really quickly, much more quickly than I think any of us ever could have imagined."

Even if the world could halt global warming now, scientists still expect that more than 90 percent of corals will die by 2050. Without drastic intervention, we risk losing them all.
"To lose coral reefs is to fundamentally undermine the health of a very large proportion of the human race," said Ruth Gates, director of the Hawaii Institute of Marine Biology. Coral reefs produce some of the oxygen we breathe. Often described as underwater rainforests, they populate a tiny fraction of the ocean but provide habitats for one in four marine species. Reefs also form crucial barriers protecting coastlines from the full force of storms.

They provide billions of dollars in revenue from tourism, fishing and other commerce, and are used in medical research for cures to diseases including cancer, arthritis and bacterial or viral infections. "Whether you're living in North America or Europe or Australia, you should be concerned," said biologist Ove Hoegh-Guldberg, director of the Global Change Institute at Australia's University of Queensland. "This is not just some distant dive destination, a holiday destination. This is the fabric of the ecosystem that supports us."

And that fabric is being torn apart. "You couldn't be more dumb ... to erode the very thing that life depends on — the ecosystem — and hope that you'll get away with it," Hoegh-Guldberg said. Corals are invertebrates, living mostly in tropical waters. They secrete calcium carbonate to build protective skeletons that grow and take on impressive colors, thanks to a symbiotic relationship with algae that live in their tissues and provide them with energy.

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