Friday, October 9, 2015
Major coral bleaching crisis spreads worldwide (?)
This utter bulldust is typical of SETH BORENSTEIN -- though he appears to have been suckered by NOAA operatives. Warm water is NOT bad for corals. They are in fact at their most vigorous and diverse in very warm seas like the Torres strait -- which is not far from the equator (at 10.5 degrees South; Hawaii is 21 degrees North). The warmer the water, the happier the coral. A warmer world would have MORE coral. Periodic bleaching does occur but it is not well understood. All we know is that corals always bounce back from it fairly rapidly. You can drop a hydrogen bomb on coral and it will recover. It did at Bikini Atoll
The bleaching of colorful coral is spreading into a worldwide, devastating crisis, scientists say, and they predict it will likely get worse.
Triggered by global warming and the El Nino, record hot ocean water is causing fragile coral to go white and often die, threatening picturesque reefs that are hotspots of marine life, experts say.
The spread of sickly white started more than a year ago in Guam, then devastated Hawaii, infected the rest of the tropical Pacific and the Indian oceans and has now infested Florida and the Caribbean. On Thursday, the National Oceanic and Atmospheric Administration and international reef scientists pronounced it a global coral bleaching event, only the third in recorded history.
No place with coral has been spared, though some regions — such as Hawaii — have been hit harder than others, experts said. Excessive heat stresses the living coral, which turns white and then becomes vulnerable to disease.
"We may be looking at losing somewhere in the range of 10 to 20 percent of the coral reefs this year," NOAA coral reef watch coordinator Mark Eakin said. "The bad news for the U.S. is we're getting hit disproportionately just because of the pattern of the warming."
He called bleaching a crisis, especially with worsening global warming forecast for the rest of the century: "If that's not a crisis, what is?"
Eakin said he's especially concerned about Hawaii, which already suffered through bad bleaching in 2014.
"Hawaii is getting hit with the worst coral bleaching they have ever seen, right now," Eakin said. "It's severe. It's extensive. And it's on all the islands."
In one part of northwestern Hawaii, "the reef just completely bleached and all of the coral is dead and covered with scuzzy algae."
Florida started getting hit in August. The middle Florida Keys aren't too bad, but in southeast Florida, bleaching has combined with disease to kill corals, Eakin said. It has also hit Cuba, Haiti and the Dominican Republic and is about to hit Puerto Rico and the Virgin Islands, he said.
Warm water causes bleaching and ocean temperatures are at record high levels, partly because of steady manmade global warming and partly because of the El Nino, which is an occasional warming of the central Pacific that changes weather worldwide, Eakin said. Add to that Hawaii's "blob," a pool of warm water that has stagnated in the northeast Pacific.
The last super El Nino, in 1997-1998, was the first global bleaching event. A smaller El Nino in 2009-2010 was the second.
So far the 1998 bleaching was worse, but that was the second year of an El Nino and we're in the first of two years now, Eakin said.
Monday, August 24, 2015
Study shows Pacific island reefs can match rising sea levels
Coral reefs are a lot more resilient than previously thought. At least according to a new study published yesterday that showed Pacific island coral reef can grow fast enough to match rising sea levels, even with increased ocean temperatures. coral reefs
Because they grow vertically on shallow reef flats, researchers observed that Porites microatolls coral is keeping pace with current sea level rise, but may have trouble under the worst-case IPCC scenarios. The Porites microatoll, whose growth is largely lateral and limited by exposure to air, is named for its resemblance to island atolls (see picture).
Researchers at the Florida Institute of Technology, who published their study in the Royal Society Open Science, say their findings provide the first evidence that "well-managed reefs will be able to keep up with sea-level rise through vertical growth." However, if CO2 emissions rise past 670 parts per million (ppm), which may cause ocean temperatures to increase 2.2 degrees Celsius, reefs will have a hard time keeping up with the projected sea level rise.
Currently CO2 levels worldwide are 400 ppm (.o4 percent), but once they cross the 670 ppm threshold, the corresponding rise in ocean temperatures may hamper even a healthy reefs ability to survive. "Reefs will continue to keep up with sea-level rise if we reduce our emission of greenhouse gases," said Florida Tech’s Rob van Woesik, a professor at FIT's Department of Biological Sciences and the study's lead author. "If reefs lose their capacity to keep up with sea-level rise they will drown."
The study, which focused on Palau island in the western Pacific Ocean, was also co-authored by researchers from the University of Queensland and the Palau International Coral Reef Center. Palau is an island country that is part of the larger Pacific island group of Micronesia and relies on the reef system to break apart storm waves.
The researchers measured "570 reef-flat Porites microatolls (a type of coral) at 10 locations around Palau, which revealed recent vertical skeletal extension (78±13 mm) over the last 6–8 years," consistent with the observed increase in sea level. The study's authors then used the Intergovernmental Panel on Climate Change (IPCC) greenhouse-gas concentration trajectories from its 2014 fifth Assessment Report to model four different outcomes for the Porites microatolls. It showed that under the low- to mid-RCP scenarios, reef-coral growth will keep up with sea-level rise."
These IPCC's RCP pathways are primarily used for climate modeling and research and "describe four possible climate futures," depending on how much greenhouse gases are emitted in the future.
However, under the IPCC's worst-case RCP scenario, where "greenhouse gas concentrations exceed 670 ppm atmospheric CO2 levels with a concomitant increase of 2.2 degree Celsius in sea-surface temperatures by 2100," their "predictions indicate that Poritesmicroatolls will be unable to keep up with projected rates of sea-level rise."
CO2 levels have increased at a rate of approximately 2 ppm/year since recordkeeping began. That means if current trends continue, CO2 levels will have increased only 170 ppm by the year 2100, much less than the 670 ppm or higher needed to affect the reef systems described in the study. There is also an annual fluctuation of about ~10 ppm that is negatively correlated with the Northern Hemisphere's growing season (plants absorb CO2 during the spring/summer/early fall).
As reported here, other studies have also shown coral reefs are far more resilient then previously estimated. One 13-year study of coral reefs showed "them spontaneously recovering," refuting the "often doomsday forecasts about the worldwide decline of the colorful marine habitat." Tom Frazer, professor of aquatic ecology at the University of Florida and part of that study, told Reuters, "People have said these systems don't have a chance. What we are saying is: 'Hey, this is evidence they do have a chance.'"
Another study—funded by NOAA—showed that coral reefs can also adapt to warmer ocean temperatures through a variety of processes. Even after the great coral die-off in 1998 from a particular brutal El Niño, most of the coral reefs across the planet rebounded to their original numbers. Coral can also perish from a variety of issues: environmental stressors, such as elevated temperature; changes in salinity; high solar radiation; pollutants; and/or diseases.
This latest study from the Florida Institute of Technology will be good news to the thousands of people who populate these Pacific islands and rely on the intricate reef system for protection and tourists.
Thursday, July 30, 2015
A mystery that is a mystery to Warmists only
In science, when something shows your theory is wrong, you change your theory. In Warmism, if something shows your theory is wrong, it's a "mystery". The finding below shows that coral deaths presently being attributed to warming are NOT produced by warming
AN ancient coral reef specimen now on display at the Natural History Museum in London is at the centre of a global warming mystery spanning 160 million years.
THE exhibit is proof that ancestors of modern corals somehow thrived during the Late Jurassic period when temperatures were warmer and atmospheric levels of carbon dioxide higher than they are today.
Yet global warming in the 21st century is already associated with serious damage to coral reefs caused by "bleaching".
Dr Ken Johnson, coral reefs researcher at the London museum, said: "By researching historical fossil corals like this, we can understand and predict the impact of climate change and other environmental factors on coral reefs over time.
"This 160-million-year-old specimen is an ancestor of some of the corals on our planet today, showing us that a sustainable future for coral reefs is possible because they can survive severe global environmental changes."
Early corals also managed to survive the mass extinction at the end of the Cretaceous period 65 million years ago that wiped out the dinosaurs and many other species.
If greenhouse gas emissions continue unchecked, atmospheric carbon dioxide is expected to match Late Jurassic levels by 2100 and to exceed them by 2250.
Bleaching occurs when stressful environmental conditions cause corals to expel the symbiotic algae living in their tissues, turning them white.
Corals depend for their survival on the algae, which provide them with oxygen and nutrients. When they bleach they begin to starve.
Professor Richard Twitchett, palaeoecology researcher at the Natural History Museum, said: "At the time this coral reef was alive, 160 million years ago, our planet's marine biodiversity was as high as it had ever been.
"The fact that this coral reef lived in a much warmer world shows that if we monitor and control future changes, coral reefs can remain one of the most important ecosystems on Earth."
Monday, July 20, 2015
Australian Federal minister Takes To Twitter To Threaten Green Groups Will Lose Their Charity Status
Federal Queensland Liberal-National Party politician George Christensen has issued what appears to be a veiled threat to non-government organisations to “get the donations in” before a committee he sits on strips environmental charities of their tax-exempt status.
Yesterday, the National Party Deputy Whip grilled environmental groups in the first of a series of public hearings which the House of Representatives Standing Committee on the Environment will stage as it considers whether to strip environmental organisations from receiving tax-free donations.
The Queensland Minerals Council - which has allied itself to Christensen in the debate over how huge new coal mines in the Galilee Basin will affect the Great Barrier Reef - appeared first, yesterday morning.
Then Christensen turned his attention to environmental groups, who he described as “morons” during a technical exchange over whether land should be considered to be part of the Great Barrier Reef’s ecosystem.
Felicity Wishart from the Australian Marine Conservation Society was interrogated by the Queensland MP, whose electorate takes in a swathe of coastline adjacent to the Great Barrier Reef.
“He was questioning me about our commitment to accurate information that wasn’t misleading and then trying to grasp at straws and find something that we had done that was misleading,” Wishart told New Matilda.
The Marine Conservation Society had used an image in its campaign material which superimposed a ‘grab dredger’ over the Calley Valley Wetlands and an image of Abbot Point Port, 25km north of Bowen.
Reportedly, Christensen’s main gripes were that the wetlands are ‘not part of the reef’, and the type of dredge to be used for the Abbot Point Port expansion was ‘suction dredger’, not a ‘grab dredger’.
While maintaining the wetlands are an important part of the reef’s ecosystem, Wishart said that the image of a grab dredger was a metaphor for the “one million cubic metres of dredge spoil… that was to be dumped on the wetlands” under previous plans.
After grilling Wishart about the integrity of her organisation’s campaigning, Christensen took to Twitter insisting “they were caught out fibbing, and the committee will sort these sort of lies out”.
The Australian Marine Conservation Society denounced Christensen for “unparliamentary” behaviour, accusing him of “announcing the outcome of the inquiry before it has concluded”, but Christensen said he was “just reading the tea leaves”.
Christensen has previously attacked “gutless green grubs” and “eco-terrorists” for campaigning to win more stringent protections for the reef and battling against an increase in Queensland’s coal exports, which would pump out emissions roughly equal to those created by the United Kingdom, South Africa, or Italy.
The Member for Dawson, who has questioned widely accepted understandings of climate science, has a history of Tweet-controversy. Last month he was forced into an apology over comments linking the American right to bear arms with a recent court decision which legalised marriage equality across the US.
Yesterday, at the inquiry, groups like the AMCS got the distinct impression Christensen was pressing the gun harder to their temples.
“This sounds very much like a government member of the Inquiry threatening environment groups who have been vocal about issues like dredging, dumping and increased shipping in the Reef’s waters,” said Wishart, who acts as a Great Barrier Reef Campaign Director.
In late March, Wishart’s work was singled out as part of a pack of “extreme greens” working for organisations like “Greenpeace, the Australian Marine Conservation Society, Friends of the Earth, Get Up, and the Environmental Defenders Office” who Christensen said “act like Wormtongue from The Lord of the Rings”.
“That is treason,” Christensen told Parliament, “flying overseas and whispering in the ears of the decision-makers and diplomats who have anything to do with UNESCO and the World Heritage Committee, poisoning their minds on the state of the reef”.
“What treachery,” Christensen said, “to go against the interests of your own nation and your own people for no sound reason at all!”
Monday, July 13, 2015
NOAA's estimate of coral bleaching likely two times too high
Written by Thomas Richard
NOAA sounded the alarm yesterday that coral reefs are dying off at an unprecedented rate, even though a recent paper shows that these statements may be more alarmist than accurate. coral bleachingThe National Oceanic and Atmospheric Administration (NOAA) said multi-yearwarm ocean temperatures are creating conditions that are causing corals to die off and turn white (bleached), and they believe that global warming is the culprit. But a new paper, published in Marine Biology in April 2015, shows that even though some corals appear bleached, it doesn't mean they are dead, as conventional tracking methods can't distinguish between white and bleached (dead) colonies.
The paper, by Cruz et al, says that "although bleaching leaves the coral skeleton visible under its transparent tissue, not all white coral colonies display this feature," which "raises the question as to whether all 'white'-shaded colonies are indeed bleached." To answer that question of whether bleached coral is actually dead, Cruz et al studied different colored specimens of the coral M. cavernosa sampled off the east coast of Brazil, and found thatwhite corals exhibited the same lifelike features as their multi-colored cousins.
Simply put, white corals were physiologically healthy when compared to dark and light-brown colonies, which would lead to the "potential overestimation of coral bleaching" by nearly twice as much. One reason for this overestimation is that traditional coral monitoring is unable to detect between white and bleached (dead) colonies. Video transects from reef monitoring surveys off the coast of Brazil showed that the "proportion of bleached and white colonies is similar, thus suggesting that current coral reef surveys may be overestimating the bleaching of M. cavernosa by nearly twofold."
That didn't stop Mark Eakin, NOAA's Coral Reef Watch coordinator, from saying, "The bleaching that started in June 2014 has been really bad for corals in the western Pacific. We are worried that bleaching will spread to the western Atlantic and again into Hawaii." The announcement from NOAA appears to be part of the Obama administration's ongoing campaign to attribute global warming to any event as it gathers commitments from other countries ahead of the Paris Climate Talks.
NOAA also added that only warm ocean temperatures can cause the widespread bleaching that monitoring has found since last year, but this new paper also contradicts that statement. Coral bleaching, the paper says, "is a physiological mechanism triggered by environmental stress, such as elevated temperature, changes in salinity, high solar radiation, pollutants or diseases." They note that "although bleaching leaves the coral skeleton visible under its transparent tissue, not all white coral colonies display this feature."
Once corals die, they turn "white" and have a bleached appearance. But other studies have shown corals are more resilient then previously estimated. One 13-year study of coral reefs showed "them spontaneously recovering," refuting the "often doomsday forecasts about the worldwide decline of the colorful marine habitat." Tom Frazer, professor of aquatic ecology at the University of Florida and part of the research team, told Reuters, "People have said these systems don't have a chance. What we are saying is: 'Hey, this is evidence they do have a chance.'"
One study—funded by NOAA—shows that coral reefs could even adapt to warmer ocean temperatures through a variety of processes. Even after the great coral die-off in 1998 from a particular brutal El Niño, most of the coral reefs across the planet rebounded to their original numbers.
This isn't the first time that NOAA has used dubious data to justify global warming alarmism. In early June, NOAA rewrote the historical climate record by making it "cooler" so the present appears warmer. Even climate scientists who believe that man is primarily responsible for the planet warming less than one degree Celsius over the last 100 years rejected NOAA's readjustments to hide the 18-year-and-counting global warming hiatus.
Monday, June 15, 2015
Coral not co-operating with Warmist theory
As the ocean absorbs atmospheric carbon dioxide (CO2) released by the burning of fossil fuels, its chemistry is changing. The CO2 reacts with water molecules, lowering the ocean's pH in a process known as ocean acidification. This process also removes carbonate ions, an essential ingredient needed by corals and other organisms to build their skeletons and shells.
Will some corals be able to adapt to these rapidly changing conditions? If so, what will these coral reefs look like as the oceans become more acidic?
In addition to laboratory experiments that simulate future ocean conditions, scientists are studying coral reefs in areas of the ocean where low pH is naturally occurring to try and answer important questions about ocean acidification, which threatens coral reef ecosystems worldwide.
One such place is Palau, an archipelago in the far western Pacific Ocean. The tropical, turquoise waters of the Palau Rock Islands are naturally more acidic due to a combination of biological activity and the long residence time of seawater within its maze of lagoons and inlets. Seawater pH within the Rock Island lagoons is as low now as the open ocean is projected to be as a result of ocean acidification near the end of this century.
A new study led by scientists at Woods Hole Oceanographic Institution (WHOI) found that the coral reefs there seem to be defying the odds, showing none of the predicted responses to low pH except for an increase in bioerosion -- the physical breakdown of coral skeletons by boring organisms such as mollusks and worms. The paper is to be published June 5 in the journal Science Advances.
'Based on lab experiments and studies of other naturally low pH reef systems, this is the opposite of what we expected,' says lead author Hannah Barkley, a graduate student in the WHOI-MIT joint program in oceanography.
Experiments measuring corals' responses to a variety of low pH conditions have shown a range of negative impacts, such as fewer varieties of corals, more algae growth, lower rates of calcium carbonate production (growth), and juvenile corals that have difficulty constructing skeletons.
'Surprisingly, in Palau where the pH is lowest, we see a coral community that hosts more species, and has greater coral cover than in the sites where pH is normal,' says Anne Cohen, a co-author on the study and Barkley's advisor at WHOI. 'That's not to say the coral community is thriving because of it, rather it is thriving despite the low pH, and we need to understand how.'
Friday, June 5, 2015
Coral growth and thriving shows no clear connection to temperature variations
The paper below is not easy for a non-specialist to follow but my heading above sums up its major finding. Global warming won't bother it, in other words
Regional coral responses to climate disturbances and warming is predicted by multivariate stress model and not temperature threshold metrics
Timothy R. McClanahan, Joseph Maina, Mebrahtu Ateweberhan
Oceanic environmental variables derived from satellites are increasingly being used to predict ecosystem states and climate impacts. Despite the concerted efforts to develop metrics and the urgency to inform policy, management plans, and actions, few metrics have been empirically tested with field data for testing their predictive ability, refinement, and eventual implementation as predictive tools. In this study, the abilities of three variations of a thermal threshold index and a multivariate stress model (MSM) were used to predict coral cover and community susceptibility to bleaching based on a compilation of field data from Indian Ocean reefs across the strong thermal anomaly of 1998. Field data included the relative abundance of coral taxa 10 years before the large-scale temperature anomaly, 2 years after (1999–2000), and during the post-bleaching recovery period (2001–2005) were tested against 1) a multivariate model based on 11 environmental variables used to predict stress or environmental exposure (MSM), 2) estimates of the time until the current mean maximum temperature becomes the mean summer condition (TtT), 3) the Cumulative Thermal Stress (CTS) for the full satellite record, and 4) the 1998 Annual Thermal Stress (1998 ATS). The MSM showed significant fit with the post-1998 cover and susceptibility of the coral community taxa (r2 = 0.50 and 0.31, respectively). Temperature threshold indices were highly variable and had relatively weak or no significant relationships with coral cover and susceptibility. The ecosystem response of coral reefs to climatic and other disturbances is more complex than predicted by models based largely on temperature anomalies and thresholds only. This implies heterogeneous environmental causes and responses to climate disturbances and warming and predictive models should consider a more comprehensive multiple parameter approach.
Climatic Change, April 2015
Friday, May 15, 2015
Is Australia's Great Barrier Reef 'In Danger'?
If I have the time I do sometimes read Australia's far-Left "New Matilda". I would like to start a blog that regularly demolished their articles -- perhaps to be called "Walzing New Matilda" -- but I have weightier matters to spend my time on. Anyway, the article below is up to its usual standard of presenting only half of the story. Balance is the Devil incarnate to Leftists.
Some scientists do say that the GBR has shrunk by 50% but the interesting question is why there has been any shrinkage at all. The Warmist below knows why, of course. It's because of global warming. Pesky that there has been no global warming for 18 years though. Can something that does not exist cause anything? They also seem to think that Richard Branson is a climate scientist. Enough said on that.
The key point, however, is that the reef does get heavily impacted by natural events such as the many cyclones that have hit North Queensland in recent years. Cyclones are very destructive of coral. HOWEVER, when we look at that storm destruction, we also find that corals grow back rapidly. While that happens, the GBR is in no "danger". Any changes are temporary. See here and here, for instance.
Warmists will say that the cyclones were caused by global warming but again I ask: Can something that does not exist cause anything?
Billionaire Richard Branson has urged the United Nations to list the World Heritage value of the Great Barrier Reef as ‘in danger’ after being approached by advocacy group 1Million Women.
While admitting the campaign may seem “counter intuitive”, Branson argues it is an effective way to “stop further irreversible damage” to the reef “and to protect it for generations to come”.
“Saying the Great Barrier Reef is ‘in danger’ could be just what it needs,” Branson wrote in a blog post yesterday.
The United Nations World Heritage Committee is set to make a decision on whether to change the listing of the reef at a meeting in Bonn, Germany, in June this year.
Like Branson, the UN has expressed concern that port developments and coal ships set to service Australia’s largest ever coal mine, which the federal government approved last year, will further damage the reef.
The Great Barrier Reef has already lost half of its coral cover in the last three decades, and it faces further threats from the Crown of Thorns Starfish and increased agriculture run-off.
In 2013, a federal government report noted that 24 out of 41 attributes which make up the ‘Outstanding Universal Value’ of the reef under the World Heritage Convention are deteriorating.
But the greatest threat to the reef, according to government scientists, is climate change. “The reef’s plight, like many others, is unbearably sad,” Branson said. “It is being totally overwhelmed by climate change impacts through a destructive combination of heat-driven coral bleaching, ocean acidification and tropical storms.”
Despite climate change being the greatest threat to the reef, a recent Australian Government plan designed to guide conservation efforts for the next 35 years and address UN concerns made next to no mention of the risk to the reef from rising emissions.
On Thursday, the United Nations warned that for the first time in millions of years the concentration of carbon dioxide in the earths atmosphere exceeded 400 parts per million.
The Greens environment spokesperson, Larissa Waters, said on Wednesday that she doesn’t “think the government has done enough policy-wise to avert the threat of a world heritage in danger listing for the Great Barrier Reef”.
“Which is an absolute tragedy,” she said, “because we’re talking about one of the seven wonders of the world.”
“The foremost World Heritage Committee has for the past four years now said to Australia ‘slow down, you’re on this path of industrialisation, we’re worried about the future of the reef, your own scientists are worried about the future of your reef, what are you going to do about it?”
“And the government has consistently thumbed its nose at the key recommendations, and it’s made some changes around the edges.”
Waters said she hopes the reef is not listed as ‘in danger’, despite the fact it is “in serious jeopardy”.
Yesterday, The World Wildlife Fund has released a ‘to do’ list, lobbying the government to do more than is proposed in its ‘Reef 2050’ plan.
At least one federal MP is likely to be unimpressed with these recent developments.
George Christensen MP, whose electorate of Dawson takes in part of the Great Barrier Reef, is standing by the government’s “exemplary document”.
The outspoken backbencher recently voiced his outrage at “eco-traitors” who are committing the “treason” of advocating for an ‘in danger’ listing.
“These extreme greens act like Wormtongue from The Lord of the Rings, flying overseas and whispering in the ears of the decision-makers and diplomats who have anything to do with UNESCO and the World Heritage Committee, poisoning their minds on the state of the reef,” Christensen said.
“They belong to groups such as Greenpeace, the Australian Marine Conservation Society, Friends of the Earth, Get Up, and the Environmental Defenders Office.”
Thursday, May 14, 2015
Parental environment mediates impacts of increased carbon dioxide on a coral reef fish
Fish adapt rapidly to climate change -- within one generation
Gabrielle M. Miller et al.
Carbon dioxide concentrations in the surface ocean are increasing owing to rising CO2 concentrations in the atmosphere1. Higher CO2 levels are predicted to affect essential physiological processes of many aquatic organisms2, 3, leading to widespread impacts on marine diversity and ecosystem function, especially when combined with the effects of global warming4, 5, 6. Yet the ability for marine species to adjust to increasing CO2 levels over many generations is an unresolved issue. Here we show that ocean conditions projected for the end of the century (approximately 1,000 μatm CO2 and a temperature rise of 1.5–3.0 °C) cause an increase in metabolic rate and decreases in length, weight, condition and survival of juvenile fish. However, these effects are absent or reversed when parents also experience high CO2 concentrations. Our results show that non-genetic parental effects can dramatically alter the response of marine organisms to increasing CO2 and demonstrate that some species have more capacity to acclimate to ocean acidification than previously thought.
Nature Climate Change 2, 858–861 (2012) doi:10.1038/nclimate1599
Tuesday, April 14, 2015
Heat Resistance in Reef-Building Corals
Discussing: Bay, R.A. and Palumbi, S.R. 2014. "Multi-locus adaptation associated with heat resistance in reef-building corals". Current Biology 24: 252-2956.
Introducing their informative study, Bay and Palumbi (2014) write that "physiology and gene expression patterns have shown that corals living in naturally high-temperature microclimates are more resistant to bleaching because of both acclimation and fixed effects, including adaptation," citing in this regard the slightly earlier work of Palumbi et al. (2014). And in further searching for potential genetic correlates of these fixed effects, they go on to describe how they "genotyped 15,399 single nucleotide polymorphisms (SNPs) in 23 individual table top corals, Acropora hyacinthus, within a natural temperature mosaic in backreef lagoons on Ofu Island, American Samoa."
This effort led to the two researchers identifying 114 highly divergent SNPs that appeared to be good candidates for environmental selection, as a result of multiple stringent outlier tests they conducted, as well as the corals' evident correlations with temperature. More specifically, they report that "corals from the warmest reef location had higher minor allele frequencies across these candidate SNPs, a pattern not seen for non-candidate loci." In addition, they discovered that "within backreef pools, colonies in the warmest microclimates had a higher number and frequency of alternative alleles at candidate loci."
In discussing the significance of their findings, Bay and Palumbi say they imply a "mild selection for alternate alleles at many loci in these corals during high heat episodes and possible maintenance of extensive polymorphism through multi-locus balancing selection in a heterogeneous environment," which leads them to their ultimate conclusion that a natural population of these corals "harbors a reservoir of alleles preadapted to high temperatures, suggesting potential for future evolutionary response to climate change."