Coral reefs bleach under extreme heat

[flacaltenn]

Great Barrier Reef suffered worst bleaching on record in 2016, report finds

Higher water temperatures in 2016 caused the worst destruction of corals ever recorded on Australia's Great Barrier Reef, a study has found.

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.

Great Barrier Reef suffered worst bleaching on record in 2016, report finds - BBC News

A major bleaching event last year, doesn't look much better for this year.

Very unscientific statements in that piece. Especially about the "cooking" -- because bleaching can be a COOLING event as well. Especially in the greater than +/-2 degC over weeks type time frame.

In fact bleaching CAN BE any of one of about 6 or 8 factors. Including changes in salinity, UV exposure, sea level rise/fall, non-organic pollution, etc..

And I don't suppose that this chart BELOW would have ANYTHING at all with the fragile eco system..

Naaawww. Couldn't be. There would be NO FUNDING to investigate it..

Except that we NOW KNOW that LOCALIZED bleaching events can be blamed on agriculture runoff, EVEN minute amounts of sunscreen components at popular dive sites. But CERTAINLY, not things like UV shifts, pollution or ENSOs or even COOLING events.

Real fucking dumb. The article states that the temperatures were the hottest ever record on the reef. What is it with you, Mr. Flacaltenn? Why are you trying to divert and lie about what the article states in very clear english?

You must have read a different article

"the report shows that the loss of parrotfish and sea urchin – the area’s two main grazers – has, in fact, been the key driver of coral decline in the region. An unidentified disease led to a mass mortality of the sea urchin in 1983 and extreme fishing throughout the 20th century has brought the parrotfish population to the brink of extinction in some regions. The loss of these species breaks the delicate balance of coral ecosystems and allows algae, on which they feed, to smother the reefs."

This is a good example of how enviro issues and science have been "dumbed downed" by looking to GW as the PRINCIPAL and primary driver of EVERY eco issue. There's PLENTY of new work that contradicts the "consensus" GW propaganda. One of my favorites is ----

Coral Reefs in Palau Surprisingly Resistant to Naturally Acidified Waters

The team collected water samples at nine points along a transect that stretched from the open ocean, across the barrier reef, into the lagoon and then into the bays and inlets around the Rock Islands of Palau, in the western Pacific Ocean. With each location they found that the seawater became increasingly acidic as they moved toward land.

“When we first plotted up those data, we were shocked,” said lead author Kathryn Shamberger, then a postdoctoral scholar at Woods Hole Oceanographic Institution (WHOI) and a chemical oceanographer. “We had no idea the level of acidification we would find. We’re looking at reefs today that have levels that we expect for the open ocean in that region by the end of the century.”


The new research, published in Geophysical Research Letters, a journal of the American Geophysical Union, explains the natural biological and geomorphological causes of the more acidic water near Palau’s Rock Islands and describes a surprising second finding – that the corals living in that more acidic water were unexpectedly diverse and healthy. The unusual finding, which is contrary to what has been observed in other naturally low pH coral reef systems, has important implications for the conservation of corals in all parts of the world.

Learning tip here is -- that almost EVERY PAPER of this type starts off with an HONEST scientific appraisal of how LITTLE we know about the bounds of "normal" in these bio-systems. YET -- everyone rushes to point to ONE variable as the evil tweaker in every case.

 

[flacaltenn]

AND another bit of ACTUAL coral science -- not tainted by the focus on GW/CC..

Swimmers' Sunscreen Killing Off Coral

Swimmers' Sunscreen Killing Off Coral
Ker Than
for National Geographic News
January 29, 2008
The sunscreen that you dutifully slather on before a swim on the beach may be protecting your body—but a new study finds that the chemicals are also killing coral reefs worldwide.

Four commonly found sunscreen ingredients can awaken dormant viruses in the symbiotic algae called zooxanthellae that live inside reef-building coral species.


The chemicals cause the viruses to replicate until their algae hosts explode, spilling viruses into the surrounding seawater, where they can infect neighboring coral communities.

Danovaro and his team studied the effects of sunscreen exposure on coral samples from reefs in the Pacific, Atlantic, and Indian Oceans.

Even low levels of sunscreen, at or below the typical amount used by swimmers, could activate the algae viruses and completely bleach coral in just four days, the results showed.

Seawater surrounding coral exposed to sunscreen contained up to 15 times more viruses than unexposed samples.

Any reef structure that even gets CLOSE human contact is at threat by this. Article estimates that 4000 to 6000 TONS of this junk get released at beaches and dive sites.. So if there's PHOTOGRAPHS of damage -- there's exposure to human sun screens. Remote places can still get it by run off from beaches and storm drains.

 

[Olde Europe]

So, there's an actual bit of good news:

Coral Reefs in Palau Surprisingly Resistant to Naturally Acidified Waters

Through analysis of the water chemistry in Palau, the scientists found the acidification is primarily caused by the shell building done by the organisms living in the water, called calcification, which removes carbonate ions from seawater. A second reason is the organisms’ respiration, which adds CO2 to the water when they breathe.

“These things are all happening at every reef,” said Cohen. “What’s really critical here is the residence time of the sea water.”

“In the Rock Islands, the water sits in the bays for a long time before being flushed out. This is a big area that’s like a maze with lots of channels and inlets for the water to wind around,” explained Shamberger. “Calcification and respiration are continually happening at these sites while the water sits there, and it allows the water to become more and more acidic. It’s a little bit like being stuck in a room with a limited amount of oxygen – the longer you’re in there without opening a window, you’re using up oxygen and increasing CO2.”

Ordinarily, she added pushing the analogy, without fresh air coming in, it gets harder and harder for living things to thrive, “yet in the case of the corals in Palau, we’re finding the opposite.

“What we found is that coral cover and coral diversity actually increase as you move from the outer reefs and into the Rock Islands, which is exactly the opposite of what we were expecting.”

The scientists’ next steps are to determine if these corals are genetically adapted to low pH or whether Palau provides a “perfect storm” of environmental conditions that allows these corals to survive the low pH. “If it’s the latter, it means if you took those corals out of that specific environment and put them in another low pH environment that doesn’t have the same combination of conditions, they wouldn’t be able to survive,” said Cohen. “But if they’re genetically adapted to low pH, you could put them anywhere and they could survive.”

“These reef communities have developed under these conditions for thousands of years,” said Shamberger, “and we’re talking about conditions that are going to be occurring in a lot of the rest of the ocean by the end of the century. We don’t know if other coral reefs will be able to adapt to ocean acidification – the time scale might be too short.”

The scientists are careful to stress that their finding in Palau is different from every other low pH environment that has been studied. “When we find a reef like Palau where the coral communities are thriving under low pH, that’s an exception,” said Cohen. “It doesn’t mean coral reefs around the globe are going to be OK under ocean acidification conditions. It does mean that there are some coral communities out there – and we’ve found one – that appear to have figured it out. But that doesn’t mean all coral reef ecosystems are going to figure it out.”​

So, to sum this up. Conditions in parts of Palau's waters are fairly unique, as there are reservoirs with little water exchange. Corals building shells (calcification) and breathing CO₂ in these areas have a long time to make these waters more acidic before these waters are being flushed out, and have done that for thousands of years. In an as of yet not determined way, these corals have adapted to the conditions they themselves have been creating for a long time, and thrive in conditions otherwise unhealthy for other corals. Acidification in these areas is primarily caused by the corals, not by increasing CO₂ levels in the atmosphere.

So, maybe some of these corals can be transferred to other reefs to replace the corals there dying off there. Whether that's even possible, whether these corals survive in conditions to which they aren't specifically adapted, and whether they survive the rising sea temperatures is also not known. It's probably overly optimistic to say they will survive the combination of rising temperatures, overfishing, and pollution that characterizes much of coastal sea life, even if the acidification won't kill them off.

Some good news: Coral can adapt - over thousands of years - to conditions that would otherwise be unhealthy. The bad news is, corals the world over won't get thousands of years to adapt to the conditions they'll be facing at the end of this century, as the devastating bleeching at the most pristine northern part of the Great Barrier Reef demonstrates.

 

[flacaltenn]

So, there's an actual bit of good news:

Coral Reefs in Palau Surprisingly Resistant to Naturally Acidified Waters

Through analysis of the water chemistry in Palau, the scientists found the acidification is primarily caused by the shell building done by the organisms living in the water, called calcification, which removes carbonate ions from seawater. A second reason is the organisms’ respiration, which adds CO2 to the water when they breathe.

“These things are all happening at every reef,” said Cohen. “What’s really critical here is the residence time of the sea water.”

“In the Rock Islands, the water sits in the bays for a long time before being flushed out. This is a big area that’s like a maze with lots of channels and inlets for the water to wind around,” explained Shamberger. “Calcification and respiration are continually happening at these sites while the water sits there, and it allows the water to become more and more acidic. It’s a little bit like being stuck in a room with a limited amount of oxygen – the longer you’re in there without opening a window, you’re using up oxygen and increasing CO2.”

Ordinarily, she added pushing the analogy, without fresh air coming in, it gets harder and harder for living things to thrive, “yet in the case of the corals in Palau, we’re finding the opposite.

“What we found is that coral cover and coral diversity actually increase as you move from the outer reefs and into the Rock Islands, which is exactly the opposite of what we were expecting.”

The scientists’ next steps are to determine if these corals are genetically adapted to low pH or whether Palau provides a “perfect storm” of environmental conditions that allows these corals to survive the low pH. “If it’s the latter, it means if you took those corals out of that specific environment and put them in another low pH environment that doesn’t have the same combination of conditions, they wouldn’t be able to survive,” said Cohen. “But if they’re genetically adapted to low pH, you could put them anywhere and they could survive.”

“These reef communities have developed under these conditions for thousands of years,” said Shamberger, “and we’re talking about conditions that are going to be occurring in a lot of the rest of the ocean by the end of the century. We don’t know if other coral reefs will be able to adapt to ocean acidification – the time scale might be too short.”

The scientists are careful to stress that their finding in Palau is different from every other low pH environment that has been studied. “When we find a reef like Palau where the coral communities are thriving under low pH, that’s an exception,” said Cohen. “It doesn’t mean coral reefs around the globe are going to be OK under ocean acidification conditions. It does mean that there are some coral communities out there – and we’ve found one – that appear to have figured it out. But that doesn’t mean all coral reef ecosystems are going to figure it out.”​

So, to sum this up. Conditions in parts of Palau's waters are fairly unique, as there are reservoirs with little water exchange. Corals building shells (calcification) and breathing CO₂ in these areas have a long time to make these waters more acidic before these waters are being flushed out, and have done that for thousands of years. In an as of yet not determined way, these corals have adapted to the conditions they themselves have been creating for a long time, and thrive in conditions otherwise unhealthy for other corals. Acidification in these areas is primarily caused by the corals, not by increasing CO₂ levels in the atmosphere.

So, maybe some of these corals can be transferred to other reefs to replace the corals there dying off there. Whether that's even possible, whether these corals survive in conditions to which they aren't specifically adapted, and whether they survive the rising sea temperatures is also not known. It's probably overly optimistic to say they will survive the combination of rising temperatures, overfishing, and pollution that characterizes much of coastal sea life, even if the acidification won't kill them off.

Some good news: Coral can adapt - over thousands of years - to conditions that would otherwise be unhealthy. The bad news is, corals the world over won't get thousands of years to adapt to the conditions they'll be facing at the end of this century, as the devastating bleeching at the most pristine northern part of the Great Barrier Reef demonstrates.

There are MAJOR uncertainties in saying that Palau is unique because if you read any papers on the ranges and limits of coral reef chemistry and bio variables -- they mostly ALL start out with admissions of "how little we actually know" ..... To leap from THERE to causality conclusions is arrogant, sloppy, and unprofessional...

 

[flacaltenn]

Honest "we don't knows" are just fine. And preferable to pointing fingers to ONE CAUSE because your study sponsor PAID for that direction of your work..


High-Frequency Dynamics of Ocean pH: A Multi-Ecosystem Comparison

The effect of Ocean Acidification (OA) on marine biota is quasi-predictable at best. While perturbation studies, in the form of incubations under elevated pCO2, reveal sensitivities and responses of individual species, one missing link in the OA story results from a chronic lack of pH data specific to a given species' natural habitat. Here, we present a compilation of continuous, high-resolution time series of upper ocean pH, collected using autonomous sensors, over a variety of ecosystems ranging from polar to tropical, open-ocean to coastal, kelp forest to coral reef. These observations reveal a continuum of month-long pH variability with standard deviations from 0.004 to 0.277 and ranges spanning 0.024 to 1.430 pH units. The nature of the observed variability was also highly site-dependent, with characteristic diel, semi-diurnal, and stochastic patterns of varying amplitudes. These biome-specific pH signatures disclose current levels of exposure to both high and low dissolved CO2, often demonstrating that resident organisms are already experiencing pH regimes that are not predicted until 2100.


For example, recent data on the heterogeneity of pH in coastal waters of the Northeastern Pacific [31], [32] that are characterized by episodic upwelling has caused biologists to re-examine the physiological tolerances of organisms that live there. Specifically, resident calcifying marine invertebrates and algae are acclimatized to existing spatial and temporal heterogeneity [17], [18], and further, populations are likely adapted to local to regional differences in upwelling patterns

[33].


Similar underestimates of CO2 variability were observed at nine other open ocean locations, where the Takahashi pCO2 climatology overlaps PMEL moorings with pCO2 sensors (not shown). Thus, on both a monthly (Fig. 2) and annual scale (Fig. 4), even the most stable open ocean sites see pH changes many times larger than the annual rate of acidification. This natural variability has prompted the suggestion that “an appropriate null hypothesis may be, until evidence is obtained to the contrary, that major biogeochemical processes in the oceans other than calcification will not be fundamentally different under future higher CO2/lower pH conditions” [24].

In distinct contrast to the stability of the open ocean and Antarctic sites, sensors at the other five site classifications (upwelling, estuarine/near-shore, coral reef, kelp forest, and extreme) captured much greater variability (pH fluctuations ranging between 0.121 to 1.430) and may provide insight towards ecosystem-specific patterns. The sites in upwelling regions (Pt. Conception and Pt. Ano Nuevo, Figure 2C), the two locations in Monterey Bay, CA (Figure 2D), and the kelp forest sites (La Jolla and Santa Barbara Mohawk Reef, Figure 2F) all exhibited large fluctuations in pH conditions (pH changes>0.25). Additionally, at these 6 sites, pH oscillated in semi-diurnal patterns, the most apparent at the estuarine sites. The pH recorded in coral reef ecosystems exhibited a distinct diel pattern characterized by relatively consistent, moderate fluctuations (0.1<pH change<0.25; Figure 2E). At the Palmyra fore reef site, pH maxima occurred in the early evening (~5:00 pm), and pH minima were recorded immediately pre-dawn (~6:30 am). On a fringing reef site in Moorea, French Polynesia, a similar diel pattern was observed, with pH maxima occurring shortly after sunset (~7:30 pm) and pH minima several hours after dawn (~10:00 am).

 

[mamooth]

So, the corals bleached in regions of high water temperature. The higher the temp, the more bleaching.

Hence, the denier conclusion is that anything except high temperature has to be the cause.

It's sunscreen, you know. But it's apparently magic sunscreen, as it knows to only bleach coral in the warmest areas. Or it's fish. Except the fish or lack of fish don't bleach coral, they kill it. Just throw everything at the wall, and hope something sticks, because the totally obvious just can't be true.

 

[flacaltenn]

So, the corals bleached in regions of high water temperature. The higher the temp, the more bleaching.

Hence, the denier conclusion is that anything except high temperature has to be the cause.

It's sunscreen, you know. But it's apparently magic sunscreen, as it knows to only bleach coral in the warmest areas. Or it's fish. Except the fish or lack of fish don't bleach coral, they kill it. Just throw everything at the wall, and hope something sticks, because the totally obvious just can't be true.

Don't think you're reading close enough. A couple degrees COOLER for a week will cause bleaching as well. AND -- GW of 1degC hasn't exceeded that seasonal variance in most regions --- yet.

Also the loss of urchins and parrot fish is a BIG deal for reef hygiene. Seems you want to downplay that. Or just the actual "run-off" from resorts, beaches and human habitation.

But HEY --- stay ignorant my friend..

 

[flacaltenn]

Also seems like REASONABLE folks would dismiss these other stressors FIRST before spending $15TRILLION to reduce the global temp by 0.25degC.. But -- not everyone is "reasonable"...

Or at least spend money focused on quantifying general reef chemistry and enviro limits WITHOUT the focus on just ONE parameter. Until the papers stop starting their abstracts with "... not much is known about ...... ".. .

 

[polarbear]

From Wikipedia, bleached coral up front, same species of healthy coral behind.

Global's warming surgical Coral strike

mamooth, post: 9220775, member: 39072"]From Wikipedia, bleached coral up front, same species of healthy coral behind.
These lefty wing-nuts are the only anomaly that is real and global warming strikes them with surgical precision as it did to that coral in the midst of the other healthy ones.
I clicked on that New York Times (top rank fake news) link:
“I am significantly depressed by the whole situation,” said Clive Wilkinson, director of the Global Coral Reef Monitoring Network, an organization in Australia that is tracking this year’s disaster.
And it lands you on a quick cash loan web page.
Payday Loans With No Credit Check – Is there such a thing?
No wonder Clive Wilkinson the director of this organization is "significantly depressed" by this situation

 

[Olde Europe]

I clicked on that New York Times (top rank fake news) link:
“I am significantly depressed by the whole situation,” said Clive Wilkinson, director of the Global Coral Reef Monitoring Network, an organization in Australia that is tracking this year’s disaster.
And it lands you on a quick cash loan web page.
Payday Loans With No Credit Check – Is there such a thing?
No wonder Clive Wilkinson the director of this organization is "significantly depressed" by this situation

Yeah, extremely funny.

The NYT article is from 2010. It provides the same link as this site, and a host of others. Seemingly, the organization no longer maintains its own website, and the web address has since been taken over by that cash loan thingy. Instead, the GCRMN apparently became a supporting part of the International Coral Reef Initiative, and has a small internet presence on its website, including their publications for download here.

Instead of doing some research and figuring things out, you went for the cheap shot at folks who actually care for coral reefs, which form the basis for a large portion of marine life on earth, but are dying off due to multiple stressors, locally run-off / pollution or overfishing, globally due to heat stress and acidification. That, in turn, defines you.

 

[skookerasbil]

nobody is caring about the coral reefs.............still...............

[URL=http://s42.photobucket.com/user/baldaltima/media/Nobody%20cares.gif.html][/URL]