NOAA is dialing back the alarm a bit with realizations that nature has equipped these organisms with adaptation strategies that have served them over the millennia.
New study suggests coral reefs may be able to adapt to moderate climate change
Coral reefs may be able to adapt to moderate climate warming, improving their chance of surviving through the end of this century, if there are large reductions in carbon dioxide emissions, according to a study funded by NOAA and researched by the agency’s scientists and its academic partners. Results further suggest corals have already adapted to part of the warming that has occurred.
“Earlier modeling work suggested that coral reefs would be gone by the middle of this century. Our study shows that if corals can adapt to warming that has occurred over the past 40 to 60 years, some coral reefs may persist through the end of this century,” said study lead author Cheryl Logan, Ph.D., an assistant professor in California State University Monterey Bay’s Division of Science and Environmental Policy. The scientists from the university, and from the University of British Columbia, were NOAA’s partners in the study.
Warm water can contribute to a potentially fatal process known as coral “bleaching,” in which reef-building corals eject algae living inside their tissues. Corals bleach when oceans warm only 1-2°C (2-4°F) above normal summertime temperatures. Because those algae supply the coral with most of its food, prolonged bleaching and associated disease often kills corals.
The study, published online in the journal Global Change Biology, explores a range of possible coral adaptive responses to thermal stress previously identified by the scientific community. It suggests that coral reefs may be more resilient than previously thought due to past studies that did not consider effects of possible adaptation.
The study projected that, through genetic adaptation, the reefs could reduce the currently projected rate of temperature-induced bleaching by 20 to 80 percent of levels expected by the year 2100, if there are large reductions in carbon dioxide emissions.
“The hope this work brings is only achieved if there is significant reduction of human-related emissions of heat-trapping gases,” said Mark Eakin, Ph.D., who serves as director of the NOAA Coral Reef Watch monitoring program, which tracks bleaching events worldwide. “Adaptation provides no significant slowing in the loss of coral reefs if we continue to increase our rate of fossil fuel use.”
“Not all species will be able to adapt fast enough or to the same extent, so coral communities will look and function differently than they do today,” CalState’s Logan said.
While this paper focuses on ocean warming, many other general threats to coral species have been documented to exist that affect their long-term survival, such as coral disease, acidification, and sedimentation. Other threats to corals are sea-level rise, pollution, storm damage, destructive fishing practices, and direct harvest for ornamental trade.
According to the Status of Coral Reefs of the World: 2000 report, coral reefs have been lost around the world in recent decades with almost 20 percent of reefs lost globally to high temperatures during the 1998-1999 El Niño and La Niña and an 80 percent percent loss of coral cover in the Caribbean was documented in a 2003 Science paper. Both rates of decline have subsequently been documented in numerous other studies as an on-going trend.
Tropical coral reef ecosystems are among the most diverse ecosystems in the world, and provide economic and social stability to many nations in the form of food security, where reef fish provide both food and fishing jobs, and economic revenue from tourism. Mass coral bleaching and reef death has increased around the world over the past three decades, raising questions about the future of coral reef ecosystems.
In the study, researchers used global sea surface temperature output from the NOAA/GFDL Earth System Model-2 for the pre-industrial period though 2100 to project rates of coral bleaching.
Because initial results showed that past temperature increases should have bleached reefs more often than has actually occurred, researchers looked into ways that corals may be able to adapt to warming and delay the bleaching process.
The article calls for further research to test the rate and limit of different adaptive responses for coral species across latitudes and ocean basins to determine if, and how much, corals can actually respond to increasing thermal stress.
In addition to Logan, the other authors of the paper were John Dunne, NOAA Geophysical Fluid Dynamics Laboratory; Eakin, NOAA’s Coral Reef Watch; and Simon Donner, Department of Geography at the University of British Columbia. NOAA’s Coral Reef Conservation Program funded the study.
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
…an 80 percent percent loss of coral cover in the Caribbean was documented in a 2003 Science paper.
Caribbean-wide, or some locality within it? Anybody got a citation? This doesn’t seem to pass the sniff test….
juan slayton says:
October 29, 2013 at 3:38 pm
Abstract doesn’t say what the suspected causes may have been:
https://www.sciencemag.org/content/301/5635/958
so, let me get this right – ‘they’ have decided that corals can adapt to warmer seas (even though most like warmer seas anyway!) – no sh$t Sherlock? – I can’t remember exactly when corals first appeared (but I think they could even be some from Precambrian?) but I know they were around at least 500Mya – so I’d hazard a rough guess that they are pretty good at adapting??????
Re: Good news from NOAA: coral reefs can adapt to warming, 10/29/13 (bold added):
Point of Order: All life on Earth can adapt; those forms that couldn’t are extinct. The conjecture in the article is that extant coral reefs are robust enough to survive some hypothesized warming.
If the hypothetical warming is, as warmists claim, significant and unprecedented, then the coral are likely doomed because species shed unused robustness over a goodly number of generations. The conclusion of the paper suggests that the hypothesized warming is either insignificant or not unprecedented.
The model depends on the number of generations involved. Biology appears yet to have quantified the length of a generation in coral species. Meanwhile, IPCC climatologists have no idea how far back to claim the unprecedented span in the upcoming warming in their failing AGW conjecture. How many times will a guess go into a guess?
Kev-in-Uk says:
October 29, 2013 at 4:01 pm
Though they may appear “primitive”, corals are actually quite “advanced”, ie “derived” animals. Depending upon definition, they might have evolved in the later Paleozoic, ie Carboniferous to Permian Periods, but definitely by the early Mesozoic, ie Triassic Period.
Lauren R: “And then the corals grew back again after the brief spike in temperatures from the major El Niño and La Niña events subsided.”
Worth mentioning here, as another poster mentioned it, that ‘bleached but living’ is called ‘loss’ and you are supposed to that to mean “It’s dead, Jim.” Coral grows faster than most folks give it credit for. But it does *not* grow quickly as such. So whenever you see a fast turnaround, you know that they buried the victim alive.
Let’s see, corals can be traced back half a billion years. It has been mostly warmer with higher CO2 levels in the atmosphere over those hundreds of billions of years. So they can no longer survive when it gets warmer. Oh, I get it. Those weren’t MODERN corals (/sarc). Yeah, right.
http://www.oum.ox.ac.uk/thezone/fossils/inverts/coral.htm
Coral reef are almost exclusively found in the tropics. This hardly suggests that the water is too warm for them.
The warmest waters in the world are found in the Red Sea, which also has some of the best corals in the world.
The problem is not with corals, it is with scientists that know so little about them. Bleaching is not a fatal condition in corals. It is a changing of the guard to better make use of different water temperatures.
Tom J says:
October 29, 2013 at 1:32 pm
Thanks for reminding readers that corals may bleach themselves periodically, for whatever hygienic or environmental reason. It’s not always a bad thing. But in any case slight differences in surface water pH is a minor factor in a long list of natural changes affecting corals & their relationship with symbiont algae.
agimarc says:
October 29, 2013 at 4:51 pm
That’s a misleading site. Reefs 500 Ma weren’t built by corals.
The Cambrian reef systems were built by different organisms, some animals & some not. Different marine invertebrates built new reef systems in the Ordovician, Silurian, Devonian, Carboniferous & Permian. Corals might have evolved in the late Paleozoic, but as free swimmers, not sessile reef builders.
First coral reefs from the Late Triassic, or at least scleractinian reefs:
http://coral.aims.gov.au/info/reefs-mesozoic.jsp
The Earth has had well, well over 1500 ppm in the atmosphere as well as being much warmer in the previous interglacials – the corals survived somehow. Even under ‘business as usual’ per IPCC we won’t hit 1,500ppm this century. I vaguely recall that coral evolution took of at a time of far, far higher co2 than today? The IPCC’s temperature projections for 2100 now look very iffy indeed.
The Warmest sea in the world is apparently the Red Sea which is said to range from 20 to 30C depending where you measure. The warmest parts are inhabited by some funny looking things that resemble corals. 🙂
Red sea corals
http://www.coral-reef-info.com/red-sea-coral-reefs.html
Warm water can contribute to a potentially fatal process known as coral “bleaching,”….
really?…..I’m so glad corals found a way to survive it……by getting out of the water
http://img133.imageshack.us/img133/8561/016szk1.jpg
idiots……….
Jimbo says:
October 29, 2013 at 5:15 pm
Mesozoic coral reefs thrived under CO2 regimes possibly over 3000 ppm & surely above 1500 ppm. This study find ~3400 ppm in the Jurassic:
http://caos.iisc.ernet.in/faculty/pghosh/content/Publications/19.pdf
Seawater was remarkably hot in the Cretaceous (despite probably lower CO2 than the cooler, or less warm, Jurassic).
As you can see they point out that coral bleaching events don’t necessarily kill corals. Regeneration can occur and has.
http://www.livescience.com/28440-coral-reefs-can-regenerate.html
As you can see they point out that coral bleaching events don’t necessarily kill corals.
===
Jim, bleaching is a normal process….the corals are just changing one dinoflagellate, or group of, or mess of, or even just some…..for another…or less of some, so there’s more of another
Someone wrote something similar in 2003 and said we needed more research. I knew there had to be reasons corals were still with us after millions of years and quite a few interglacials.
If a nuclear bomb was exploded on some corals would it get too hot? Of course, but could they come back? You betcha. It’s funny how delicate these things really are. They are doomed.
Jimbo says:
October 29, 2013 at 5:57 pm
Who knew that the best thing for coral diversity was first to detonate a number of fission bombs on an atoll, then follow that up by a gigantic 15 megaton thermonuclear (fission-fusion) explosion as the coup de grace, for a total energy release of 42.2 megatons?
If we really want coral reefs to flourish, then the best thing to do would be to hit them with a modern, multi-stage fission-fusion-fission device not once, not twice, but thrice for good measure. Also has the added advantage of possibly speeding up evolution.
But one more molecule of CO2, up from three to four, out of 10,000 dry air molecules, plus of course in the tropics about 400 water vapor molecules, that’s a killer!
I suppose all these Holocene coral remnants and all Pacific atolls’ architecture must have survived somehow whatever was thrown to them during the Quaternary… or perhaps not: cores are so old fashioned data and not post modern science… /sarc
I see in the top image caption “corals. The picture was taken in Papua New Guinea ” which reminded me of a story on WUWT with co2 bubbling between corals there. They were being given an ‘acid’ bath for want of a better phrase.
http://wattsupwiththat.com/2011/12/28/the-fishes-and-the-coral-live-happily-in-the-co2-bubble-plume/
@Jimbo: “Someone wrote something similar in 2003 and said we needed more research”
Only thing is, bleaching is a condition, not a cause. Bleaching from pathogens that attack zooxanthellae? Fatal if prolonged. Bleaching from gustatory delight? Not. Fatal. Probably doesn’t need reminded that temperature is not a pathogen.
@milodon: Nuke it from orbit. It’s the only way to be sure.
And finally……………..there are other reasons for coral bleaching too. So next time you hear about coral bleaching ask yourself, what’s the cause???
Cold, dark, deep water corals:
http://en.wikipedia.org/wiki/Deep-water_coral
Shallow Water Corals Evolved From Deep Sea Ancestors
http://www.sciencedaily.com/releases/2008/06/080617204512.htm
superficial
(adjective)
4. concerned with or comprehending only what is on the surface or obvious
(dictionary.com)
Earlier modeling work suggested that bees shouldn’t be able to fly.
But bees did fly, proving that the models were wrong.
That’s what Cherly Logan is saying today.