Corals survived massive Caribbean climate change – likely to do so again

From the SMITHSONIAN TROPICAL RESEARCH INSTITUTE

Half of all coral species in the Caribbean went extinct between 1 and 2 million years ago, probably due to drastic environmental changes. Which ones survived? Scientists working at the Smithsonian Tropical Research Institute (STRI) think one group of survivors, corals in the genus Orbicella, will continue to adapt to future climate changes because of their high genetic diversity.

Orbicella, a genus of reef-building corals, may be able to survive future climate change. CREDIT Monica Medina, NMNH

Orbicella, a genus of reef-building corals, may be able to survive future climate change. CREDIT Monica Medina, NMNH

“Having a lot of genetic variants is like buying a lot of lottery tickets,” said Carlos Prada, lead author of the study and Earl S. Tupper Post-doctoral Fellow at STRI. “We discovered that even small numbers of individuals in three different species of the reef-building coral genus Orbicella have quite a bit of genetic variation, and therefore, are likely to adapt to big changes in their environment.”

“The implications of these findings go beyond basic science,” said Monica Medina, research associate at STRI and the Smithsonian’s National Museum of Natural History and associate professor at Pennsylvania State University. “We can look forward to using similar approaches to predict demographic models to better manage the climate change threatened Orbicellareefs of today.”

To look back in time, the team of researchers working at the Smithsonian’s Bocas del Toro Research Station and Naos Molecular and Marine Laboratories collected fossils from ancient coral reefs and used high-resolution geologic dating methods to determine their ages. They compared the numbers of fossilized coral species at different time points. One of the best-represented groups in the fossil collections were species in the genus Orbicella. In addition to the fossil collections, they also used whole genome sequencing to estimate current and past numbers of several Orbicella species.

Within a single individual there are two copies of their genetic material, in some instances, one copy is different than the other and is called a genetic variant. The authors first assembled the full genomic sequence of an individual from Florida and then, using it as an anchor, reconstructed the genetic variation contained within single individuals. Depending on the amount of the genetic variation at certain intervals across the genome, the authors were able to recover the population sizes of each species at different times in the past.

Between 3.5 to 2.5 million years ago, numbers of all coral species increased in the Caribbean. But from 2 to 1.5 million years ago, a time when glaciers moved down to cover much of the northern hemisphere and sea surface temperatures plunged, the number of coral species in the Caribbean also took a nosedive. Sea levels fell, eliminating much of the original shallow, near-shore habitat.

“Apart from the species that exist today, all species of Orbicella that survived until 2 million years ago suddenly went extinct,” write the authors. When huge numbers of species die out, it makes room for other species to move in and for new species to develop to occupy the space the others held.

Two species that grow best in shallow water doubled in number at about the same time that their sister species and competitor, the organ pipe Orbicella (O. nancyi) disappeared.

When a species declines during an extinction event, it loses more and more genetic variation, and sometimes does not have much to work with during the recovery period. Scientists call this a genetic bottleneck. Orbicella was able to recover after the bottleneck. “It’s incredible how predictions from genetic data correlated so well with observations from the fossil and environmental record,” said Michael DeGiorgio (assistant professor of biology at Pennsylvania State University).

“We see hope in our results that Orbicella species survived a dramatic environmental variation event,” said Prada. “It is likely that surviving such difficult times made these coral populations more robust and able to persist under future climatic change.”

“The in-depth analysis of population size in a now ESA-threatened coral, as well as the release of its genome and that of its close relatives (which are also threatened) would be of great interest to coral reef researchers addressing conservation issues,” said Nancy Knowlton, senior scientist emeritus at STRI, currently at the National Museum of Natural History.

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54 thoughts on “Corals survived massive Caribbean climate change – likely to do so again

    • What is your objection to the analogy? Evolution is driven by chance – the more variation in the genes the
      more likely it is that one will survive and produce more offspring. Just as the more lottery tickets you buy the greater your chances of winning.

    • That’s how evolution works. You can’t know which mutations will prove beneficial until after the fact.

    • If you buy more lottery tickets you have a greater chance of winning. Everyone can understand that.

      Real experts can explain their field in terms that their audience can understand. Posers hide behind a wall of bafflegab.

      The trouble is that the simplified explanation may be inadequate and will lead to trouble if people try things based on their limited understanding.

      The thing I like best about the lottery analogy is that it emphasizes dumb luck. People tend to underestimate the importance of dumb luck.

    • who writes nonsense like that?
      …my guess would be no

      Sea levels fell, eliminating much of the original shallow, near-shore habitat.
      Two species that grow best in shallow water doubled in number at about the same time

      At least they are admitting that bleaching is normal…..but they don’t realize that either

  1. Reblogged this on Climatism and commented:
    Corals evolved during the Cambrian era when atmospheric CO2 levels were at 6,000-7,000 ppm, around 4,000 percent higher than today’s “CO2-starved” environment of 400 ppm.

    It’s no wonder corals have survived millions of years of dramatic and “massive” climate change.

  2. If i read the article correctly, it was the number of Orbicella genus corals that were reduced, not corals in general. What the authors might be missing is changing conditions also encouraging a disease. If one had fossil records of American Elms or Chestnuts, they became nearly extinct in a very short time period due to disease.

      • That’s OK, Tom, ….. the extinction of the Passenger Pigeon didn’t leave any fossil evidence either ……. and there were literally BILLIONS of them that had existed in North America prior to September 2, 1914,

      • Yup. Real-world population dynamics are famously upsy-downsy, just like the Assyrian Empire. It takes a green catatrophist to studiously ignore everything that has been learnt about this in recent decades.

      • @ asybot, ….. I stopped reading the linked commentary you cited when I read this, to wit:

        This ammonia joins with other particles rising from the ocean to make cloud condensation nuclei – the seeds around which water droplets condense in the atmosphere to form clouds.

        Like I stated on another thread, …… atmospheric H2O molecules don’t need no damn condensation nuclei for two or more of them to cohesively attract one another to form visible water droplets in the atmosphere.

        And neither does the H2O molecules in my breath when I exhale it on a cold n’ frosty morning.

      • That something can happen, is not evidence that something must happen.
        Seeds make the formation of droplets easier.

      • MarkW – November 20, 2016 at 10:30 am

        Seeds make the formation of droplets easier.

        Easier, HUH?

        Are those “seeds” the atmosphere’s version of “K-Y Jelly”, …… maybe?

        Mark, please define the word “easier” as in a process or function in/of science,

  3. ” “We can look forward to using similar approaches to predict demographic models to better manage the climate change threatened Orbicellareefs of today.”

    How arrogant of them to think that organisms that clearly handle large climate fluctuations by themselves need us to “MANAGE” them? How stupid are these people? We see that they can handle great changes in climate and then presume that we need to manage them? Is there anything in the world that “arrogant” man does not think he needs to manage?

    • We can arrogantly put them on a Boeing 777 and fly them half way around the world – something they can’t manage on their own. There might be any number of chaotic repercussions for doing that but humans are big on dragging species around the world with them. Hence English Sparrows, mongoose, goats, and miniature deer now live in Hawaii. What could possibly go wrong?

      • If a sea-level canal is built in Central America a lot of the (locally) extinct corals will undoubtedly re-colonize the Caribbean.Conditions are probably quite acceptable for them during interglacials. It’s the glaciations that kill.

      • Hi Paul
        I live in SW, they fly in flocks of a dozen or two creating lot of racket for hour or two and they are off, than come back few days later.

      • I remember seeing a documentary of similar Parakeet flocks on Long Island near New York City. Apparently descended from escapees from bird-owners.

      • Don’t forget the Norway or black rat. Along with it’s fleas.

        Another bird market gunned into extinction for city slicker ‘ils mangeaient’, is the Carolina parakeet.

    • Higley7–that line caught my eye also, I agree with your comment completely. In the game of life, momma nature has the home field advantage, and always gets to bat last–no matter what our “arrogant” species wants to think.

  4. The article is interesting, I took the time to check out the authors. I am confused, are they employees of the Smithsonian which is run by the U.S. government or are they employed by Penn state.
    The Smithsonian Tropical Research Institute, is located in Panama and the Labs that did the physical research are part of that facility.
    Does anyone else have any thoughts?

    michael

  5. This study dovetails with any number of others on Pleistocene extinctions. A lot of species have gone extinct since the Pliocene. And the pattern is always the same. Do they go extinct during interglacials? No, during glacials. Cold climate kills species, not warm.

  6. 1-2 million years ago- wasn’t that when Central America became one solid belt, and closed up circulation between the Atlantic and Pacific oceans? I would bet that played a role also.

    • No. That was about 3 million years ago. The first major NH glaciation was 2.6 million years ago, and the shift from “small short glaciations” to “big long” ones was about 1 million years ago.

  7. At the beginning and again at the end of their so-called “research” they should be made to state the total amount of OPM (other people’s money / grants) they receive.

    WL

    • Until truly remarkable scientific calculations and research are carried out on the kitchen table and during vacation camping trips …After work, Money will be the driving source.

  8. Coral at Bikini atoll, vaporized at 50,000 degrees in the 1950s from nuclear bombs , today are in pristine condition and growing like a forest.

    • That won’t last beyond Trump’s EO to allow drilling in the Arctic Ocean. What is created by the pen can be destroyed by the pen.

    • Not quite.
      Obama has blocked, by red tape, any Arctic or offshore drilling. Death by bureaucracy.

      “Very little is known about the cold-water corals of the Canadian Arctic: the deep-waters there simply remain largely unexplored, and much of the Arctic archipelago bathymetry remains to be mapped. However, rich coral assemblages have been identified in the Davis Strait, Baffin Island and Labrador Sea, which are predominantly gorgonians and black coral species likely associated with the meeting of the Arctic and Atlantic Oceans.

      Corals also occur off Nunavut at approximately the shelf break.”

      Little known and little explored does not mean without corals. Corals are very widespread with viable communities in many surprising places.
      Maybe we can get the eco-loons to highlight divers visiting the Arctic corals?

  9. Richard- it’s hard to find data, but most of the energy, maybe 95+% goes into blast, thermal, and air pressure. Even particles of the uranium/plutonium survive the explosion. Actually vaporized material is pretty small. The actual nuclear part of the explosion is over in less than a millisecond and the nuclear material partially vaporized but mostly simply blown apart, stopping the chain reaction. It’s the after effects from the gamma ray burst, the immense amount of energy released, shockwaves, and other physical effects that do the damage.

  10. The famous Flower Garden reefs off the Louisiana/Texas border are at the current extreme and formed since the last glaciation. Interesting and well researched complex of reefs. There is a fossil delta there nearby, so if cold doesn’t kill coral, freshwater and sediment will even if they survive exposure.

    Suter, J. R., H. L. Berryhill, Jr and S. Penland. 1987. Late quaternary sea-level fluctuations and depositional sequences, southwest Louisiana continental shelf. pp., 199-219, In, D. Nummedal, O. H. Pilkey and J. D. Howard (Eds.). Sea-Level Fluctuation and Coastal Evolution. Special Publication 41, Society of Economic Paleontologists and Mineralologists.

    I think they also cite a reference in the Bulletin of the American Association of Petroleum Geologists on late quaternary shelf-margin deltas in the northwest Gulf of Mexico, but I don’t have the reference handy.

    • No coral reef ever lasts longer than one interglacial (10,000-30,000 years), though a new one will often grow on top of the old one come next interglacial c. 100,000 years later. And of course at the same time the new coral reefs that has grown further down on the continental slope during the glaciation are drowned. Nature is never static.

      • Depends on how fast the waters rise. If the coral is capable of growing as fast as the water is rising, they don’t drown.

      • That is also true with toads.

        If the toads are capable of hopping as fast as the water is rising, they won’t drown.

  11. More nonsense research from the blind.

    Terrible assumptions driving results before research is attempted.

    A complete lack of understanding, how lotteries work.
    Nor, is there any chance to ‘prove’ their assumptions. Placing verification in the hands of belief.

    “They compared the numbers of fossilized coral species at different time points. One of the best-represented groups in the fossil collections were species in the genus Orbicella. In addition to the fossil collections, they also used whole genome sequencing to estimate current and past numbers of several Orbicella species.”

    Use of circular reasoning where the researchers fossil and geological data to develop their genetic models and assumptions, then used the same initiating data to verify their work.

    “To look back in time, the team of researchers working at the Smithsonian’s Bocas del Toro Research Station and Naos Molecular and Marine Laboratories collected fossils from ancient coral reefs and used high-resolution geologic dating methods to determine their ages. They compared the numbers of fossilized coral species at different time points.”

    “It’s incredible how predictions from genetic data correlated so well with observations from the fossil and environmental record,” said Michael DeGiorgio (assistant professor of biology at Pennsylvania State University). ”

  12. But the seal levels falling just moves the shoreline – it can’t eliminate it. And the rate of sea level change was probably not drastic enough to prevent corals from being able to move with the shoreline. There would have been localized changes in topography of the shallow water, but it seems reasonable to assume overall there was about the same amount of favorable conditions due only to moving the shoreline.

    To me that argument falls flat. Other changes have to be the driver of the need to adapt. Temperature was the key. It needs no additional explanation due to changing shorelines, especially since that is illogical..

    • It is quite likely that the change in sea level was accompanied by changes in water temperatures. The symbiotic relationship that exists in coral is hundreds of millions of years old and has hundreds of variations. It can thrive in an equal variety of settings. All it requires is that water conditions stay stable long enough for the spores to establish. When conditions change, as they regularly do, some species die off and some survive, and some species move in. Different weeks, different lottery winners.

  13. Its good to see that they acknowledged coral palaeo history back 2-3 million years with the Quaternary, to confirm basic evolutionary theory of genetic diversity and environmental perturbations.

    It would be good to see scientists take the next step and address the question of how corals and all other phyla of calcified marine organisms evolved and flourished during the Cambrian while atmospheric CO2 levels were at 10,000 – 50,000 ppm.

    It’s annoying to see that a major environmental perturbation from cooling – the onset of Quaternary glaciation amd sea level fall, morphs by sleight of hand into a conclusion about speculative environmental perturbation from the exact opposite – conjectured warming and sea level rise. Not to mention sea water pH.

    • Ocean “acidification” gets top prize from me as the stupidest of all the Warmist memes. Total sensationalist nonsense that denies all scientific knowledge regarding ocean chemistry, historic CO2 levels, biology, the fossil record and rational, intelligent analysis. Pathetic tripe!

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