Little Cayman corals bounce back after El Nino

| 10/10/2013

(CNS): A 14 year study of the coral reefs off Little Cayman, which were devastated by the global 1998 El Nino event, found that they have made a complete recovery, despite dire predictions of the complete mortality of corals by 2050, giving hope for coral reef ecosystems everywhere. A paper published this week by the researchers suggests that the island’s isolated setting, stringent protection of a significant portion of the reefs and minimal stress from local human activities were key factors in the reefs’ recovery. Dr Carrie Manfrino, President of the Central Caribbean Marine Institute and one of the authors of the paper, said the researchers involved have speculated that the corals that have rebounded may provide a new, more resilient stock of corals. (Left: Acropora palmata branching coral grows on top of previously dead coral skeleton)

However, while it brings good news, the paper, “A Positive Trajectory for Corals at Little Cayman Island”, published in ‘PLOS One’, also warns that protection of the reefs is critical: “Although any documented recovery of coral is encouraging, it is unlikely that such positive effects will spread throughout the Caribbean unless protection from local stresses is improved. Without such improvements, recovery from natural cataclysms, including those exacerbated by global change, remains unlikely. Ultimately, management of local and global stresses will be required to sustain coral reefs and ensure their capacity to recover from disturbance.”

“The 1998 El Nino event wreaked havoc on reefs in every ocean on earth,” Manfrino explained ina release. “It elevated seawater temperatures and stressed the coral animals to such an extent that they expelled their symbiotic algae and turned bright white (tiny algae live in the coral polyp tissue and provide the color and metabolic resources for corals). This response is called coral bleaching and though corals can recover, many corals died after the 1998 event. The relatively healthy reefs of Little Cayman lost 40% of their corals.” (Right: this sick coral was typical of the reefs in the Caribbean after the 1998 event)

She said this single disturbance was the most extensive and but also the best recorded global mortality on coral reefs in human history. Subsequent debates in the scientific community predicted that the coral would continue to die as a result of global warming and more frequent thermal stress events. 

“The complete recovery of the corals at Little Cayman has important similarities with the recovery reported earlier this year for Scott’s Reef in north Western Australia,” Manfrino noted. “The reefs, though thousands of miles apart, are in remote locations with little human impact, a commonality that may help resolve at least one of the debates about the capacity for corals to regenerate and survive.

“Coral recruitment requires a synchronous dispersal of coral gametes that eventually settle to the sea floor, where they plant themselves and begin to grow calcium carbonate skeletons. Successful coral regeneration requires the arrival of coral larvae from nearby undisturbed corals,” Manfrino explained. “It has been previously thought that remoteness make reefs more vulnerable to global disturbances because they are isolated from sources of coral larvae and lack the connectivity required for regeneration. However, at these two distant coral reefs, being remote also means being isolated from local anthropogenic stress. The isolation from humans appears more important than the lack of connectivity.” 

Nevertheless, she said that whether reefs could continue to rebound from local and global warming events was unknown. “The work of researchers at Little Cayman will now focus on understanding what factors were most important to this recovery.”

Dr Manfrino, who is also Associate Professor at Kean University, said there have been three additional coral bleaching events since 1998 with no mortality and over the past four years the reefs have been bouncing back. 

“Beginning in 2009, we’ve seen a remarkable recovery of all species on just about all reefs surrounding Little Cayman. We speculate that the corals that have rebounded may provide a new, more resilient stock of corals.” 

Read more about the Central Caribbean Marine Institute.

Category: Science and Nature

Comments (24)

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  1. pmilburn says:

    Gentlemen,Ladies(if any on here)Let us remember the most important thing here and that is we CANNOT continue to put pressure on our valuable natural resources and expect that all will be well.I have been writing,talking about all this ever since I set foot upon this wonderful group of islands in Jan 1965 and yet too many people are greedy,selfish and dont give a damn about what we need to preserve for our future generations.Its all about let me get my share and to hell with the rest.Little Cayman (I consider the jewel of these three islands)is fast becoming the same and I have repeatedly asked our Govt (s)to keepLC as pristine and a place that we can use for REPLENISHING our conch,lobster fish whatever but this falls on deef (spelt like that on purpose)ears and only today after over 20 years of trying the PPM has now said that they will pass into law the Conservation bill.This is a no brainer as without a sound but reasonable law how can we sustain our tourism product?This is the ONLY thing that brings the bulk of our tourists here and without it we will lose many more thousands of jobs.I cannot understand for instance our PLANNING board that has in the past allowed developers to totally destroy the natural vegetation and then these same developers bring in other plants which do not grow here naturally.It seems to me that keeping as much of the trees etc that are on that piece of property would enhancetheir plans but no one is ready to stand up and say sorry but we insist that you keep as much in place as possible.Are we afraid that we might lose out on these fancy plans?Our various boards need to get some balls and do what is right for the country as a whole and stop pandering to these people.I am not against proper sustainable development but lets mix the two for a better end product.Like everything else in this country things take way too long to be decided on so lets hope that this time around we get it right because folks time is running out and time waits for no man(or woman)Thanks PPM for at least getting something started.Lets see you finish the job and to keep our future generations in mind.

  2. Diver Dan says:

    I was really excited by this until I went ands read the science article. The research started in 1999. As the CNS article says, the major bleaching related coral die-off was in 1998. SO the research does not show a 'bounce-back to pre die-off levels'. What it actually shows is that there has not been significant loss of coral cover since1999. After the major bleaching event. (There was a small decrease in the early 2000s which has since recovered.) To claim that "Little Cayman Corals Bounce Back After El Nino" is therefore innaccurate. Thats like claiming that the American Indians bounced back after the "Trail of Tears" without counting the thousands that died before and during the event. Just those that survived. Very bad spin-doctoring on thepart of CCMI to claim that after a 40% die-off (their estimate for the 1998 event in the CNS article) there has been a 'recovery' and not clarify that that 'recovery' was to post-die-off levels. Better than continued decline, but not cause for celebration (much less Who-Dat-Ism).

    • Whodatis says:

      (Cheap point alert.)

      Please stand on your own two feet as you submit your opinions.

      Try to resist the temptation to ride the anti-Whodatis wave that exists on this forum – it will make you a stronger and more independent person.

      Thank you.

      • Diver Dan says:

        Fair Enough. Not 'Who-Dem-Is' but the Climate Change Deniers (CCDs). Feel better?

    • noname says:

      Hey Dan, you are mostly correct.   We hear so much about the negatives inpacts in our natural world it is easy to get caught up in a possitive story.  Coral cover from a report in the 1980’s shows that coral cover was about the same as what CCMI saw in 1999.  The 1998 El Nino event bleached the corals but the corals at LC died largely from white plague disease….not just from bleaching and it took several years for the decline to stop (it was not until 2004 the the corals had lost 40%.  And the recovery was to pre-1999 levels.)  The positive news is there is significant recruitment ("baby" coral colonies) on Little Cayman and it is the responsibility of all of us to protect what is left so our children can experience a world at least as good as we see it ourselves.  I think CCMI is doing a good job trying to figure this out.

      • Anonymous says:

        Can you site your sources? (Online links would be ideal of course, so that we can compare them to the CCMI report.) As your numbers counter the ones that CCMI reported in the article you're changing the story. That the 40% die-off was to the 2004 nadir (which they didn't say) and that the recovery was to pre-1999 levels, even though the CCMI published data doesn't go back that far. – Also they were reporting, IIRC, % coral cover, not number of corals. Yes coral recuitment continues apace (considering no one was probably checking what recrutiment rates were back in the 60s) but its going to take a lot more than 10 years growth for a new coral to take up as much % room on the reef as the old 100-year coral did.

        As you say, its easy to get caught up in a psoitive story. Lets not get so caught up we try to make things match what we want them to (Full Coral Recovery).

  3. Whodatis says:

    Fully recovered, eh?

    For pete's sake … this is nothing but nature being nature.

    "El Nino" is a natural phenomenon which has a NATURAL impact on other elements of NATURE.

    I wish the over-zealous tree huggers would stop disrespecting and underminding the power and purity of nature doing its work and back off the scare-mongering and doomsday predictions.

    Much of what they do is actually contrary to everything for which they claim to stand.

    *AGW – never heard such a croc in all my life.

    ** Also, wasn't this same alleged "coral bleaching" a significant basis and "evidence" for the fraudulent and money-hungry theory of CO2 causing "climate change"?

    Looks like a big fat oops on their part … yet again.

    Those who believe in the crap are free to do so, however, kindly leave my hard-earned money out of it.

    Fund your own lunacy.

    • Holy Troller says:

      Please. Just go back under your bridge.

      • Whodatis says:

        The cheapest point in all things CNS is to forward any critical reply to Whodatis – for doing so you are guaranteed plenty support.

        By now I have learned to ignore this phenomenon, however I will take the bait on this occasion – but only to challenge your implication.

        Rest assured, there is absolutely nothing disingenuous or typically "trollish" about my post.

        I believe in that particular perspective with every fiber of my being – regardless of the mainstream backlash.

        Therefore, I reiterate … fund your own lunacy.

        *Then again, you didn't even speak to the issues at hand – you opted to only address the fact that Whodatis submitted a post. In reality we probably see eye to eye on these issues – not that it would make a difference to you though.

    • Anonymous says:

      Please explain the near total distruction of the conch population on LC, oh sorry that's not El Nino, that'll be selfish locals who can't seeas far as their own bellies or pockets. The same will happen on GC if we don't crack down on poaching.

      But Whodatis won't see that, he'll just blame the UK.

      • Whodatis says:

        What the heck does poaching have to do with these issues?

        Let me guess, because I don't support the AGW bullcrap being rammed the throat of the world, I must be some polluting, destructive and environment abusing individual, right?

        Too many Enviro-Nazis in the world today.

        🙂

    • Anonymous says:

      its so good to hear from Doctor Whodatis attacking climate change.

      Its obvious from your high level training that its you we should have spoken to first.

      By the way on the money hungry side we have the millions and millions of the alarmist and other the other side we have the billions and billions of oil users. Please stop using that bogus agruement.

      • Whodatis says:

        Even if the oil users had "trillions and trillions" of dollars it would make no difference to me as I draw my conclusions on the actual science and data surrounding this issue.

        No amount of money can alter science and the naturally random climatic cycles of Planet Earth.

        Neither could it regrow decades of "dramatic arctic ice shelf decline" in a mere 3 months.

        Anyway, as I always say, this is the new religion of the day – one either believes or doesn't. You have a right to your opinion as I do mine.

        However, one significant difference is that your opinion comes with a hefty price tag – as, according to recent reports, the colder western countries are all about to realize this coming winter.

        • Anonymous says:

          But you are not a scientist and have no training in that area and yet you speak as if you do.

          Can you discern when someone is telling you stupidness in this field?

          Al Gore is a spokesmanfor the issue but Gore has no training in the area and many people realise this and to a certent extent it has backfired for them.

          And there are professionaly trained people on both sides of the fence in this issue but the largets number by a mile and then some is for global warming.

          As for thr price tag. it is being painted as if the climate change people are in it for the money. But the largest financial advantage is to be had on the other side. So yes it comes with a hefty tag but the other costs are much larger and involves lost lives.

        • jaybird says:

          The Arctic ice cap actually has INCREASED by 60% this year. 

        • Anonymous says:

          The reason Climate Change is used as opposed to Global Warming is due to the uncertainty that surrounds the entire issue. We are not exaclty sure what the ramafications will be because of our continual pumping of C02 and other GH gasses into the atmosphere. So, it could mean sever fluctuations in the weather, i.e cold some times in different places and vice versa in others. There is no sure way to know exaclty. But what we do know is the last centuray has seen record heat and within this same time frame there is record levels of C02 and other GHG levels as well. As we all learnt in high school, methane gas and C02 are very good at absorbing energy (heat) and creating latent heat. I will not disbute that the earth has its own cycle of climate mitigation, but the science is clear that man is interupting that natural cycle with our activities.  

    • Anonymous says:

      I don’t always agree with you, but in this case I do completely. I am so tired of these “scientists ” scaremongering in order to get grant money. When the catastrophic results they predict don’t come true, they make up some totally random excuse.
      All sea ice would be gone by now- actually growing.
      Continued use of carbon based fuels would continue to increase earth’s temperature – not happening
      Global warming would kill arr coral – coral regrowing.

      So tired of the environmental mafia

  4. Bai says:

    This is great- hopefully such results are to be seen further into the future.