Barrier Reef ‘can adapt’ to warmer times

  • Updated (13/07) – See Dr van Oppen’s response below.

So said a headline in The Australian this morning.

Based on a study coming from the lab of Dr Madeleine van Oppen, the article made the amazing leap from a study in which scientists have found that many corals have several varieties of symbionts to saying that the Great Barrier Reef can adapt to climate change.

And it wasn’t the papers fault (which was published in the peer-reviewed journal, Coral Reefs – doi 10.1007/s00338-007-0244-8).  This is actually what the senior investigator on the paper, Dr van Oppen, said “”This flexibility discovered in our research is important in understanding the past evolutionary success of these coral species and their future survival capacity in the face of changing climate,”

Yes, that is true to some extent. However, estimating the survival capacity of coral species involves a lot more than simply looking at the genetic identity of their symbiotic algae. The authors, for example, have not shown that the different algae do better or worse under climate change. Secondly, the fact that the authors have shown variability does not imply the flexibility needed if corals are to respond to the rapid changes in climate. We need to remember that the rate of change over the past 50 years is 100-200 times faster than the very rapid shifts in climate seen as our planet warmed out of ice ages. The ability to deal with the new conditions imposed by climate change requires that novel not pre-existing symbioses form. Alas – the authors cannot and do not claim this.

I also have an issue with the belief attributed to the research team that ‘bleaching, widely associated with the death of coral, is part of coral’s natural cycle of life.’ Given that natural is good – the implication to the uninitiated is that bleaching is OK. Given that the world lost 16% of its corals in a single cycle of global bleaching in 1998, this ‘belief’ is a stretch – see Dr Paul Marshall’s comment from a few days ago.

At the end of the day, we need to respond to these sorts of data sets logically. Yes, it is interesting that there is variability in the genetics of the symbiotic algae. However, given the complexity of potential climate change impacts on coral reefs, it does not prove that coral reefs will sail on into a warming world without problems as is implied by this rather poor newspaper article.

11 thoughts on “Barrier Reef ‘can adapt’ to warmer times

  1. The article in today’s Australian is a miss-representation of our work.

    What we have shown, using a novel genetic method, is that many GBR corals harbour more than one species of algal symbiont. It is believed by many coral reef scientists that most corals harbour only a single species of alga. In our paper, we show that this notion is likely to be wrong, because the genetic methods generally used to identify a coral’s algal symbionts lack the sensitivity to detect symbionts occurring at low abundances, i.e., cryptic symbionts. The finding of more than one symbiont species in the corals’ tissue led us to hypothesize that these corals may be able to increase the relative abundance of the cryptic algal species, a process called “shuffling”. We have previously shown for one coral species on the GBR, that shuffling can slightly increase the heat tolerance of the coral. This increase in heat tolerance is an advantage during bleaching events, but insufficient to allow corals to cope with global climate change. We now need to examine whether the other corals that harbour cryptic algal symbionts, are able to shuffle those and increase their heat tolerance as a consequence.

    The statement “The research team believes bleaching, widely associated with the death of coral, is part of coral’s natural cycle of life.” is something we have never said. We believe coral bleaching is a stress response and detrimental to the coral.

  2. Firstly it might be helpful to your blog readers if they are told that the study in question was published in Coral Reefs (Mieog et al. (2007)Real-time PCR reveals a high incidence of Symbiodinium clade D at low levels in four scleractinian corals across the Great Barrier Reef: implications for symbiont shuffling. Coral Reefs doi 10.1007/s00338-007-0244-8).

    I also note that in the comment by Ove Houeg-Guldberg (13 July), he attributes the statement “bleaching, widely associated with the death of coral, is part of coral’s natural cycle of life.” directly as a quote by Dr van Oppen, and is then highly critical of this statement. My own reading of the article in the Australian is that this is clearly not a direct quote but rather part of the report by the journalist concerned. It is not contained in quotation marks and the full text is very different from that selectively edited by Dr Hoegh-Guldberg. We all know how journalists and the media easily misinterpret and write what they ‘think’ needs to be said rather than reporting the facts. Hopefully those contributing to this blog will attempt to be more accurate.

    I suggest that your readers access the actual scientific report in Coral Reefs before posting further about this subject.

  3. Thanks Richard. You are right. I should have referred to the original article and consequently have added this reference to the original posting. I will endeavor to do this in the future! Your keen eye has also identified the fact that the Australian newspaper did not attribute the statement in question as a direct quote from Dr. van Oppen (‘bleaching, widely associated with the death of coral, is part of coral’s natural cycle of life’), but rather as a belief associated with the research team. I’ve also corrected this error in my original posting.

    I guess that this type of exchange illustrates the beauty of the blog – an opportunity for open discussion and the evolution of concepts in ways not possible in the fixed format of other forms of communication (e.g. journals, newspapers etc.) Indeed, I hope that you and many others will join in the opportunity to correct, discuss and evolve concepts to do with coral reefs, natural ecosystems, politics and climate change. I also hope that people will not hang back from commenting and that we can have some robust debates and feisty exchanges over matters of common interest!

  4. Guys – maybe so – but you guys and gals in coral research need to not be so naive – check the AIMS press release at their web site

    TITLE HIGHLIGHT “This work shatters the popular view that only a small percentage of corals have the potential to respond to warmer conditions by shuffling live-in algal partners…” van Oppen

    – “shatters !!”

    “This flexibility discovered in our research is important in understanding the past evolutionary success of these coral species and their future survival capacity in the face of a changing climate,” Dr van Oppen adds.

    Implies that has survived past turmoil and will survive the future.

    You now have a whole cottage industry dedicated to promoting the view that any threat to the reef is rampant alarmism and the the whole climate change case and terrestrial runoff case are major unsubstantiated beatups.

    So guys – be VERY precise with your press releases. You need to also state what they don’t mean. I’m not surprised what the Australian did with provided material. It’s not misinterpreted – you guys didn’t manage it !!

  5. Thanks for your comments Luke.

    The words of the press release, however, are chosen carefully. The text “have the potential to respond to warmer conditions by shuffling live-in algal partners” does not imply that climate change is not a problem for coral reefs. This is also the opinion of the senior author (above). See my discussion previously about the paper (also above) – the authors see a small increase in tolerance (1-1.5oC) by shuffling symbionts that the coral already has a symbiosis with. That is, it is a small shift that does not give them protection against the elevated sea temperatures of today (during bleaching events, 2-3oC) or the future (3-5oC).

    I take your point however that the use of words like “shatters” is not helpful. Neither is the implication that this study shows that more than few corals have this feature – after all, they only studied 4 species (there are at least 600 species of corals)!

  6. Ove – you may think that. You may even be 100% correct. But bad press is bad press. You have to watch the b_ggers carefully.
    Unfortunately you almost have to say what the press releases also do NOT imply. So best wishes to the researchers but watch those darn press releases.

  7. Thanks Madeleine, Richard, Luke and Ove for clarifying the issues raised in The Australian’s story on this research.

    I was surprised by the story when I read it and I agree with Luke that the press release invited the misrepresentation of the research that The Australian was so happy to oblige with.

    I asked Ray Berkelmans, who is supervising some of the research on this issue at AIMS, to clarify the findings of the research for me and he explained that at present it appears shuffling coral symbionts can gain about 1 to 1.5 deg more thermal tolerance. As Ray pointed out to me, if this is the case it may be enough to buy time but not enough to keep up with temperature rises of more than 2 degrees that are expected in coming decades under mid-range IPCC projections. I believe that this final point should have been clearly spelt out in the press release.

    Finally, as a non-scientist but someone very interested in protecting the GBR, I want to say that I think this research is very important and I congratulate Madeleine, Ray, Ove and their colleagues for the work they are doing.

  8. Thanks Chris. I believe it is important to get it right. I am sure that Ray, Madeleine and their colleagues appreciate your support.

  9. Luke – good point. I think it would be a mistake if we used only spun-up press releases to communicate the messages of science!

  10. Ove – Thanks for coming over to Marohasy’s and taking up the challenge. Good to see the scientists in the blog trenches with the amateurs – despite Jen’s position her site is a furnace of pro and anti forces. A veritable subduction zone. Although an improvement in the tone of debate is sorely needed.

    I’d encourage you to return with something reducing alkalinity and changes to calcification rates in reaction to CO2 acidification.

  11. Always a pleasure to get into the trenches – I take your point on the issue of acidification. Takes the risk from CO2 to another level. Hard to argue with that one!

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