[Coral-List] Reef biodiversity under global change, new paper

Rupert Ormond rupert.ormond.mci at gmail.com
Fri Oct 29 08:42:34 UTC 2021


Dear Listers,

I  can not help but agree with Austin on his main point. At a time when 
nine ICRS members are about to arrive in Glasgow as observers to lobby 
delegations to COP26, papers suggesting that reef systems can cope, or 
can be adapted to cope, with an extra degree or two of heat are not 
helpful. We have already experienced 1.2 deg C of global heating (since 
pre-industrial times), the clear evidence is that by the time we reach 2 
degs warming most reefs will experience severe annual bleaching, yet the 
prediction is that we will be lucky given current inadequate commitments 
by the world's governments to keep warming to 2.7 deg C. If negotiators 
get the sense that things may not be so bad as some scientists predict, 
warming could get far worse, as we hit the slippery slope of positive 
feedbacks resulting from methane release and reduced reflectance. And I 
have already experienced snorkelling over reef flats with a water 
temperature not far off human body temperature. The deep ocean floor 
supports a surprisingly high invertebrate biodiversity (depending on how 
and over what area it is measured), but that does not produce highly 
productive ecosystems capable of supporting and enriching the lives of 
hundreds of millions of people.

Rupert

Professor Rupert Ormond
Co-Director, Marine Conservation International
Hon. Professor, Centre for Marine Biodiversity & Biotechnology, 
Heriot-Watt University, Edinburgh
Editor REEF ENCOUNTER (news journal of the International Coral Reef Society)


On 29/10/2021 05:07, Austin Bowden-Kerby via Coral-List wrote:
> Thanks Christopher for sharing this very useful publication.
>
> With reluctance, I am writing yet again to the Coral List to raise my
> concern to authors and reviewers and publishers: to be more careful about
> ensuring accurate public perceptions - to speak with a united voice to
> reaffirm the seriousness of climate change impacts on coral reefs, and that
> the collapse of this most diverse system is just beginning- and that
> massive changes in society must happen if we are to save them.
>
> Unfortunately there has been a string of positive sounding titles published
> in the past year or so on how coral reefs are adapting in the onslaught of
> climate change, and this paper follows that trend.  My fear is that all of
> this focus on hints of light among the spreading darkness, no matter how
> well intentioned, might backfire by downplaying the urgency of action to
> save coral reefs and to lower carbon emissions.
>
> Of course most people have no idea what cryptobiota are, and how much can
> persist even if all or most of the corals die! But that is not clearly
> spelled out.  So in spite of the papers well developed and precautionary
> discussion, the press and non-scientists will not likely read much beyond
> the title or abstract, and might conclude that coral reef scientists are
> changing their minds about the severity of climate change impacts to coral
> reefs, and that it will not be not so bad for coral reefs after all?
>
> My belief is that any title or abstract that presents a positive face on
> the dire situation that coral reefs now face, will have the opposite impact
> to what we need.  How else will the press perceive these words: "Contrary
> to expectations, species richness in the combined future ocean treatment
> with both warming and acidification was not significantly different from
> the present-day control treatment.  Rather than the predicted collapse of
> biodiversity under the dual stressors..."
>
> Besides the positive spin, I have a few other comments and thoughts:
>
> 1. I find that this work is most relevant to life in tide pool and reef
> flat environments, but that is not discussed in the paper.  Already living
> experiments are taking place on many reefs in the extreme shallows, and not
> at temperature peaks of only 30C, but at peaks of >35C every summer!  Some
> of these areas are also fringed by mangroves and so have a low pH as well.
> Based on the realities in the field, I would crank the temperature up
> another 2C and see what you get, because this is too mild as far as the
> present situation- also, does a 2C increase in the cool open ocean
> translate into a much higher increase in the nearshore?  .
>
> 2. I believe that the study has an experimental flaw that makes it unlikely
> to represent future conditions that we will face on coral reefs.  The flaw
> is the fact that unfiltered seawater flowed in from a diverse and not yet
> badly altered coral reef ecosystem, where larvae and various propagules
> were abundantly available, but this will certainly not be the case once
> coral reefs die.   Again, if the conclusions had focused on understanding
> the stressors in the hot and acidified shallows adjacent to relatively
> intact coral reef systems, conditions that already exist, I would agree
> completely.  The study is relevant to life in the shallows, but I disagree
> that we can deduce from it any sweeping conclusions about the future of
> coral reef biodiversity.
>
> 3. For most of the IndoPacfic, Acropora dominance is typical, while coral
> reefs in Hawaii are dominated by Porites and Montiipora, which elsewhere
> can indicate degraded reef systems, so Hawaii may not be the best place to
> look for trends with respect to coral reefs in general.  The reefs of most
> of the IndoPacific are ecologically more similar to the Caribbean than they
> are to Hawaii.  Not just the lack of Acropora corals and their obligate
> species, but the winter water temperatures in Hawaii, are cool to the point
> where they look more subtropical than tropical, and so that might explain
> why a 2C warming might be beneficial to some organisms?
>
> 4. Corals and fish are discounted in the study, supporting the idea that as
> long as biodiversity remains high, regardless of a shift in species
> composition, that somehow high biodiversity is the goal, regardless of
> ecological functioning, geological functioning, and the like.  The
> cryptobionts are put on equal standing with the dominant organisms which
> create, structure, and maintain the reef, and at face value, and without
> that balance, the conclusions are disconnected from the grave reality of
> the present crisis.
> It is like saying "let's study rainforest diversity by removing the trees
> and birds and raising the temperature a little bit, and lowering pH, but
> let's keep the inputs coming from the rainforest seeding the experiment
> with organisms day by day week by week"  But doesn't discounting the source
> of all the biodiversity coming from intact living coral reefs make the
> entire experiment meaningless, as far as peering into the future of climate
> change and when corals on reefs are mostly dead?
>
> Yes there is a lot of good discussion as to what this all means, and a lot
> is cautionary, but it never discusses the relative importance of the
> cryptobionts in comparison to the loss of coral cover, and so it does not
> remove the simple public take home message that the reefs are still doing
> fine and that these results are very hopeful for the future of coral reefs
> everywhere.
>
> My sincere apologies Molly and Christopher and team!  As this is way too
> critical....  I have let this sit and was thinking of sending this message
> to the trash, as I really don't want to hurt people's feelings and to be so
> horribly negative.  Sending this off might not be a good move
> professionally either, as I need all the friends I can get, but seriously
> we really need to correct this very bad trend- I did not want to pick on
> this particular paper other than to use it as the latest example in a
> series of publications that have the unintended potential to undermine the
> resolve of governments and all those who might do something to turn this
> situation around.
> .
> My observation is that the more authors that a publication has listed, the
> least cautious and self-critical the authors seem to become.  But where
> were the reviewers, who should have enough background to catch this sort of
> stuff I have raised here?  If the peer review process were working in this
> case, would it have prevented such bold and possibly erroneous speculations
> from being published as facts as well as a key missing assumption, while
> missing the true significance of the work?  And now we have what might
> become international news, misinterpreted by many, that scientists were
> wrong, and that the coral reefs will survive in spite of global warming.
>
> I see the field of coral reef science at a critical juncture, like
> foresters who see the glow of the wildfire on the horizon, yet there is no
> unified firefighting or disaster management strategy, few staff, and no
> funds.  What could we save if we acted now?  The recent GCRMN report showed
> a 14% decline in coral cover, which is bad enough, but it was only
> reporting on coral cover, and thus has completely missed the phase shift
> that is happening on some reefs, from Acropora to Porites, with numerous
> local species extinctions in Kiribati and Chagos etc., which are on the
> leading edge of the collapse. The GCRMN will only show impact when the
> corals die, it does not measure coral diversity or species extinctions. It
> is as if the diverse broadleaf rainforest (Acropora reefs) has been flipped
> into a lower diversity pine forest (Porites reefs), but the foresters see
> all trees as equal, so the monitoring only picks up the change when the
> forest shifts to a grassland (algae dominated).
>
> Besides speculations being presented as facts, if your mother, or cousin,
> or taxi driver were to read this report on the Hawaii article below, what
> would the take home message be?  Judge for yourself.
>
> https://scitechdaily.com/coral-reef-biodiversity-predicted-to-shuffle-rather-than-collapse-as-climate-changes-with-ocean-warming-and-acidification/
>
>
> "New research led by scientists at the University of Hawai‘i (UH) at Mānoa
> reveals that the species which dominate experimental coral reef communities
> shift due to climate change, but the total biodiversity does not decline
> under future ocean conditions of warming and acidification predicted by the
> end of the century. The study was published on September 20, 2021, in
> the *Proceedings
> of the National Academy of Science*. “Rather than the predicted collapse of
> biodiversity under ocean warming and acidification, we found significant
> changes in the relative abundance, but not the occurrence of species,
> resulting in a shuffling of coral reef community structure,” said Molly
> Timmers, lead author who conducted this study during her doctoral research
> at the Hawai‘i Institute of Marine Biology (HIMB) at the UH Mānoa School of
> Ocean and Earth Science and Technology (SOEST).
> Feeling very sad, and not wanting to push "send", but it appears that I am
> the only one willing to do this.
>
> The harsh fact is that no one is in charge, so there is no war on the
> collapse of coral reefs, no unified strategy, no generals, no battle plans-
> not that I can see at least!  Please inform me if I am wrong..... the old
> strategies of cleaning up the waters and establishing no-take areas is not
> the armor that we had hoped.  The only newer strategy that I have read
> abandons the front line and focuses on the coral reefs which are doing the
> best.  But isn't the devastated front line where the most important lessons
> might be learned that might slow the spreading fires from reaching the core
> areas? Anyone who has adopted that triage strategy, will not work in or
> fund Kiribati, as the reefs are already too far gone- admitting defeat, and
> retreat.  But the saddest thing is that the Kiribati government, who are
> the only ones who might do something now, relies on the scientific
> community for their information, but all they have received is 4-5 very
> hopeful sounding reports, so they remain unaware that in spite of the
> positive spin, that their coral reefs are mostly dead or have shifted into
> an alternate state- with massive local species extinctions- the reefs most
> impacted by bleaching on the planet, as indicated by the online multi-year
> NOAA data.  Horrific ciguatera and food insecurity is unfolding in this
> nation, as the sea level rises.... This is the reality of the front lines.
>
> We are developing battle plans, and are carrying out an assisted natural
> recovery strategy for Kiritimati Atoll, published in the recent Vaughn
> Edited book on active restoration, and we are also implementing a strategy
> to facilitate and accelerate bleaching resistance and adaptation on the
> coral reefs of the less impacted areas like Fiji, and I am writing that up
> now.
>
> Kind regards,
>
> Austin
>
>
> Austin Bowden-Kerby, PhD
> Corals for Conservation
> P.O. Box 4649 Samabula, Fiji Islands
> https://www.corals4conservation.org
> TEDx talkhttps://www.youtube.com/watch?v=7PRLJ8zDm0U
> https://www.globalgiving.org/projects/emergency-response-to-massive-coral-bleaching/
> <https://www.globalgiving.org/projects/emergency-response-to-massive-coral-bleaching/>
>
>
> Teitei Livelihoods Centre
> Km 20 Sigatoka Valley Road, Fiji Islands
> (679) 938-6437
> http:/www.
> <http://permacultureglobal.com/projects/1759-sustainable-environmental-livelihoods-farm-Fiji>
> teiteifiji.org
> http://permacultureglobal.com/projects/1759-sustainable-environmental-livelihoods-farm-Fiji
> https://www.globalgiving.org/projects/happy-chickens-for-food-security-and-environment-1/
>
>
>
>
>
> On Tue, Oct 26, 2021 at 4:55 AM Christopher Jury via Coral-List <
> coral-list at coral.aoml.noaa.gov> wrote:
>
>> Dear colleagues,
>>
>> Given recent discussions regarding reef biodiversity responses to global
>> change I wanted to direct you to our new article published in PNAS. The
>> title, abstract, and link to the paper follow:
>>
>> Title: Biodiversity of coral reef cryptobiota shuffles but does not decline
>> under the combined stressors of ocean warming and acidification
>>
>> Abstract: Ocean-warming and acidification are predicted to reduce coral
>> reef biodiversity, but the combined effects of these stressors on overall
>> biodiversity are largely unmeasured. Here, we examined the individual and
>> combined effects of elevated temperature (+2 °C) and reduced pH (−0.2
>> units) on the biodiversity of coral reef communities that developed on
>> standardized sampling units over a 2-y mesocosm experiment. Biodiversity
>> and species composition were measured using amplicon sequencing libraries
>> targeting the cytochrome oxidase I (COI) barcoding gene. Ocean-warming
>> significantly increased species richness relative to present-day control
>> conditions, whereas acidification significantly reduced richness. Contrary
>> to expectations, species richness in the combined future ocean treatment
>> with both warming and acidification was not significantly different from
>> the present-day control treatment. Rather than the predicted collapse of
>> biodiversity under the dual stressors, we find significant changes in the
>> relative abundance but not in the occurrence of species, resulting in a
>> shuffling of coral reef community structure among the highly species-rich
>> cryptobenthic community. The ultimate outcome of altered community
>> structure for coral reef ecosystems will depend on species-specific
>> ecological functions and community interactions. Given that most species on
>> coral reefs are members of the understudied cryptobenthos, holistic
>> research on reef communities is needed to accurately predict
>> diversity–function relationships and ecosystem responses to future climate
>> conditions.
>>
>> https://www.pnas.org/content/118/39/e2103275118
>>
>> Best,
>>
>> Chris Jury (on behalf of co-authors)
>>
>> --
>> Christopher P. Jury
>> University of Hawai'i at Manoa
>> Hawai'i Institute of Marine Biology
>> P.O. Box 1346
>> Kane'ohe, HI 96744
>> Academia.edu profile<http://manoa-hawaii.academia.edu/ChristopherJury>
>> Google Scholar profile
>> <
>> http://scholar.google.com/citations?hl=en&view_op=list_works&gmla=AJsN-F5XCN2Wpv5xaVKMvH49ZNlcyGQ9rhPTlY17Hu0OBXETn1dZp8lplT8l6DdCxoZc1BzbTHMoxJZRVRQhxFt5X8TBa4clDA&user=oLuIGVAAAAAJ
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