[Coral-List] FW: Loss of reef biodiversity - any recent data?

[Austin Bowden-Kerby]

Dear Peter and Zoe,

Thanks for bringing this shared concern to the forefront.

Many species of Acropora corals have been lost from the Line Islands,
Kiribati, since the 2016 severe ten-month mass bleaching event, the most
intense bleaching event ever recorded in the NOAA data series.  With no
reefs directly upcurrent, where larvae might recruit from, these locally
extinct species have little chance of returning unassisted- within my
lifetime at least. Surviving remnants are so few and far apart that sexual
reproduction has obviously failed. Could a similar problem be emerging for
other reefs globally, especially at the fringes of present coral
distribution, and for reefs likewise isolated from upcurrent coral larval
sources?

Of the Acropora species originally found on Kiritimati (Christmas) Atoll,
after several years of searching, we have found a total of 5 acropora
species persisting, out of at least 11 original species. Two of the
Acropora species, *A. globiceps* and *A. retusa*, have in recent years been
recognized and listed as threatened corals internationally.

We have collected samples of all the surviving Acropora species that could
be found on the atoll, however only a few genotypes are available for some
species.  Using the sampled fragments, we have created a coral nursery in a
sheltered area with good water flow.  Adult colonies now are growing and
likely spawning seasonally in the nursery, and second generation fragments
have also been replanted into multi-genetic patches on the reef, in hopes
of re-booting successful spawning and natural recovery processes. We
predict that these survivors are more bleaching resistant than those corals
which died. The Kiritimati case study is included as chapter 17 of the new
book, "Active Coral Restoration, Techniques for a Changing Planet", edited
by Dr. David Vaughn.

In the new climate change realities that we now face, I believe that coral
reef restoration must become more focused on endangered species recovery
and on nurturing bleaching resistance and disease resistance among diverse
corals, as well as restoring sexual reproduction, so that natural adaptive
processes are encouraged.  Rather than "upscaling" restoration based on the
numbers of fragments planted per square meter, I think we should measure
success based on securing diversity and resilience within declining or
threatened coral species, helping secure and restore reproductive and
ecologically functioning coral populations, which in turn facilitate
natural recovery processes. We can not replant the whole reef, and we must
ask ourselves if what we replant today will survive a rapidly warming
world?  Are we imposing a technology on the reef system that will increase
coral cover now, but that is ultimately doomed when mass bleaching hits, or
are we working to increase bleaching resistance within the coral population
that will hopefully spread, buying us precious time, while the world
struggles to bring climate change under control?

Most importantly, I think that we now need to invest energy into ensuring
long term survival of our most resilient coral populations, which may
already exist at the upper limit of thermal tolerance.  Unfortunately,
Kiribati shows us that these most resistant corals are just as vulnerable
to mass bleaching events, as the shallow lagoon waters can become
superheated and exceed the maximum heat threshold of all corals.  If we had
only gotten to Kiritimati Atoll before the bleaching induced mass die-off
in 2015-16, we might have saved multiple genotypes of the most resistant
corals of the lagoon from local extinction- simply by moving coral samples
out to cooler waters near the passes and establishing them within
nurseries.   But alas, the entire population of bleaching resistant corals
died out when the water became so hot that even the fish died.  Just
imagine a large lagoon covered in thickets of dead and standing staghorn
and massive corals- all we could find alive after a day of searching was
one small colony of foliose Montipora.

Learning from this tragedy, in Fiji we now focus on identifying hot pockets
on the reef and inshore that are near the upper limit of thermal tolerance,
and sampling those corals, moving them out to cooler water nurseries where
even in severe condition two bleaching, temperatures will never go above
the threshold for these specific corals.  But this is a race against time,
and ours is only a tiny effort when compared to the scale of the reefs and
the numbers of nearshore and shallow lagoon hot pockets in Fiji, the
region, and globally.  Unless this is recognized as a time sensitive
opportunity, within a decade, most of these heat adapted coral populations
will be gone.

Even if we can solve the climate crisis with massive changes in production
and consumption, unless coral restoration efforts can begin to visualize
conditions 10-20 or even 30 years into the future, will they succeed?
Based on clear trends, many of the Acropora species that we are working
with now will likely be the first to go, becoming threatened species or
locally extinct in our lifetimes.  Right now, we continue to have a range
of species and genotypes with broad thermal and disease tolerances to work
with.  But as the die offs arrive, unless heat adapted corals that are
presently living near their upper thermal limits are secured, we stand to
lose much of this diversity of resilience that is so important to long term
coral reef survival.

We welcome self-funded researchers and students into our sites, once the
planes start flying again in this region. For those searching for a topic
along the lines of ecological restoration or facilitated adaptation, we
have a long list of research questions that might help pin down a research
topic of global relevance.

Regards to all,

Austin

Austin Bowden-Kerby, PhD
Corals for Conservation
P.O. Box 4649 Samabula, Fiji Islands
https://www.corals4conservation.org
TEDx talk https://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
https://www.globalgiving.org/projects/happy-chickens-for-food-security-and-environment-1/





On Mon, Aug 30, 2021 at 8:27 AM Zoe Richards via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> Hi Peter,
>
> Thanks for raising this timely and really interesting question - it is one
> I am particularly interested in with Indo-Pacific corals.
> Its my suspicion that coral biodiversity is quietly slipping away through
> an ongoing series of local extinction events, but yes as you say, genuine
> species losses are very hard to detect in dynamic ecosystems like coral
> reefs.
> You may be interested in a recent study where my colleagues and I examined
> the spatio-temporal persistence of scleractinian coral species at Lizard
> Island on the Great Barrier Reef:
> https://link.springer.com/article/10.1007/s00338-021-02144-4
> This location has been subjected to various disturbances over the years,
> COTS, cyclones, coral bleaching and while a large portion of the species
> appeared temporally stable based on available records from the last 44
> years, I found ~28 species were at risk of local extinction and another ~
> 31 were at risk of local range reduction. Interestingly, it was not always
> the rare species that disappeared, some common species like Acropora aspera
> and A. abrotanoides were among the missing species.
> I can't answer the question of how far along the path to biodiversity
> collapse we are, but given corals are among the best studied taxa and we
> don't know the answer for them, there is good reason to be concerned about
> the remainder of marine invertebrate biodiversity - much of which remains
> to be described!!
>
> News article on the paper can be found here:
> https://theconversation.com/almost-60-coral-species-around-lizard-island-are-missing-and-a-great-barrier-reef-extinction-crisis-could-be-next-163714
>
> All the best,
> Zoe Richards
>
> Marine Invertebrate Curator | Department of Aquatic Zoology
> Senior Research Fellow | Coral Conservation and Research Group Leader |
> Curtin University
>  @ZoeR_Coral
>
> 150 William Street, Perth WA 6000
> Locked Bag 49, Welshpool DC, WA 6986
> T. 61 8 9212 3872
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>
> -----Original Message-----
> From: Coral-List <coral-list-bounces at coral.aoml.noaa.gov> On Behalf Of
> Peter Sale via Coral-List
> Sent: Sunday, 29 August 2021 11:19 AM
> To: coral-list at coral.aoml.noaa.gov
> Subject: [Coral-List] Loss of reef biodiversity - any recent data?
>
> Hi coral-listers,
> I was recently reading some papers concerning the apparent extinction,
> across the Florida reef tract of Dendrogyra cylindrus, the pillar coral:
> Chan et al 2019, Front. Mar. Sci. doi: 10.3389/fmars.2019.00218 ; Jones et
> al 2021, Scient. Rep. doi.org/10.1038/s41598-021-93111-0 ; and Neely et
> al 2021, Front. Mar. Sci. doi: 10.3389/fmars.2021.656515 .  They reveal,
> rather convincingly, that Dendrogyra has likely been extirpated throughout
> Florida by a combination of bleaching and SCTLD between 2015 and 2020.
> Chan et al also provide genetic data suggesting the species had been
> reproductively extinct in Florida (only asexual propagation happening) for
> 'many' years before that.  Each paper makes clear that the situation may be
> different elsewhere in the Caribbean.  I summarized what I gleaned from
> these papers here:
> https://aus01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.petersalebooks.com%2F%3Fp%3D3165&data=04%7C01%7Czoe.richards%40museum.wa.gov.au%7C068d69d9d4ab4979ec0508d96b042736%7Cc1ae0ae2d5044287b6f47eafd6648d22%7C0%7C0%7C637658487865227773%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=hNGqcHx%2FBtzkNnI3%2BpOG6z0vNWg6TmiiegvC4ulIPp8%3D&reserved=0
>
> The story provided by these papers has led me to wonder about all the rare
> species on coral reefs around the world.  Reef ecosystems are characterized
> by having relatively few common species (across taxa, not just corals) and
> long tails of rare species.  Dendrogyra has been rare in most locations in
> its range for decades if not much longer, but it is a large and conspicuous
> species.  When it disappears, that is obvious.  But most rare species are
> also small, inconspicuous, even cryptic.  Their disappearance would be a
> lot harder to detect unless one was actively looking for them.  So, just to
> add to the problems faced by coral reef systems, how far along the path to
> biodiversity collapse are they?
>
> Serious question.  If someone has done a lot of work on this topic,
> meaning I should already know the answer, forgive an old fish ecologist.
> (And if the work was done on reef fishes, please let me down gently!)
>
> Peter Sale
> University of Windsor (Emeritus)
>
>