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

[Steve Mussman]

Dear Austin,

I think you absolutely nailed it with this narrative. In addition, there would be far more in the way of a cooperative spirit in the coral science community if coral restoration and assisted evolution proponents would take note and adopt your thoughtful analysis. I would only add that in addition to a more ultraprecise and measured approach to restoration what is needed is a more forthcoming assessment of not only the role of climate change, but the imperative need to restore some semblance of the natural ecological balance. To paraphrase what Phil Dustin recently said here, no matter how spectacular a genotype you breed, it is unlikely to survive in an ever warming sea full of human waste.

Regards and stay safe there in Fiji,

Steve Mussman

On 9/1/21, 6:19 PM, Austin Bowden-Kerby via Coral-List <coral-list at coral.aoml.noaa.gov> wrote:

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/

Teitei Livelihoods Centre

Km 20 Sigatoka Valley Road, Fiji Islands

(679) 938-6437

http:/www.

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 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)

>

>

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