[Coral-List] amazing recovery of corals in the Southern Line Islands after bleaching mortality

Thu Nov 3 13:21:35 UTC 2022

Hi Austin:

>From your post I glean that a missing component of the 'recovery ' studies you cited is an assessment of the fish communities that depend on specific coral species.

Alina

Dr. Alina M. Szmant,  CEO
CISME Instruments LLC

-------- Original message --------
From: Austin Bowden-Kerby via Coral-List <coral-list at coral.aoml.noaa.gov>
Date: 11/2/22 8:53 AM (GMT-05:00)
To: Douglas Fenner <douglasfennertassi at gmail.com>
Cc: coral list <coral-list at coral.aoml.noaa.gov>
Subject: Re: [Coral-List] amazing recovery of corals in the Southern Line Islands after bleaching mortality

Thanks Doug,

Yes, this sounds encouraging- on the surface, and the photos are
beautiful!   However if you look more deeply, it is a lot less hopeful.
What this represents is yet another case of near total phase shift in the
coral population, and the local extinction of a whole list of species.  The
actual reality is this: due mass bleaching, the coral population of the
Southern Line Islands has gone from a diverse population dominated by
Pocillopora and Acropora, to one dominated by a single species of
Montipora.

A similar phase shift has happened in Tarawa, in the Gilbert chain, due to
bleaching, with the end state being a single species: Porites rus (Cannon
et al, 2021).  In Kiritimati Atoll, the mass bleaching resulted in the
local extinction of many Acropora species and a big reduction in
Pocillopora, leaving behind only remnants of massive Porites and massive
Pavona, (Bowden-Kerby et al, 2021).  In Moorea, the phase shift has gone
from Acropora dominated to Pocillopora dominated (Edmunds, 2018; Carlot et
al, 2020), related to bleaching and COTS predation.  This phase shift has
been well documented for the Red sea as well (Riegl et al, 2013), with a
shift away from Acropora towards Pocillopora and Porites, attributed to a
combination of mass bleaching and COTS predation.

These phase shifts transform the habitat characteristics of the reef, away
from what the original species.  The resulting reefs provide poor habitat
for juvenile fish and plankton-feeding fish like Chromis, which require
branching coral species.  These phase shifts represent weedy and
long-lasting coral species, which can dominate the settlement surfaces and
prevent larval based recovery of the reef back to its original coral
population. Few of these authors seem to understand this, and so they
celebrate and use the word "recovery" in their titles.  However, these
phase shifts represent degraded alternate steady-state conditions.
Unfortunately GCRMN will support these authors, as it only looks at coral
cover, not genera, and so it will not pick up or highlight these phase
shifts and species extinctions either.

I have two recommendations related to this information:
1. GCRMN needs to be updated to include coral genera!  Seriously- how can
GCRMN be missing so much of the plot?
2. The authors of these sorts of "recovery" studies need to present phase
shifts with less glee and celebration. A more detached and honest view will
present the tragedy that has happened.  Yes, the alternative state
sometimes is rather glorious and beautiful, appearing to be an improvement
over barren rock, but the fact is that these phase shifts represent local
extinction events for coral species essential to ecosystem function,
fisheries, and coral reef geology.  And these phase shifts might also
prevent the return to the original populations, cementing in the extinction
event.

We can not allow increasing coral cover to trick us into thinking that an
actual recovery has happened.
If we do, we risk being seduced by the enemy and missing the evil plot that
climate change is weaving, tricking us into inaction!

I think that there is enough evidence to come to the conclusion that coral
reefs are dying out as a series of phase shifts.  Only this recognition
will help us refrain from celebrating the shift, and to stop labeling it
recovery.
Only by understanding these basic processes occurring on coral reefs under
increasing stress, can we then begin saving the reefs.

What happens when the next mass bleaching event or perhaps predators or
disease kills off much of the Montipora of the Southern Line Islands?  Will
this unstick the alternative steady state and allow recovery? Not unless
there is a source of coral larvae from the original, now missing coral
species.  How does a high coral cover single-species dominated reef get
restored to its original highly diverse state?  On Kiritimati, after the
mass coral die-off in 2015-16, and while coral cover was still under 5% for
the two remaining massive species, we turned our focus to finding the few
remnant survivors of formerly dominant Acropora and Pocillopora coral
species, and growing them within a recovery nursery.  The focus was on
restoring sexual process to the corals, by collecting the widely spaced and
ecologically extinct survivors, growing them, and getting them back
together.  While several formerly abundant Acropora coral species could not
be found, we have succeeded in restoring reproduction to patches of seven
Acropora and two Pocillopora species.

A 22 minute presentation on our 'Reefs of Hope' strategies is here
https://youtu.be/arkeSGXfKMk    And to the list: we welcome self-funded
research partners and graduate students in our sites.

Vinaka, and kind regards to all,

Austin

Cannon SE, Aram E, Beiateuea T, Kiareti A, Peter M, Donner SD (2021) Coral
reefs in the Gilbert Islands of Kiribati: Resistance, resilience, and
recovery after more than a decade of multiple stressors. PLoS ONE 16(8):
e0255304. https://doi. org/10.1371/journal.pone.0255304

Edmunds, P.J.  Implications of high rates of sexual recruitment in driving
rapid reef recovery in Mo’orea, French Polynesia. 2018.  Nature: Scientific
Reports.  8:16615 doi:10.1038/s41598-018-34686-z

Carlot J., Rove`re A., Casella E., Harris D., Grellet-Mun C., Chancerelle
Y., Dormy E., Hedouin L., Parravicini V.  2020. Community composition
predicts photogrammetry-based structural complexity on coral reefs. Coral
Reefs. doi: 10.1007/s00338-020-01916-8

Riegl B., Berumen M., Bruckner A. 2013.  Coral population trajectories,
increased disturbance and management intervention: a sensitivity analysis.
Ecology and Evolution 3(4): 1050–1064

doi: 10.1002/ece3.519

Bowden-Kerby, A., Romero, L., and Kirata T. 2021. Chapter 17: Line Islands
Case Study. In: Active Coral Restoration: Techniques for a changing planet,
David Vaughn, Editor. 610pp.

Austin Bowden-Kerby, PhD
Corals for Conservation
P.O. Box 4649 Samabula, Fiji Islands

https://www.globalgiving.org/projects/emergency-response-to-massive-coral-bleaching/
<https://www.globalgiving.org/projects/emergency-response-to-massive-coral-bleaching/>

On Wed, Nov 2, 2022 at 6:01 AM Douglas Fenner via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> Once devastated, these Pacific reefs have seen an amazing rebirth
>
>
> https://www.nationalgeographic.com/magazine/article/once-devastated-these-pacific-reefs-have-seen-an-amazing-rebirth-feature
>
> Cheers, Doug
>
> --
> Douglas Fenner
> Lynker Technologies, LLC, Contractor
> NOAA Fisheries Service
> Pacific Islands Regional Office
> Honolulu
> and:
> Coral Reef Consulting
> PO Box 997390
> Pago Pago, American Samoa 96799-6298  USA
>
> Switching to renewable energy could save trillions-up to $12 TRILLION by
> 2050.
> https://www.bbc.com/news/science-environment-62892013
>
> 1 in 6 deaths worldwide can be attributed to pollution, new review shows
>
> https://www.msn.com/en-us/health/medical/1-in-6-deaths-worldwide-can-be-attributed-to-pollution-new-review-shows/ar-AAXozQh
>
> UN: World on fast track to disaster, but we can avert it
> https://www.youtube.com/watch?v=9xBVD8r0aHQ
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