[Coral-List] In memorium. Remembering pillar coral

[Douglas Fenner]

      So the extinction of coral species due to humans is now beginning.
The next couple of decades or so could be quite grim for coral species.
Another species of coral that is hanging by a thread is Ctenella chagius,
like Dendrogyra the only species in its genus, and in the same small
family.  It is endemic to the Chagos archipelago in the Indian Ocean,
though it has also been found in one other spot in the Indian Ocean, though
we don't know how much of it is at the other spot.  The first surveys in
Chagos after the 2016 mass coral bleaching could find no colonies alive.
The second round found a few colonies that had islands of living tissue
remaining, and a subsequent survey found one small group of intact
colonies.  An attempt at keeping them alive in captivity failed, unlike
Dendrogyra.  The next mass bleaching event that strikes Chagos could well
drive it to global extinction.
     There is a paper that brings up your point about the more cryptic
species and the fact that we would not know it if any of them went
extinct.  Richards and Day, 2018.
      My understanding is that while cryopreservation of sperm works, it
doesn't work with eggs yet     .  Maybe it works with larvae??  If
it doesn't work with eggs or larvae, it won't protect species from global
extinction.  If people can keep them alive in captivity, that could keep
them from going globally extinct, but it is a bit precarious, a power
failure could kill them when air pumps stop, and there are other things
that can happen in captive systems for coral.
      I remind people that the lethal SCTLD disease that kills so many
Dendrogyra is sweeping through the Caribbean, my guess is that it is likely
to do to Dendrogyra there what it did in Florida.

Cheers, Doug

Sheppard, C., et al.  2020.  Coral mass mortalities in the Chagos

    Archipelago over 40 years: Regional species and assemblage extinctions
and

    indications of positive feedbacks. Marine Pollution Bulletin 154: 111075


Richards, Z. T., and Day, J. C. 2018. Biodiversity of the Great Barrier
Reef- how

              adequately is it protected? *Peer J*: 6: e4747.

On Wed, Jun 21, 2023 at 12:21 AM Peter Sale via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> Hi Joe and others,
> Dendrogyra.... Back in 2021, when I had more time to blog than I now seem
> to, I reflected on the sad story of Dendrogyra:
> https://www.petersalebooks.com/?p=3165
> The story I told is still worth reading even though the situation for that
> iconic species is far more dire than even then.
> The naked ape is proving day by day that it is not a very effective
> steward of this planet.  When it too is gone, or at least knocked down and
> allowed to scrabble together a new semblance of a civilization, perhaps
> there will be an opportunity for the planet to repair its many wounds and
> begin a new cycle of growing wondrousness.  Wondrousness that naked apes
> will likely never see, perhaps including coral reefs with a species a
> little bit like Dendrogyra.
>
> Peter Sale
> U. Windsor (emeritus)
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