[Coral-List] Great Barrier Reef intense bleaching event underway

[Douglas Fenner]

Australia's Great Barrier Reef is "transforming" from repeated coral
bleaching

https://www.nature.com/articles/d41586-024-01151-z

"Marine biologist Terry Hughes says the solution to the bleaching problem
is clear: “Reduce greenhouse gas emissions. Full stop.”

Hopefully, some corals will survive and start to repopulate.  But 5 mass
bleaching events on the GBR in 8 years doesn't allow time for recovery, as
they point out.  The reef community will change.  Unfortunately, the
endpoint of that change may be an algae bed with only a few corals, much
like what the Florida Reef Tract now has.  The reef geological structure
will not disappear overnight, but the coral reef ecosystem is likely, in
time, to become an algae bed.  One reef in Florida was reported to have
100% coral mortality last summer.  Loss of corals will reduce shoreline
protection, hit tourism, and reduce fish catch, the three main ecosystem
services that coral reefs provide to humans.   There are millions of fisher
families in developing countries that depend on coral reef fish catch for
survival.  And rare species may be driven to local extinction.  Rare
endemic species could be at risk of global extinction.  Coral species in
the Indo-Pacific are numerous and difficult to identify, and generally not
monitored at the species level because of that.   A vast number of species
depend on hard corals for their survival, so this may apply to many of them
as well.  There are too many species of these dependent species to
monitor.  We could lose some of them before we know what has happened,
which is called "silent extinction."  (Richards and Day, 2018)

Note the list of related articles below this article, those are links.

I note that in the web page "Links to marine research and climate change
2023" that Martin pointed to (https://reefscapers.com/links-2024/), there
is a box about Chagos, one of the world's most remote coral reef
archipelagoes, which as of April 2 had 7 degree heating weeks, and is
likely to get much worse.  Chagos has an endemic coral, *Ctenella chagius*,
the only member in its genus, and one of only a few species in its family.
That species has already been pushed by previous mass bleaching events
close to extinction.  A few years ago there were only a very few scattered
colonies with partial mortality known left alive.  The present bleaching
event could finish completely wiping them out in Chagos, it could drive
that species to global extinction (Sheppard et al, 2020.
       Anyone want to place bets on whether *Ctenella chagius* or pillar
coral in the Caribbean will be the first reef-building coral in the world
to be documented to have been driven to global extinction in the wild??
Tip of the iceberg, the thin edge of the wedge of the disaster now upon us,
predicted to happen in 20-30 years, but now happening as we speak.

      I strongly recommend the page Martin referred to
https://reefscapers.com/links-2024/   It is a gold mine of information on
climate change and its effects on coral reefs.  Check it out!

Terry Hughes hit the nail on the head "Reduce greenhouse gas emissions.
Full stop."

Cheers, Doug

Sheppard, C., Sheppard, A., Fenner, D.  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.

-- 
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

Costanza, R. 2023. To build a better world, stop chasing economic growth.
Nature 624: 519-521.   https://www.nature.com/articles/d41586-023-04029-8

Fossil fuel air pollution kills 5 million people world-wide per year
https://www.yahoo.com/news/research-shows-disturbing-between-millions-200000257.html

World's richest 1% emit as much as 5 billion people
https://makerichpolluterspay.org/climate-equality-report/

Huge expansion of fossil fuels planned, will be very destructive
https://www.theguardian.com/environment/2023/nov/08/insanity-petrostates-planning-huge-expansion-of-fossil-fuels-says-un-report

"without policy changes, the world will heat up enough by the end of the
century that more than 2 billion people will live in life-threatening hot
climates"         Will you be in that area???
https://www.yahoo.com/news/scientists-sounding-alarm-dangerous-problem-123000792.html

World subsidies for fossil fuels reached an all-time high of over $1
TRILLION in 2022, the last year for which data is available.  The subsidies
MUST end.

https://blogs.scientificamerican.com/observations/fossil-fuel-subsidies-must-end/