Epicentre of Mass Coral Bleaching – Still So Beautiful (Part 1)

Originally posted at Jennifer Marohasy’s Blog

Jennifer Marohasy

It is all over the news, right across the world: the Great Barrier Reef is bleaching – again.   Children can’t sleep at night: it is not only the war in the Ukraine keeping them awake at night, but also our apparent disregard for nature.


On 10th April 2022 I went to the very epicentre of the claimed latest severe mass coral bleaching, and found a coral wonderland.

There was some bleaching, especially around the perimeter of John Brewer Reef – on the sandy sea floor where the Australian Institute of Marine Science (AIMS) surveyed and concluded coral cover is never more than 30% – but most of John Brewer Reef is still covered in more than 80% colourful corals.    This high percentage is denied by AIMS because they never survey the reef crest.

This coral reef, John Brewer Reef,  has been described as one of the worst bleached by the ABC, The Conversation, and The Guardian.   The Guardian uses the same photographs as the ABC which have been sourced from environmental group the WWF.

At John Brewer Reef just yesterday, I swam over the top – over the reef crest – and I also swam along the walls that drop down to the sandy sea floor.

My buddy swam in front of me between the walls of coral at John Brewer Reef on 10th April 2022. Photographed by Jennifer Marohasy.

I will show you some of the snap shots that I took with my Olympus TG6, no lights.  I also swam around the sandy perimeter, and I will show you these photographs in my next blog post – that will be Part 2 of this series.   In Part 3 and 4 I plan to show you video of transects that will be swum later in the week when I return to John Brewer Reef with one of Australia’s best underwater cinematographers.

My buddy swimming along the front wall of John Brewer Reef on 10th April 2022. Photographed by Jennifer Marohasy.

John Brewer Reef is 70 kms (38 nautical miles) east of Townsville, part of the central region of the Great Barrier Reef.   Rising from the sandy sea floor are two huge flat-topped blocks of consolidated limestone that represent layer upon layer of dead coral (that you can’t see) with a topping (that you can see) of colourful plates and so many tiny fish.  Running between these two reefs is a deep canyon with walls of more coral and more fish.

Most of the corals were very healthy with lots of chocolate brown zooxanthellae, but you can see a bleached coral in the distance that is very white.  Photographed by Jennifer Marohasy at John Brewer Reef on 10th April 2022.

While most of the corals at the reef crest were healthy, there were some corals that were bleaching white and others were bleaching colourful.

The pink to purple coloration in some of the corals at the reef crest is not from zooxanthellae, which are the symbiotic algae, but rather from increased pigment accumulation from the coral itself as the zooxanthellae are expelled.  Zooxanthellae are expelled when the coral becomes stressed from water that is a bit too hot or a bit too cold.  These colourful corals are often described as fluorescing.

This plate coral has bleached and is fluorescing. Photographed by Jennifer Marohasy at John Brewer Reef on 10th April 2022.
This is a closeup of a plate coral with its pink tips are still alive.  The coral colony will likely recover.  According to the technical literature, some corals florescence/go this pink colour within 2 to 3 weeks of exposure to unusually warm temperatures.  More usually this coral would be a deep chocolate brown. Photographed by Jennifer Marohasy at John Brewer Reef on 10th April 2022.
This is a close-up of a brown plate coral, that has not bleached and is not fluorescing. Photographed by Jennifer Marohasy at John Brewer Reef on 10th April 2022.
This is a closeup showing the coral polyps of a healthy brown coral colony (top) and also a bleached colony (foreground). If you look closely you will see tentacles that enable the coral to feed even when all the zooxanthellae have been expelled. Photographed by Jennifer Marohasy at John Brewer Reef on 10th April 2022.

********   The photograph at the very top of this blog post was taken just yesterday (10th April 2022) while I (Jennifer Marohasy) swam over the top of John Brewer Reef.  The coral in the foreground is not bleached, but rather a beige-coloured and with naturally white tips.  The very pink coral in the centre of the photograph is ‘bleaching colourful’. The pink to purple coloration in some of the corals at the reef crest is not from zooxanthellae, which are symbiotic algae, but rather from increased pigment accumulation from the host tissue/the coral itself as the zooxanthellae are expelled.  This is often referred to as fluorescing and/or bleaching colourful.

The corals at the reef crest at John Brewer Reef that are bleaching colourful/fluorescing are likely to make a full recovery.

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Tom Halla
April 13, 2022 10:04 am

Rather blatant gaslighting by the Grauniad and others.

April 13, 2022 10:15 am

These corals look good unlike the people in ND who are experiencing a blizzard right now. We need some global warming now…this has been a long winter.

Reply to  Derg
April 13, 2022 10:37 am

That beats Ukraine and a lot of other reality checks.

MM from Canada
Reply to  Derg
April 13, 2022 1:44 pm

Southern Manitoba is being slammed by the same blizzard.

Climate believer
April 13, 2022 10:26 am

Thank you for showing the reality of the situation.

April 13, 2022 11:06 am

Hopefully, the ranks of whistle-blower scientists like Jennifer will grow exponentially as more “climate scientists” reach the point in their careers where they can no longer stomach the perfidy.

I mean, imagine what self deprecation must be required by those IPCC contributors who have to swallow watching their research findings get “interpreted” by a gaggle of shiny-bum bloated bureaucrats for inclusion in the Summary For Policy Makers.

Self esteem can’t be enhanced by having to wear a sh1t-eating grin.

Smart Rock
April 13, 2022 11:22 am

Jennifer – the sane people owe you a great big vote of thanks. Unfortunately, there don’t seem to be enough of us to turn back the green tide.

April 13, 2022 11:29 am

I posted a while back about the two pipefitters/welders from Australia who were working in a refinery near where I live. They had all kinds of pictures from multiple locations along Great Barrier Reef and other locations they dive. And they just laughed when asked about all the dead coral there.

Thanks for these beautiful photos, ma’am, and keep up the good work.

Rud Istvan
April 13, 2022 11:36 am

Nice post,JM. Let’s compare some WG2 stuff, IPCC AGW claims versus reality:

  1. GBR endangered. Nope, in great shape as you prove.
  2. Polar bears endangered. Nope, in great shape.
  3. Maldives endangered. Nope, in great shape.
  4. Sahel endangered. Nope, greening.
  5. Costa Rica’s golden toad extinct from AGW. Nope, extinct from chytridiomycosis fungal disease brought in to Brilliante Ridge by ecotourists.

Not a great alarmist environmental AGW disaster track record.

Reply to  Rud Istvan
April 14, 2022 8:51 pm

“Costa Rica’s golden toad extinct from AGW. Nope, extinct from chytridiomycosis fungal disease brought in to Brilliante Ridge by ecotourists.”

No doubt ecotourists contributed…
Ecotourists strike me as types that stay high and dry.

It is my understanding that the researchers counting and studying the frogs wore the same contaminated boots and leggings that initially spread the fungus.
It wasn’t until frog populations were disappearing that sterilizing was used.

April 13, 2022 11:45 am


Many thanks the news and the cracking photos. Just a minor, pedantic whinge – there is no need for epicentre. That would mean the point on the surface vertically above the centre! Too many people seem to think using epicentre sounds more important.

Kevin Hilde
Reply to  Disputin
April 13, 2022 3:21 pm

Yep … It’s a common error among particular anal types, especially pedants; only the original denotative meaning should be allowed. There can be allowed no connotative usage, no simile, and nothing figurative, allegorical or metaphorical.

For such people therefore, in this instance for example, “epicentre” can only mean anything at all if specifically referring to a seismic event. All other usage is simply incorrect.

In analyzing such people, their motivators and general makeup, one could basically conclude that their lives revolve around narrow points of meaning with their anuses at their very epicentres. Oops, I did it again. Sorry.

Anyway, God and Americans, who actually learned proper phonics, know it’s correctly spelled “epicenter.”

Have a nice day.

Reply to  Kevin Hilde
April 13, 2022 5:56 pm

While I don’t always like it, I understand that language, like DNA, changes almost daily.

Reply to  AndyHce
April 13, 2022 6:30 pm

And before you know it, the idiocracy is here.

Kevin Hilde
Reply to  AndyHce
April 14, 2022 3:22 pm

It’s a damn good thing …. imagine the required vocabulary size of a language in which each word could have only a single denotative meaning.

Imagine the pedant pointing out that Trump didn’t actually run for office or even run a business, your engine doesn’t really run and water can’t run downhill or any other direction.

Imagine a language in which one could never turn the phrase “in the running.” One would quickly run into all forms of communication walls, likely run out of patience and run back to a more malleable and useful language such as the mongrel, creole language that is English.

Bob Ernest
Reply to  Kevin Hilde
April 14, 2022 7:36 am

You are probably one of those people who thinks literally doesn’t need to mean what literally used to mean. I won’t even bother you about the lion’s share 😂🤦🏻‍♂️

Kevin Hilde
Reply to  Bob Ernest
April 14, 2022 2:34 pm

Interesting assertion, which says more about you than it does about me. Do you literally believe it?

Lewis P Buckingham
Reply to  Disputin
April 14, 2022 4:08 pm

Me Belonga English.
Yep, lets narrow the language down a bit.

Ron Long
April 13, 2022 12:10 pm

Another great Reality Check from Dr. Jennifer. Us geologists, especially when thinking in terms of Sequence Stratigraphy, think of reefs as “Limestone Factories”, as the common stratigraphic unit limestone is generated by the debris from the reef as it moves or sometimes dies. There are even reefs that were alive preserved insitu by some catastrophic event. The stratigraphic unit limestone appears regularly in the stratigraphic record since at least the Precambrian to Cambrian transition (I have seen texture suggesting life forms in limestone of the Pioche fm in Nevada) or since about 600 million years ago. Think of the grand climate variations the reefs (Limestone Factories) survived in to get to the Great Barrier Reef today, where they posed for photos by Dr. Jennifer.

April 13, 2022 12:19 pm

It seems even sponges are imperilled…

“Bleaching of marine sponges observed in warming Tasmanian waters for the first time

The researchers said more work was necessary to precisely establish the threshold temperature – and duration of warming”



Mike Lowe
Reply to  fretslider
April 13, 2022 12:59 pm

… grant-harvesting!

john harmsworth
Reply to  fretslider
April 13, 2022 1:01 pm

They need to be paid for a few hundred more dives in beautiful tropical waters before they’re really sure. Couldn’t they just mount some cameras there to keep an eye on things? No fun in that.

Reply to  john harmsworth
April 13, 2022 4:46 pm

You don’t want to dive in freezing Tasman waters.

Ron Long
Reply to  fretslider
April 13, 2022 1:21 pm

I took a sponge-bath in hot water once, and the sponge seemed OK.

Michael in Dublin
April 13, 2022 12:30 pm

Jennifer Marohasy does what all scientists should be doing, not just looking at computer models but at what is happening in the real world. It is high time climate alarmists in their ivory towers got out far more often. We live in a wonderful world – the natural one – not one on the brink of total extinction. Our biggest threat is not CO2 but greedy people.

Last edited 11 months ago by Michael in Dublin
another ian
Reply to  Michael in Dublin
April 13, 2022 3:36 pm

But it is air conditioned comfortable and easier to be one of “The Empixellated”

April 13, 2022 12:40 pm

I don’t care which government it is, which news outlet it is or which activist organization it is I am sick and tired of being lied to. We need more good reports like this.

William Diller
April 13, 2022 12:49 pm

The Green Industry relies on their knowledge that either, 1. The majority of people have no way to check the claims. 2. The majority of people are clueless about anything, particularly in nature other than what they’re spoon fed by the media which is the mouth piece of the Green Industry.

john harmsworth
April 13, 2022 12:55 pm

Coral is like any other life form. It will survive and spread to any area that offers a tolerable set of conditions, even if the life form doesn’t realize that those conditions are only temporary or not reliable. That means it will find itself inhabiting places that are not livable under all circumstances, and they will die when those circumstances come around again. That’s why we find young trees taking root above the tree line on mountains. They may survive there for a few years until a harsher winter comes around. This is also how organisms evolve. By occupying even the most difficult locations they try out their genes against new opportunities. Thousands fail, but if even one can take hold, its genotype can have a new environment to itself. When we look at stable species, we are actually looking at the latest product of billions of years of testing. It may be on the very edge of what is possible for that species, in that place, at that moment in time.

Last edited 11 months ago by john harmsworth
Reply to  john harmsworth
April 13, 2022 4:48 pm

I have had corals ‘die’ in my marine display only to start growing again YEARS later!

April 13, 2022 2:20 pm

Corals grow roughly at the same rate as toenails or MidAtlantic rift about 2-3 cm/year, whereby a daily growth record can be identified.
400 million years old fossils have 420 lines/growth band indicating 420 days in a year, i.e the Earth was rotating about 15% faster or one day was 21.8 hours long,
Apparently during this period, the Earth was in a long, warm greenhouse phase, supported by high CO2 levels of 4500 ppm, and warm shallow seas covered much of the equatorial landmasses.

Reply to  Vuk
April 13, 2022 4:53 pm

That depends, I have some spicies of sps corals that grow a lot faster and by manipulating water chemistry can generally increase colouration and growth rates substantially. Only recently have the research marine biologists stumbled upon what marine aquariums have known decades. Eg growing full size specimens from tiny fragments.

Reply to  Vuk
April 13, 2022 6:11 pm

supported by high CO2 levels

or co-existing with.

April 13, 2022 2:43 pm


Its natural changes in cloud cover.

Global warming is the same, natural changes in cloud cover.

2001-2019 Warming Driven By Increases In Absorbed Solar Radiation, Not Human Emissions (notrickszone.com)

Pat from kerbob
Reply to  Neil
April 14, 2022 8:04 pm

It must be as a slightly warmer atmosphere cannot warm the ocean more than the atmosphere has
Physically impossible

April 13, 2022 4:42 pm

That “fluorescing” is actually growth.

Stephen W
Reply to  Streetcred
April 13, 2022 7:47 pm

Yes, I wonder if people even know that new growth coral looks identical to bleached coral.
Coral is in fact already white, and it’s the colonisation by the zooxanthellae which gives it its colour.
So I suppose a growing coral will appear bleached, because it is – in that it doesn’t yet have colour.

April 13, 2022 4:49 pm

This excellent article by Jennifer Marohasy should be enough, on its own, to utterly destroy the vacuous Meme that Climate Change is destroying the Great Barrier Reef.

Craig from Oz
April 13, 2022 9:43 pm

If the reefs are dead there is absolutely no reason to still have them protected areas.

Hence we should be allowed to mine them, dredge them to open new shipping lanes and put up massive offshore windfarms.


Cause they are dead?

ABC and Guardian wouldn’t lie to us about the deadness, right?

April 14, 2022 6:15 am

Corals have survived 450 million years of climate change, why should they die out from 0.8 degrees K of warming ?

Pat from Kerbob
April 14, 2022 1:17 pm

Love your stuff Jennifer, there is no better coral data than swimming up to it and taking pictures close up.
I assume you piss off a lot of people, keep it up.

Edit; you cannot be everywhere but you should set up a network of collaborators the length of the reef, and the moment a story screams about an area or section bleaching and dying the local network member beetles out there to dive and take pictures.

I’m sure a gofund me would be subscribed to, to help offset costs of countering the climate/insane.

Last edited 11 months ago by Pat from Kerbob
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