Not Expecting Coral Bleaching During a La Niña

From Jennifer Marohasy’s Blog

March 19, 2022 By jennifer 

The ABC has uploaded some footage from John Brewer Reef that is part of the Underwater Museum of Art, the footage was apparently taken by WWF in February.   It does not show a lot of bleached coral, but it does show some badly bleached individual colonies – and a lot of healthy beige corals.  (Remember, my first short film, about Beige Reef, explaining that most corals the world-over are beige in colour.)

I was not expected to hear about widespread coral bleaching.  I’ve been watching the Southern Oscillation Index (SOI) fluctuate around +10 (so a La Niña with more and normally cooler waters along the Western Pacific/east coast of Australia), seeing the global satellite temperatures coming down with Australia’s February 2022 anomaly at minus 0.5 °C – in other words, half a degree cooler than the 30-year average.

Yet according to the Great Barrier Reef Marine Park Authority, water temperatures have been up to a full 2 °C hotter (I will be looking for this data) and coral bleaching is now widespread and most severe in the central area with ‘most reefs severely bleached’ off Townsville.

I have been wanting to film coral bleaching since I visited the Ribbon Reefs back in January 2020.   Do you remember the short film that followed, my second short film, after all the swimming, only to find The Monolith and other well-known corals had completely recovered from what had reportedly been devastating coral bleaching in 2016?   I was too late.  The Monolith was back to being a brilliant beige.

More recently I was at Heron Island looking for coral bleaching.  I was shown where all the corals had bleached stark white back in early 2020, but by November 2021 when I visited, they were fully recovered.  I was too late.  I was told the bleaching lasted all of two months, with no significant coral mortality.

When I visited Heron Island in November 2021, all the stands of Acropora were a healthy beige in colour. Washed out images of these same corals are all over the internet suggesting the Great Barrier Reef is dying.

It is my experience that it is difficult to find corals bleaching at the Great Barrier Reef.   The bleached corals either quickly recover – before I get there – or apparently rot and disintegrate so there is no evidence of them.  Remember though, we did find some dead plate corals, covered in algae, at Britomart Reef and I show them in my third film, Finding Porites.    We hypothesised that those plate corals died from bleaching, but I didn’t see any actual bleaching on that week-long trip to Myrmidon reef that also involved a lot of swimming and looking.

If I finally manage to get some footage of widespread coral bleaching and it is during a La Niña event I’m not going to complain.

I have been wanting to visit a badly bleached reef and capture it in that state so I can monitor its recovery for quite a while now.

Remember, I went to Pixie Reef and, with Leo and Stuart, got all that transect footage and all the transect photographs back in February 2021 – the reef was apparently one of the very worst bleached reefs according to a peer-reviewed publication by Terry Hughes.  (Scroll down from the link to the Pixie Reef Data Page 2021 and you can open the 360 photographs from 36 transects laid in February 2021 at this reef and make-up your own mind about the state of this reef.)

Much of Pixie Reef, did look bleached from a drone at 120 metres up, which is about the altitude that Terry Hughes flies when he undertakes his surveys out the window of the airplane.

Can you see me? I’m floating above Pixie Reef looking at the most beautiful corals, just to the south of the boat – in red bathers. Much of this photograph shows what looks likes bleached corals, but that is the reef crest and those corals have been dead since sea levels started to fall a couple of thousand years ago!

When you get down to Earth and under-the-water, well Pixie Reef was magnificently healthy.  I am going to visit it again, soon, to check how it is this year.

One of 360 the transect photographs from Pixie Reef. I am planning to go back and see if this reef has been bleached, it is an inshore reef just to the north-east of Cairns.
A large and healthy plate coral photographed by me at Pixie Reef. I visited that reef because according to media reports and published peer-reviewed papers it is one of the worst bleached of all the Great Barrier Reef reefs.

Be sure to know what I find when I visit the reefs off Townsville and Cairns,  consider subscribing for my monthly e-newsletters.  (The email is usually sent on the last day of each month – if you can’t find it check your junk folder.)


If you were wondering what I was looking at as I floated above the corals at Pixie Reef (face down) while Stuart photographed me from the drone 120 metres up, it is the blue staghorn/Acropora coral in the feature photograph at the very top of this blog post.   This reef, Pixie Reef, is listed as one of the worse bleached of all the Great Barrier Reefs, yet we found it so healthy.

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Tom Halla
March 19, 2022 2:05 pm

On the list of things that just didn’t happen.

John Tillman
March 19, 2022 2:06 pm

Sorry, Jen! Your actual expedition to the site doesn’t count.

Without alarmist models*, you’re beyond the Pale of post-post-modern, consensus “science”.

Observations of nature need no longer apply.

*GIGO computer games.

The remarkable biology of corals gets grossly distorted in the Watermelon Wars, but they are fascinating creatures offering a window into the dawn of animal time. Or early morning.

For the dawn of animals, please see sponges and placozoa. But sponges, like their fellow heterotrophic corals, also rely heavily on symbiosis with photosynthetic (hence autotrophic) cyanobacteria. The micro-chemical environments created by close association with oxygenic organisms means that sponges can actually be net producers of O2, despite being animals reliant on ambient excess oxygen.

Discovery of sponges’ astonishingly low O2 requirement, with or without cyanobacterial symbionts, upset formerly popular explanations for animal evolution.

Last edited 1 year ago by Milo
John Burdick
March 19, 2022 2:39 pm

That was my experience snorkeling for a month the Great Barrier Reef in 2019 near Townsville and Cairns. We also snorkeled several South Pacific isles Northeast of New Zealand in 2017. The reefs at Great Barrier Reef were recovering nicely in most spots with some bleached and dead corals in the shallows. Vanuatu, Fiji, New Caledonia with beautiful corals and fish. It seems the bleaching narrative is similar to other climate change narratives. Few people check out these areas for themselves.

Reply to  John Burdick
March 19, 2022 3:00 pm

Yes, “worse-than-we-thought” climate crises are always happening in places where your random person can’t access without government-funded transport & facilities.

Not much climate crisising ever happens at Piccadilly Circus or 5th Avenue though 🤔

Pat from kerbob
Reply to  Mr.
March 19, 2022 4:06 pm

Exactly what I tried to ask our new mayor here in Calgary.
What data did she use to decide we needed to declare climate emergency?

Ben Vorlich
Reply to  John Burdick
March 19, 2022 3:04 pm

If Terry Hughes does all his research in an aircraft at 120 metres above the sea surface then I’d say he’s not checking either. Hardly research at all, very similar to claiming Polar Bears are endangered after spotting a couple of dead bears out of an aeroplane window.

Reply to  Ben Vorlich
March 20, 2022 4:50 pm

Can you imagine the speed of the aircraft at 120m altitude … you’d not “see” much more than a blur!

Dave Fair
March 19, 2022 3:07 pm

Jennifer, do you believe that much of the reported bleached areas are simply misidentified ancient dead coral? Could that be affecting estimates of bleaching events?

Pat from kerbob
Reply to  Dave Fair
March 19, 2022 4:09 pm

Seems to me her main point is most healthy corals are beige and it’s impossible to tell if they are bleached from the air as they look the same.

So I suspect all these bleached coral reports are simply from the air

And meaningless

Jennifer Marohasy
Reply to  Dave Fair
March 20, 2022 4:59 am

Hi Dave

There are different habitats at any one coral reef. Typically there is the highest part of the reef, which is the reef crest. At the Ribbon Reefs, which are true barrier reefs running along the north easter section of the Great Barrier Reef this section of reef may be flat topped and completely dead. My favourite part of a reef is usually the back lagoon where the waters are more protected and there is often a greater diversity of corals in deeper water.

Certainly Terry Hughes unashamedly has, as his explicit research method, aerial surveys of reef crests. These are the most exposed and highest sections of reef. Some reef crests are completely dead and I can show co-ordinates from his 2016 survey that correspond with a section of Ribbon Reef No 10 that would have been dead for thousands of years.

More usually Prof Hughes is surveying reef crest that is sometimes exposed at lowest tides, and often with healthy corals, but nevertheless will be more vulnerable to sporadic bleaching. But I would argue he is not going to be able to distinguish bleached from unbleached in any depth of water and certainly not from 120 metres in the air. Here is a fun video showing some pale coloured, but healthy corals, and from the air they look bleached. And I was flying this drone at a lot less than 120 metres.

Terry Hughes is quite specific in his technical papers that he does not survey reef fronts, back lagoons or reef flanks that anyone familiar with corals reefs would know more usually have a much higher diversity of corals and these are reef habitats less prone to bleaching.

We know from Peter Ridd’s work that there is no quality assurance of Great Barrier Reef research. There is no one within the system calling Prof Hughes out on his nonsense methodology.

Dave Fair
Reply to  Jennifer Marohasy
March 20, 2022 9:49 am

Thank you for the information, Jennifer.

Ron Long
March 19, 2022 3:15 pm

With Dr. Jennifer keeping track of healthy corals and Dr. Susan keeping track of healthy polar bear populations we get a continuous stream of Reality Checks. Keep up the good work.

John Tillman
Reply to  Ron Long
March 19, 2022 4:13 pm

Godesses of reality and sanity!

Last edited 1 year ago by Milo
Rud Istvan
Reply to  Ron Long
March 19, 2022 6:25 pm

Agree. Warmunists lose to both fact based scientists.

John Garrett
March 19, 2022 3:19 pm

Somebody ought to tell the Associated Press. They’re reporting widespread bleaching of the entire Great Barrier Reef.

Pat from kerbob
Reply to  John Garrett
March 19, 2022 7:06 pm

Hate to do this to the non-insane in OZ like JM but someone should boycott all travel to OZ especially tourism because it’s “destroying the reef”.
Let’s see how long it takes the Oz Govt to crack down on this bleaching nonsense when the tourism economy collapses

Reply to  Pat from kerbob
March 20, 2022 3:18 am

quite a lot of aussies wouldnt be at all sad if they did

Reply to  John Garrett
March 19, 2022 8:53 pm

Widespread bleaching would be pretty much expected after this amount of fresh water flowed into the sea around the Queensland coast, changing the salinity, pH, clarity of water and temperature. By the way, most surprised Whatsupwiththat has not covered the link between the particulates from the Tonga volcanic eruption and the recent high rainfall events.

Reply to  Gaz
March 19, 2022 9:18 pm

Do you realize how far the GBR proper is off the Qld coast in the Coral Sea?

Rainfall runoff is not going to be evident at 65 to 200 kms out to sea.

Reply to  Mr.
March 20, 2022 3:21 am

well they STILL keep blaming farm runoff for causing it so theres that

Reply to  Gaz
March 20, 2022 3:21 am

its been mentioned by some webpages BUT proof?
we didnt get huge rains after the other biggie years ago from memory but I could be wrong
we ARE having a nice long La Nina and it was being rather slow in giving decent floods until now;-)

Jennifer Marohasy
Reply to  Gaz
March 20, 2022 5:05 am

Gaz, Most/all of the really bad flooding was to the south of the Great Barrier Reef. The central section of the Great Barrier Reef where they are reporting the worst bleaching has been hot and dry.

Reply to  John Garrett
March 20, 2022 4:27 am

not surprising after their recent multi million dollar “ gift “ from climate alarmists

Jennifer Marohasy
Reply to  John Garrett
March 20, 2022 5:26 am

John Garrett,

The Marine Park Authority made the announcement but without providing any maps or footage.

My friend Stuart Ireland has just published this footage from off Cairns, it is quite beautiful and only at Facebook:

The Australian Broadcasting Corporation, was providing the footage at this link: 
It shows mostly healthy beige coral covers, with some individual colonies badly bleached.

Just this evening I been shown footage from coral reefs fringing Magnetic Island (just off Townsville) showing more than 50% bleaching at Geoffrey Bay:

This relatively comprehensive survey of the Magnetic Island reefs would suggest that there is a lot of variability in coral cover but overall it is down across these fringing inshore reefs.

Reply to  Jennifer Marohasy
March 20, 2022 4:55 pm

Magnetic Island sits in the shallow inner ‘lagoon’ of the GBR … Peter Ridd has much to say in his book about confusing these reefs with the GBR proper.

March 19, 2022 3:52 pm

La Nina causes warmer waters over the GBR. Attached is the latest sea temp anomalies.

I have tried to get the paper referred to in the above article but I wasn’t a climate scientist so they wouldn’t send it to me.

But it makes sense, if coral bleaching is common during El Nino and not during la Nina it is because of natural cloud cover changes. A lack of cloud cover causes sunlight to warm water over shallow coral. Ocean temp has little to do with it. Its all cloud cover and sun light.

Fri 18 March 22.png
a happy little debunker
March 19, 2022 4:58 pm

Some of the biggest impacts on shallow coral reefs (like the GBR) occur when sea levels fall.

During the 2010-11 La Nina Queensland recorded a corresponding drop of sea level by over 5mm.

Chris Nisbet
March 19, 2022 7:11 pm

Last night on NZs TV state news we were told that bleaching events on GBR are now so common (every year or two) due to warming seas that the corals no longer get time to recover.
We listened to a few very concerned scientists tell us how dire the situation was,and how we need to stop burning FF ASAP for the reef to have any chance.

Reply to  Chris Nisbet
March 19, 2022 10:31 pm

Yes, such events have occurred every couple of years since the Holocene high stand. Their observation period is quite limited and prone to misinterpretation.

March 19, 2022 11:02 pm

Nice report.

March 20, 2022 1:52 am

This contradicts the actual recent scientific survey information from March 20th:

“Australia’s famous Great Barrier Reef has been hit by a new wave of coral bleaching.
A new survey by the Great Barrier Reef Marine Authority – a government agency who looks after the the reef – is currently underway, but early findings have revealed that there has been “widespread” and “severe” coral bleaching.

“This is a very serious event. There is no question about that.” said the authority in a statement.”

so I think we must mark this as inaccurate.

Reply to  griff
March 20, 2022 3:04 am

From a 120 meters above. May as well view it from the moon. Give it a rest Griff

Reply to  aussiecol
March 20, 2022 3:30 am

Sorry about that. I spelt griff’s name with a capital ‘G’. That’s giving him/her too much credence.

Reply to  griff
March 20, 2022 3:22 pm

Show us detailed visual evidence or piss off. Your choice.

Richard Page
Reply to  griff
March 20, 2022 3:35 pm

I agree with you. After Jennifer’s more in depth analysis and critique of the bad standard of analysis done by others in the field then I would join you in labelling the ‘scientific’ survey you mention as inaccurate.

March 20, 2022 3:16 am

abc was all over the severe bleaching blather just on time for some os knobjob err hobnobs visit
sorta figures theyre trying to get it locked away and grab $ of course

March 20, 2022 4:35 am

This article by a very experienced oceanographer puts to bed the global warming scam on reef bleaching. See the section on How the Oceans Get Warm.

Reply to  Clive
March 20, 2022 9:47 am

Great article especially for any lay person, not full of high end physics etc., just really good explanations with back up. Griff should read it and then every politician on the planet.

Mark Amey
March 20, 2022 11:45 pm

I always look forward to Jennifer’s reports on the Reef. They are a great mix of science, beautiful photography and some good old fashioned fun!

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