WUWT Preface:
While our critics, climate alarmists, and others, often accuse us at WUWT of ideology, tribalism, motivated reasoning, or just plain for-pay corruption, in fact, we are truth seekers.
This can sometimes displease our majority audience, but if we are trying to bring truth to light, or reinvigorate the scientific process, we should not and cannot suppress information that can be perceived as harmful to our version of “the cause”
A specific story about record coral cover at the Great Barrier Reef has been loudly trumpeted in the skeptosphere.
Bjorn Lomborg tweeted about it multiple times.
I personally wrote a post about it.
However, the following post from Jennifer Marohasy casts serious dount on the above stories, with a credible first hand account and observations. It would be remiss of us to not correct the record.
Cyclone Causes Increase in Coral Cover – If You Believe Their Nonsense Number
Jennifer Marohasy
If you believe Bjorn Lomborg, we have record high coral cover and we can fix climate change. Both are nonsense propositions. In fact, this last year has been devastating for many reef ecosystems because of weather events that are part of natural climate cycles.
In the central Great Barrier Reef, we had the double whammy of coral bleaching and Tropical Cyclone Kirrily. Three reefs (Davis, Chicken and John Brewer) that were included in the recent AIMS’ Long-Term Monitoring Program surveys bore the brunt of Kirrily’s fury that hit as a severe category three before making landfall as a category one.
The basis of most Great Barrier Reef statistics is the survey. Get that wrong and add in an extraordinary amount of hubris – the type often found amongst academics who concern themselves with climate change – and we end-up with more lying headlines.
There are some major problems with the AIMS’ LTMP as a measure of total coral cover at the Great Barrier Reef:
- It does not consider how the distribution and abundance of corals varies with different reef habitats,
- It is a perimeter survey unlikely to include habitats with higher percentage coral cover,
- In not surveying shallower reef habitats, including the reef crest, it cannot measure the true impacts of cyclones or bleaching.
Meanwhile, Peter Ridd has gone to some effort over the last few years to suggest that the health of the Great Barrier Reef can be reduced to a single number representing coral cover based on these LTMP perimeter surveys.
And his political interest is not actually in this number but in the trend.
Yet even after John Brewer Reef took a direct hit from Tropical Cyclone Kirrily on 25th January 2024 pummelling much of the crest clean of coral and strewing coral around the reef perimeter, the LTMP registered no significant change in coral cover at this reef.
The latest number for total coral cover at the Great Barrier Reef, as extracted and calculated first by Ridd, and following his lead by Lomborg, include recent surveys of three large reefs in the central regions of the Great Barrier Reef – Chicken, Davies and John Brewer.
Until TC Kirrily these were exceptionally beautiful reefs in warm crystal-clear waters, with the most magnificent corals – reaching their climax as ecosystems with more than 100 percent coral cover in some places.
I write more than 100 percent, because these reef crests can be of densely packed corals, competing for space and especially light; corals growing over each other with so many fishes – crowded, colourful and bustling like little metropolises on top of platforms rising from the sea floor.
Then these bustling metropolises were obliterated – by Tropical Cyclone Kirrily. And they came to look more like Gaza.
When I visited these reefs soon after that cyclone, I found that many of the very largest of the plate and branching corals had been picked-up, turned-over and dropped-off the edge of sections of these reefs that rise from the sea floor, sometimes as platforms. There was coral strewn about their perimeters.
Indeed, the entire wall of coral that featured in the short film I made last November about the ‘Café Latte Coral’ at John Brewer Reef that entire wall of coral has collapsed. It has broken off from the reef crest proper and has fallen seven meters to the perimeter.
As absurd as it might seem, only now is their opportunity for these broken corals to be part of the AIMS’ surveys used by Lomborg and Ridd to claim record cover coral at the Great Barrier Reef.
The LTMP data that these academics rely on is from surveys that are only ever of the perimeter and at a depth of between 6-9 meters – where so much broken coral landed after TC Kirrily.
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It appears to me that Jennifer Marohasy basically only argues that the metric used by Peter Ridd c.s. is flawed. That may or may not be the case. However I would have expected a mention of what metric should be used instead, and I assume she herself uses, and then how that better metric has changed since the mid eighties. Just saying Ridd’s data are nonsense doesn’t really cut it.
Thank Ed. There are two issues. The issue of what is surveyed, and how the current data is analysed. First, by way of background information, let me give you some idea of the layout of a reef, and how it is not dissimilar to a city, so you and others can start thinking about the problem.
Surveying the perimeter of a coral reef to know total coral cover is as ridiculous as surveying the outskirts of a city, the acreage, and from this attempting to calculate the population of the entire city.
You can’t know a city’s population if you don’t also survey areas where there are more people, including the central business district and inner suburbs. To know the total population of a city, first get some idea of density by zoning and know what percentage of the total area that each of these different land uses represents.
In the same way, to know total coral cover at an individual reef, we need to know what coral cover is at particular habitats. Coral cover is a measure of density that is a measure of abundance, and it changes with the reef habitat.
To reiterate, just like cities have different types of suburbs with different densities of people depending on zoning, reefs have corals growing at different densities according to whether, for example, they are at the front exposed to the prevailing south easterly winds, or in the more sheltered back lagoon, or at the exposed top – at the reef crest.
Each of these different habitats, with different coral cover, may be affected differently by a cyclone.
At John Brewer Reef, the reef crest was very badly affected by TC Kirrily. Much of the coral from the crest ended up at the reef perimeter. Then Bjorn Lomborg and Peter Ridd took the results from the perimeter surveys and extrapolate to conclude that coral cover has increased. I then extrapolated to conclude that cyclones cause an increase in coral cover.
We can do better than this. :-). And I have much more to contribute, by way of solutions. And I have a page of data from Pixie Reef here: https://jennifermarohasy.com/coralreefs/pixie2021/
Thanks for that, the point is clearly made. However, I notice that you too consider the reef to be in good health. And be careful with extrapolation. The mathematician in me notices that for one reef (only) and one cyclone (only) the observed cover according to Ridd’s metric has increased :-).
If you go across to my blog you will read about the more general state of the Great Barrier Reef. The reefs just across from where I live, part of the southern Great Barrier Reef, I estimate about one third of the coral lost to bleaching this last summer. The last six months have been difficult for many reefs across the Great Barrier Reef. And then in the north there was TC Jasper that dumped more rain than any time since 1911. There is more information, but let’s begin with a first reef. And get some clarity here. Then we can move to other reefs and other regions and get a feel for the natural cycles. Meanwhile I must get to this course, I will be offline most of the rest of today. :-).
I know very little about coral so I don’t know whether this is a good meytic or not. But reading the article I was wondering whether if collapsed or broken coral that has fallen 7 metres dies completely or does it continue to live on in its new location?
Ben, not Jen. But likely depends. See comment immediately below.
The staghorns at Trunk Bay died because their symbiotic zooanthalea were adapted to more sunlight than Turner Bay seafloor sunlight, plus lots of the living polyps got beat up (smashed) by the wave action, as evidenced by the many broken staghorn fragments.
Thanks Rud
An old answer where I grew up was “maybes it will maybes it won’t that depends”. Which was what I thought but generally one step backwards.
I can personally attest to the damage hurricanes can do to shallow
coral reefs. I took my family on a 10 day spring vacation to the 5 star Carambola Resort on St. Croix in the USVI in 1990. One of the purposes was to get our then still subteen but swimming proficient kids truly snorkel proficient. After they got good on the shallow reefs adjacent to the resort (good meaning no more need for resort dive instructors), we took a two hour sailboat ride over to Buck Island to snorkel the only USNPS underwater coral reef ‘trail’ at Trunk Bay (trail is marked by seafloor placards showing the way and explaining everything—coral species, parrotfish,…
Unfortunately, USVI had been devastated by Hurricane Hugo the previous fall. The forested cove hillside above Carambola was still stripped mostly bare 9 months later. 100% of the formerly majestic staghorn corals at Trunk Bay were lying broken and dead on the seafloor. Only the porities and some small plate corals had survived relatively unscathed. Park Ranger said it would be 5-10 years before things grew back sufficiently to make a good reef snorkeling trail again. Sure enough, it has become magnificent again—a National Park Service bucket list experience like the Grand Canyon, Yosemite, and Yellowstone.
And then there’s the Bikini Atoll reefs that totally resurrected themselves in ~ 60 years after being obliterated by atomic bomb testing in the 1950s.
Coral reef resilience is why I regard corals as marine weeds – you can’t ever get rid of the buggers.
(and like many weed varieties, they come in a wide spectrum of visual attractiveness –
bog plain to stunningly colorful)
I’ve always wondered what happened to the Bikini Atoll reefs. Nice to see how resilient nature is. Lefties think it’s wimpy- like kittens and puppies.
The US detonated 67 nuclear tests on Bikini Atoll, including the Castle Bravo bomb (March 1st 1954) which was 1000 times more powerful than the Hiroshima bomb.
A scientific survey of the atoll in 2008 found 70% of coral species had resettled the lagoon and evidence that the coral began growing again as soon as 10 years after testing ended.
Weeds are just plants in the wrong place
Thanks Ed. In my first response (see above) to your comment, I detailed what needed to be considered when surveying coral cover at a coral reef. I will be getting on to Ridd’s nonsense +/-0.04 uncertainty value in due course. Not today, because I’m about to go do a refresher first aid course (some of today I will be attempting to resuscitate dummies :-). Anyway, if you prefer politics to thinking about how to survey for the distribution and abundance of organisms, consider these facts:
The corals off Townsville, which is where Peter Ridd lives, had been looking magnificent for some years. Despite one of these reefs, John Brewer Reef making headlines in 2022 as the epicentre of a sixth mass bleaching. https://jennifermarohasy.com/2022/04/epicentre-of-mass-coral-bleaching-still-so-beautiful-part-1/
Because the claims of ‘mass death from bleaching’ that made international headlines have been so at odds with the reality I have been profiling this reef and visiting regularly. You may remember the short documentary film entitled ‘Bleached Colourful’,
. It is specifically about John Brewer Reef.
There is a regular charter (three days a week) from Townsville to John Brewer Reef that is the reef I have been profiling and was described as one of the worst bleached. I was last there last October 2023 with Peter Ridd. The coral was looking magnificent.
Then Cyclone KIrrily hit on 25th January, and the reef we had been profiling (John Brewer Reef) took a direct hit.
John Brewer Reef was pummelled for two long hours by this severe category 3 system. I watched the satellite imagery (on the internet) as the cyclone moved in from the Pacific at some speed and then stopped, as the eye came up against this massive limestone platform that rises from the sea floor that is John Brewer reef.
It was painful to watch the live satellite imagery; to know that one of my favourite reefs was being smashed.
Peter Ridd could have gone out with the first boats to see the damage, but he didn’t. Instead, he went to Melbourne and reported that Kirrily was only a category 1, and the reefs were fine. This address that he gave was recorded and is here,
There is even a transcript here: https://ipa.org.au/research/climate-change-and-energy/dr-peter-ridd-culture-wars-on-the-great-barrier-reef-ipa-academy
What he specifically said about Kirrily in Melbourne was: “So when that cyclone went through Townsville last week, fortunately, it was only a category one really, maybe a category two. But if it had been a category four, the reefs that we’ve been working on out there would’ve gone from spectacular to be complete wipeout …”
The earliest I could get out to see John Brewer was three weeks later. The reef was a mess. I blogged about it here, https://jennifermarohasy.com/2024/02/cyclone-kirrily-smashed-my-favourite-coral-reef/
The heartbreak, to see my favourite massive plates that once sat over one of the deeper crevasse that cuts across part of the reef crest, to see them so smashed up. The underwater videographer Stuart Ireland, who came with me, described this section of reef after the cyclone as ‘bull in a china shop alley’.
Peter Ridd is still refusing to even visit that coral reef that is the main tourist attraction just off shore from the city in which he lives.
Thanks Jennifer.
An analogy to support the essential value of first-hand direct observations of any situation rather than desk-bound summations, is when the police publicly call for eye witnesses and CCTV of robberies, vandalism, assaults, accidents, fires, etc etc etc
Assumptions about what happened just don’t cut it when the consequences & repercussions are serious.
“…some of today I will be attempting to resuscitate dummies…” Isn’t that what your article is trying to do?
Only Biden
Here is an example of why I put more credit in ideas than individuals. Here is the primary question: is CAGW destroying coral reefs? The answer is no, the reason the answer is no is because CAGW is a discredited hypothesis. Another important question is are coral reefs in danger? I don’t think they are. A related question is do coral reefs die off or undergo destruction? Clearly a cyclone can destroy parts of them. I wouldn’t know how they die. We do know they experience periodic bleaching and may look dead but most likely are undergoing a natural change.
In the end I think too big a deal is being made of this. There is little good that can come from internal pissing matches. Having said that yes this information does belong on WUWT.
A separate very high level philosophical observation about the Ridd/Merohasy tiff revealed by this post. Is relevant to much at WUWT.
Cook University has a vested interest in saying GBR is endangered by AGW. Ridd had a vested interest in the ‘scientific truth’ that it actually isn’t, for which Cook fired him for ‘uncollegiality’. For the record, I contributed bigly to his lawsuit and was bigly disappointed when he ultimately lost.
The underlying informational problem is when any vested interest on anything leads to overstatement to ‘make the case clear’. The TC palpably damaged ‘his’ reef in some ways. I saw the same thing personally in USVI, posted above. That does not mean the reef is endangered. It is storm damaged but will grow back as is a living thing—as in my USVI example.
.
Pretending no TC damage based on a flawed coral survey is a ‘bridge too far’. Truth is nuanced—most advocates on either side do not like nuanced truth because it turns black/white into some shade of grey.
Bravo to Jen for speaking here nuanced reef truth. To recall a lesson learned (in German) in Munich many years ago from a then consulting client: ‘If you proclaim something absolutely then it must be absolutely wrong. Don’t do that.’ Nuance counts.
Einstein’s general theory of relativity may be an exception. Or maybe not, since no quantum theory of gravity yet exists—despite the physically obvious fact that they MUST be somehow related since both are ‘true’ according to many experimental tests.
A hurricane can “destroy” a forest- knocking down every tree. 30 years later, go there and see 50′ trees. I’m starting to think coral reefs are similar. Never studied them but learning stuff here.
Arguing about coral cover is like arguing if you had 5 or 6 olives on your pizza.
However, self important researchers continue to write volumes on inconsequential (and highly boring) drivel. Even worse are the arrogant rent seekers pretending to make a difference by growing corals in tanks and ”studying” them.
Coral will still be there long after humans have stopped measuring them.
In this case, we’re not going back 30 years later, we’re assessing just after the storm, In your forest we would count 0 trees. The coral may indeed all be back in some years time, but right now a lower assessment would be more credible.
Well said.
We need to constantly remind ourselves of this.
Huzzah! No flame wars in the comments section!
I was about to give up on this, but this glimmer of hope will keep me on.
I do very much respect Jen’s position on a proper metric for reporting reef condition. On the other hand, the AIMS perimeter survey metric is what the “official” government supported body uses to support the alarmist “climate change is killing the GBR” narrative. It is thus, I think, quite appropriate to point out that the official data actually shows the opposite of the alarmist claims of imminent demise. I would not fault Ridd or Lomborg for pointing this out.
That doesn’t mean that a much better means of measuring GBR health should not be implemented. Jen makes a very good case that such a change is necessary to accurately assess the health of the reef. AIMS should undertake this task, but I’m not going to hold my breath.
https://www.youtube.com/watch?v=34G7s30sMQU
What’s going on with the Great Barrier Reef?
He begins making some good points. Then his comments regarding sea level are a bit nonsensical. The coral grows up to the sea level. :-).
Jennifer Marohasy argues that the survey reported on by Peter Ridd is “nonsense”, and then gives an anecdotal statement about tropical cyclone damage. She has not reported a survey with data to back up her observations. What am I missing here?
Hi John,
You seem to be missing a lot.
I may not have the big ships that AIMS has to collect nonsense data, but I have the capacity to observe. The first thing you should know how to do is get out and OBSERVE if you want to have an opinion when it comes to the distribution and abundance of plant and animal species.
And if their method can not detect damage from a direct hit from a cat 3 cyclone, there is reason to doubt it. I have been doubting it for years, and now I have evidence.
Tropical cyclones can be damaging. We have had two really big ones in the last six months, Jasper in the northern region and Kirrily in the central region. Kirrily absolutely smashed John Brewer reef that contributes to their latest AIMS figures suggesting an increase and yet if you look at their survey results the TC has had no impact. My specific post on my observations from my first visit to that one reef are here: https://jennifermarohasy.com/2024/02/cyclone-kirrily-smashed-my-favourite-coral-reef/
And my comments on the latest AIMS data for that one reef versus from the AIMS assessment of this is here: https://jennifermarohasy.com/2024/06/denying-the-most-precious-natural-cycles-part-1/
And if anyone had been reposting my blog posts from the last six months you would know that I have reported about one third of the corals by area lost from my local Keppel Island reefs, lost to coral bleaching. It is the worst bleaching in the southern region for about 18 years.
What you are missing is that it would be better if we acknowledged natural disasters when they occur. Then we might be able to begin to understand the natural climate cycles.
But instead the right of politics, like the left of politics, prefers to just repeat nonsense when it comes to so much that concerns the natural environment. We prefer our experts to be well credentialed in physics even if they just repeat numbers that are meaningless.
It is a disgrace.