Peter Ridd on Great Barrier Reef Recovery: Technical Details of Coral Cover Statistics, and Background

By Peter Ridd – August 4, 2022

Since 1986, the Australian Institute of Marine Science (AIMS) surveys roughly 100 of the 3000 coral reefs of the Great Barrier Reef (GBR). Ridd used this data to construct the coral cover since 1986 (Figure 1) which shows that the GBR has record high coral cover.

Figure 1: Coral cover since 1986: Coral cover for 2022 is very high.

What is coral cover? Coral cover is the percentage of the seabed that is covered with coral. It is a measure of the abundance of coral. Coral cover reduces after major cyclones, when coral eating starfish numbers increase, and after some bleaching events. Coral cover at a given location usually takes five to ten years to recover from these events. Coral cover on an individual reef can drop to just a few percent after a major mortality event. It fluctuates naturally with time.

AIMS data: Raw data can be found at this link

https://www.aims.gov.au/docs/research/monitoring/reef/latest-surveys.html

The data for the GBR is broken into three regions, Northern, Central and Southern. These regions are broken into ‘sectors’ with 3, 5 and 3 sectors in the Northern, Central and Southern regions respectively. For each of the 11 sectors, there are roughly 5-10 individual coral reefs surveyed. The survey for each reef is done by towing a diver around the perimeter of each reef. The diver observes coral cover over a 140 meter distance and records the percentage estimate. Each reef is many kilometers/miles around its perimeter so there could be roughly 50 to 100 of the 140 m long sample transects for each reef.

The coral cover for each reef is an aggregate of the coral cover of all the 140-meter-long sample points. The coral cover for each sector is an aggregate for all sampled reefs in the sector. The coral cover for the major regions can be calculated by aggregating the data from the contributing sectors. The coral cover from the entre GBR can be calculated by aggregating the data from all 11 sectors (note: AIMS no longer does this last calculation).

The sector data, as found on the AIMS website, is shown in table 1 below.

Sector2022Coral cover
Cape Grenville47.0%
Princess Charlotte Bay41.0%
Cooktown/Lizard Is.25.3%
Cairns29.5%
Innisfail15.6%
Townsville34.7%
Cape Upstart30%
Whitsunday37.4%
Pompey31.8%
Swains21.8%
Capricorn Bunkers58.6%
Average33.9%

Table 1: Coral cover for each sector of the Great Barrier Reef in 2022. Uncertainty estimates vary, but are typically between 5% and 10% according to the AIMS graphs for an individual sector.

Using these data, the coral cover for the entire reef can be calculated by averaging all the sectors, and is found to be 33.9% with an uncertainty of about 4%. This assumes equal weighting of each sector. AIMS no longer does this last calculation to get the average for the entire GBR (of 33.9%), i.e. AIMS no longer provides the final average statistic that is of most interest. It shows data for individual reefs, sector data, and region data, but not the average/aggregate for the entire GBR.

However, up 2016, AIMS did publish the average for the Great Barrier Reef (see for example the report for 2016/17 found at the above link) as shown in figure 2 below.

Figure 2: Screen-shot of the coral cover for the entire GBR from the AIMS website.

To produce the GBR average data from 1986 to 2022 (Figure 1) Ridd has used the graph published by AIMS (figure 2) for 1986 until 2017, and from 2017/8 to 2022, the sector data (as shown in Table 1 for 2022) is averaged (see Table 2).

Sector2017/182018/192019/202020/212021/22
Cape Grenville23.826.429.234.647
PCB20.420.516.326.941
Cooktown lizard910.212.821.425.3
Cairns14.613.113.522.929.5
Innisfail10.412.310.213.315.6
Townsville19.418.819.626.634.7
Cape Upstart24.224.224.225.830
Whitsunday29.624.424.429.337.4
Pompey20.218.525.133.431.8
Swains29.720.424.225.421.8
Cap Bunker39.449.144.552.658.6
GBR Average assuming equal weight by sector21.921.622.228.433.9
Northern RegionGrenville,PCB, Cooktown/Lizard17.719.019.427.637.8
Central RegionCairns to Whitsunday19.618.618.423.629.4
Southern RegionPompey Swains Cap Bunker29.829.331.337.137.4

Table 2: Summary of AIMS data since 2017/18. Yellow entries indicate sector not surveyed and result of previous survey has been used.

AIMS has effectively hidden the very good news about the Reef in 2022 by not publishing the GBR average data since 2017. This is because it is very unusual for all three major regions, and almost every sector, to be well above average at any moment in time. For example, the waves caused by a large cyclone will often kill large amounts of coral over a vast region, so some sectors are often recovering from such an event and have low coral cover. Only by seeing all the data aggregated as an average for the entire reef can the exceptional state of the coral cover be appreciated. AIMS shows graphs for all three major regions, and all have very high coral cover – but none are record breaking high. Because there is roughly a one in three chance that a region has very high coral cover, there is only a 1 in 27 chance that ALL three are high simultaneously. 2022 is exceptional because all three regions have very good coral cover at the same time.

It is surprising that AIMS no longer provides an average coral cover for the entre GBR because they have previously made far reaching claims about the poor state of the GBR based on data of GBR-wide average data. For example, when the coral cover hit a low point in 2011, after major cyclones destroyed large amounts of coral, AIMS authors (De’ath et al., 2012)[1] wrote in a very high-profile paper, that was widely quoted in the world media, the following:

Without significant changes to the rates of disturbance and coral growth, coral cover in the central and southern regions of the GBR is likely to decline to 5–10% by 2022. The future of the GBR therefore depends on decisive action. Although world governments continue to debate the need to cap greenhouse gas emissions, reducing the local and regional pressures is one way to strengthen the natural resilience of ecosystems (7, 9).

This prediction of 5-10% for 2022 has turned out to be incorrect as the average coral cover for all the regions is now over 30%. By no longer publishing the GBR average, it obscures the good data for 2022, and their inaccurate prediction of a decade ago.

Reason given for AIMS no longer providing GBR-average data

One reason, stated informally, seems to be that AIMS regards a single figure (the average) as not representative of the full diversity of the conditions on the reef. That is correct, but the average is nevertheless an interesting statistic, and the region, sector, reef and 140 m transect data is available for a more detailed discussion of the data.

AIMS is being inconsistent. It aggregates transect data to produce a single number for each surveyed reef. It aggregates reef data to produce a single number average for a sector. It aggregates reef/sector data to produce a single number average for each region – so why does it not aggregate reef/sector/region data to produce a single number average for the entire reef?

Nevertheless, AIMS should be congratulated for collecting such a remarkable data set over more than 3 decades. It is a huge data set, and Ridd estimates that AIMS has towed a diver roughly equivalent to around the world over this time.

Why is coral not 100% on a coral reef:

Coral cover is the percentage of the seafloor covered with coral. It is often assumed that coral cover should be 100% on a healthy coral reef. However, a reef is made of many different ecosystems. These include coral sand made from broken down coral, ancient dead coral ‘rock’, soft corals, algal beds, and crustose coralline algae which is a hard algae that helps cement together the dead coral on a coral reef. Dead coral is like concrete – it does not rot like wood. Coral grows on the dead bodies of their ancestors, and in doing so build ‘reefs”. Most of the reefs of the GBR have built up 50 to 100 meters above the surrounding seafloor in the last million years.

Final Comment:

The latest data on the GBR indicates it is in good shape. It happens to have a great deal of coral in 2022 because there have been few major mortality events over the last five to ten years. The three of four beaching events since 2016, which have been widely reported in the media, could not have killed much coral otherwise the 2022 statistics would not be so good.

The data since 1986 shows every region, every sector and most reefs have had periods of very low coral cover. This is entirely natural. Much is often made of this in the media. But a measure of the health of a system is the ability to recover from a major stress. Frail systems will not recover. Robust systems recover well. It is analogous to the ability of healthy people to recover well from inevitable diseases like covid19. Frail people are often killed by diseases. The GBR has proven to be a vibrant healthy ecosystem. This should not be a surprise; there is minimal people-pressure on the reef, and it is well protected. It is also unreasonable to expect that the small temperature rise over the last century (1oC) will have caused much impact, especially as it is well known that most corals grow faster in warmer water.

The data collected by AIMS shows that the GBR is a robust system with rapidly fluctuating coral cover. We must expect that, sometime in the future, a sequence of events will cause the coral cover to halve, as it did in 2011. We must then remember that this is almost certainly natural, and not allow the merchants of doom to depress the children.

[1] De’ath, G., Fabricius, K.E., Sweatman, H. and Puotinen, M. (2012). The 27-year decline of coral cover on the Great Barrier Reef and its causes. Proceedings of the National Academy of Sciences, 109(44), pp.17995–17999.

For more on this topic see here and here.

Peter Ridd is a Member of the CO2 Coalition as well as a a geophysicist with over 100 publications, 35 years’ experience working on the Great Barrier Reef, and works on the physical oceanography of the reef, and also developed a wide range of world-first optical and electronic instruments for measuring environmental conditions near corals and other ecosystems.

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John V. Wright
August 12, 2022 2:27 am

Dear Professor Ridd,

Unfortunately, despite the compelling data here and the wonderful lucidity of its presentation, your conclusions do not match the accepted view of your department and you will henceforth be cast out from academia…..

…Seriously though, WUWThatters, James Cooke University will always be a byword for toe curling embarrassment and academic irrelevance. How anyone could know the Peter Ridd story and still enroll there is a mystery.

By the way, despite the serious issues of deception, cover-up, lack of probity and academic failure that now dog JCU’s daily life, Peter’s sense of humour helps to keep his worldwide supporters grounded. Get this from the article above…

It is surprising that AIMS no longer provides an average coral cover for the entre GBR because they have previously made far reaching claims about the poor state of the GBR based on data of GBR-wide average data.”

Come on folks, admit it – like me, your still giggling at that one…

Ben Vorlich
August 12, 2022 2:28 am

A couple of questions from an interesting article.
Does the dropping of average since 2017 mean things have been improving si ce before then?
Is there any checking to see how the perimeter of the reefs changes?

Ron Long
August 12, 2022 3:41 am

Again, thanks to Dr. Ridd, we are treated to a Reality Check which shows normal conditions, not the disasters reported in the media, by the CAGW Weasels. Thanks to Peter Ridd and others for maintaining scientific integrity. Maybe the USA does not need the billions of dollars to combat climate change? The final vote is today. Don’t wait for it, the money will flow.

Old Man Winter
August 12, 2022 4:09 am

If the GBR continues to improve, it won’t be long before AIMS, etal.,
abandon their “merchants of doom” philosophy to claim credit for the
success. Expect them to then claim even more of their policies must be
implemented immediately everywhere, along with even more new plans
they’ve devised, which will only speed up the overall disaster of them.

Instead of apologizing to Prof Ridd & restoring him with the honors that
he deserves, they’ll find a way to justify their cruelty. What a total bunch
of #$&*$%#!&# losers!

Last edited 1 month ago by Old Man Winter
Richard Page
Reply to  Old Man Winter
August 12, 2022 6:36 am

They can’t and won’t ever admit to any part of it being a success – to do so would discredit their core beliefs that modern warming is entirely due to the demon CO2 and damaging to the environment. They will ignore the growth, cherry pick their data, manipulate and twist the facts until it bears no relation to the truth – the recent story about it being the ‘wrong type of coral’ will, I’m afraid, be the first of many attempting to backtrack and push back against the good news. It’s going to be a longer struggle to get the truth out and more needs to be done to expose their lies and fabrication.

lee
August 12, 2022 4:09 am

“U-Th dating reveals regional-scale decline of branching Acropora corals on the Great Barrier Reef over the past century”

https://www.pnas.org/doi/pdf/10.1073/pnas.1705351114

Dated 2017

Now –

“But in this instance, it’s more likely the reef is being dominated by only few species, as the report states that branching and plating Acropora species have driven the recovery of coral cover.

Acropora coral are renowned for a “boom and bust” life cycle. After disturbances such as a cyclone, Acropora species function as pioneers. They quickly recruit and colonise bare space, and the laterally growing plate-like species can rapidly cover large areas.

Fast-growing Acropora corals tend to dominate during the early phase of recovery after disturbances such as the recent series of mass bleaching events. However, these same corals are often susceptible to wave damage, disease or coral bleaching and tend to go bust within a few years.”

https://theconversation.com/record-coral-cover-doesnt-necessarily-mean-the-great-barrier-reef-is-in-good-health-despite-what-you-may-have-heard-188233

So the acropora were dying with much gnashing of teeth. Now acropra is resurgent again with much gnashing of teeth.

observa
Reply to  lee
August 12, 2022 4:53 am

The lore of average dooming works in mysterious ways my son.

Rod Evans
August 12, 2022 4:19 am

The ebb and flow of nature, along with the impacts of that continues its fascinating journey. The track/road called ‘normal’ variation, is endless.
Thanks Peter, we need more people like you who are able and prepared to put the actual picture of truth before the public.
Sadly, far too many ‘scientists’ have become so fearful when speaking the truth they simply speak accepted truth, as instructed to do by their academic institutions

AlanJ
August 12, 2022 4:49 am

The problem with such discussions is that coral cover is presented as the singular metric by which reef health should be measured. We know that biodiversity is diminishing, with a single species of fast growing coral dominating areas of recovery. Typically a lack of diversity is not a good signal of a strong and resilient ecosystem. The fact that recovery in areal coverage is occurring is good, but it doesn’t mean there is no need to concern ourselves with the well being of the reef, particularly not in a continually warmer world with more frequent and severe storms and bleaching events.

observa
Reply to  AlanJ
August 12, 2022 5:46 am

particularly not in a continually warmer world with more frequent and severe storms and bleaching events.

Bleaching Background (noaa.gov)
In particular-

“Coral bleaching is not well understood by scientists….

Until the 1980’s, the only coral bleaching event recorded was due to flooding from Hurricane Flora that resulted in a large drop in salinity that bleached and killed many corals in Jamaica (Goreau 1964). Mass coral bleaching was first recognized on the Pacific coast of Panama following the 1982-83 El Nino event (Glynn 1984).”

The study of mass coral bleaching events (along with noticing Crown of Thorns predation) only really entered our consciousness with the widespread uptake of SCUBA in the 1980s. Where’s your history of coral bleaching since 1788 let alone with the first inhabitants before that? Ditto all your frequent and severe storms historical evidence?

Where are your hubristic infinitesimal timeline statements spawning from?
History of The GBR – The Great Barrier Reef Library

AlanJ
Reply to  observa
August 12, 2022 8:43 am

The rest of the paragraph that you omitted:

Until the 1980’s, the only coral bleaching event recorded was due to flooding from Hurricane Flora that resulted in a large drop in salinity that bleached and killed many corals in Jamaica (Goreau 1964). Mass coral bleaching was first recognized on the Pacific coast of Panama following the 1982-83 El Nino event (Glynn 1984). The warm SSTs associated with the El Nino event were identified as the cause of death of over 99% of corals and the complete loss of reef structures in the Galapagos Islands and the death of over 50% of corals in Panama (Glynn and D’Croz 1990; Glynn 1993). The sensitivity of corals to small temperature changes then became a major concern of researchers as predictions of global warming and stronger, farther-reaching El Nino events came to light. The 1997-98 El Nino event is the strongest on record to date, resulting in unprecedented coral bleaching and death across the globe (Wilkinson et al. 1999). SSTs are expected to continue to increase worldwide (Hoegh-Guldberg 1999) and El Nino events are expected to increase in frequency, strength and duration, endangering the future survival of coral reefs.

paul courtney
Reply to  AlanJ
August 12, 2022 9:28 am

A commenter here named Rick Will has presented compelling data showing the Southern ocean is on a cooling trend. How does that fit into your imagined “climate change diminishing coral diversity” meme? Note that I’m not disputing “diminishing diversity”, I’m just wondering how global warming causes something when it’s cooling? Isn’t the GBR in the southern ocean?
Where will the racehorse run?

AlanJ
Reply to  paul courtney
August 12, 2022 9:42 am

I don’t see any commentary by that user in this thread, but the waters around the GBR are indeed warming:

comment image

And:

https://i.imgur.com/OhYg0Y6.mp4

Last edited 1 month ago by AlanJ
paul courtney
Reply to  AlanJ
August 12, 2022 11:00 am

He will run to “oh, not in this thread” before posting a chart on ocean temps from 1910. Did you go back into the kitchen to check how your chart was made? Mr. Will shows more reliable charts, so you better not go looking for them.

AlanJ
Reply to  paul courtney
August 12, 2022 11:45 am

I know very well how the graphs were produced, do you? If not, why are you objecting to things you don’t even understand? You can either link to your buddy’s work or or not, I could not possibly care less. You are the one trying to convince me of the veracity of Will’s work.

paul courtney
Reply to  AlanJ
August 13, 2022 6:04 am

Mr. J: Wrong again. I find any effort to convince a willfully-blind fool is wasted, as Mark Twain noted. No, I’m exposing you as an AGW troll to other readers, and it worked. Thanks for confirmation that you are not worth a response.

Geoff Sherrington
Reply to  AlanJ
August 12, 2022 5:29 pm

AlanJ,
This UAH data has associated relevance. Not definitive data for GBR waters, but hypotheses need to explain and incorporate the (contrary?) UAH data. Geoff S
http://www.geoffstuff.com/uahaug2022.jpg

lee
Reply to  AlanJ
August 12, 2022 8:21 pm

“Repeat bleaching of a central Pacific coral reef over the past six decades (1960–2016)”
https://www.nature.com/articles/s42003-018-0183-7

1960 was before global warming.

Your graphic shows the whole of Australia, which wasn’t well sampled in 1910.

Also based on ERSST. You do know what the “E” stands for?

Last edited 1 month ago by lee
Mr.
Reply to  paul courtney
August 12, 2022 10:20 am

Paul, the GBR is in the South Pacific Ocean (Coral Sea), predominately north of the Topic Of Capricorn.

paul courtney
Reply to  Mr.
August 12, 2022 11:02 am

Mr Mr.: Thanks, but I was trying to show Mr. J is a racehorse. Succeeding, I say.

Matt Kiro
Reply to  AlanJ
August 12, 2022 4:22 pm

Since El Ninos are natural events, which we have not completely figured out why they happen, there is no way you can say they are increasing in frequency or strength. Also since it has been 25 years since the strongest one on record… it seems like they are not strengthening. There is also no evidence that storms are becoming stronger or more frequent. In fact I believe the total of all pacific tropical storm strength/energy has been decreasing for quite a while.
Tropical storms

YallaYPoora Kid
Reply to  AlanJ
August 12, 2022 6:12 am

More ignorant nonsense with no references other than ‘we know’. No you don’t know since you have no idea.

observa
Reply to  YallaYPoora Kid
August 12, 2022 6:39 am
AlanJ
Reply to  YallaYPoora Kid
August 12, 2022 8:39 am

Read the AIMs survey, here is their summary graphic:

comment image

Mr.
Reply to  AlanJ
August 12, 2022 10:31 am

AlanJ, to allay your bed-wetting over the resilience of the GBR, consider the story of the Bikini Atoll coral reefs 85% resurrection in just 60 years after total obliteration by a-bomb testing in 1953.

Note – no human interventions in this recovery – all nature’s own unobserved work.

paul courtney
Reply to  Mr.
August 12, 2022 11:03 am

Mr. Mr.: My take is, he prefers the damp.

observa
Reply to  Mr.
August 12, 2022 7:09 pm

The weather worriers like Alan will never get it-
Ancient ‘Western Great Barrier Reef’ discovered off northern Australia (smh.com.au)
It’s a pathological anxiety condition with no known treatment yet. Giving them subsidies for Teslas and rooftop solar panels is apparently meant to ameliorate the condition. Elon and President Xi swear by it.

Lrp
Reply to  AlanJ
August 12, 2022 11:23 am

Rubbish! You don’t know coral diversity is diminishing the same way you didn’t know coral mortality was overstated.

Matt Kiro
Reply to  AlanJ
August 12, 2022 4:32 pm

Since corals have been around for hundreds of millions of years, and the ocean has been warmer in the past, I would expect corals to be able to survive some slight warming over the past 150 years. Maybe some species will need to migrate to cooler waters, or new species will emerge that can handle warmth better. This is what has happened for all the history of living species on the earth.

If the ocean level went up 200-300 feet at the end of the last ice 12,000 years ago, wouldn’t that mean any coral within the top 200 feet of water, were not there 12,000 year ago? The corals seemed to survive the increase in water temperature from that event.
Unless humans are poisoning the Reef with chemicals in the water, I do not see much to worry or that there is much we can do.

Yooper
August 12, 2022 4:58 am

Dr. Ridd,
I have wondered for a long time why Australia’s East Coast has a GBR and the U.S. East Coast does not. Australia has a very narrow continental shelf while that of the U.S. is quite wide. Additionally the U.S. has the Gulf Stream that brings warm water and nutrients relatively close to the coast. Could it be that the U.S. experiences much more cyclones that keep “things stirred up” so coral can’t establish too far north along the shelf?

Reply to  Yooper
August 12, 2022 5:31 am

The GBR extends north of about Latitude 22.5° S
The equivalent area in the Americas would be south of Lattidue 22.5° N
That is a line through Mexico and Cuba, not the US.

Yooper
Reply to  StuM
August 12, 2022 6:04 am

No. The GBR extends towards the South Pole from, nominally, The Tropic of Capricorn. Analogous for NH would be from The Tropic of Cancer to the North Pole.

Zig Zag Wanderer
Reply to  Yooper
August 12, 2022 7:16 am

I’m not sure where this comes from. Coral doesn’t grow in cooler waters, and the Great Barrier Reef certainly doesn’t extend that far.

The coolest place I’ve ever seen coral is Norfolk Island. It’s a lot, but not very colourful at that temperature.

Ben Vorlich
Reply to  Zig Zag Wanderer
August 12, 2022 8:20 am

There are coral reefs, cold water coral off the coast of Scotland.

Around Scotland, reefs form mainly on continental slopes off the west coast, at a depth of 200 to 400m. But L. pertusa has also been found in shallower water above 150m in several places, notably near Barra* and Mingulay. The complex of reefs here covers about 100 sq km and is more than 4,000 years old. Some coral colonies appear to be relatively young (less than five years old), which suggests recruitment is still occurring.

Nature Scot

Although the article has missed a trick (climate emergency) by saying
Threats to coral reefsThe abundance of fish life makes the reefs a target for fisheries. Reefs are slow growing, fragile and easily damaged and thousands of years of growth can be destroyed in a few minutes by heavy fishing gear.
Growth in fishing for deep-sea species like redfish and grenadiers has devastated some coral reefs.
Other potential threats to coral reefs include:

  • oil and mineral exploitation
  • the laying of cables and pipelines

*Barra 56.9809° N

Mr.
Reply to  Zig Zag Wanderer
August 12, 2022 10:25 am

Lord Howe Island has a good lagoon of coral as well.
Sits astride the south-flowing Australian East Coast Current, so benefits from warm sub-tropical water.

From the movie “Finding Nemo” –
“You’re ridin’ it, dude!”

Jit
Reply to  Yooper
August 12, 2022 8:12 am

comment image

Yooper
Reply to  Jit
August 12, 2022 12:10 pm

Thanks. What’s the source, it’d be an interesting read.
My bad, I should have said from the Tropic of… to the Equator.

Last edited 1 month ago by Yooper
Geoff Sherrington
Reply to  Yooper
August 12, 2022 5:36 pm

Yooper,
Wrong, utterly wrong. The GBR has one end up near the Equator south of New Guinea and the other end a bit south of the Tropic of Capricorn.
StuM just above is correct.
Geoff S

BCofTexas
August 12, 2022 6:41 am

Not many years ago the media was in a panic about pollution causing major problems for the GBR. Now, not so much. Has the pollution problem been solved? The threat to the reef from pollution is easy to document and very real. Global warming, not so much.

Zig Zag Wanderer
Reply to  BCofTexas
August 12, 2022 7:25 am

Pollution probably hasn’t changed much. Rules are added, but I believe the growing industries may negate that. You’re right that it is the main problem, along with tourists’ sunscreen. I just wear a t-shirt when snorkelling, it’s much better.

Geoff Sherrington
Reply to  BCofTexas
August 12, 2022 5:51 pm

BCofTexas,
If you read the Dr Ridd scientific papers on the Reef, you will find measurements of soil and silt and fertilizer runoff that alarmists claim are from farming of the mainland to the west. (Said to be one of the major threats.)
The levels of soil and silt on the main reef are too low to cause plausible harm. Fertilizer remnants are flushed to the deep open ocean by currents and are again low for plausible damage sources.
My comments here are from memory. If you dispute them, read the papers.
I snorkeled near-mainland reefs off Townsville in the 1950s. I did not then know what coral bleaching was, but there was abundant dead white coral scattered everywhere. Who knows? Geoff S

Bob irvine
Reply to  Geoff Sherrington
August 13, 2022 5:33 am

Geoff. The Great Barrier Reef waters are completely replaced every 2 to 3 weeks. They are fed by and drained by massive ocean currents and are, therefore, virtually impossible to pollute.
Fiords in Norway take about 6 months to replace. Pollution, therefore, is a problem for them.
The GBR is 50 + km off the coast.
The coastal areas are silt ecosystems.
Silt has built up over thousands of years and is regularly stirred up by cyclones etc. incremental river runoff is insignificant.

August 12, 2022 8:10 am

i have read articles about the dying GBR since the 1960s.
This is not like a conventional death.
This is like a Hollywood movie death,
where the victim is shot three times,
and then gives a long soliloquy,
making it appear that he will survive.
After reading his last line, the victim dies.
And the screen says “The End”

The GBR coral are in the “long soliloquy” stage,
when we are sure they will easily survive,
and then KAPUT, they will all die.
I know this is true because scientists said so.

Last edited 1 month ago by Richard Greene
Robert Wager
August 12, 2022 8:59 am

Sure the GBR is improving? Next you will tell us the polar bear population is doing fine. [sarc/off]

Rick C
August 12, 2022 9:10 am

Thanks for an interesting article and the exposure of the obvious AIMS hypocrisy.

I get that the 140m transects of the reef perimeters provides a consistent methodology upon which the change in the level of cover can be estimated. But I wonder if the % coverage would be much different if the entire reefs were sampled. Jen Marohasy has written several posts recently that seem to clearly demonstrate that judging the true health of the GBR would require a much broader approach to sampling and surveying. Obviously such an approach would be expensive given the huge size of the GBR, but it’s not like hundreds of millions of dollars haven’t been lavished on reef researchers.

Patrick B
August 12, 2022 9:40 am

How good is the coral coverage data?
I’m not a coral expert, but the first area “Grenville” jumps from 34.6% to 47% in one year.
Is that possible? Does coral coverage increase that rapidly? What are the margins of error in these measurements? How are they determined?

How consistently are measurement standards followed?

In other words, is any of this reef measurement really science?

I don’t think the world’s reefs are in any danger from global warming. Over fishing, tourism, runoff pollution etc., sure.

Climate believer
August 12, 2022 10:43 am

So “average” works for global temperature but not GBR coral, got it.

Complicated innit sciency fings.

Tom Abbott
August 12, 2022 12:52 pm

The higher the CO2, the better the GBR seems to be doing.

Geoff Sherrington
Reply to  Tom Abbott
August 13, 2022 2:26 am

Tom,
Coral carbonate is made largely from CO2, so what is unusual? Geoff S

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