According to the latest Australian Institute of Marine Science report, there is record coral cover at the Great Barrier Reef. Yet this is less than 30 percent at about half of the reefs surveyed.
The relatively low percentage cover is because only the reef perimeter is surveyed by AIMS, which is the equivalent of reporting on the population of Sydney after skirting around the outer suburbs.
Such a method (skirting around the outer suburbs) would give no indication of population trends in more densely populated inner-city areas. And so the latest AIMS report gives no indication of coral cover at reef crests, which for all we know given the methodology underpinning this latest survey, may have collapsed entirely across the Great Barrier Reef.
We cannot know.
Furthermore, despite advances in both underwater and aerial drone mapping, which could provide automated quantitative assessments by habitat with photographic and/or visual records, AIMS persists with a method that involves towing an observer who guestimates coral cover.
Their method is subjective and archaic. It is not scientific.
My early career was spent as a field biologist in Africa. If I had submitted the AIMS survey method as the intended survey method for any one of the many insect species that I monitored, my supervisors would have rejected it. Whether attempting to monitor changes in the population of an insect species, number of people in a city, or hard coral cover at the Great Barrier Reef, there are certain factors that need to be considered if the method is to be considered scientific and therefore reliable.
Key deficiencies in the current AIMS long-term monitoring program include:
1. Conclusions are drawn about overall coral cover at each reef without ever measuring coral cover at key habitats (E.g. at the reef crest).
2. Variability in coral cover is never quantified by habitat type (E.g. reef crest versus back lagoon).
3. The area surveyed at each reef (defined by AIMS as total ‘reef perimeter’ measured as sum of manta tows) incorporates results from different habitats, and as a consequence it is doubtful that the sample plan is adequate in terms of number of replications (manta tows) per treatment (habitat) at each reef perimeter.
4. Numerical values represent subjective guesses.
5. There is no photographic or video record enabling quantification of the accuracy of the guesses.
If we consider John Brewer Reef, as an example, most of the healthy coral grows over the reef crest where it exceeds 100 percent cover in many places. The corals at the reef crest grow on a sturdy limestone platform built up of layer upon layer of dead coral. This reef crest is about 9 metres above the reef perimeter in the northern lagoon where the corals grow amongst rubble and sand with coral cover much patchier. Because the AIMS long term monitoring program only surveys the perimeter, it has determined coral cover at this reef to be 22 percent. To be clear, there could be major mortality of corals at the crest, where most of the corals are, and yet this would never show up in the long-term monitoring results for John Brewer Reef.
I have shown the potential for an alternative method at Pixie Reef laying 10 metre photographic transects (instead of manta tows) repeated (replicated) at least 9 times (to enable quantification of within habitat variability) for three different habitat types (crest, back lagoon and reef front).
The photographs from these transects, and more information about the method, are at my Pixie Reef 2021 data page, that is here: https://jennifermarohasy.com/coralreefs/pixie2021/
Fundamental to the success of any survey designed to detect change, must be a consideration of the distribution of the population of interest (E.g. corals by habitat or people by suburb) before attempting to quantify it – to count it. Only then is it possible to know with any level of certainty if there is any significant change in the overall population of the city or coral reef and/or some component of it.
It is unfortunate that so much time and money and diesel has been spent for so many years by AIMS, at the expense of the Australian tax payer, without any discussion or explanation of the method. Most people who take an interest in the results assume all the key habitats are surveyed, but they are not. They assume actual corals are counted, but they are not.
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The feature image at the top of this blog post is an aerial drone photograph of Pixie Reef looking from the back lagoon across the reef crest to the reef front that is exposed to the dominant prevailing winds. Coral cover, and species diversity, vary significantly by habitat.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Peter Ridd vindicated – the Bolt Report last night, 4 August – brilliant.
John Miller,
I thought it most disappointing that Peter Ridd did not explain any of the limitations of the AIMS survey method to Andrew Bolt.
Viewers would have assumed that the survey result included all key habitats at coral reefs, including the reef crest. They would have assumed the results represented something more scientific than towing a snorkeler behind a boat with coral cover reported as a best guess of what was seen.
Peter Ridd purports to be the leading proponent of quality assurance of Great Barrier Reef science. He is paraded by conservatives as exactly this. He has an intimate knowledge of the AIMS survey method. He was given ample opportunity to explain on television even one of the limitations last night but he didn’t. He never does.
And this purported champion of free speech, now blocks all comments on his Facebook posts.
GBR health reports over the past 2 decades have been drafted for 2 distinct purposes –
1) doomsday headlines for the media;
2) to suck more funding from governments.
My question is, what is going on here? Is this an attempt to get ahead of the collapse of the Deep State Cabal, whose plans for a Great Reset in 2030 were rudely interrupted in 2016 by the election of Donald K Trump? Sorry for the pun, but something truly fishy is going on here. Those who might consider my comment a ‘conspiracy theory’, well l suggest you think again … as why on earth would the report from the Institute of Marine Science, albeit flawed, go against their long held and false narrative, then suddenly present such a positive report?
And as our Great Barrier Reef is so well known around the globe, I have a gut feeling that the whole Climate debate, just like all other false Deep State narratives, is about to be turned on it’s head. As we all know, real science was never applied to any aspect of Global Warming, or it’s love child, Climate Change, nor this time!
In my humble opinion, this is the prelude to far bigger and positive things to come, and although early days, it looks to me we may be getting our lives back.
So, basically, the AIMS report is just more “political science”.
And I was told that “Economics” was the “dismal science”.
Imagine if they proposed an offshore wind farm over the GBR. I wonder what the Greenies would say? Yet there are over 50+ existing or planned wind farms over Australia.