By Bob Irvine
Decades of activist science by Australian scientists has now led to the Great Barrier Reef being possibly labelled as “In Danger” by the Chinese run UN World Heritage Committee.
Statements from the Reef’s scientific watchdogs, AIMS and the GBRMPA, have led to this catastrophic situation. See Appendix “A”.
“While the Reef is already experiencing the impacts of climate change,..” Josh Thomas CEO GBRMPA; 2019 Outlook Report.
2019 Outlook Report;
Climate change is threatening the Reef and other World Heritage Areas globally. Australia is now caring for a changed and less resilient Reef. Global action on climate change is critical.
There is, however, a good dataset that indicates that these statements are exaggerated.
Each year since 1986, AIMS has run surveys on the 11 GBR sectors that measure Crown of Thorn infestation (COTS) and percent cover of Hard Coral. These surveys have been described as having “good quality-control systems” by Peter Ridd.
These 11 sectors contain 135 separate reefs. Not all these reefs are surveyed each year. This could be a source of some inaccuracy as some reefs naturally have less cover than others.
Having said that, this is still the best dataset we have for evaluation of GBR health over a period where CO2 concentration has increased significantly. The most recent survey has average hard coral cover at 28% for all 11 sectors in 2021, which is equal to the cover recorded in 1986.
The dataset used here is. https://www.aims.gov.au/…/reef/latest-surveys.html…
Two of the sectors, Pompey and Swains, have experienced significant COTS infestation from 2005 to the present. Pompey also, suffered 4 cyclones from 2009 to 2017 which reduced coral cover significantly. The three El Nino’s in 2016,2017 and 2020 also tended to reduce coral cover.
Figure 1 shows hard coral cover with Pompey and Swains removed to correct for some of these factors.
Figure 1. Hard Coral cover for 9 of the 11 sectors. Pompey and Swains removed.
Figure 2 below is hard coral cover for the entire dataset with nothing removed.
Figure 2, Hard Coral cover for the entire AIMS dataset of 11 sectors.
You will notice a drop in cover from 2006 to about 2012 that looks significant. This drop is partly explained by the COTS outbreaks in the Pompey and Swains sectors as seen in Figure 1 and 2. The GBR also suffered 4 severe cyclones in 2006 and may have taken some time to recover.
Cyclone activity has not generally increased in the GBR reef region, in fact it appears to have fallen slightly. See Figure 3.
Figure 3, Cyclone Activity for Eastern Australia from the BOM website. Blue are less severe cyclones, while orange are more severe cyclones.
We are constantly told that cyclones will be more common and more severe due to human CO2 emissions. The BOM dataset in figure 3 does not support this narrative.
The anomalously large number of severe cyclones in 2006 is, therefore, likely coincidence and could explain some of the drop in coral cover from 2006 to 2012.
Activist scientists have consistently blamed COTS outbreaks on nutrient run off from farms etc. This does not pass the pub test. The outbreaks at Pompey’s and Swains are exclusively in mid or outer reefs that are 50 or more kilometres from the coast. It is almost impossible to pollute the GBR as it is fed and drained by massive ocean currents that replace the entire water body every 2 to 3 weeks. COTS infestations are likely a part of the natural ebb and flow of a beautiful ecosystem.
Tropical waters do not readily warm as they are subject to large convective forces and evaporation that dampen any potential temperature rise. For this reason, the accurate AIMS dataset with over 500 individual points of measurement, indicates no sea surface warming in the GBR since 1994. Something the activists should bear in mind when trying to blame Global Warming for the reef’s demise.
Reefs also prefer warmer water. They grow nearly twice as quickly in the warm tropics around New Guinea and Indonesia as they do on the GBR. Something else the activists should bear in mind.
The important point here is that the reef has recovered well in 2021 as any healthy ecosystem will. This does not mean that we don’t study and attempt to understand this complex ecosystem. AIMS monitoring of Hard Coral Cover is an example of the type of program that needs to be funded.
APPENDIX A
Examples of activist science.
https://www.abc.net.au/…/great-barrier-reef…/12107054
4 ABC Radio National. (2016). Widespread coral bleaching detected on the Great Barrier Reef. [online] Available at: https://www.abc.net.au/…/widespread-coral…/7212760
Josh Thomas CEO GBRMPA; 2019 Outlook Report.
“While the Reef is already experiencing the impacts of climate change, its future is one we can change — and are committed to changing. Local, national and global action on the greatest threats facing the Reef is needed now.
…
“Gradual sea temperature increase and extremes, such as marine heat waves, are the most immediate threats to the Reef as a whole and pose the highest risk. Global action on climate change is critical,” he said.
2019 Outlook Report;
Climate change is threatening the Reef and other World Heritage Areas globally. Australia is now caring for a changed and less resilient Reef. Global action on climate change is critical.
GBRMPA; Blueprint to Action, 2018
Climate change is the single biggest threat to the Great Barrier Reef’s future survival. There is an urgent need to curb global warming as climate related disturbances outpace the Reef’s ability to recover.
Australian Dep. Of the Environment and Energy,
State party Report, 1/12/2019.
“However, significant components that underpin all four natural world heritage criteria for which the world heritage area was inscribed in 1981 have deteriorated since its inscription.
One criteria – habitats for the conservation of diversity – is assessed as poor, which aligns with the assessment findings in chapter 2. Given the impacts from climate change are accelerating, the overall assessment of the reef’s world heritage and national heritage values is good, borderline poor.”
via Watts Up With That?
June 29, 2021
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