By Bob Irvine
Decades of activist science by Australian scientists has now resulted in the Great Barrier Reef possibly being labeled “in danger” by the Chinese-led UN World Heritage Committee.
Testimony from the reef’s scientific watchdogs, AIMS and GBRMPA, has led to this disastrous situation. See Appendix “A”.
“While the reef is already experiencing the effects of climate change …” Josh Thomas CEO GBRMPA; Outlook 2019 report.
Outlook 2019;
Climate change threatens the reef and other world heritage areas around the world. Australia is now taking care of a modified and less resilient reef. Global action against climate change is vital.
However, there is a good set of data to suggest that these statements are exaggerated.
Every year since 1986, AIMS has conducted surveys of the 11 GBR sectors that measure Crown of Thorns (COTS) and the percentage of stony coral coverage. These surveys have been described by Peter Ridd as “good quality control systems”.
These 11 sectors contain 135 separate reefs. Not all of these reefs are examined every year. This can lead to inaccuracies as some reefs are naturally less covered than others.
Even so, this is still the best data set we have for assessing GBR health over a period of time when CO2 levels have increased significantly. The most recent survey has an average hard coral cover of 28% for all 11 sectors in 2021, which is the same as 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 infestations from 2005 to date. Pompey also suffered from 4 cyclones from 2009 to 2017 which significantly reduced coral cover. The three El Ninos in 2016, 2017 and 2020 also tended to reduce coral cover.
Figure 1 shows the 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 away.
Figure 2 below shows the hard coral cover for the entire data set with nothing removed.
Figure 2, Hard coral cover for the entire AIMS dataset of 11 sectors.
You will notice a decrease in coverage from 2006 to around 2012 that seems significant. This decline is partly explained by the COTS outbreaks in the Pompey and Swains sectors, as seen in Figures 1 and 2. The GBR also suffered 4 major cyclones in 2006 and it may have taken some time to recover.
Cyclone activity has generally not increased in the GBR reef region, it even appears to have decreased slightly. See figure 3.
Figure 3, Cyclone activity for Eastern Australia from the BOM website. Blue are less severe cyclones, while orange is more severe cyclones.
We are constantly told that cyclones are becoming more common and severe because of human carbon emissions. The BOM record in Figure 3 does not support this representation.
The unusually large number of severe cyclones in 2006 is therefore likely a coincidence and could explain part of the decline in coral cover from 2006 to 2012.
Activist scientists have consistently blamed the COTS outbreaks on nutrient runoff from farms, etc. This fails the pub test. The outbreaks at Pompey’s and Swains occur exclusively in central or outer reefs that are 50 or more kilometers 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 body of water every 2 to 3 weeks. COTS infestation is likely part of the natural ebb and flow of a beautiful ecosystem.
Tropical water does not heat up easily because it is exposed to large convection forces and evaporation, which dampen any possible temperature rise. For this reason, the exact AIMS dataset with over 500 individual measurement points shows no warming of the sea surface in the GBR since 1994. Something activists should keep in mind when trying to blame global warming for the sinking of the reef.
Reefs also prefer warmer water. They grow almost twice as fast in the warm tropics around New Guinea and Indonesia as on the GBR. The activists should consider something else.
The important point here is that by 2021 the reef has recovered well, as any healthy ecosystem will. This does not mean that we are not studying this complex ecosystem and trying to understand it. Hard Coral Cover’s AIMS monitoring is an example of the type of program that needs funding.
APPENDIX A.
Examples of activist science.
https://www.abc.net.au/…/great-barrier-reef…/12107054
4 ABC-Radio-National. (2016). Widespread coral bleaching discovered on the Great Barrier Reef. [online] Available at: https://www.abc.net.au/…/widespread-coral…/7212760
Josh Thomas CEO GBRMPA; Outlook 2019 report.
“While the reef is already experiencing the effects of climate change, we can change its future – and we are determined to change. Local, national and global action against the reef’s greatest threats is needed now.
…
“Gradual increases in sea temperature and extremes such as sea heat waves are the most immediate threats to the reef as a whole and pose the greatest risk. Global action against climate change is vital,” he said.
Outlook 2019;
Climate change threatens the reef and other world heritage areas around the world. Australia is now taking care of a modified and less resilient reef. Global action against climate change is vital.
GBRMPA; Blueprint for Action, 2018
Climate change is the greatest threat to the future survival of the Great Barrier Reef. There is an urgent need to stem global warming as climate-related disruptions exceed the reef’s ability to recover.
Australian Dept. of Environment and Energy,
Party report, January 12, 2019.
“However, essential components that underpin all four natural heritage criteria for which the World Heritage area was registered in 1981 have deteriorated since its registration.
One criterion – habitats for the preservation of diversity – is rated as poor, which agrees with the assessment results in Chapter 2. Given the accelerating effects of climate change, the overall rating of the reef’s world and national heritage is good, marginally poor. “
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