The truth about the Great Barrier reef: Peter Ridd explains

The IUCN (International Union for Conservation of Nature) report, World Heritage Outlook 3: A Conservation Assessment of All Natural World Heritage Sites, published in November 2020, is the third in a series since 2014. IUCN describes itself as “the official advisory body on nature to the UNESCO World Heritage Committee”.

IUCN’s “critical” listing entails a site being “severely threatened and/or deteriorating … [requiring] immediate large-scale additional conservation measures”.

The report says: “Climate change, poor water quality from catchment runoff, impacts from coastal development, impacts of fishing and crown-of-thorns starfish pose the biggest threats to the long-term conservation of the Great Barrier Reef.”

Dr Peter Ridd has spent a lifetime studying the GBR and has debunked claims that it is in peril.

Dr Ridd said, “firstly, there aren’t excess nutrients” on the GBR and that crown-of-thorns starfish (COTS) outbreaks on Australia’s northwest coast and in the middle of the Pacific Ocean where there is no agriculture is more confirmation that “the link between nutrients from farms and the crown-of-thorns starfish is almost non-existent. In my view, they just make it up … Where’s the data, where’s the evidence?”

(Dr Ridd was dismissed from James Cook University for questioning the accuracy of claims by colleagues on the state of the GBR. He has sought leave to appeal to the High Court over his sacking, and his appeal is progressing. The Court will hear arguments in February.)

He added that claims of overfishing of COTS’ predators such as the Triton snail was leading to COTS plagues were “extremely weak”, as nobody has been taking Tritons from the reef for decades. Evidence of starfish plagues in coral cores from thousands of years ago, before fishing of Tritons, further discredits the claims.

The IUCN report makes this claim: “The primary pressure from coastal development is from agricultural land use.”

“How the heck did they get through the last 200 million years if they can be knocked over by one degree? …. All these same corals live in the Indo-Pacific warm pool (the Coral Triangle), where it’s two or more degrees hotter, and they grow faster – the hotter the better. It’s where the best coral is.” – Dr Peter Ridd

In relation to nutrients, Dr Ridd said: “When you actually look at the nutrient concentrations on the reef, they are totally unaffected by agriculture … There are 100 times more nutrients cycling naturally across the seabed than what comes down all the rivers.”

And, in relation to pesticide levels, he said: “They’re so low, you just can’t measure them on the outer reef.”

The IUCN report claims that “direct impacts continue to occur from coal dust contamination, which escapes as coal is transferred between train and ship”.

Dr Ridd told a News Weekly livestream presentation last year, and reiterated recently in The Australian, that the discredited study claiming coal dust was affecting the reef was in error by 3000 per cent and, in any case, was not even measuring coal dust but naturally occurring poly-aromatic hydrocarbons. Yet the claim is repeatedly cited as established scientific fact.

The report lists as “high” the “potential impacts of the Carmichael (Adani) coalmine”, 300 kilometres inland, because of “possible impacts” from increased coal shipping and expansion of the Abbot Point port, without presenting any evidence of how the reef would actually be affected.

Dr Ridd said that corals are remarkable in possessing the ability to change the zooxanthellae (algae that lives inside them) so that, after bleaching from heat, cold or freshwater stress, they can adapt to survive in hotter or colder waters.

A doubling of carbon dioxide from pre-industrial levels would have a modest effect (a one-degree temperature increase), in fact it has clear benefits for increased plant productivity, Dr Ridd said. The waters of the GBR have increased by “maybe 0.7 of a degree … there is no way … that all these corals are within one degree of their peak thermal threshold.”

“How the heck did they get through the last 200 million years if they can be knocked over by one degree? And remember, it was one degree hotter a few thousand years ago,” he said. “The idea that the reef is in trouble now from a less than one-degree temperature change is just ridiculous.

“All these same corals live in the Indo-Pacific warm pool (the Coral Triangle), where it’s two or more degrees hotter, and they grow faster – the hotter the better. It’s where the best coral is.”

If only more scientists would speak the truth like Dr Peter Ridd.