Reports of the Great Barrier Reef’s doom are exaggerated

Master reef guide Natalie Lobartolo has a first-hand window into what the world thinks about the Great Barrier Reef. She says the most common comment from tourists after they experience the reef and waters around Lady ­Musgrave Island where she works is: “I thought the reef was dead but it’s amazing."

Federal Environment Minister Sussan Ley had a similar experience last week when she snorkelled over two reefs off Cairns.

On her first official visit to the Great Barrier Reef, Ley said she found it difficult to reconcile what she saw in the water with what had been said around the world.  “The reef is not dead," was her appraisal. “It is not dying. I would not even say it is on life support.

“Tourism operators want a very clear message that the reef is definitely not dead, that it is amazing and one of the true wonders of the world and it is worth visiting.

“Having seen it for myself I can certainly endorse that. That is a ­really clear message that I want people to hear."

The results of first-hand observations from two snorkels may not meet the test of scientific rigour. But along the Queensland coast there is a pushback that challenges the now familiar message of the reef’s doom.

A lecture tour by controversial marine scientist Peter Ridd has ­attracted hundreds of people and is only half way through a program that stretches throughout the ­sugar cane centres from Bundaberg to Cairns.

The tour has been promoted by the sugar cane and other agriculture ­industries that face the prospect of strict new regulations under a reef water quality bill before state parliament. Liberal National Party MPs at state and federal level have embraced Ridd’s call for greater quality assurance of the science. But conservation groups are alarmed Ridd is getting a platform to express his views.

Ridd was sacked by James Cook University after being disciplined for not being collegiate. That sacking was ruled unlawful by the Federal Court but its finding is being appealed by JCU.

Like it or not, science groups have been forced to engage with Ridd’s message that the findings of key reef research should be checked.

Ridd’s message on his lecture tour is that coral cover has not changed and that there is still excellent coral cover on all 3000 reefs across the Great Barrier Reef system. He also says there is almost no land sediment on the reef from run-off from agricultural processes.

Ridd’s findings have struck a chord with canegrowers, who are being asked to change their practices to satisfy UNESCO requirements that Australia is respecting its obligations to retain World Heritage status for the reef.

A suite of measures by the ­Abbott government, including a ban on dredge spoils from new port developments being dumped in reef waters, was enough to ­remove the threat of an “in-danger" listing for the reef.

Since then there have been two bleaching events and damaging cyclones that have had a big impact on coral cover, which is now recovering.

The Great Barrier Reef is again due to be considered by the World Heritage Committee next year and the proposed Queensland water quality regulations are seen as part of a broader campaign to keep the reef off the in-danger watch list.

Environment groups are ­pushing for more regulation and most likely would welcome intervention by UNESCO. But the bruising campaign last time damaged the global reputation of the reef among potential tourists and left the tourism industry crying foul.

Ridd says this is a prime reason to get the science right. He says reef science is affecting every major industry in north Queensland: mining, agriculture and ­tourism.

The legislation before state parliament will hurt agriculture badly, he says. It sets nutrient and sediment pollution load limits for each of the six reef catchments and ­limits fertiliser use for crops and grain production, covering agricultural activities in all Great Barrier Reef catchments.

The message Ridd wants people to take home from his talks is that there has been a massive exaggeration of threats to the Great Barrier Reef. He accuses the reef institutions of producing untrustworthy results because of inadequate quality assurance systems and says that must be corrected before any new legislation is introduced.

And he says there is an urgent need for an independent body to run through the Auditor-General’s office and examine the science used for public policy.

Bundaberg Canegrowers manager Dale Holliss says Ridd has ­allowed many to articulate concerns they may have already had. “Peter Ridd basically when he talks says … it is the only science we have, so we do need a process where we actually check it," Holliss says. However, environment groups say Ridd’s tour has been “simply spreading misinformation".

The Australian Coral Reef ­Society says several of Ridd’s claims are not true, while others could be characterised as straw-man arguments that ignore much greater challenges faced by the Great Barrier Reef.

“As the reef is facing fundamental challenges from rapidly warming oceans, it is important that governments take action to support a rapid reduction in greenhouse gas emissions while taking all available steps to reduce the amount of sediments, nutrients and pesticides that reach the reef lagoon," the society argues.

Ley says she is “not downplaying the seriousness of climate change" but acknowledges that some people are understandably confused. “Tourism operators are saying they want somewhere to go to say that is the truth," she says. “My answer is they can go to the Australian Institute of Marine Science."

So what does AIMS say about water quality and the issues raised by Ridd? In a statement to ­Inquirer, AIMS chief executive Paul Hardisty says there is a natural improvement in water quality from inshore to offshore reefs ­because inshore reefs are exposed to increased sediment from wind and rough seas.

Mid-shelf and offshore reefs typically have better water quality as these regions are flushed more frequently with waters from the Coral Sea. As such, material ­delivered into the inshore region via rivers remains close to the coast for extended periods.

When it comes to water quality on the Great Barrier Reef, researchers agree it is uncommon for sediment plumes to regularly reach outer-shelf reefs. During flood events, most sediments are deposited relatively close to river mouths.

Hardisty says enhanced sediment loads from farmed catchments increase the amount (and duration) of sediment that is resuspended locally around river mouths, on inshore reefs close to rivers and along the inner shelf.

He says analysis of 11 years of satellite imagery for the whole Great Barrier Reef shows water clarity is significantly reduced for up to six months after every big flood from the central and southern rivers, but not so much from the far northern rivers.

Several studies have shown fine particles of nutrient-enriched and organic-rich sediments can settle on inshore and mid-shelf reefs during calm periods and have the potential to kill young corals within 48 hours and adult corals in three to seven days, depending on the species.

Hardisty agrees there are many conditions that increase nutrient concentrations, including oceanographic processes and upwelling, liberation of nutrients contained in sediments, and inputs from ­riverine systems that may be ­enhanced above natural levels by residual nutrients from agricultural or industrial activities.

The AIMS says long-term monitoring of cycles of ecosystem decline and recovery tells us that the Great Barrier Reef is under stress. Its latest condition report, published last month, found average hard coral cover had continued to decline in the central and southern Great Barrier Reef while stabilising in the northern region this year.

This decline is because of ­numerous and successive disturbances including outbreaks of the crown-of-thorns starfish, tropical cyclones and coral bleaching. The central region’s highest recorded average coral cover was 22 per cent in 2016 compared with 12 per cent this year, and the southern ­region had 43 per cent coral cover in 1988 compared with 24 per cent this year. Hard coral cover in the northern region increased slightly from 11 per cent in 2017 to 14 per cent this year but was down from 30 per cent in 1988.

Hardisty says disturbances such as bleaching, cyclones and crown-of-thorns outbreaks are ­occurring more often, are longer-lasting and more severe.

This means coral reefs have less time to recover. Right now, however, there is still plenty to see.

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