The UN’s World Heritage Committee is now expected to decide whether to list the Reef as a “World Heritage Site in Danger” in February next year. It’s important to be clear upfront: dredging is not the most significant threat to the Great Barrier Reef’s future. Discussing that would require a whole other article about climate change and countless other factors. But the truth is not as simple as these QRC ads make out. So let’s get the facts straight on the Great Barrier Reef. What the ads don’t tell you The ads – which you can watch below or on the QRC website – say that:

Paid for by the Resources Council, both ads end by pointing to a Queensland government Reef Facts website. The basis for the statistics in the two QRC ads come from an excellent 2012 peer-reviewed paper, “The 27–year decline of coral cover on the Great Barrier Reef and its causes”, published in the international journal Proceedings of the National Academy of Sciences. The paper found, just as the ad shows, that 48% of coral death was attributed to cyclones, 42% to crown of thorn starfish and 10% to bleaching. But the way that those facts are used in the ads is highly misleading.

The data in the 2012 study come from coral reefs predominantly on the mid-shelf of the Great Barrier Reef – that is, 30 to 100 kilometres from the coast. The study does not address the causes of death and decline among inshore reefs, seagrass meadows, dugongs, turtles and inshore dolphins. All these ecosystems and species are also in decline, with inshore coral reefs – those found up to 40km from the coast – seagrass and dugongs in severe decline in most of the reef south of Cooktown. It is misleading for these ads to selectively quote one study that only looks at coral mortality on mid-shelf reefs, and then claim that shipping and port activity has no impact on “the environmental health of the Great Barrier Reef”. The Great Barrier Reef: more than coral It might seem like a statement of the obvious, but the Great Barrier Reef is not only world-famous – and World Heritage-listed – because of its coral. To borrow from Bill Clinton’s famous campaign line: it’s the ecosystem, stupid.

The largest living structure on Earth, it spans 2300km and is home to 600 types of coral, more than 100 species of jellyfish, 500 species of worms, 1625 types of fish, 133 varieties of sharks and rays, 14 breeding species of sea snakes, 215 species of birds, six of the world’s seven species of marine turtle, 30 species of whales and dolphins, and one of the world’s most important dugong populations. Protecting mid-shelf coral reefs is important. But unlike the QRC ads, most studies on threats to the Great Barrier Reef consider threats to the complete range of species and ecosystems that make it so unique. The main water-quality threats to these ecosystems are sediment, nutrients, pesticide, toxic metals and hydrocarbons from the land. These come from agricultural activities and from coastal development – including ports. So is it true, as the ad claims, that:

In fact, the very limited coral monitoring that has occurred associated with dredging at Gladstone Harbour has suggested some changes to the benthic communities (organisms living on the sea floor, such as sponges and corals) in the area. But as with so much of the monitoring, the design of the study was not robust enough to firmly ascribe the actual cause. So without more scientific evidence, it’s impossible to fairly conclude whether any coral loss can be attributed to ports or shipping activity. However, the ads make a broader claim that: And this is where the ads really don’t tell the full story.

Get the facts So should the QRC be declaring so absolutely in its TV ads that: Based on my knowledge of the science: no. Several robust studies have now established that dredging and spoil dumping on a large scale have had impacts on species and ecosystems of the Great Barrier Reef World Heritage Area.

And that’s concerning, given the likelihood of further massive dredging programs potentially generating up to 80 million tonnes of dredge spoil, which presents a significant threat to the inshore ecosystems and species of the Great Barrier Reef. Jon Brodie does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations. This article was originally published on The Conversation. Read the original article.