In early June a UNESCO report expressed concern about port developments in Queensland that might threaten the Reef. That was followed by a conference of scientists in Cairns in mid July which said that the Reef was in great danger from climate change. Oh, and port development, shipping, ocean acidification, tourism, population growth, agriculture — you name it. The threats were dutifully reported in the media, because of the Reef’s status as an Australian ‘icon’ and our standard-bearer on the World Heritage List.
My long memory tells me that it was the Crown of Thorns starfish that was the first of the many ‘threats’ we now hear about, and that was in the early 1960s. We were told then that the reef would die, and both the Queensland and Commonwealth Governments put money into finding out more about the starfish and what to do about it. It is a widespread organism, found across the Pacific and the Indian Oceans, and infestations seem to come and go. The starfish doesn’t in fact kill the coral, and after infestations the infected reef recovers quite quickly.
But more to the point, the way we hear about the Reef is always as a threatened jewel. I doubt that most people have any real conception of what the Great Barrier Reef is, even those, like me, who have visited sites on it many times. It is, first of all, an enormous ‘structure’, 2,000 kilometres long, containing over 3,000 reefs and several hundred islands. Hardly any of it is regularly inspected or even visited. Most of it is well away from the coast, out toward the fringing reef at the edge of the continental shelf, and there is no great population centre anywhere near it.
Wikipedia will tell you that anthropogenic global warming is the Reef’s great enemy, and that coral bleaching caused by elevated sea temperatures will become an annual event. It hasn’t done so yet, and a likely cause is a combination of winds and currents keeping warm water in place. In any case, the coral reefs near Papua New Guinea flourish in water that is a couple of degrees warmer than that in the southern parts of the Reef. And the threat caused by rising sea-levels is the silliest I’ve heard: corals grow, and you can see how much lower the sea-level was if you dive down a little on the edge of any reef. The sea has risen 120 metres since the end of the last ice age, and corals have coped by growing upwards. They would strongly dislike a lowering of the seas!
It is much the same with the other scares. All of them are possible, but none of them is as yet real. ‘Ocean acidification’, for example, is a scary way of saying that the seas may have become, on average, a little more alkaline over the past couple of decades. But we really don’t know, and the ph levels of the sea vary horizontally and vertically. Yes, ships come to grief in the Reef (forgive the rhyme), and more than 1500 have done so since Europeans began sailing there. Yes, oil has spilled (not much of it). But as we saw in the Caribbean, oil is seen as a food by other organisms, and they break it down quickly. It may or may not be true that the seas are becoming appreciably warmer — at the moment I think it is an open question.
Yes, nutrients wash down the rivers, and so do pesticides, and so does soil and debris after floods. The Reef seems to take it all in its stride. Storms damage bit of it, as does bleaching, as do the starfish. But it is a giant system, and nothing yet seems to have occurred on a system-wide basis.
Let u by all means keep a watchful eye on it, but it would be pleasant if we heard bit less of ‘imminent threats’, and a bit more of what is pristine and unspoiled in the Great Barrier Reef.There is a lot of that.