The crown of thorns starfish was going to devour the reef 40 years ago and if we didn't "do something" the reef would be ruined. I haven't been up there to look, but I'm pretty sure the reef is still there and doing fine (despite the screeching of the doomy-warmers).
In the last 40 years we've had the threats of runoff of water from farming areas which is supposedly contaminated with fertilisers and now there's supposed "ocean acidification", due to the increase in CO2 in the atmosphere.
There is an interesting article in Quadrant July/August 2011 Volume LV Number 7/8, the latest issue, about the crown of thorns starfish and what it does to The Great Barrier Reef. What is most interesting is what the crown of thorns does for The Great Barrier Reef!
Let me quote the opening paragraphs and see if you can grasp the message.
The rise of environmentalism as a socio-political movement has brought about a fundamental shift in values and activity across a range of scientific disciplines. Fisheries, forestry, wildlife management, ecology, systematics, marine biology and indeed the whole spectrum of field biology and environmental disciplines have been strongly affected. Climatology itself has become virtually synonymous with catastrophic anthropogenic climate change.Don't stop there, keep reading Fishy Science on the Great Barrier Reef by Walter Starck and find out how the crown of thorns is now thought to be beneficial to reef growth.
Before the ascendancy of environmentalism, the scientific ideal was an objective, evidence-based, value-neutral search for truth. Basic research, aimed only at better understanding the world in which we live, was pursued with considerable success. Over recent decades, however, basic research in natural history has been largely supplanted by studies predicated on environmental concerns. As a consequence, acquisition of new understanding of the nature and functioning of the natural world has declined. In addition, much of the research into purported environmental problems suffers from bias and distortion arising from adherence to faith-based notions of environmental correctness.
This shift in emphasis from basic research to environmentalism began innocuously in the 1960s and 1970s when an expanding scientific community began to outgrow its funding, and competition for research grants became stronger. At the same time, government was also coming to realise that scientific research was a black hole that could devour ny amount of funding and always be hungry for more. Moreover, much of the research appeared to be highly esoteric with little prospect of ever yielding anything of practical or even intellectual value. Governments started to demand a greater consideration of utility.