For at least fifty years, agitated academics have been predicting the end of  Australia's Great Barrier Reef. Now international "experts" are also sprouting coral calamity. But despite the alarms, the reef is still there.

An early scare focussed on the Crown of Thorns Starfish which was going through one of its sporadic population booms. Such plagues come and go with the natural cycles of growth and decay. But the reef survived.

Then experts got scared in case someone drilled for oil on the Reef - so we had a Royal Commission and banned all that. However marine life seems to flourish around all artificial reefs such as jetties, shipwrecks and drilling platforms. Rigs have to be regularly cleaned of marine growth.

Natural hydrocarbons have been part of the wild environment for longer than corals, which may explain why corals are remarkably tolerant of hydrocarbons. Despite natural oil and gas seeps, man-made spills, and hundreds of offshore drilling rigs, corals still thrive.

After the worst oil spill ever during the First Gulf War there was no clean-up attempt apart from oil skimming because the 700 oil-well fires had priority. Fresh crude oil floats and is a danger to sea birds, but it soon reacts with air and salt water to become solid tar balls which sink to the sea floor. An inspection of the sea bed later to catalogue "the disaster" found teeming wildlife, with sea-grass, snails and fish thriving after the fertilising effect of the oxidising oil.

Corals are even thriving at the exact spot in the Montebello Islands where two atomic devices were tested by the British in 1952.

Another scare concerned coastal development and agricultural run-off. Again destruction of the Great Barrier Reef was forecast. Academics were summoned and a huge national park was established for their playground. Run-off still occurs, rivers still flood, but the reef is still there.

Lately global warming scares such as coral bleaching and ocean acidity have mesmerised the media. These are supposedly caused by wicked humans burning hydrocarbons and using energy by doing things. So we introduced a carbon tax, despite the fact that no unusual warming or acidity can be measured. And the reef is still there.

Now we are told that port dredging near Bowen is going to destroy the Reef. The Great Barrier Reef is 2,400 km long - stirring some mud at one small spot 40 km from the reef is unlikely to be noticed by the coral. Moreover, the stuff being dredged is comprised of natural material eroded from the land and put there over millennia by coastal rivers. Compared with the silt load discharged by rivers like the mighty Burdekin in a normal wet season, or stirred up by cyclonic surges, dredging is a non-event. The Reef has been coping with sediments like that for thousands of years.

All plants and animals need minerals for optimum health. Marine life gets its minerals from erosion of rocks on the land. Coastal rivers (and dredging of river silt) stir up the minerals which supply the off-shore environment. Like all nutrients, some is necessary, too much brings harm.

Corals are among the greatest survivors on Earth and have been here for about 500 million years. Many of the types of corals found on reefs today were present in similar forms on reefs 50 million years ago.

Since corals first appeared there have been five mass extinctions when over 50% of all life forms on land and in the seas died. These episodes usually included massive volcanic events that filled air and sea with debris, lava, heat and acid fumes. And still corals survived.

Then there were asteroid impacts that created huge craters that dwarf man's puny ports. Debris, rock, mud and slush were flung in all directions - far more and further than man's dredging will ever do. Corals even survived this.

Corals also survived several deadly ice ages when sea levels fell so low that many coral reefs left their skeletons stranded as limestone hills on dry land. But always some colonisers followed the retreating seas and survived.

Then came the hot climate eras when the great ice sheets melted and sea levels rose dramatically. Some coral reefs drowned, but others just built on top of the old drowned corals forming the beautiful coral atolls we see today. Corals flourish in gently rising seas such as we have today - it gives them room to refresh and grow vertically.

And if the water gets too warm, coral larvae just drift into cooler waters closer to the poles. The Great Barrier Reef would move slowly south.

Corals have outlasted the dinosaurs, the mammoths and the sabre-toothed tiger. Captain Cook's ship was almost disembowelled by the sturdy corals of the Great Barrier Reef in 1770. If Cook came back today, he would be unable to detect any changes in the Reef.

We should of course minimise soil erosion, human pollution of offshore waters and direct damage or interference with the Reef. However, green extremists would like to sacrifice all of Queensland's coastal industry on the coral altar - exploration, mining, farming, land development, tourism, forestry, fishing, and shipping. They need reminding it is only rich societies who can afford to care for their environment.

No matter what the future holds, corals are more likely than humans to survive the next major extinction.

In the event of yet another Ice Age we must hope that reef alarmists have not denied us the things we will need to survive - food, energy, chemicals, shelter, concrete and steel generated by carbon fuels.