By Geoffrey Lean
Take one of the world's greatest waste problems, and turn it into one of the planet's most precious habitats. It seems a classic green win-win. But dumping used tyres in the sea to make artificial coral reefs has proved to be an environmental disaster.
This summer US military divers will start removing - one by one - some two million of them from the world's biggest "tyre reef", a mile out in the sea off Fort Lauderdale, Florida, after they had been found to be killing coral, rather than creating it.
Waste tyres are a problem. Leave them in piles and they can catch fire; dumps have burned uncontrollably for years. Bury them and they rise eerily to the surface. Yet more than a billion tyres require disposal worldwide every year.
So the idea of turning them into artificial coral reefs, mimicking the Earth's richest underwater wildlife habitats, seemed ideal. Corals would attach themselves to the rubber and grow, it was thought, providing shelter and breeding grounds for fish - and boosting catches.
Fort Lauderdale was one of the first to try it. In spring 1972, more than 100 private boats came to help. Goodyear provided the tyres, dropping a gold-painted one into the water from a blimp to launch the project.
The idea spread. Malaysia and Indonesia were among developing countries that launched huge programmes; by 1995 there were 67 tyre reefs off Malaysia alone.
But corals refused to grow on the smooth surface of the tyres. The only life attracted to them were "weedy" sponges and stinging hydroids. Worse, the tyres broke free of restraining chains , and were carried by currents to slam into real coral reefs. Many settled on the corals, doing more damage. And storms dumped the tyres, up to half a million at a time, on North Carolina and Florida beaches.
William Nuckols ofCoastal America, which is helping to organise the clean-up, calls them a "a constantly killing coral-destruction machine".
It is expected to take three years, and at least $40m (£20m) to remove the tyres, and that's just for Florida.
Malaysia and Indonesia have similar stories. Dr Bill Alevizon, who conducted a review of reefs in Malaysia, calls tyres "undersea juggernauts". James Francesconi, artificial reef co-ordinator in North Carolina, adds: "I encourage no one else to put another piece of freaking rubber in the ocean again."Reuse content