A project to create an artificial reef off the French Riviera by dumping hundreds of thousands of used rubber tyres has proved a total flop, prompting the decision to fish thousands out in time for the Cannes film festival. They were dropped off the Mediterranean coast in the 1980s in piles or rows to a depth of around 30 metres as part of an attempt to restock the waters with marine life by giving fish and coral a new home. In all, hundreds of thousands of the inert objects were dispatched to the seabed off southern France, emulating similar large-scale projects, notably in Florida. However, the well-intentioned plan proved to be almost entirely useless, as nothing but a few incredibly hardy sponges took to the tyres. Fish ended up plumping for natural rock or concrete structures sunk for the same purpose. Worse, undersea currents ended up dispersing the tyre reefs, with thousands piling up, crushing coral and plant life and blighting the seabed. Environmentalists claim they also release toxic hydrocarbons into the sea. "Things didn’t work as we had imagined at the time,” Elodie Garidou of France’s protected marine areas unit, AMP, told Le Monde. So the agency decided to begin fishing them all out with EU financial support, starting with a first batch of 2,500 in the bay of Antibes off Vallauris Golfe-Juan. A team of six divers created “necklaces” of 10 to 30 tyres at a time, which were winched up to a 40m boat with two cranes on board. "We had a pretty short window to finish this operation as we had to finish by the Cannes Film Festival at all costs,” Ms Garidou told Le Monde. The last of the tyres were recovered on May 12. Ten times more still lie beneath the waves in other spots off France. However, this pales into comparison next to the 700,000 still lying in coastal Florida waters, part of the Osborne Reef - an underwater cemetery of two million tyres that were placed there in 1972 and that have proved an ecological disaster. Over the years, many were dislodged by tropical storms and hurricanes and caused damage to nearby existing coral reefs. Similar reefs have been constructed in the northeastern United States, the neighboring Gulf of Mexico, Indonesia, Malaysia, Australia and Africa.