A Sydney Aquarium diver uses a vacuum to clean the gravel in the Great Barrier Reef tank as a Ray Shark swims by September 26, 2006 in Sydney, Australia. The Aquarium is undergoing its annual spring clean to prepare for the school holidays using vacuums, along with sea creatures like Sea Cucumbers, Sea Urchins, Cleaner Wrasse Fish and Sea Stars to help complete the job. (Photo by Ian Waldie/Getty Images)

22 Apr 2011 10:57:00