Artificial Reef

Environmental concerns
A multi-million-dollar cleanup of Osborne Reef, a tire dump near Fort Lauderdale, Florida is underway. The tires started posing a particular threat after breaking free from the reef and damaging nearby natural reefs.
According to The Ocean Conservancy, a Washington-based environmental group, the Florida reef may be an indication that the benefits of artificial reefs need to be re-examined. Jack Sobel, a senior scientist at the group, has said "There's little evidence that artificial reefs have a net benefit.".
A proposed artificial reef using the ex-HMAS Adelaide that was to be sea-dumped at Bulbararing Bay on the New South Wales Central Coast was stopped in 2010 by local residents alarmed at the potential for beach erosion, PCBs and heavy metals entering the marine environment, and changes to surf conditions.