Tonnes of Portland stone has been dumped off the Dorset coast to form an artificial reef sanctuary for lobsters.
The small rocks have been placed just off the coast of Weymouth and Portland near Ringstead Bay.
A barge spread the 1,750 tonnes of stone out in a 200m wide circle where 6,000 lobsters will be released.
It is part of a project by community and local business group Wreck to Reef to boost lobster stocks to help the fishing industry.
The lobsters are expected to be established on the reef in a year when another 6,000 will be introduced.
Rocks have been used for the reef as lobsters like to live in stony crevices.
Project co-ordinator Neville Copperthwaite said: "The idea is not to catch these lobsters, but to let them grow and wander off into the wider environment to breed."
After the Olympic Games, there are plans to sink two warships in the bay for a dive site similar to the artificial diving reef off Plymouth, where HMS Scylla has been sunk.
The former Royal Navy frigate was sunk in Whitsand Bay in 2004 to create the reef, which is home to more than 250 species of marine life.
Mr Copperthwaite said: "It's estimated sinking a single ship brings in £1.6m to the local economy. This is borne out by the sinking of the Scylla which has been very successful and we hope to do the same here."
A second community reef is planned in the bay which will be built by artists, and other local groups.