Underwater caves in sheltered bays could house a wealth of untapped pre-European archaeological treasures, say Australian researchers. And people involved in coastal developments need to be more aware of the potential for disturbing this underwater heritage, they say.
     Sydney-based archaeologist Cosmos Coroneos and colleagues will report on possible underwater sites in Sydney at the Australian Archaeology Conference at the University of Sydney next month. "About 6000 years ago, the coast of Sydney was probably about 20-30 km off shore," says Coroneos. "As the sea levels rose people retreated inland." He says this means that there is probably a lot of evidence of Aboriginal occupation that is now under water.
     Aboriginal people are known to have occupied rock shelters around Sydney that are currently above water. So Coroneos and colleagues reasoned there must be equivalent sites under water that contain archaeological treasures dating back at least 6000 years.
     Previous attempts to find such submerged sites in Australia have so far not been very successful, says Coroneos. He says one reason is that many sites have been exposed to wild waves that have washed away sediments that might contain archaeological material. So the researchers decided to focus on sheltered bays in Sydney. One area they chose was in Port Hacking where there were known to be caves above water that Aboriginal people had inhabited.
     With help from volunteer divers from the Underwater Research Group of New South Wales the researchers systematically surveyed below the water and found some likely candidate sites. "We've basically found caves under water," says Coroneos. "If they were dry, up on land, we would consider an excavation of these areas as being prospective rock shelters." The researchers now hope to get permission from the local Aboriginal landowners to collect sediment cores from the caves in the hope of finding stone tools.

Source: ABC Science Online (24 August 2007)