MULTI-MILLION pound proposals to harvest tin deposits from the seabed could have serious consequences for the environment and tourism, it has been claimed.
But the plans to reclaim marine deposits of the metal between St Ives and St Agnes could create up to 100 jobs and spark major investment in the region.
Cornish company Marine Minerals has been given permission by the Marine Management Organisation (MMO) to investigate the possibility of recovering the tin deposited on the seabed as a result of mining in an environmentally, socially and economically viable way.
The rising price of tin could see millions of pounds worth of the metal brought ashore.
But Surfers Against Sewage's (SAS) campaign director Andy Cummins said it had concerns about the effect the project could have on "a very valuable" stretch of coastline.
"It can have negative consequences for the beach so you can rob the beach of its golden sand and for surfers the waves rely on the sand bank to produce quality waves," he said.
Mr Cummins said removing the sand could damage these banks, which in turn may have a detrimental affect on the economy.
"Surfing is worth £64 million to the Cornish economy and provides 1,600 year-round jobs so ... we need to protect what we have got," he said.
Mr Cummins was also concerned that moving the sediment on the seabed could release pathogens and other pollutants trapped in the sand from years of sewage discharges.
Marine tin deposits have been mined off the Cornwall coast, most recently in the 1980s, but Marine Minerals believes techniques used then, such as dredging, are not environmentally acceptable.
It is looking into alternatives including a method of filtering the sand at sea, with only the portion containing tin – less than 5 per cent – being taken ashore.
The company is also considering how and where the sand can be brought ashore for processing and the possibility of using Hayle Harbour, which could see major investment in the port.
Work to start extracting about 40 core sand samples is due to start in the coming months.
A spokesman for Marine Minerals said: "This is potentially a very valuable resource and potentially very valuable for Cornwall.
"It can only go ahead if it can be recovered in an environmentally satisfactory way."
A formal environmental impact assessment will be submitted to the MMO.