JOHANNESBURG - South African police have set up roadblocks to protect thousands of rock lobsters which have been leaving the ocean north of Cape Town. The crayfish, whose combined weight of 1,000 tonnes represents half of the country's annual commercial quota, have been scuttling onto the beach at Elands Bay to escape a deadly red tide which is robbing the water of oxygen. Thousands of people have rushed to the coast to take advantage of the unexpected harvest.