Work to expand the port of Rotterdam has led to the discovery of the first signs of human presence in the Dutch delta 9,000 years ago, port authorities said Friday. \"An archaeological investigation has been conducted on the site of Rotterdam port\'s expansion ... with some very interesting results,\" said Rotterdam port spokesman Sjaak Poppe. \"Archaeologists found traces of animal bone, flint and charcoal from around 7,000 BC. It\'s the first indication of human society in western Netherlands,\" he said. Digging at a depth of 20 metres (65 feet) in the so-called Yangtzehaven, an undersea mud scooper has brought small artefacts to the surface, which archaeologists say show traces of life in the Early and Middle Stone Ages. \"Due to its rich fauna and flora, the convergence of the Rhine and Maas Rivers was an attractive place for hunters and gatherers,\" Poppe said. People lived in small groups of around 10, with a particular preference for river dunes, which provided safety from flooding. After the archaeological excavations, the Yangtzehaven is to serve as the access waterway to Rotterdam\'s new Maasvlakte 2 harbour, designed to increase Europe\'s biggest port by 20 percent, including two new container terminals, Poppe said. The port, among the world\'s 10 largest, on Thursday said it had handled some 327 million tonnes of cargo in the first nine months of 2011