The site of what is now Yangtzehaven - Rotterdam's seaport currently under construction - was inhabited by humans in the Mesolithic. At a depth of 20 metres, in the sea bed, underwater archaeological investigation found traces of bone, flint and charcoal from around 7000 BCE. These finds are the very first scientific proof that humans lived at this spot in the Early and Middle Mesolithic. The striking results were announced by the Port of Rotterdam Authority and the Cultural Heritage Agency of the Netherlands.
     Some 9000 years ago, the area where the North Sea and the port of Rotterdam can now be found was a river landscape created by the Rhine and the Maas. Due to the rich flora and fauna, this was an attractive place for prehistoric people. They wandered around the area, showing a particular preference for river dunes, which provided safety when the rivers flooded. The river dune on which they lived at the time now lies 20 metres below the New Amsterdam Water Level.
     The bone remains found up to now are small fragments (smaller than 1 cm) of burnt and unburnt animal bone. The unburnt bone points to the presence of animals at and in the vicinity of this spot. The burnt bone is burnt in such a way that it must be the result of human action. The fragments of flint prove that flint was worked on site to make all kinds of implements, such as arrowheads, knives and scrapers to clean hides.
     "Nowhere in the world has such research been carried out at such an exceptional depth under water", said Henk Weerts, senior researcher in Physical Geology and Palaeogeography at the Cultural Heritage Agency of the Netherlands. The areas which are now being excavated measure about 9 by 16 metres. From pontoons, grabs systematically scrape 2 x 3 metre slices of ground in 20 cm layers from the sea bed. It will take a few months to process the remains.
     Up to now, very few other traces of life in the Early and Middle Mesolithic (9000-7000 BC) have been found in the western Netherlands. Other parts of the country are known to have been inhabited during this period, but the finds there are limited mainly to scattered remains of flint.

Edited from Dredging Today (8 November 2011)