Femern A/S must establish 42.5 hectares of stone reef off Fehmarn as a replacement for the destroyed reefs in connection with the Fehmarn project. For that purpose, the state-owned building company has launched a market survey that will lead to an actual tender, amounting to 150,000 tonnes of stone.
Difficult to find a supplier
It turns out, however, that Femern A/S probably finds it more difficult than usual to find a supplier of the many stones. In the preliminary material, Femern A/S writes that the stones must be between 60-100 centimetres in diameter. In addition, the stones must be unbroken, and this excludes blasting them out of a quarry. To complicate the whole thing further, the stones must also be from the Ice Age and come from the Baltic Sea area.
Total ban on stone fishing
This is what lay people would call a boulder, Femern A/S is in the market for. And such ones cannot be sucked up from the seabed from the approved raw material extraction zones. Rock fishing has been totally banned in Denmark since 2010, so you can’t pick them up from the seabed with a crane either. This means that the many stones must be collected either in fields or in gravel pits.
3,750 wagon loads
It will require in the neighbourhood of 3,750 truckloads of boulders – at least. They must then be driven to a shipping port and sailed to their destination off Fehmarn, and this will mean a significant CO2 footprint for something that is essentially nature restoration. Boulders are not stock items in the gravel pits; and especially not in such large quantities:
Only found here and there
– It sounds like a difficult task. Such large rocks are only found here and there. An ordinary gravel pit will perhaps be able to deliver 500 tonnes. “Just” 5,000 tonnes would be a challenge, so it is a very large quantity, says Søren Evald Jensen, who is area director for Råstoffer East in NCC Industry and chairman of the marine committee in Danske Råstoffer.
Unable to bid
Søren Evald Jensen then also reports, on behalf of NCC, that they are incapable of bidding for the task:
– We can not. You have to know your limitations. It is theoretically possible but not in practice. You usually sell 1, 5 or ten at a time – not 150,000 tonnes, says Søren Evald Jensen.
Fish and sea creatures don’t care
FemernReport has spoken to several marine biologists and geologists who wonder about the requirements for the size and origin of the stones. Fish and sea animals are basically indifferent, and if only the stones have a diameter of 20 centimetres, then that is enough for them to stay put and not be moved around by ocean currents.
The market price of 150,000 tonnes of boulders is estimated to be between 5-10 million euros.
