Rostock, Germany- The pillars of a bridge connecting Germany to the Danish archipelago are likely to sharply reduce the supply of oxygen to the innermost parts of the Baltic Sea, German marine scientists warned Wednesday. Copenhagen is keen to build a 20-kilometre-long bridge across the Fehmarn Belt, a strait between Germany and the Danish island of Lolland. It agreed in February with Berlin on a financing package, but Danish legislators fear the strain on Denmark will be too heavy.
The strait is a continuation of the Great Belt, a channel through the archipelago which was bridged in 1997.
The Leibniz Institute for Baltic Research in Warnemuende (IOW) said data showed that the pillars of the Great Belt Bridge had upset a deep current of oxygen-rich water from the North Sea to the Baltic.
A second bridge was likely to further reduce the purity of the current, cutting the oxygen supply in the sea which extends as far as Russia. Large numbers of marine animals and plants would die, the IOW said.
The institute said three quarters of the exchange of water between the Baltic and the world's seas took place through the Great Belt, with the rest via narrower channels.
It said the pillars caused turbulence and vertical displacement of the oxygen-rich water, mixing it with surface water that is less salty. Reduced salinity made the oxygen-rich water less dense, and this stopped it from penetrating the deeper parts of the Baltic.
IOW said past environmental impact reports had only considered the overall quantity of water on the move, not this effect.
If legislators approve the 5.5-billion-euro project, work on the bridge, which would replace a ferry link, could begin in 2012.
