Germany and Denmark are planning to build a road and rail link between their two countries across a body of water called the Fehmarnbelt.  One proposal is to construct a 19 kilometer long bridge but environmental activists oppose the five billion euro project.Environmental groups say the project will cause massive disruption to the Baltic Sea’s ecosystem. They argue the proposed bridge's piers will affect the sea's water-exchange pattern, threatening species that live there in the process. Business leaders on the other hand support the project. They say it will provide a big stimulus to the region's economy. An alternative to the bridge design is a tunnel, which is both competitively priced compared to the bridge and, it's supporters say, would be kinder to the environment as well.