Fehmarnbelt Fixed Link

In 2008, Germany and Denmark signed a state treaty for the construction of a fixed link spanning the 18 km broad Fehmarnbelt and connecting Puttgarden (Fehmarn) with Rødby (Lolland, Denmark).

Planning and execution of the currently largest infrastructural project in Europe is carried out by Femern A/S. After considering various types of bridges and tunnels during the initial planning stages, the final decision was made to build an immersed tunnel.

Between 2008 and 2010, BioConsult SH has, as part of an international consortium, carried out the baseline surveys for marine mammals, resting birds, bird migration as well as bat migration for the environmental impact assessment.

In a plausibility check in 2015, BioConsult SH simultaneously carried out digital aerial surveys of marine mammals and birds using the HiDef-system and conventional aerial surveys (where an ornithologist counts visually from the aircraft) to ensure comparability. These surveys served to verify the results of the baseline surveys carried out between 2008 and 2010.

The environmental impact assessment for the individual features of conservation interest was based on the following investigations:

• Description of the occurrence and distribution of different non-breeding waterbirds by performing monthly aerial surveys (transect and additional surveys to record moulting mute swans)
• Description of the occurrence and distribution of non-breeding waterbird by performing monthly ship-based surveys
• Investigation of the foraging ecology of seaducks (common eider, long-tailed duck, common scoter) in the study area by stomach analysis and VHF radio telemetry
• Investigation of small and large scale movements of seaducks (common eider, long-tailed duck, common scoter) by satellite telemetry

Description of bird migration across the Fehmarnbelt based on bird migration observations from two land-based stations close to Puttgarden and Rødby as well as from an offshore location based on a ship using:

• Land- and ship-based surveillance radar observations
• Land-based pulse-radar fire control system “Super Fledermaus” in cooperation with the Swiss Ornithological Institute
• Land- and ship-based visual observations of bird migration
• Recording of flight calls at night

• Recording and description of bat migration using stationary recording devices (bat recorders) at various locations along the coasts of the islands of Fehmarn and Lolland as well as onboard the Scanlines ferries from Puttgarden to Rødby and own vessels
• Recording and description of bat migration using bat detectors along the coasts of the islands of Fehmarn and Lolland
   

Current results and detailed method descriptions of construction phase monitoring for the Fehmarnbelt immersed tunnel are available via the Femern A/S environmental portal. Next to BioConsult SH's waterbird and marine mammal surveys, data and models of further investigations can be found here.