Fehmarnbelt Fixed Link – environmental impact assessment

On behalf of Femern A/S, BioConsult SH has accompanied the German plan approval procedure for the construction of the Fehmarnbelt Fixed Link between the islands of Fehmarn and Lolland.

Environmental impact assessment for marine mammals, non-breeding waterbirds, bird as well as bat migration


Between 2008 and 2010, BioConsult SH, as part of an international consortium, has 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, surveys of marine mammals and birds were again carried out using the HiDef system. The study served to verify the results of the baseline study carried out between 2008 and 2010. To ensure comparability, the digital aerial surveys were carried out simultaneously with conventional aerial surveys where an ornithologist counts visually from the aircraft.

 

 

Environmental impact assessment

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

Marine mammals (harbour porpoise, harbour seal, grey seal)

  • Description of the occurrence and distribution of harbour porpoises, harbour seals and grey seals by performing monthly aerial surveys (transect and additional surveys to record seals at their haul-out sites)
  • Additional description of harbour porpoise occurrence in the area of the planned fixed link by performing monthly surveys from onboard the ferry between Puttgarden and Rødby
  • Description of the occurrence and distribution of harbour porpoises using C-PODs (acoustic detection of porpoise echolocation signals using specific underwater hydrophones)
  • Assessment of a possible barrier effect of a bridge on harbour porpoises based on visual (aerial surveys, land-based observations) and acoustic (C-PODs) investigations.
  • Investigation of habitat use and movement patterns of harbour seals in the Fehmarnbelt area using satellite telemetry
  • Investigation of underwater noise levels (noise emissions) in the study area

Non-breeding waterbirds

  • Description of the occurrence and distribution of different non-breeding waterbird species by performing monthly aerial surveys (transect and additional surveys to record moulting mute swans)
  • Description of the occurrence and distribution of non-breeding waterbirds 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

Bird migration

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

Bat migration

  • 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 from onboard the Scandlines ferries between Puttgarden and Rødby and own vessels
  • Recording and description of bat migration using bat detectors along the coasts of the islands of Fehmarn and Lolland

Papers and reports


Žydelis, R., Dorsch, M., Heinänen,S., Nehls,G. & Weiss,G. (2019)

Comparison of digital video surveys with visual aerial surveys for bird monitoring at sea

Journal of Ornithology (2019) 160:567–580

Further information


Current results and detailed method descriptions of the environmental construction 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, the portal presents data and models of further investigations.

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