6 
Part A - Framework conditions 
2 Possible adverse impacts 
Regarding possible impacts of offshore wind farms on the marine environment, various risks 
have been identified for the construction, operation, and decommissioning phases. These can 
be summarised as follows: 
2.1 Construction phase 
• Visual and acoustic stress due to building activities 
• Sound and light emissions by vehicles/vessels and machinery during construction, amongst 
other things 
• Temporary/permanent loss of habitats (e.g. resting, moulting and/or feeding areas) due to 
construction activities 
• Pollutant emissions 
• Turbidity of water due to sediment disturbance during foundation installation, cable laying 
and anchoring/propping of vessels and machinery on the seabed. 
2.2 Operation phase 
• Visual impact and annoyance due to noise emission of turbines during operation 
• Shadow flicker from rotor blades 
• Vibration 
• Additional electric and magnetic fields 
• Land use by the required infrastructure (foundations, cables etc.) 
• Potential discharge of pollutants (oils, greases) 
• Changed sediment distribution and dynamics 
• Changed current patterns 
• Potential impact on water quality 
• Collisions of birds with wind turbines 
• Barrier effect on fauna (e.g. barrier effect on birds during migration, or blocking of paths 
between different resting and/or feeding areas) 
• Disturbances (e.g. birds, long-term loss of resting and feeding areas) 
• Adverse impacts of maintenance and repair operations. 
2.3 Decommissioning phase 
• Visual and acoustic annoyance due to dismantling activities 
• Annoyance from vehicle and machinery operation during dismantling activities 
• Loss of habitats (resting and feeding areas) due to decommissioning activities 
• Pollutant emissions 
• Turbidity of water due to sediment disturbance during foundation removal, cable removal 
and anchoring/propping of vessels and machinery on the seabed.