Reduction and avoidance measures

Photoattraction reduction in construction

Objectives and methodology

The impact study showed that some species of birds in flight were more sensitive to light than others. In the absence of mitigation measures, the potential effects of light attraction were rated as moderate for petrels and shearwaters and low to negligible for other bird species. Although limited information is available on their (migratory) behaviour.

This measure is intended to reduce the impact of lights on ships in the construction phase.

In accordance with the conditions attached to AU IOTA, the effects of light attraction can and should be mitigated:

By switching off any unnecessary light source


By minimizing light intensity


By directing the light sources downwards

If possible

These requirements have been transcribed in the specifications of the construction companies that will have to follow these obligations.

Initial feedback from the works contractors during the analysis of the tenders shows that, in general, each vessel participating in the project will be equipped with all the external lights necessary to carry out its operations at night, namely :

Navigation lights, complying with international regulations, classification and flag administration rules (i.e. oriented horizontally (parallel to sea level), with prescribed angular sectors) ;

Traffic lights for warning aircraft and helicopter landings, in accordance with international aviation rules and regulations (oriented towards the sky, but put into service only when necessary) ;

Searchlights for search and rescue operations and passage through the channels (the orientation is variable but these are only used in emergencies) ;


Floodlights for launching life-saving equipment and boarding, in the event of emergency abandonment of the vessel, always directed downwards and towards the boat systems and the sea directly surrounding it, if necessary ;

Common deck lights for safe movement of personnel (facing down) ;

Floodlights to illuminate the work area, ensuring the operational safety of the project.

This initial feedback shows that most lighting, unless prescribed by regulations or specific needs (to ensure the safety of flight and working personnel in particular), will be directed downwards.

Location of actions

On construction ships.

Planning and Status

Measure under development

This measure is planned for the entire duration of the construction phase.

All reduction measures

Follow-up actions

Compensation measures

Accompanying measures