Reduction and avoidance measures

Reduction of photoattraction under construction

Objectives and methodology

The impact study highlighted that certain 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 medium for petrels and shearwaters and weak to negligible for other bird species. Although limited information is available regarding their (migratory) behavior.

This measure aims to reduce the impact of lights on ships during the work phase.

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

By turning off any unnecessary light source


By reducing light intensity to a minimum


By directing the light sources downwards

If possible

These requirements have been transcribed into the specifications of the works companies which will have to follow these obligations.

The first feedback from construction companies during the analysis of the offers shows that generally speaking, each vessel participating in the project will be equipped with all the external lights necessary to carry out its night operations, namely:

Navigation lights, in compliance with international regulations, classification and flag administration rules (either oriented horizontally (parallel to sea level), with prescribed angular sectors);

Signaling lights intended to warn aircraft and helicopters landing, in accordance with international aviation rules and regulations (pointed towards the sky, but only used when necessary);

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


Floodlights for launching rescue equipment and boarding, in the event of emergency abandonment of the vessel, always oriented downwards and towards the boat systems, as well as the sea which directly surrounds it. here, in case of need;

Common deck lights to enable personnel to move around safely (pointing downward);

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

These first returns demonstrate that most lighting, unless prescribed by regulations or specific needs (in particular to ensure the safety of flight and working personnel) will be oriented downwards.

Location of actions

On construction ships.

Schedule and Status

Measure under development

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

All reduction measures

Follow-up measures

Compensation measures

Accompanying measures