Accompanying measures

The wind farm off the coast of Saint-Brieuc Bay, supported by Ailes Marines , obtained on April 18, 2017, from the Prefecture of Côtes-d'Armor, the administrative authorization known as "Single IOTA Authorization" under the provisions of the articles L.214-1 et seq. of the Environmental Code.

This authorization prescribes several environmental monitoring, reduction, compensation or support measures. The accompanying measures are part of a more global strategy and aim to improve the efficiency of compensatory measures.

Monitoring of marine mammals by photo-identification

During construction:

Habitat loss/modification
Risk of mortality/injury due to noise (threshing)
Disturbance from ships and noise
Risk of collision with ships

During operation:

Negligible impacts

The objective is to contribute to the knowledge of marine mammals in the GNB by contributing to the catalog currently being created by the GECC. This measure therefore includes outings financed by Ailes Marines .
Two species are targeted by this measure: the bottlenose dolphin and the Risso's dolphin.

The bottlenose dolphin

Risso's dolphin

The objective is therefore to participate in the enrichment of the photo identification catalog of individuals of bottlenose dolphins present in the GNB, and to participate in the creation of this catalog for Risso's dolphins. This method thus makes it possible to acquire valuable information relating to fidelity to a site, movement zones and living space, periods of attendance, individual relationships, the life cycle and the ecology of the site. species in the broad sense.

A letter of intent from the GECC has been issued for the implementation of this measure. Discussions will take place with this organization in 2022 to prepare for the implementation of this measure.


Location of the GECC action zone

Schedule and Status

Measure under development

Three follow-up sessions will be organized:

  • 2023-2024 2% 2%
  • 2027-2028 0% 0%
  • 2032-2033 0% 0%

Noise impact study on fisheries resources

During construction:

Crushing (presence of piles and protections, anchoring of ships and laying and protection of cables)
Resuspension of sedimentary particles and their deposition
Noise pollution and vibrations

During operation:

Habitat modification
Reef effect

This support measure focuses on evaluating the impact of noise on various emblematic species of the fishery resource of interest in the Bay of Saint-Brieuc, which are: scallops, clams, lobsters and cuttlefish. Indeed, knowledge of the impact of sounds on invertebrates and crustaceans at different stages of their development is still very incomplete.

This study in a controlled environment (laboratory) but also natural for the case of the Scallop, aims to better understand the effects of noise on these organisms (like the lobster) and to subject certain species to the sounds of beating and drilling of stakes of various intensities (to simulate a distance gradient between the individual and the noise source). This completely pioneering study brings together a college of international scientists at the forefront of research in underwater bioacoustics (CNRS, LEMAR, MNHN, BeBEST and Polytechnic University of Catalonia) as well as the contribution of CDPMEM 22.

This study is divided into two sub-parts, one dealing with cuttlefish (SONSETC project led by Michel André) and the second with other species studied (IMPAIC project led by Laurent Chauvaud).

These two studies will be the subject of several scientific publications in international journals. All results will be presented publicly once the scientific articles have been submitted. All the preliminary results were presented to the fisheries committees as well as to state services.

the scallop





Illustration of an experimental device allowing the exposure of individuals to a known sound environment.

Schedule and Status


Measure implemented

  • IMPAIC study 85% 85%

The IMPAIC study started in December 2018 and will be completed by the end of 2020. Three preliminary oral presentations were organized, in the presence of State Services and representatives of professional fishing, between 2019 and 2020.

  • SONSETC study 100% 100%

The SONSETC study began in March 2019 and ended in February 2020. An oral presentation was held in May 2020 before State Services and representatives of professional fishing.

Participation in the management of marine protected areas

Measure MS22 is presented in the IOTA authorization in article 24. It is stipulated:
"Independently of the financing of the ERCA regulatory measures listed in articles 21 to 23 of this decree, and in order to compensate for the losses of habitats of birds and marine mammals, the project owner contributes financially to the management of existing or future protected areas, contiguous or not to the area, but close and functional for the species considered.
The amount of this contribution represents the financing of a project manager position at minimum technician level, full-time, over a period of 40 years. This point will be the subject of subsequent agreements between the project owner and the stakeholders concerned (State, public establishments, communities, etc.), in association with the management and monitoring committee. »

The objective will be to aim for actions to protect the species of birds and marine mammals concerned by the request for a protected species exemption.

The terms of implementation of this measure are currently being discussed between Ailes Marines , the DDTM 22 and the OFB. The aim is to reach an agreement before the end of the year.

The following points were discussed in particular:

  • Lead organization for the measurement
  • Calls for projects for durations of 3-5 years, with specifications and selection committee
  • Type of projects that could be funded: The chosen area(s) or project(s) must result from collective decisions, involving State services and Ailes Marines . The choices should not relate to a single MPA for the entire duration of the measure.
  • Actions may focus on mapping, site restoration, or studies on marine mammals or birds, aimed at improving knowledge. They can also turn to financing a mission manager position, or purchasing equipment to carry out studies.

Several zones are currently being considered, including the Natura 2000 zones shown in the figure above.

Schedule and Status

Measure under development

The measure is intended to be implemented over the entire duration of operation of the wind farm off the bay of Saint-Brieuc.

Modeling of turbidity during the works phase

During construction:

Modification of water quality
Disturbance of fishery and benthic species
Disruption of uses
Modification of the transparency of the water column

AU-IOTA prescribes that prior to starting work on the foundations, the project owner carries out modeling of the dispersion of suspended matter and assesses their impacts on the fishery resource.
The project owner presents for opinion to the management and monitoring committee:


The results of the modeling and impacts on the fishery resource

The conditions and operating methods for carrying out the work

Conditions for carrying out monitoring and surveillance measures

The alert and critical thresholds conditioning the completion of the work

In order to evaluate the influence of drilling work for the discharge of residues taking place near the bottom or the surface, a three-dimensional hydrodynamic and sedimentary modeling system was set up, calibrated and validated by comparison with the measurements acquired. by Ailes Marines in the implementation area (Actimar, 2019). It then makes it possible to represent the variation of the different parameters (current, turbidity, deposition) over the entire water column and to estimate the influence of the vertical position of the discharge on the dispersion of sediments at sea, necessary to identify the conditions lower impacts with regard to the preservation of the environment.

In line with previous studies carried out by Actimar on the same subject, the hypotheses on drilling scenarios have been considerably refined for greater realism. In particular, as the work technique depends on the vertical structure of the nature of the funds, this was taken into account from core drilling and particle size analyzes in order to reproduce, as realistically as possible, the volumes of materials discharged at sea and the phasing of operations within the modeling system.

The study led by Actimar also sought to assess the natural variability of turbidity in situ and the impact of the work on local fisheries resources. Ultimately, these studies led to the proposal of thresholds and a turbidity monitoring program during the work phase. The thresholds, as well as the monitoring methodology, were the subject of a prefectural decree.


Schedule and Status

Measurement finalized

The modeling was carried out and presented to the Management and Monitoring Committee.

Noise reduction during the works phase

The construction phase will induce a significant noise level due to the driving of piles for 34 foundations. Today, systems to reduce the propagation of underwater acoustic waves are implemented when site conditions permit (bubble curtains for example, Hydro Sound Damper, cofferdam, etc.).

Ailes Marines will follow the requirements for testing a noise reduction system during pile driving operations on 2 foundations.

Special site conditions require the development of a specific system. The implementation of the system will be done on two beaten foundations. Several hydrophones will be installed at different distances to evaluate the effectiveness of the system in the specific oceanographic conditions of the Bay of Saint-Brieuc.

In accordance with AU-IOTA, the measures will be tested and validated within 2 years from the start of the installation work.

bubble curtain

Photo trianel-borkum


Windfarmbase diagram

At the same time, and in line with the logic of reducing the impacts linked to driving noise as presented in the AU-IOTA, Ailes Marines is working to reduce noise during the construction phase by reducing the number of driven piles in favor of drilling. of lower intensity.

The technical studies are underway and Ailes Marines will present to the local authorities as well as the CGS the measures that could have been taken to reduce noise pollution and the impact of noise.

Experimentation with a collision avoidance system for avifauna

During operation:

Risk of collision
Loss / Modification of habitat

This support measure concerns the testing of a system to avoid bird collisions with the blades of wind turbines in operation. The system is composed of a network of cameras, which detect the trajectories of different categories of birds, connected to a sound scaring system, which is activated once a bird enters a risky perimeter around the rotor of the wind turbine. Different systems are available on the market and operational for several years on onshore wind farms. Marinated versions adapted to offshore sea conditions are currently being developed, however they do not benefit from as much feedback as their land-based counterparts. This is why the choice of system was not fixed in the prefectural authorization orders.

This measure aims to test an existing system, consisting of 3 devices each attached to a wind turbine, distributed at the southern and northern ends as well as in the center of the park (see figure below).

Ailes Marines has approached potential suppliers and a call for tenders will be launched soon.



The three devices will be distributed along a north/south axis, wind turbines no. 57, 31 and 3 are currently preferred, subject to technical validation.

Schedule and Status

Measure under development

Monitoring will begin when the wind turbines in the park are commissioned for a period of 2 years during the operating phase of the park, i.e. in 2024 and 2025.

definition and implementation of a tourist offer in conjunction with local stakeholders

During construction:

Gradual modification of the landscape perception
Opportunity to build a new tourism, based on the values ​​of the territory and people

During operation:

New identity of the territory
Support tourism stakeholders in an “all-weather offer”
Participate in a better opening of the hinterland and networking of tourist providers
Enrich the tourist offer, by revitalizing it and revealing it
Territory showcase innovative

The measure concerns the commitments made by Ailes Marines when responding to call for tenders n°2011/S 126-208873 organized by the French State to develop a wind project off the coast of Saint-Brieuc and those of administrative authorizations for the offshore wind project, obtained in December 2017.

Tourism being the second sector of economic activity in the Côtes-d'Armor department, the question of including the offshore wind farm in the department's tourism offering was raised. Ailes Marines is committed to promoting the attractiveness of the department and the integration of the wind project into the region's tourist offering.

Ailes Marines approached the Côtes-d'Armor Departmental Tourism Committee (now CAD) and signed a first agreement with the organization on October 1, 2015, renewed by amendments on June 28, 2017. A second agreement was signed on 07/18/2019 in order to continue the study aimed at integrating the offshore wind farm in the bay of Saint-Brieuc into the current tourist offer of Côtes-d'Armor.

By highlighting the landscapes of the east and west coasts of the bay of Saint-Brieuc, through the proposal of a high added value route based on the GR 34 (Sentier des Douaniers), the tourism project aims for a global approach to territory by facilitating the practice of itinerant stays (GR furniture, gourmet stops, unusual nights) and by creating new viewpoints over the bay (artistic belvederes), suggesting to visitors a new angle of view on the territory and integrating places of mediations linked to the offshore wind farm (information panels).

The tourist project linked to the offshore wind project is based on the GR34 (Customs Trail) which runs along the bay of Saint-Brieuc on the east and west sides.

Schedule and Status

Measure under development

The tourism project program will be implemented from 2020 to 2024 after approval by all stakeholders.