Source: Remy Dubas (ECOCEAN)
Introduction
Until very recently, the main energy sources used were responsible for 40% of the world's carbon emissions. In order to combat climate change by limiting our emissions, the replacement of fossil fuels with renewable energies is an essential lever today. To encourage this, in 2008 the European Commission, Parliament and Council set a target of at least 30% renewable energy in total European energy consumption by 2030 (declaration/18/4155). For nations with coastal and oceanic territories, the development and exploitation of marine renewable energies represents an attractive potential contribution to achieving this objective.
Faced with the challenges of climate change and energy security, the construction of offshore wind farms is booming. However, the construction of these wind farms will involve interactions with the marine ecosystem. It is therefore necessary to better understand the effects of these installations on coastal marine ecosystems.
Coastal marine areas play a crucial role for fish and invertebrates, providing feeding, breeding, refuge and nursery areas. These varied and productive habitats are essential for marine biodiversity and coastal ecosystems. However, the further we move away from the coast, the less we know about the functioning of marine ecosystems and their connectivity with coastal habitats.
ECOCEAN, in partnership with the Centre de Recherche sur les Ecosystèmes Marins (CREM - UPVD/CNRS) and EFGL, proposed this ambitious CONNEXSTERE pilot project to enhance our understanding of the connection processes between juvenile and adult populations between the open sea and the coast, as well as the potential habitat functions of offshore, nature includive designed infrastructures and the possible valorization of the produced ressources by fisheries or aquaculture. The project was located on the future location of the first floating windmills in the Gulf of the Lion, near Port Leucate in France. The connexion was studied between the BoB offshore buoy located in the future offshore wind park, intermediate artificial reefs and the shoreline.
Fundings: the project received fundings from EFGL, France Energies Marines and Agence de l'Eau Rhône Méditerranée Corse.
Offshore wind energies are often seen as a constraint from the point of view of professional fisheries. In that part of the Mediterranean, small scale fisheries is well developed and the fishermen have been involved from the beginning in the project. They have been involved in the discussions from the beginning, and in the project as service provider (boats, support).
The important accumulation of organisms like sea urchins (Paracentrotus lividus) suggest a possible use of this biomass as a commercial resource for fishermen.
The ecological monitoring (acoustic, UVC, eDNA, invertebrates, camera traps) has been done by different stakeholders during 4 years (CREM, Chorus, Ecocean, FEM, Spygen).
Different authorizations have been mandatory for the project, especially to install a 9m high offshore scientific buoy in order to monitor the colonization of organisms on the nature inclusive designs that equip the buoy.
This authorization to occupy the territory, from the French State has been extanded and lasted from 2019 to 2023.
Lessons learnt
- Possibility to involve small scale fishermen in offshore wind projects from the beginning.
- Offshore artificial floating structures are colonized by coastal species, that take profit of nature inclusive designs.
- Some species develop in important numbers and can be commercially exploited without impacting natural ecosystems or populations.
- Offshore technical test of 4 years for the buoy and the NID structures, in very rough conditions (+10m waves).
Relevant links
Connexstere project page (in French)
Contacts
Etienne Abadie : etienne.abadie [at] ecocean.fr (etienne[dot]abadie[at]ecocean[dot]fr) ; gilles.lecaillon [at] ecocean.fr (gilles[dot]lecaillon[at]ecocean[dot]fr)