Background
Offshore wind power immersed structures are analogous to artificial reefs that promote the installation of fixed fauna and flora in an environment where they were initially absent. Most jellyfish have a fixed developmental phase (polyp) which set up on rocky or reefs habitats; pelagic jellyfish phase develops from this fixed phase. Essentially large jellyfish are present in the Bay of Biscay. They can significantly impact fisheries by predation on juveniles and fish larvae, competition for the planktonic resource, and disturbance of fishing when they outbreak: e.g. net clogging and rupture. The set up of windpower farms offshore Loire Atlantique coasts may therefore impact the local fishing activity by potentially promoting the development of jellyfishes. Monitoring the impact of Loire Atlantique offshore windpower farms on jellyfish and fish population is therefore necessary to anticipate the potential change of services provided by the ecosystem, and its impact on human activities, in the vicinity of the farm.
Scientific advances and innovation
- Innovative coupling between imaging (ImageSonde) and acoustics (Ec(h)osonde) for the monitoring of RME installations impacts on micronekton and jellyfishes
- Data collection to study the interaction between RME and fisheries
- Development and use of efficient machine learning tools and methods to automatize the analysis of imaging data.
Expected technical and economic impact
- Development of an integrated methods for the monitoring of RME impacts on micronektonic and gelatinous organisms (fish larvae and jellyfishes) by coupling acoustics (Ec(h)osonde) and imaging (ImageSonde).
- Proof of concept for a technically robust, scientifically efficient and economically competitive monitoring method thanks to the partial automation of acquisition and treatment of data.
Key project milestones
- October 2017 - Start – Ec(h)osonde survey
- May & June 2018 - PELGAS & PHENIX surveys
- October 2018 - Ec(h)osonde survey
- Autumn 2018 - First results
- Winter 2018-2019 - First communications
- Autumn 2019 - Presentation of deliverables
Prospects
The coupling of benchtop imaging and in-situ acoustics in the context of a wired sea bottom observatory development opens the way to a fully integrated sea bottom observatory coupling in-situ imaging, in-situ acoustics and real-time big data fluxes management.
Imaging for analyzing gelatinous plankton and micronekton is already a well-established technique in the academic research community. ImageSonde will be a good demonstrator to validate the transfer of imaging to ecological monitoring in the RME industrial framework.

© Ecotaxa – Picheral M, Colin S, Irisson J-O (2017). EcoTaxa, a tool for the taxonomic classification of images. http://ecotaxa.obs-vlfr.fr.