The experimental station SEM-REV (off Croisic) is situated in a zone where fields of Haploops (tube-dwelling amphipods) were listed. The sedimentary structures built by Haploops constitute a particular ecosystem which welcomes specific faunae and thus represent a potential source of biodiversity for the maritime part of the estuary of the Loire. Nevertheless, the interactions between Haploops and their environment are little known. The role of these fields of Haploops on flows (sedimentary and geochemical) as well as on the concentration of certain contaminants will be examined, by insisting on the analysis of foraminifera assemblages.
The main objective is to estimate the potential impact of the anchoring of the wind power structures and the electric cables buried on this specific habitat and to determine the adequate indicators to follow the evolution of the disturbances engendered on the seafloor by such structures.
Scientific advances and innovation
- Original pluridisciplinar approaches at different spatial scales.
- New geochemical tools (2D imagery of pore water chemistry) performed for the first time in Haploops fields.
- Determination of a biotic index based on benthic foraminifera for wind power farming problematics yet non-existent.
Expected technical and economic impact
- Physical chemical characterization of micro-habitats colonized by Haploops
- Foraminiferal ecology description
- Temporal dynamics of Haploops fields and subsequent impact on nutrient recycling
- Impact of anchorings and partially buried cabling from the experimental station SEM-REV on this ecosystem
- Development of indexes of ecological state based on studied indicators (i.e., foraminifera and Haploops)
Key project milestones
- November 2016 - Project kickoff
- January 2018 - Haploops field mapping follow up
- January 2019 - Ecological and geochemical description
- November 2020 - Scientific publications, index elaboration, PhD thesis defense
- Impact of embedded or buried structures from the SEM-REV station on the geographic coverage of Haploops fields.
- Comparison of foraminiferal ecology and sedimentary geochemistry between bare sediment, colonized sediment and impacted sediment.
Publications and papers published
- New evidence of perfect overlapping of Haploops and pockmarks field: Is it a coincidence?, Jean-Baptiste Champilou (Université d’Angers); Agnès Baltzer (Université de Nantes); Anne Murat (Unicaen / Cnam/Intechmer); Marine Reynaud (Centrale Nantes); Grégoire M.Maillet (Université d’Angers); Maria Pia Nardelli (Université d’Angers); Édouard Metzger (Université d’Angers), Marine Geology Volume 415, september 2019