Benthos / water / sediment monitoring
Objectives and methodology
This multiple monitoring, comprising 3 distinct compartments, benthos/water/sediment is divided into 3 subparts :
A) Bio-evaluation of the benthic macrofauna and geochemical characterization of sediments.
This involves monitoring the epifauna and endofauna around 4 stations, representative of the diversity of habitats present on the study site. Two stations are located on soft substrates, two on substrates considered hard. Each of these stations is composed of 4 substations, positioned along a potential incidence gradient in the major axis of the current.
Soft substrates: Sampling using i) a standard bucket (0.1m²; 5 replicates) and ii) a towed video system allowing transects to be carried out. An average sediment sample will be collected for geochemical analysis in the laboratory.
Hard substrates: Realization of a 10' fixed point video sequence.
B) Water quality and water body monitoring.
Seawater sampling at 1 station located in a central position within the wind farm's perimeter.
Sampling using a Niskin trigger bottle. The sample is taken at a single average depth.
C) Monitoring the impact of sacrificial anodes.
Task 1: Quantification of anode corrosion products in the environment (seawater, sediments).
This "task" (fieldwork/dosing) is fully integrated into the protocol for monitoring the quality of water, water bodies and sediments.
Task 2: Assessment of the health and environmental risk induced via potential bioaccumulation mechanisms of aluminium and zinc.
The species monitored as part of this monitoring are the scallop (Pecten maximus), filter-feeding bivalve, whelk (Buccinum undatum), scavenging gastropod and the common pout (Trisopterus luscus), predatory fish. The sampling effort for these species is the result of experimental fishing carried out during the monitoring of the fishery resource.
Location of actions
Planning and Status
Measure put in place
Every year in September between 2020 and 2023 (only for monitoring benthic biocenoses), the first 3 years of operation (2024 to 2026) and then every 5 years.