Sampling design
To assess the potential impacts of chemical emissions, samples were taken in offshore wind farms (impacts), nearby offshore wind farms, and at reference locations. Impact samples were taken in different offshore wind farms, allowing us to assess different corrosion protection systems as well as different paints. Samples were taken at 150 and 300 m from the turbines from which half the samples were taken in an area where sedimentation was expected. For each offshore wind farm, nearby samples were taken following a gradient towards the offshore wind farm. Due to the high number of activities in the North Sea, different reference areas were selected: an area with low human activity, with high human activity and close to shipping tracks. In each reference area, at least three samples were taken.
Box Corer coming back aboard after sampling
Box corer sediment sampling
The sediment samples were taken with a box corer (see Figure). This device allows the sampling of sediment without disturbing the original layers. This is important, as in the Anemoi project, only the top sediment layer will be analysed. The top layer of the box corer will be used to measure organic and inorganic pollutants as well as microplastic particles.
Mercos water sampler after sampling.
Mercos water sampling
Seawater is sampled using a Mercos water sampler. The inlet tubes are closed prior to sampling to avoid seawater entering the sampling bottles. Once the water sampler reaches the desired depth of 10 m, a communicator weight is attached to the cable. This weight will open the inlet tubes when reaching the sampler allowing for the seawater to flow into the bottles. The sampling device (and cable) are completely made out of plastic, making it an ideal sampling device to measure potential metal leachates.
Filtration device
Water filtration sampling device
The water filtration system consists of three filters with a mesh size of 300, 100 and 10 µm that are connected in series. This device is used to collect and analyse potential paint flakes and microplastic fragments that are floating in the water column. At each sampling station, at least 2000 litres of seawater are filtered and the collected particles per filter are collected for analysis.
Future prospects
Samples collected during both campaigns are currently being analysed. Stay tuned and follow us on linked in to remain informed with the latest Anemoi news!