Monitoring the effect of windmills on the marine benthos of soft substrates (OFFSHOREWIND)

How do offshore wind farms affect the fauna living on the sandy seafloor? Within this project, we investigate medium to long term effects of the construction and exploitation of offshore wind farms on the soft substrate epifauna and demersal fish. Additionally, we examine the effects of windmill farms on the trawling fishery (and alternative techniques), and the attraction effects of hard substrates on exotic (invasive) species.

For every wind farm concession in the Belgian part of the North Sea, a baseline situation prior to construction is established. During and after construction (since 2008 for the Thorntonbank, 2009 for the Bligh Bank, 2013 for the Lodewijkbank), semestral surveys are organised to monitor changes in diversity, density, biomass and length-frequency for the epibenthos and demersal fish fauna. The sampling design is based on a comparison of impact and reference areas, before and after the wind mill construction activities. The effects on and of fishery activities are monitored using VMS (Vessel Monitoring System) data and logbook data of vessels active in the vicinity of the wind farms.

The construction of an increasing number of wind farms is expected to result in three major changes for the fishery. First is the loss of fishing ground, because trawling is prohibited inside the farms. Second is the impact on the food web as the habitat changes from sandy to hard substrates, which promotes the growth and prevalence of mussels, sea bass and lobster. Third comes the opportunity to use alternative fishing techniques such as angling or aquaculture at sea. This creates a need for continual research regarding the base of the local food chain (i.e. the epibenthos and juvenile demersal fish). Also, we need to stay alert for ecological pitfalls, since an increased attraction of organisms may lead to an increased fishing pressure around the wind farms, which can be detrimental to both the resident organisms and the fishery itself.

Funding provider(s)
KBIN - Koninklijk Belgisch Instituut voor Natuurwetenschappen