The southern North Sea is a relatively shallow shelf sea, heavily utilised by human activities. All surrounding countries are developing offshore wind farms and all countries have plans for significant upscaling in the coming decades. The introduction of thousands of turbines in the system may influence local hydrodynamics, stratification patterns, SPM-dynamics and therefore also fundamental ecological processes, such as primary production – the basis of the marine food web.  Our aim is to assess which areas of the North Sea may be susceptible to fundamental changes in ecosystem functioning. With a suite of coupled state-of-the-art models, we have run scenarios without any wind farms, and scenarios with different levels of upscaling.   Scenarios with significant upscaling of offshore wind indicate that there are large areas in the North Sea, where potentially significant effects may occur on the physical functioning of the system, which in turn may affect the North Sea ecosystem. Ecosystem effects differed in different areas of the North Sea, some areas are likely to see an increase in primary production, others a reduction. Changes can also be expected in the timing of the spring bloom.   Within this project we are trying to understand the bottom up effects of offshore wind farms on the North Sea food web and the potential knock-on effects on higher trophic levels. This presentation shows the first steps to understand effects that are perhaps not so visible and obvious, but potentially far-reaching.

Primary Presenter: Lauriane Vilmin, Deltares (lauriane.vilmin@deltares.nl)

Authors:

Lauriane Vilmin, Deltares  ()

Luca van Duren, Deltares  ()

Firmijn Zijl, Deltares  ()

Stendert Laan, Deltares  ()

Thijs van Kessel, Deltares  ()

Vincent van Zelst, Deltares  ()

Luka Jaksic, Deltares  ()

Erik Hendriks, Deltares  ()

Lisa Schneider, Deltares  ()

Jelle Rienstra, Deltares  ()

Jaap van der Meer, Wageningen Marine Research  ()

Tony Minns, Deltares, RHDHV  ()

Peter Herman, Deltares  ()