By understanding if and how the electromagnetic fields (EMFs) from offshore power cables needed to bring wind energy from sea to shore impact sharks and rays, we can (if needed) optimize the design to ensure the continuation of the energy transition using offshore sources without compromising the North Sea elasmobranch populations.
Aims and Objectives
This study aims to reveal the effects of EMF associated with existing and planned offshore wind power cables on elasmobranchs. The following five aspects will be studied:
- EMF field levels - Determine actual EMF levels emitted by cables associated with offshore wind including high-voltage alternate current and high-voltage direct current levels and the influence of different variables as burial depth, substrate, power output and currents.
- Dose-response levels - Determine the avoidance threshold and other behavioral changes in dose-response experiments to EMF levels typical of elasmobranch North Sea species.
- Field validation - Determine effects of EMFs on relative abundance, biomass and behavior of elasmobranchs in the field using Baited Remote Underwater Video Systems (BRUVs) at different EMFT types and levels in an OWF (Ofshore Wind Farms).
- Habitat use - Determine effects of EMFs on selection of artifical habitat, e.g. scour protection, for egg deposition by elasmobranchs applying field ROV video surveys in OWF.
- Impact assessment - Determine the impact ranges of EMFs of existing and future Dutch OWFs on elasmobranchs using developed models and (if required) advise on potential mitigation measures.
- Dissemination - Make the study results available for environmental impact assessment and appropriate decision making by end users.
This research will be conducted through a combination of laboratory and field work studies including BRUVs, ROVs and eDNA. The research will be conducted in six steps as detailed in the figure below.