Assessing the effects of electromagnetic fields generated by submarine power cables on the soft-bottom community: An...

This study represents the first in situ investigation into the effects of magnetic fields (MFs) on soft-bottom macrofauna communities, laying the groundwork for further studies to better understand their potential consequences on marine ecosystems. Conducted in the Natural Park of the Strait (Southern Iberian Peninsula), the study measured MFs generated by HVAC cables and assessed their impact on soft-bottom macrofauna communities by comparing areas exposed to MFs with two control areas at different depths. Measured MF intensities were relatively low, with a maximum deviation from background levels of 34 nT near the cable, decreasing to 1 nT at 250 m distance. These intensities are considerably lower than those typically used in laboratory experiments inducing physiological effects (0.1-30 mT). Results revealed an increasing pattern of species richness (S) with depth, associated with sediment stability and different sediment characteristics. While analyses did not show significant effects of the magnetic field on macrobenthic communities overall, some indications were observed, such as decreased species richness at the deepest station and community homogenization across depths in the cable area compared to control zones. However, the varying patterns observed across different sites and depths necessitate further investigation, particularly considering the differences in MF intensities between field settings and controlled laboratory environments.