Do electromagnetic fields from subsea power cables effect benthic elasmobranch behaviour? A risk- based approach for the Dutch Continental Shelf

Abstract

Overview

Subsea power cables emit electromagnetic fields (EMFs) into the marine environment, raising concerns about their potential impact on benthic elasmobranchs such as rays, skates, and sharks. These species are especially vulnerable due to their electromagnetic-receptive sensory systems, which are vital for orientation, navigation, and detecting prey or conspecifics. Intersections of cables with egg laying sites, mating, pupping, and nursery grounds, as well as important foraging and migration routes, increase the relevance of understanding EMF impacts.

Findings

• Behavioural responses to EMFs observed in elasmobranchs include attraction, disturbance, and indifference.
• Effects depend on EMF characteristics, exposed life stage, exposure level, and duration.
• The study estimated the levels of elasmobranch exposure to subsea cable EMFs using modelled magnetic fields from the Dutch Continental Shelf and compared these to known sensory sensitivity and experimental effect ranges from literature.

Conclusion

• Risks from subsea power cables for elasmobranchs are marked by substantial uncertainty and are influenced by species ecology and life stage.
• The estimated no-observed effect levels, ranging from 10^-3 to 10^-1 μT, help identify which species and life stages are likely most affected.
• Critical knowledge gaps remain, necessitating further research to reduce uncertainty in risk assessments related to EMF exposure effects on benthic elasmobranchs.