Magnetic fields produced by subsea high-voltage direct current cables reduce swimming activity of haddock larvae

Abstract

Overview

High-voltage direct current (HVDC) subsea cables are integral for power transportation between different locations, including offshore facilities. These cables generate magnetic fields (B-fields) that could pose risks to marine life, particularly to species such as the Atlantic haddock (Melanogrammus aeglefinus).

Findings

• The study focused on the larvae of the Atlantic haddock, a demersal fish that uses Earth's magnetic field for orientation and is susceptible to disturbances from anthropogenic magnetic fields.
• Experimental exposure involved 92 haddock larvae in a tank simulating conditions near HVDC cables, with B-field intensities between 50 to 150 µT.
• Although the spatial distribution of the larvae was unchanged, there was a significant reduction in swimming speed (60% decrease) and acceleration (38% decrease) among the majority of nonexploratory larvae, highlighting a potential impairment in their natural behavior.

Conclusion

The research suggests that HVDC cable emissions could selectively impair the swimming performance of nonexploratory haddock larvae, proposing serious concerns regarding their survival and development in natural habitats. The impact on nonexploratory individuals suggests potential broader population effects that necessitate further investigation and consideration in environmental management and cable design.