Investigating the effect of electromagnetic fields on fish behaviour

As part of the UK Government’s targets to reduce carbon emissions they have committed to producing 20% of the UK’s energy requirements from renewable resources by 2020. Offshore wind power represents an immense renewable energy resource in the UK and, as such, is a rapidly expanding industry. Under UK and EU law, offshore wind farm developers are required to undertake environmental impact assessments. Submarine cabling of the type used to transport electricity produced by offshore wind turbines emits electromagnetic fields (EMFs) within the range of detection of electro-sensitive aquatic animals. The major electro-sensitive fish species in the UK are the elasmobranchs (sharks, skates and rays) which have a fundamental reliance on sensing the bioelectric fields (weak electric fields emitted by all organisms as a result of muscle activity such as respiratory movements and cardiac contractions) of their prey. They may also rely on bioelectric fields to find mates, detect predators, and possibly also to migrate and orientate to the Earth’s geomagnetic field. However, it is currently unknown whether these species will be affected by the large scale deployment of sub-sea cable networks.

A collaborative team comprising Cranfield University’s Natural Resources Department, The Centre for Environment, Fisheries and Aquaculture Science, The Centre for Marine and Coastal Studies Ltd and Liverpool University’s Centre for Intelligent Monitoring Systems are undertaking a novel, large scale field-based experiment to investigate the behavioural response of the bottom-dwelling thornback ray (Raja clavata) and the free-swimming spurdog (Squalus acanthias) to EMFs emitted by offshore wind farm sub-sea cables. Fish will be placed into large scale (40m diameter) submerged fish net pens (mesocosms) through which an electric cable will run. Fish behaviour in response to the switching on and off of the electric cable will be monitored using real-time 2-D acoustic tracking and archival depth records.

The remote waters of Loch Ceann Traigh, adjacent to Ardtoe Marine Laboratory, provide the ideal location for this research as it is necessary to eliminate human EMF influence in order to manipulate EMF presence and absence. The laboratories well-equipped office space overlooks the loch, providing line of sight with the study site and thus enabling the remote acoustic tracking of individual fish behaviour. In addition, the laboratories excellent fish holding facilities and husbandry expertise provide vital logistical support for the project.

This research will provide a definitive answer as to whether the elasmobranch species studied respond to the EMF emitted, thereby providing specific scientific guidance for environmental policy and legislation associated with offshore wind energy developments. The results will be the first of their kind in the world and will have wide application to other countries developing offshore wind power and other technologies.

This project is funded by COWRIE (Collaborative Offshore Wind Research into the Environment).

Contact: Dr Andrew Gill
Email: a.b.gill@cranfield.ac.uk