IAP-24-021

The impacts of electromagnetic fields from offshore cabling on lobster (Homarus gammarus) and crab (Cancer pagurus) behaviour

Berwick Bank Offshore Wind Farm is located in the outer Firth of Forth in Scotland and the developer is preparing to place up to four high voltage direct current (HVDC) offshore export cables (OEC) to be connected at Cambois, Blyth. Where possible the cable will be buried at least 0.5m below the seabed, but where this isn’t possible (i.e. on hard substrates) the cable will be placed on the benthos covered by cable protection measures (e.g. rock amour). Such HVDV cabling emits electromagnetic fields (EMF) with estimates suggesting 0.5m above the buried cable are 540.73µT is emitted, reducing to 52.49µT at 20m above the buried cable. The main inshore fishery along the Northumberland coast is for Homarus gammarus (European lobster) and Cancer pagurus (edible crab), and the cabling route overlaps with part of these important commercial fisheries grounds. To date, limited research has been carried out on the impacts of EMF emitted from cables on these commercially important species and whether the predicted EMF emitted can impact crustacea behaviour. While in-situ results are largely inconclusive on the impacts of EMF for marine invertebrates, there is some evidence from lab-experiments to indicate that EMF can alter behaviour and larval development, which in turn could affect the fishery.

Working in collaboration with the Northumberland Inshore Fisheries and Conservation Authority (IFCA) the aim of this PhD is to investigate the impacts of EMF on the abundance, behaviour and ecology of H. gammarus and C. pagurus and in turn to understand how any impacts of EMF may affect the fishery.

Using a Before, After, Control, Impact (BACI) design the student will explore the impacts of EMF on the abundance, behaviour and ecology of H. gammarus and C. pagurus. This will involve undertaking studies along the proposed cabling site before it is put in place, once it is in place and transmitting EMF as well as at three control locations unaffected by EMF. To investigate the impacts on abundance seasonal potting studies will be undertaken at our impacted and control sites. At the same time the student will deploy and acoustic array to track the small-scale behaviour of H. gammarus and C. pagurus. This will provide fine-scale detail on movement of tagged crustaceans at the control and impacted sites and will provide evidence for changes in behaviour including whether crustaceans are avoiding or being attracted to EMF. To complement this the student will also deploy baited remote underwater video (BRUVs) to collect information on crustacean behaviour. There will also be options for the student to develop the project, depending on the research interests of the successful candidate, to potentially include laboratory experiments, exploring any changes in diet as a function of EMF, scaling up the results using modelling approaches to determine the impact for Northumberland fisheries, etc.

Year 1

The first 6 months will be spent doing a desk study to collate information on the impacts of EMF on crustaceans and potentially other marine organisms. Depending on the quantity and quality of the published literature this may take the form of a quantitative review or meta-analysis. The second 6 months of the PhD will involve deployment of the acoustic array and BRUVs prior to the cabling being put in placed using a BACI design as outlined above. Over this time potting studies will also take place to determine the abundance of lobsters at our sites. Floy tags will be used to mark the lobsters to determine recapture rates.

Year 2

Year 2 will see the continuation of the acoustic tracking work and BRUV work to include when EMF is being emitted from the cabling. Over the winter months Year 1 tracking data and BRUV data will be written up as a publication on the movement and behaviour of lobsters along the Northumberland coast. In this year the student will also be able to develop their own ideas on areas that they may want to explore in more depth via lab, field or modelling studies.

Year 3

In year 3 the student will write up for publication a paper on the in-situ impacts of EMF on crustacean abundance and behaviour. In this year they will also continue to run field, lab or modelling experiments as outlined in year 2. At the middle-end of this year the focus will be on writing up the thesis and outstanding papers for publication.

Year 3.5

The final 6 months of the PhD will involve completing the thesis and preparing the remaining papers for publication

The student will receive training in the analysis of spatial data, statistical analysis, modelling, experimental design and field and laboratory techniques. In addition they will develop skills in project management, communication to a varied audience, team work and networking. They will receive training on the handling of crustaceans, boat work based research (including undertaking a Sea Survival Course), the deployment of acoustic telemetry equipment and the tagging of crustaceans.