1 Department of Applied Sciences, Faculty of Health and Life Sciences, University of Northumbria at Newcastle, Newcastle-upon-Tyne, UK. david.pearce@northumbria.ac.uk.
2 British Antarctic Survey, Cambridge, UK. david.pearce@northumbria.ac.uk.
3 Department of Applied Sciences, Faculty of Health and Life Sciences, University of Northumbria at Newcastle, Newcastle-upon-Tyne, UK.