1. Marine Ecology and Chemistry, Scottish Association for Marine Science, Oban, Argyll PA37 1QA, UK
2. School of Geography, Earth and Environmental Sciences, University of Plymouth, Plymouth PL4 8AA, UK
3. Norwegian Polar Institute, Fram Centre, N-9296 Tromsø, Norway
4. Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economics, UiT The Arctic University of Norway, N-9037 Tromsø, Norway