1. Centre for Ecological and Evolutionary Synthesis, Department of Biology, University of Oslo, PO Box 1050 Blindern, N–0316 Oslo, Norway
2. Department of Coastal Zone Studies, Flødevigen Marine Reaseach Station, Institute of Marine Reseach, N–4817 His, Norway
3. Institute of Marine Research, PO Box 1870 Nordnes, N-5024 Bergen, Norway
4. National Centre for Atmospheric Research, Boulder, CO 80307, USA
5. Center for Advanced Studies in Ecology and Biodiversity, Pontificia Universidad Católica de Chile, PO Box 114-D, Santiago CP 6513677, Chile
6. Department of Statistics and Actuarial Science, University of Iowa, Iowa City, IA 52242, USA
7. Division of Arctic Ecology, Norwegian Institute for Nature Research (NINA), Polar Environmental Centre, N-9296 Tromsø, Norway