1. College of Oceanic and Atmospheric Sciences, Oregon State University, 104 COAS Administration Building, Corvallis, Oregon 97331-5503 USA
2. Institute of Marine Research, Flødevigen, N-4817 His, Norway
3. Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, P.O. Box 1066, Blindern, N-0316 Oslo, Norway
4. Institute of Marine Research, Bergen, P.O. Box 1870 Nordnes, N5817 Bergen, Norway