1. Department of Natural Sciences, Centre for Coastal Research, University of Agder, Kristiansand, Norway
2. Austevoll Research Station, Institute of Marine Research, Storebø, Norway
3. Department of Biosciences, Centre for Ecological and Evolutionary Syntheses (CEES), University of Oslo, Blindern, Oslo, Norway
4. Institute of Marine Research, Flødevigen, His, Norway