[1] Univ Oslo, Dept Biol, Div Zool, N-0316 Oslo, Norway
[2] Flodevigen Marine Res Stn, Inst Marine Res, Dept Coastal Zone Studies, N-4817 His, Norway
[3] Inst Marine Res, N-5024 Bergen, Norway
[4] Natl Ctr Atmospher Res, Boulder, CO 80307 USA
[5] Univ Iowa, Dept Stat & Actuarial Sci, Iowa City, IA 52242 USA
[6] Pontificia Univ Catolica Chile, Ctr Adv Studies Ecol & Biodivers, Santiago 6513677, Chile