[1] Pontificia Univ Catolica Chile, Ctr Adv Studies Ecol & Biodivers, Santiago 6513677, Chile
[2] Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA
[3] Univ Oslo, Dept Biol, CEES, N-0316 Oslo, Norway
[4] Inst Marine Res, Flodevigen Marine Res Stn, N-4817 His, Norway