1. NIOZ—Royal Netherlands Institute for Sea Research, PO Box 59, 1790 Den Burg Texel, The Netherlands
2. CIMAR/CIIMAR—Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas 289, 4050-123 Porto, Portugal
3. Department of Biology, University of Crete, PO Box 2208, 71409 Heraklion, Greece
4. Institute of Hydrobiology and Fisheries Science, University of Hamburg, Olbersweg 24, 22767 Hamburg, Germany
5. Department of Theoretical Biology, Vrije Universitei, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands