Niek Kusters, Royal Netherlands Institute for Sea Research, Ocean Systems, Den Burg, Netherlands, Mr. Sjoerd Groeskamp, PhD, Royal Netherlands Institute for Sea Research, Ocean Systems (OCS), Texel, Netherlands, Bieito Fernandez Castro, University of Southampton, School of Ocean and Earth Science, Southampton, United Kingdom and Hans van Haren, Royal Netherlands Institute for Sea Research, Den Burg, Netherlands