Hans Slagter, United States, Luis M. Laglera, University of the Balearic Islands, Departamento de Química, 07122 Palma, Spain, Martha Gledhill, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, Corina P.D. Brussaard, NIOZ Royal Netherlands Institute for Sea Research, MMB, Den Burg, Netherlands, Camila Sukekava, Federal University of Rio Grande. Av. Itália, km 8, Rio Grande, Rio grande do Sul, Brazil and Loes JA Gerringa, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, OCS, Den Burg, Netherlands