Rainer Kiko¹, Peter Brandt², Svenja Christiansen³, Jannik Faustmann⁴, Iris Kriest², Elizandro Rodrigues⁵, Florian Schütte⁶ and Helena Hauss⁷, (1)GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany, (2)GEOMAR, Kiel, Germany, (3)University of Oslo, Oslo, Norway, (4)University of Kiel, Kiel, Germany, (5)Instituto Nacional de Desenvolvimento das Pescas, Mindelo, Cape Verde, (6)GEOMAR Helmholtz-Centre for Ocean Research Kiel, Chemical Oceanography, Kiel, Germany, (7)GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany