Sebastiaan Swart¹, Marcel du Plessis², Louise C Biddle³, Sarah-Anne Nicholson⁴, Andrew F Thompson⁵, Martin Morhmann⁶, Isabelle S Giddy⁷ and Torsten Linders⁶, (1)University of Gothenburg, Department of Marine Sciences, Gothenburg, Sweden, (2)University of Cape Town, Department of Oceanography, Cape Town, South Africa, (3)University of Gothenburg, Department of Marine Science, Gothenburg, Sweden, (4)Council for Scientific and Industrial Research, Cape Town, South Africa, (5)California Institute of Technology, Physical Oceanography, Pasadena, CA, United States, (6)University of Gothenburg, Marine Sciences, Gothenburg, Sweden, (7)University of Cape Town, Cape Town, South Africa