This is the dissertation-version of: Jung, A.S., Bijkerk, R., van der Veer, H.W. & Philippart, C.J.M. (2017). Spatial and temporal trends in order richness of marine phytoplankton as a tracer for the exchange zone between coastal and open waters. Journal of the Marine Biological Association of the United Kingdom, 97, 477-489 Published version: dx.doi.org/10.1017/S0025315416001326 Link NIOZ Repository: www.vliz.be/nl/imis?module=ref&refid=281992 [Article begins on next page] The NIOZ Repository gives free access to the digital collection of the work of the Royal Netherlands Institute for Sea Research. This archive is managed according to the principles of the Open Access Movement, and the Open Archive Initiative. Each publication should be cited to its original source - please use the reference as presented. When using parts of, or whole publications in your own work, permission from the author(s) or copyright holder(s) is always needed.