Within the framework of the project “Sustaining Research Project, Marine Environmental Studies in the Arabian Gulf – Phase VI”, three coastal stations at Manifa, Khobar and Uqair were sampled monthly for size-fractionated chl a (micro-, nano- and picophytoplankton), as well as for total chl a, and for a range of physico-chemical variables. Sampling started in May 2016, this file includes the data from the first two years.

Supplement to: Heinle, Moritz; Flandez, Ace Vincent; Clardy, Todd Ryan; Prihartato, Perdana K; Hikmawan, Tyas I; Abdulkader, Khaled A; Qurban, Mohammad Ali (in prep.): Seasonal dynamics in the contribution of different phytoplankton size classes in Saudi waters of the western Arabian Gulf. Biogeosciences