At the start of the United Nations’ Decade of Ocean Science for Sustainable Development (2021-2030), this working paper explores key epistemological and institutional trends in global and European ocean science. Noting differences in how both scholars from diverse disciplines and policy makers define the boundaries of and within ocean science and the FluidKnowledge project’s focus on diverse ocean science areas, we analyse two inclusive field delineations of ocean science, and we do so in three ways. First, we study key topics and their temporal and geographic variability using term co-occurrence networks. Second, we study changes in key journals using bar charts. Third, we study key institutions and their research foci using bar charts, co-authorship networks and term co-occurrence networks. We hope this report can facilitate ongoing discussions about the present and future of ocean science. To this end, we include links to online, interactive network visualisations readers can explore.