Figure legends

Fig. 1. Abiotic variables: (a) pH, (b) water temperature, and (c) salinity, and biotic variables: (d) abundance, (e) Shannon’s diversity index, and (f) species richness.
Fig. 2. Hierarchical cluster analysis (UPGMA) of diatom communities based on (a) Bray–Curtis similarity, and (b) biogeographic zonation in the Yellow Sea (YS), South Sea (SS), and East Sea (ES) of Korea during winter.
Fig. 3. Heatmap graph on fourth root transformed abundance data for indicator species in the Yellow Sea (YS), South Sea (SS), Southern East Sea (SES), and Northern East Sea (NES) ecoregions. Colors for species denote the selected indicator species for each ecoregion: YS (yellow), SS (green), SES (orange), and NES (blue).
Fig. 4. Micrographs of representative indicator species for the four ecoregions identified in this study: (i) Actinoptychus senarius , (ii) Cyclotella littoralis , (iii) Melosira nummuloides , (iv) Paralia sulcata , (v) Thalassiosira eccentrica , (vi) Pleurosigma angulatum , (vii)Asterionellopsis glacialis , (viii–ix), Chaetoceros contortus , (x) C. curvisetus , (xi) C. debilis , (xii)C. constrictus , (xiii) Detonula pumila , (xiv)Skeletonema dohrnii-marinoii complex, (xv) Thalassiosira curviseriata , (xvi) T. nordenskioeldii , (xvii) Eucampia zodiacus , (xviii) Pseudo-nitzschia pungens , (xix–xx)Achnanthes spp., (xxi) Licmophora grandis , (xxii) L. paradoxa , (xxiii) Odontella aurita , (xxiv) Entomoneis alata , (xxv) Chaetoceros radicans , (xxvi) Corethron pennatum , (xxvii) Coscinodiscus centralis , (xxviii)Thalassiosira pacifica , (xxix) Porosira glacialis , (xxx)Licmophora ehrenbergii .
Table 1. Means and ranges of abiotic variables including pH, water temperature, salinity and biotic variables including number of diatoms species, abundance, Shannon’s diversity index (H), evenness (E), and species richness (R).