The diversity and biogeography of microeukaryotes in the euphotic zone of the northwestern Pacific Ocean

Metabarcoding Analysis of Harmful Algal Bloom Species in the Western Pacific Seamount Regions

“…Of the small portion of the ASVs that could be annotated, our analysis revealed that Dinoflagellata was the most dominant group of phytoplankton in the Western Pacific seamount regions (Figure 3). This result was not totally surprising because Dinoflagellata was also previously reported to be the most dominant phyla in the Western Pacific regions [16,47], which may be due to environmental factors (including temperature) in these regions [16,48]. However, the relatively high abundance of species in Dinoflagellata estimated by ASVs cannot be simply interpreted as high cell density of these species because the relative abundance of ASVs highly depends on the copy numbers of rDNA genes.…”

“…In recent years, the development of high-throughput sequencing methods has greatly enhanced our ability to assess the biodiversity of phytoplankton and identify their ecological significance in the ocean [15]. For example, a comprehensive study of the diversity of microeukaryotes in three different regions in the northwestern Pacific Ocean using high-throughput sequencing of the 18S rRNA gene unveiled a eukaryotic microbial community structure in different habitats [16].…”

Spatial variation of abundant picoeukaryotes in the subtropical Kuroshio Current in winter

“…This result agrees with our previous observation, in which we found that smaller dinoflagellates (cell size <10 µm) were usually dominant in the surface Kuroshio Current without external disturbances (e.g., typhoon) (Chung, Gong, & Hung, ). Using the metabarcording method, Wu et al () also found that dinoflagellates were dominant in the microplankton (cell size >1.6 µm) and widely distributed in the subtropical northwestern Pacific Ocean, which is affected by the Kuroshio Current, in spring. Moreover, the Marine Alveolata group‐I and ‐II (MALV‐I and MALV‐II) fully accounted for the other half of Alveolata.…”

“…Furthermore, while tiny phytoplankton are expected to predominate in this area as the surface of the Kuroshio is nutrient deficient, relative information is still lacking (Chen, Chen, Jan, & Tuo, ; Chung et al, ). Recent studies on the community assemblage of picoeukaryotes claimed to be conducted in the Kuroshio Current, but their sampling sites were actually located in the northwestern Pacific Ocean, close to the mainstream of the Kuroshio Current (Wang et al, ; Wu et al, ). In this paper, we describe the temporal changes in the abundance of photosynthetic picoeukaryotes in the subtropical Kuroshio Current.…”

Contrasting Community Assembly Mechanisms Underlie Similar Biogeographic Patterns of Surface Microbiota in the Tropical North Pacific Ocean

“…Studies of marine microbial biogeography have benefited greatly from the rapid progress that has been made in genomic sequencing and theoretical microbial ecology ( 11 ). Among the various spatial distribution patterns (e.g., latitudinal diversity patterns and taxa-area relationships), distance-decay patterns have frequently been reported based on studies of communities of bacteria and microeukaryotes in a variety of aquatic habitats, including rivers ( 12 , 13 ), lakes ( 9 , 14 ), intertidal zones ( 15 ), coastal ocean ( 8 , 16 ), and open ocean ( 16 , 17 ). However, there have been few studies of microbial biogeographic patterns in oligotrophic marine waters, especially at the trans-basin scale ( 17 ).…”