Monitoring harmful microalgal species and their appearance in Tokyo Bay, Japan, using metabarcoding

Sirje Sildever, Noriko Nishi, Nobuharu Inaba, Taiga Asakura, Jun Kikuchi, Yasuhito Asano, Takanori Kobayashi, Takashi Gojobori, Satoshi Nagai

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4 Scopus citations


During the recent decade, high-throughput sequencing (HTS) techniques, in particular, DNA metabarcoding, have facilitated increased detection of biodiversity, including harmful algal bloom (HAB) species. In this study, the presence of HAB species and their appearance patterns were investigated by employing molecular and light microscopy-based monitoring in Tokyo Bay, Japan. The potential co-appearance patterns between the HAB species, as well as with other eukaryotes and prokaryotes were investigated using correlation and association rule-based time-series analysis. In total, 40 unique HAB species were detected, including 12 toxin-producing HAB species previously not reported from the area. More than half of the HAB species were present throughout the sampling season (summer to autumn) and no structuring or succession patterns associated with the environmental conditions could be detected. Statistically significant (p < 0.05, rS ranging from −0.88 to 0.90) associations were found amongst the HAB species and other eukaryotic and prokaryotic species, including genera containing growth-limiting bacteria. However, significant correlations between species differed amongst the years, indicating that variability in environmental conditions between the years may have a stronger influence on the microalgal community structure and interspecies interactions than the variability during the sampling season. The association rule-based time-series analysis allowed the detection of a previously reported negative relationship between Synechococcus sp. and Skeletonema sp. in nature. Overall, the results support the applicability of metabarcoding and HTS-based microalgae monitoring, as it facilitates more precise species identification compared to light microscopy, as well as provides input for investigating potential interactions amongst different species/groups through simultaneous detection of multiple species/genera.
Original languageEnglish (US)
Pages (from-to)261-280
Number of pages20
JournalMetabarcoding and Metagenomics
StatePublished - Aug 23 2022

Bibliographical note

KAUST Repository Item: Exported on 2023-03-20
Acknowledgements: A. Kondo, R. Kubota, K. Kamiya and S. Ori are thanked for their help with the molecular work. This study was supported by grants from the “Technological developments for characterization of harmful plankton in the seawater”, Ministry of Agriculture, Forestry and Fisheries, Japan (16808839) [SN]; Japan Society for the Promotion of Science Short-term Postdoctoral Fellowship (PE18028) [SN, SS]. The writing of this manuscript was supported by the grant from the European Regional Development Fund and the programme Mobilitas Pluss (MOBTP160) and by the Estonian Research Council grant (PSG735) [SS].


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