Significant Pico- and Nanoplankton Contributions to Biogenic Silica Standing Stocks and Production Rates in the Oligotrophic Eastern Indian Ocean


The present study involves the first measurements of size-fractionated biogenic silica (bSi) standing stocks and production rates in the oligotrophic Eastern Indian Ocean. The 150-m integrated bSi standing stocks in the pico- and nanosized fractions averaged 49% and 39%, respectively, of the total; the contributions of pico- and nanoplankton to total bSi production rates were 43% and 38%, respectively, together suggesting that these smaller plankton contributed a significant proportion of both the total bSi standing stock and its rate of production. The total bSi variability appeared to be driven by smaller-plankton dynamics. Also, our results suggest that the detrital bSi stocks were potentially sustained by the pico- and nanosized siliceous organisms (for example, Minidiscus and Synechococcus) instead of broken fragments of large diatoms or other siliceous microplankton. In particular, the atomically dense structure from Synechococcus cell lysis was enriched in Si element compared with intact cells. The factors controlling size-fractionated bSi standing stocks may be biological rather than physical processes, and the clear correlation between picoeukaryotes and the < 2 μm bSi further confirmed the possibility of Si accumulation by other smaller plankton.

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Data Availability

Data and computer codes for analyses are available in GitHub repository:


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This research was financially supported by the National Natural Science Foundation of China (41876134, 41676112 and 41276124), the Tianjin 131 Innovation Team Program (20180314) and the Changjiang Scholar Program of Chinese Ministry of Education (T2014253) to Jun Sun. We would like to show our gratitude to Prof. Ju Chen and Yunkai He (South China Sea Institute of Oceanology Chinese Academy of Sciences, Guangzhou, China) for sharing their temperature and salinity data; we would also like to thank the Open Cruise Project in the Eastern Indian Ocean of National Natural Science Foundation of China (NORC2019-10) for sharing their ship time in 2019. We also acknowledged the Captain and Crews of R/V Shiyan3 for their nice cooperation in the cruises.

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Wei, Y., Wang, X., Gui, J. et al. Significant Pico- and Nanoplankton Contributions to Biogenic Silica Standing Stocks and Production Rates in the Oligotrophic Eastern Indian Ocean. Ecosystems (2021).

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  • Picoplankton
  • Nanoplankton
  • Biogenic silica
  • Diatom
  • Synechococcus
  • Prochlorococcus
  • Eastern indian ocean