Differences in diversity and photoprotection capability between ice algae and under-ice phytoplankton in Saroma-Ko Lagoon, Japan: a comparative taxonomic diatom analysis with microscopy and DNA barcoding
journal contribution
posted on 2023-05-20, 18:37authored byKazuhiro Yoshida, Hattori, H, Toyota, T, Andrew McMinnAndrew McMinn, Suzuki, K
Sea ice algae, comprised mainly of diatoms, are the main primary producers in polar ecosystems, and they are generally distributed with the highest biomass at the bottom of ice. The taxonomy of ice algae has been traditionally investigated using light microscopy, but molecular techniques, including pigment analysis, have recently provided new insights into the diversity and physiology of ice algae. However, no comparative taxonomic survey has been conducted for ice algae thus far. Here, we investigated differences and similarities in (1) the diversity and (2) the photosynthetic strategies of diatom communities in sea ice and the underlying seawater of Saroma-Ko Lagoon, Hokkaido, Japan, using algal pigment signatures determined by ultra-high performance liquid chromatography, light and scanning electron microscopy and Ion Torrent next-generation sequencing techniques targeting the 18S rRNA gene (i.e., DNA barcoding). Ice algae typically possessed greater biomass (> 20-fold) and chlorophyll (Chl) a breakdown products than under-ice phytoplankton, suggesting that the ice algae formed blooms, and cell senescence and disruption could be significant mitigating factors. At the genus level, the diversity of diatoms in sea ice was higher than in under-ice seawater, although the evenness was comparable or lower in ice algae than in under-ice phytoplankton. Ice algae had a larger xanthophyll pool size and a higher ratio of photoprotective to photosynthetic pigments (11-fold and 4.5-fold higher, respectively) than under-ice phytoplankton. The results indicated that ice algae were well adapted to changes in the light regime, which could partly support their survival capability and high taxonomic diversity.
History
Publication title
Polar Biology
Volume
43
Pagination
1873-1885
ISSN
0722-4060
Department/School
Institute for Marine and Antarctic Studies
Publisher
Springer-Verlag
Place of publication
175 Fifth Ave, New York, USA, Ny, 10010
Rights statement
Copyright 2020 Springer-Verlag GmbH Germany, part of Springer Nature