University Of Tasmania
152969 - Biogeography of Southern Ocean prokaryotes.pdf (3.39 MB)

Biogeography of Southern Ocean prokaryotes: a comparison of the Indian and Pacific sectors

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journal contribution
posted on 2023-05-21, 13:11 authored by Sow, SLS, Brown, MV, Laurence ClarkeLaurence Clarke, Bissett, A, van de Kamp, J, Trull, TW, Raes, EJ, Seymour, JR, Bramucci, AR, Ostrowski, M, Philip BoydPhilip Boyd, Deagle, BE, Pardo, PC, Sloyan, BM, Bodrossy, L

We investigated the Southern Ocean (SO) prokaryote community structure via zero-radius operational taxonomic unit (zOTU) libraries generated from 16S rRNA gene sequencing of 223 full water column profiles. Samples reveal the prokaryote diversity trend between discrete water masses across multiple depths and latitudes in Indian (71-99 degree E, summer) and Pacific (170-174 degree W, autumn-winter) sectors of the SO. At higher taxonomic levels (phylum-family) we observed water masses to harbour distinct communities across both sectors, but observed sectorial variations at lower taxonomic levels (genus-zOTU) and relative abundance shifts for key taxa such as Flavobacteria, SAR324/Marinimicrobia, Nitrosopumilus and Nitrosopelagicus at both epi- and bathy-abyssopelagic water masses. Common surface bacteria were abundant in several deep-water masses and vice-versa suggesting connectivity between surface and deep-water microbial assemblages. Bacteria from same-sector Antarctic Bottom Water samples showed patchy, high beta-diversity which did not correlate well with measured environmental parameters or geographical distance. Unconventional depth distribution patterns were observed for key archaeal groups: Crenarchaeota was found across all depths in the water column and persistent high relative abundances of common epipelagic archaeon Nitrosopelagicus was observed in deep-water masses. Our findings reveal substantial regional variability of SO prokaryote assemblages that we argue should be considered in wide-scale SO ecosystem microbial modelling.


Publication title

Environmental Microbiology










Institute for Marine and Antarctic Studies


Blackwell Publishing Ltd

Place of publication

9600 Garsington Rd, Oxford, England, Oxon, Ox4 2Dg

Rights statement

© 2022 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License, ( which permits use, distribution and reproduction in any medium, provided the original work is properly sited.

Repository Status

  • Open

Socio-economic Objectives

Biodiversity in Antarctic and Southern Ocean environments; Protection and conservation of Antarctic and Southern Ocean environments; Marine biodiversity