Skip to Main content Skip to Navigation
New interface
Journal articles

SAR11 clade microdiversity and activity during the early spring blooms off Kerguelen Island, Southern Ocean

Abstract : The ecology of the SAR11 clade, the most abundant bacterial group in the ocean, has been intensively studied in temperate and tropical regions, but its distribution remains largely unexplored in the Southern Ocean. Through amplicon sequencing of the 16S rRNA gene, we assessed the contribution of the SAR11 clade to bacterial community composition in the naturally iron fertilized region off Kerguelen Island. We investigated the upper 300 m at seven sites located in early spring phytoplankton blooms and at one high-nutrient low-chlorophyll site. Despite pronounced vertical patterns of the bacterioplankton assemblages, the SAR11 clade had high relative abundances at all depths and sites, averaging 40% (±15%) of the total community relative abundance. Micro-autoradiography combined with CARD-FISH further revealed that the clade had an overall stable contribution (45%–60% in surface waters) to bacterial biomass production (determined by 3H-leucine incorporation) during different early bloom stages. The spatio-temporal partitioning of some of the SAR11 subclades suggests a niche specificity and periodic selection of different subclades in response to the fluctuating extreme conditions of the Southern Ocean. These observations improve our understanding of the ecology of the SAR11 clade and its implications in biogeochemical cycles in the rapidly changing Southern Ocean
Complete list of metadata
Contributor : Ingrid Obernosterer Connect in order to contact the contributor
Submitted on : Monday, October 31, 2022 - 6:36:03 PM
Last modification on : Friday, November 4, 2022 - 3:50:43 AM


Files produced by the author(s)



Julie Dinasquet, Marine Landa, Ingrid Obernosterer. SAR11 clade microdiversity and activity during the early spring blooms off Kerguelen Island, Southern Ocean. Environmental Microbiology Reports, In press, ⟨10.1111/1758-2229.13117⟩. ⟨hal-03835509⟩



Record views


Files downloads