Phaeocystis antarctica blooms strongly influence bacterial community structures in the Amundsen Sea polynya
Delmont, Tom O.
Hammar, Katherine M.
Ducklow, Hugh W.
Yager, Patricia L.
Post, Anton F.
MetadataShow full item record
KeywordAmundsen Sea polynya; Phytoplankton bloom; Phaeocystis antarctica; Microbial community structure; Mutualism
Rising temperatures and changing winds drive the expansion of the highly productive polynyas (open water areas surrounded by sea ice) abutting the Antarctic continent. Phytoplankton blooms in polynyas are often dominated by the haptophyte Phaeocystis antarctica, and they generate the organic carbon that enters the resident microbial food web. Yet, little is known about how Phaeocystis blooms shape bacterial community structures and carbon fluxes in these systems. We identified the bacterial communities that accompanied a Phaeocystis bloom in the Amundsen Sea polynya during the austral summers of 2007–2008 and 2010–2011. These communities are distinct from those determined for the Antarctic Circumpolar Current (ACC) and off the Palmer Peninsula. Diversity patterns for most microbial taxa in the Amundsen Sea depended on location (e.g., waters abutting the pack ice near the shelf break and at the edge of the Dotson glacier) and depth, reflecting different niche adaptations within the confines of this isolated ecosystem. Inside the polynya, P. antarctica coexisted with the bacterial taxa Polaribacter sensu lato, a cryptic Oceanospirillum, SAR92 and Pelagibacter. These taxa were dominated by a single oligotype (genotypes partitioned by Shannon entropy analysis) and together contributed up to 73% of the bacterial community. Size fractionation of the bacterial community [<3 μm (free-living bacteria) vs. >3 μm (particle-associated bacteria)] identified several taxa (especially SAR92) that were preferentially associated with Phaeocystis colonies, indicative of a distinct role in Phaeocystis bloom ecology. In contrast, particle-associated bacteria at 250 m depth were enriched in Colwellia and members of the Cryomorphaceae suggesting that they play important roles in the decay of Phaeocystis blooms.
© The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Microbiology 5 (2014): 646, doi:10.3389/fmicb.2014.00646.
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Ice sheet record of recent sea-ice behavior and polynya variability in the Amundsen Sea, West Antarctica Criscitiello, Alison S.; Das, Sarah B.; Evans, Matthew J.; Frey, Karen E.; Conway, Howard; Joughin, Ian; Medley, Brooke; Steig, Eric J. (John Wiley & Sons, 2013-01-25)Our understanding of past sea-ice variability is limited by the short length of satellite and instrumental records. Proxy records can extend these observations but require further development and validation. We compare ...
Genome reconstructions indicate the partitioning of ecological functions inside a phytoplankton bloom in the Amundsen Sea, Antarctica Delmont, Tom O.; Eren, A. Murat; Vineis, Joseph H.; Post, Anton F. (Frontiers Media, 2015-10-26)Antarctica polynyas support intense phytoplankton blooms, impacting their environment by a substantial depletion of inorganic carbon and nutrients. These blooms are dominated by the colony-forming haptophyte Phaeocystis ...
Ciliate diversity, community structure, and novel taxa in lakes of the McMurdo Dry Valleys, Antarctica Xu, Yuan; Vick-Majors, Trista; Morgan-Kiss, Rachael; Priscu, John C.; Amaral-Zettler, Linda A. (Marine Biological Laboratory, 2014-10-01)We report an in-depth survey of next-generation DNA sequencing of ciliate diversity and community structure in two permanently ice-covered McMurdo Dry Valley lakes during the austral summer and autumn (November 2007 and ...