Spatiotemporal Variations in Antarctic Protistan Communities Highlight Phytoplankton Diversity and Seasonal Dominance by a Novel Cryptophyte Lineage

Abstract

The climate-sensitive waters of the West Antarctic Peninsula (WAP), including its many fjords, are hot spots of productivity that support multiple marine mammal species. Here, we profiled protistan molecular diversity in a WAP fjord known for high productivity and found distinct spatiotemporal patterns across protistan groups.

Bacterial, Phytoplankton, and Viral Distributions and Their Biogeochemical Contexts in Meromictic Lake Cadagno Offer Insights into the Proterozoic Ocean Microbial Loop

“…4A and B ). To better understand the relationship between the microbial guilds of Lake Cadagno, we sought phylogenetic evidence to support the origin of these putative chloroplast OTUs, as described in previous literature ( 40 , 41 ). The phylogeny of all Cyanobacteria -classified OTUs and their two nearest neighbors in SILVA ( 42 ) indicated that the chloroplast and Oxyphotobacteria OTUs clustered in clades with chloroplast 16S rRNA genes of cultured eukaryotic algae ( Fig.…”

Phytoplankton Surveys in the Arctic Fram Strait Demonstrate the Tiny Eukaryotic Alga Micromonas and Other Picoprasinophytes Contribute to Deep Sea Export

“…M. polaris was discovered in the Canadian Arctic [ 3 , 61 ] and, as mentioned above, was shown to increase in abundance in association with climate-induced changes to the ecosystem [ 10 ]. M. polaris is also present in the Antarctic Ocean, according to amplicon, metagenomic, and qPCR studies [ 6 , 26 ]. It has been hypothesized that the presence of M. polaris in both Arctic and Antarctic waters could be explained by a possible connection between poles via the thermohaline processes responsible for the global ocean conveyor belt, specifically North Atlantic Deep Water (NADW) [ 6 ].…”

“…Amplicons were generated using the 16S rRNA V1-V2 primers 27F_ill (5′-TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGagrgttygatymtggctcag-3) and 338R_ill (5′-GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGgcwgccwcccgtaggwgt-3′; capital letters represent Illumina linker sequences on the 27F/338R primer pair) as in [ 26 ] and purification was performed using a MinElute kit (Qiagen, Hilden, Germany). Amplicon products were sequenced using the Illumina Miseq platform.…”

“…This final processed PR2 database and resulting diatom reference tree contained a total of 832 sequences. Diatom amplicons from our study were then mapped onto the PR2 reference tree using EPA-ng, following the same procedures as in [ 26 ] to taxonomically identify amplicons.…”

Water masses shape pico-nano eukaryotic communities of the Weddell Sea

“…Although polar oceans belong to one of the most productive and rapidly changing ecosystems on Earth 13 , the Southern Ocean remains poorly represented in these large surveys of marine protists. With the exception of a single small-scale study that examined protists in several deep-ocean water masses 14 , most studies of protists in the Southern Ocean focused on the photic layer [15][16][17][18][19][20][21] . Given the unique conditions during the polar winter, it is reasonable to assume that the heterotrophic lifestyle is of particular importance in the polar environment.…”