Mesoscale distribution and functional diversity of picoeukaryotes in the first-year sea ice of the Canadian Arctic

Piwosz, Kasia; Wiktor, Józef; Niemi, Andrea; Tatarek, Agnieszka; Michel, Christine

doi:10.1038/ismej.2013.39

Cited by 54 publications

(62 citation statements)

References 51 publications

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“…In the Chukchi Sea samples, where size fractions were analyzed separately, the smaller size fraction was enriched in Picozoa and MAST (about 20-fold enrichment in the Chukchi Sea data), consistent with cell diameters given for HF taxa in the literature (16,20,25,65). For all samples, Picozoa and MAST were geographically less distinct in the Arctic than Cryomonadida and Telonemia, which are generally larger and in the nanoplankton size range (2 to 20 m) (15,66).…”

Section: Discussionsupporting

confidence: 81%

Biogeography of Heterotrophic Flagellate Populations Indicates the Presence of Generalist and Specialist Taxa in the Arctic Ocean

Thaler

Lovejoy

2015

Appl Environ Microbiol

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Heterotrophic marine flagellates (HF) are ubiquitous in the world's oceans and represented in nearly all branches of the domain Eukaryota. However, the factors determining distributions of major taxonomic groups are poorly known. The Arctic Ocean is a good model environment for examining the distribution of functionally similar but phylogenetically diverse HF because the physical oceanography and annual ice cycles result in distinct environments that could select for microbial communities or favor specific taxa. We reanalyzed new and previously published high-throughput sequencing data from multiple studies in the Arctic Ocean to identify broad patterns in the distribution of individual taxa. HF accounted for fewer than 2% to over one-half of the reads from the water column and for up to 60% of reads from ice, which was dominated by Cryothecomonas. In the water column, many HF phylotypes belonging to Telonemia and Picozoa, uncultured marine stramenopiles (MAST), and choanoflagellates were geographically widely distributed. However, for two groups in particular, Telonemia and Cryothecomonas, some species level taxa showed more restricted distributions. For example, several phylotypes of Telonemia favored open waters with lower nutrients such as the Canada Basin and offshore of the Mackenzie Shelf. In summary, we found that while some Arctic HF were successful over a range of conditions, others could be specialists that occur under particular conditions. We conclude that tracking species level diversity in HF not only is feasible but also provides a potential tool for understanding the responses of marine microbial ecosystems to rapidly changing ice regimes. Heterotrophic flagellates (HF) have a central role in marine food webs, particularly in the Arctic, where they can control phytoplankton biomass (1). Modeling studies indicate that they likely consume the majority of bacterial biomass in this region (2). In other marine environments, they have been found to be more important than viral lysis (3) or ciliate grazers (4) for controlling bacterial concentrations. HF range from pico-to nanosized cells (0.8 to 20 m) and are phylogenetically diverse, with representatives in most branches of the Eukaryota tree. Because taxon-specific differences in feeding behavior, population dynamics, and life histories may be important over broad ecosystem scales (5), the identification and quantification of the diverse groups can add substantially to our understanding of marine ecosystem function. However, HF taxa often have few diagnostic morphological features that enable easy identification (6) and microscopy-based studies rarely differentiate between HF taxonomic groups. Molecular approaches, such as cloning and amplicon sequencing, have provided additional information on the deep phylogenetic diversity of HF, especially in the Arctic (7). More recently, highthroughput multiplex tag sequencing of hypervariable regions of the 18S rRNA gene has become commonplace (8, 9). This is considered a semiquantitative method for retrievin...

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Section: Discussionsupporting

confidence: 81%

Biogeography of Heterotrophic Flagellate Populations Indicates the Presence of Generalist and Specialist Taxa in the Arctic Ocean

Thaler

Lovejoy

2015

Appl Environ Microbiol

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“…The progress made in molecular techniques has introduced new information on species abundance in sea ice (e.g., Bachy et al, 2011;Piwosz et al, 2013;Torstensson et al, 2015;Hardge et al, 2017). These new approaches are a major strength in studying smaller eukaryotic groups.…”

Section: Microalgal Community Structurementioning

confidence: 99%

Microalgal community structure and primary production in Arctic and Antarctic sea ice: A synthesis

Leeuwe

Tedesco

Arrigo

et al. 2018

Elementa: Science of the Anthropocene

137

133

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van Leeuwe, MA, et al. 2018 Microalgal community structure and primary production in Arctic and Antarctic sea ice: A synthesis. Elem Sci Anth, 6: 4. DOI: https://doi.org/10.1525/elementa.267 IntroductionSea ice is one of the largest biomes on earth. The area covered by Arctic (15.6 × 10 6 km 2 ) and Antarctic (18.8 × 10 6 km 2 ) sea ice is roughly 4 and 5% of the global ocean surface (361.9 × 10 6 km 2 ) at their respective maximum extents (Meier, 2017;Stammerjohn and Maksym, 2017). Sea ice is a very diverse and potentially very productive habitat, with primary production estimated to amount to 2-24% of total production in sea-ice covered marine areas (Arrigo, 2017). Sea ice is especially productive in spring and summer when, locally, carbon biomass can be ten times higher in the bottom ice than in the seawater, with values greater than 3 mg chlorophyll a) in bottom layers (e.g., Corneau et al., 2013). On some occasions, ice algae may contribute up to 50-60% of total primary production McMinn et al., 2010; Fernandez-Mendez et al., 2015). Sympagic (ice-associated) microalgae (see Horner et al., 1992, for terminology) are REVIEWMicroalgal community structure and primary production in Arctic and Antarctic sea ice: A synthesis Sea ice is one the largest biomes on earth, yet it is poorly described by biogeochemical and climate models. In this paper, published and unpublished data on sympagic (ice-associated) algal biodiversity and productivity have been compiled from more than 300 sea-ice cores and organized into a systematic framework. Significant patterns in microalgal community structure emerged from this framework. Autotrophic flagellates characterize surface communities, interior communities consist of mixed microalgal populations and pennate diatoms dominate bottom communities. There is overlap between landfast and pack-ice communities, which supports the hypothesis that sympagic microalgae originate from the pelagic environment. Distribution in the Arctic is sometimes quite different compared to the Antarctic. This difference may be related to the time of sampling or lack of dedicated studies. Seasonality has a significant impact on species distribution, with a potentially greater role for flagellates and centric diatoms in early spring. The role of sea-ice algae in seeding pelagic blooms remains uncertain. Photosynthesis in sea ice is mainly controlled by environmental factors on a small scale and therefore cannot be linked to specific ice types. Overall, sea-ice communities show a high capacity for photoacclimation but low maximum productivity compared to pelagic phytoplankton. Low carbon assimilation rates probably result from adaptation to extreme conditions of reduced light and temperature in winter. We hypothesize that in the near future, bottom communities will develop earlier in the season and develop more biomass over a shorter period of time as light penetration increases due to the thinning of sea ice. The Arctic is already witnessing changes. The shift forward in time of the algal bloom can resu...

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“…Many of the dominant taxa in Milne Fiord epishelf lake have previously been reported from Arctic water columns, and some are known to be ice-associated, such as the eukaryotes Teleaulax (Piwosz et al, 2013) and Protaspis (Werner et al, 2007), the bacterium Polaromonas (Irgens et al, 1996), and the archaeon Halobacteriales (Collins et al, 2010). Teleaulax gracilis has only been described recently, with accompanying revision of the genus (Laza-Martínez et al, 2012), and therefore there are no historic records for this species.…”

Section: Microbial Community Compositionmentioning

confidence: 99%

Microbial Community Structure and Interannual Change in the Last Epishelf Lake Ecosystem in the North Polar Region

et al. 2017

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Climate warming is proceeding rapidly in the polar regions, posing a threat to ice-dependent ecosystems. Among the most vulnerable are microbial-dominated epishelf lakes, in which surface ice-damming of an embayment causes a freshwater layer to overlie the sea, creating an interface between distinct habitats. We characterized the physicochemical and biotic environment of Milne Fiord epishelf lake (82 • N, Canada) in three successive summers (2010)(2011)(2012), and on one date of profiling (5 July 2011) we collected samples for high through-put amplicon sequencing of variable regions of small subunit rRNA to characterize the microbial community (Eukarya, Bacteria and Archaea). Potentially active water column communities were investigated using reverse-transcribed rRNA, and phytoplankton were further characterized by accessory pigment analysis. Cluster analysis of pigment data showed a demarcation between freshwater and marine communities, which was also evident in the sequence data. The halocline community of Eukarya was more similar to the deeper marine sample than to the freshwater surface community, while the Archaea and Bacteria communities at this interface clustered more with surface communities. In 2012, conductivity-depth profiles indicated shallowing of the freshwater layer and mixing across the halocline, accompanied by lower picocyanobacteria and higher picoeukaryote concentrations. Picocyanobacteria cells were more evenly distributed throughout the water column in 2012, implying partial deep mixing. Several mixotrophic taxa of Eukarya were more abundant in the freshwater layer, where low nutrient concentrations may favor this lifestyle. Unusual features of Milne Fiord microbial communities included benthic taxa not previously reported in marine water columns (notably, the archaeon Halobacteriales), and dominance by taxa that are typically present in sparse concentrations elsewhere: for example, the Chlorophyte group Radicarteria and the betaproteobacterium Rhodoferax.Thaler et al. Microbial Communities in an Ice-Dammed Arctic LakeMilne Fiord epishelf lake is the last known lake of this kind remaining in the Arctic, and the fate of this distinct microbial ecosystem may ultimately depend on the stability of the Milne Fiord ice shelf, which has experienced a negative mass balance over the past half century.

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Mesoscale distribution and functional diversity of picoeukaryotes in the first-year sea ice of the Canadian Arctic

Cited by 54 publications

References 51 publications

Biogeography of Heterotrophic Flagellate Populations Indicates the Presence of Generalist and Specialist Taxa in the Arctic Ocean

Biogeography of Heterotrophic Flagellate Populations Indicates the Presence of Generalist and Specialist Taxa in the Arctic Ocean

Microalgal community structure and primary production in Arctic and Antarctic sea ice: A synthesis

Microbial Community Structure and Interannual Change in the Last Epishelf Lake Ecosystem in the North Polar Region

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