Upper Arctic Ocean water masses harbor distinct communities of heterotrophic flagellates

Monier, Adam; Terrado, Ramón; Thaler, Mary; Comeau, A.; Medrinal, Emmanuelle; Lovejoy, Connie

doi:10.5194/bg-10-4273-2013

Cited by 30 publications

(19 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eukaryotic microbial communities from rDNA have been used to infer water mass history (Hamilton et al, 2008;Monier et al, 2013;Zhang et al, 2014), whereas taxa from rRNA are thought to more closely indicate active representatives of the community (Campbell and Kirchman, 2013;Hunt et al, 2013). Here, we found that for both DNA and RNA sourced samples, the surface communities always clustered together separate from the SCM communities.…”

Section: Interpretation Of Dna and Rna-derived Abundances And Diversitymentioning

confidence: 75%

“…All OTU representative reads were aligned in PyNast (Caporaso et al, 2010a), manually curated in BioEdit v.7.2.5 (Hall, 1999) and used to construct a phylogenetic tree (FastTree; Price et al, 2010). Assignment of taxonomic identity was performed in mothur with a 0.8 confidence threshold against the Northern Reference Database v.1.0 , which follows the Silva taxonomy but includes high-quality longer environmental sequences from the Arctic and North Atlantic (Terrado et al, 2009(Terrado et al, , 2011Charvet et al, 2012;Monier et al, 2013;Dasilva et al, 2014). However, using this database, around 30-45% of the reads were still not classified beyond "Other Dinoflagellates" or "Other Ciliates.…”

Section: Post-sequence Data Processing and Taxonomic Classificationmentioning

confidence: 99%

See 1 more Smart Citation

Seasonal and Interannual Changes in Ciliate and Dinoflagellate Species Assemblages in the Arctic Ocean (Amundsen Gulf, Beaufort Sea, Canada)

et al. 2017

View full text Add to dashboard Cite

Recent studies have focused on how climate change could drive changes in phytoplankton communities in the Arctic. In contrast, ciliates and dinoflagellates that can contribute substantially to the mortality of phytoplankton have received less attention. Some dinoflagellate and ciliate species can also contribute to net photosynthesis, which suggests that species composition could reflect food web complexity. To identify potential seasonal and annual species occurrence patterns and to link species with environmental conditions, we first examined the seasonal pattern of microzooplankton and then performed an in-depth analysis of interannual species variability. We used high-throughput amplicon sequencing to identify ciliates and dinoflagellates to the lowest taxonomic level using a curated Arctic 18S rRNA gene database. DNA-and RNA-derived reads were generated from samples collected from the Canadian Arctic from November 2007 to July 2008. The proportion of ciliate reads increased in the surface toward summer, when salinity was lower and smaller phytoplankton prey were abundant, while chloroplastidic dinoflagellate species increased at the subsurface chlorophyll maxima (SCM), where inorganic nutrient concentrations were higher. Comparing communities collected in summer and fall from 2003 to 2010, we found that microzooplankton community composition change was associated with the record ice minimum in the summer of 2007. Specifically, reads from smaller predatory species like Laboea, Monodinium, and Strombidium and several unclassified ciliates increased in the summer after 2007, while the other usually summer-dominant dinoflagellate taxa decreased. The ability to exploit smaller prey, which are predicted to dominate the future Arctic, could be an advantage for these smaller ciliates in the wake of the changing climate.

show abstract

Section: Interpretation Of Dna and Rna-derived Abundances And Diversitymentioning

confidence: 75%

Section: Post-sequence Data Processing and Taxonomic Classificationmentioning

confidence: 99%

Seasonal and Interannual Changes in Ciliate and Dinoflagellate Species Assemblages in the Arctic Ocean (Amundsen Gulf, Beaufort Sea, Canada)

et al. 2017

View full text Add to dashboard Cite

show abstract

“…One of the projects focused on sea ice sampled in the Amundsen Gulf region in spring 2008 (17). Sample collection and pyrosequencing are described in associated publications (9,17,19,24,29) and were similar for all data sets. To increase pan-Arctic coverage, additional samples that had been collected during various missions between 2005 and 2011 were also sequenced and analyzed using similar methods; these samples were from the Chukchi Sea, the Canadian Arctic Archipelago (Archipelago), Baffin Bay, Hudson Bay, and the Laptev Sea as detailed below.…”

Section: Methodsmentioning

confidence: 99%

“…However, the consequences for HF taxa are not known, in part because few studies have characterized the diversity and biogeography of different HF (15,16). Although there have been a number of studies using V4 18S rRNA gene amplicon pyrosequencing in the Arctic (9,(17)(18)(19), none were focused on pan-Arctic comparisons. All of these studies have detected an effect of environmental gradients on one or more HF taxa, but the extent to which HF with similar putative ecological roles (e.g., bacterivory) might vary in relative abundance over space and time is not yet understood, and a comprehensive analysis is lacking.…”

mentioning

confidence: 99%

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

Thaler

Lovejoy

2015

Appl Environ Microbiol

View full text Add to dashboard Cite

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...

show abstract

“…The development of molecular techniques, especially high-throughput sequencing (HTS), has made it possible to study the diversity and assemblages of pico-and nanosized eukaryotic plankton as well (19)(20)(21)(22). This has resulted in several diversity surveys of microbial eukaryotes from the Arctic Ocean and the shelf seas (23)(24)(25)(26)(27). Pico-and nanosized planktons are now known to govern major processes in the oceans to a larger degree than previously assumed (6,7,28,29).…”

mentioning

confidence: 99%

Strong Seasonality of Marine Microbial Eukaryotes in a High-Arctic Fjord (Isfjorden, in West Spitsbergen, Norway)

Marquardt

Vader²,

Stübner

et al. 2016

Appl Environ Microbiol

113

107

View full text Add to dashboard Cite

bThe Adventfjorden time series station (IsA) in Isfjorden, West Spitsbergen, Norway, was sampled frequently from December 2011 to December 2012. The community composition of microbial eukaryotes (size, 0.45 to 10 m) from a depth of 25 m was determined using 454 sequencing of the 18S V4 region amplified from both DNA and RNA. The compositional changes throughout the year were assessed in relation to in situ fjord environmental conditions. Size fractionation analyses of chlorophyll a showed that the photosynthetic biomass was dominated by small cells (<10 m) most of the year but that larger cells dominated during the spring and summer. The winter and early-spring communities were more diverse than the spring and summer/autumn communities. Dinophyceae were predominant throughout the year. The Arctic Micromonas ecotype was abundant mostly in the early-bloom and fall periods, whereas heterotrophs, such as marine stramenopiles (MASTs), Picozoa, and the parasitoid marine alveolates (MALVs), displayed higher relative abundance in the winter than in other seasons. Our results emphasize the extreme seasonality of Arctic microbial eukaryotic communities driven by the light regime and nutrient availability but point to the necessity of a thorough knowledge of hydrography for full understanding of their succession and variability. Microbial eukaryotes are critically important for the functioning of marine ecosystems as primary producers (1, 2) and consumers (3, 4) of carbon, as well as maintainers of biogeochemical cycles (5-7). In Arctic waters, where marine planktonic cyanobacteria are infrequent, marine microbial eukaryotes are the predominant primary producers (8-10). In spite of their importance, our knowledge of the diversity and role of picosized (0.2 to 2 m) and nanosized (2 to 20 m) (11) eukaryotic plankton is still limited in extreme areas.High-Arctic regions are characterized by extreme seasonality in light conditions, with 24 h of sunlight in summer giving way to several months of complete darkness in winter. The cold, dark polar night period at high latitudes strongly limits the activity of autotrophic organisms, and Arctic species in general have to adjust to the timing of seasonal events (12). The few studies performed during the Arctic winter-spring transition suggest a strong seasonal response by the microbial community to irradiance (13)(14)(15). Most studies of Arctic microbial eukaryotes have so far utilized traditional identification techniques, such as microscopy, and focused on bloom-forming pelagic protists (4, 16-18). The development of molecular techniques, especially high-throughput sequencing (HTS), has made it possible to study the diversity and assemblages of pico-and nanosized eukaryotic plankton as well (19)(20)(21)(22). This has resulted in several diversity surveys of microbial eukaryotes from the Arctic Ocean and the shelf seas (23-27). Pico-and nanosized planktons are now known to govern major processes in the oceans to a larger degree than previously assumed (6,7,28,29). Furthermore, 18S ...

show abstract

Upper Arctic Ocean water masses harbor distinct communities of heterotrophic flagellates

Cited by 30 publications

References 88 publications

Seasonal and Interannual Changes in Ciliate and Dinoflagellate Species Assemblages in the Arctic Ocean (Amundsen Gulf, Beaufort Sea, Canada)

Seasonal and Interannual Changes in Ciliate and Dinoflagellate Species Assemblages in the Arctic Ocean (Amundsen Gulf, Beaufort Sea, Canada)

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

Strong Seasonality of Marine Microbial Eukaryotes in a High-Arctic Fjord (Isfjorden, in West Spitsbergen, Norway)

Contact Info

Product

Resources

About