Carbon and nitrogen turnover in the Arctic deep sea: in situ benthic community response to diatom and coccolithophorid phytodetritus

Braeckman, Ulrike; Janßen, Felix; Lavik, Gaute; Elvert, Marcus; Marchant, Hannah K.; Buckner, Caroline; Bienhold, Christina; Wenzhöfer, Frank

doi:10.5194/bg-15-6537-2018

Cited by 24 publications

(5 citation statements)

References 103 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…or the coccolithophore Emiliania huxleyi was provided to the benthic community. The community did not respond to the algal input by an increase of total bacterial cell numbers, but by an increase of exoenzymatic activities [ 68 ]. The high diversity of Svalbard benthic bacterial communities (observed number of ASV between 2526 and 6691) is coincident with a diverse spectrum of enzymes capable of degrading different substrates as previously suggested by Teske and colleagues [ 15 ].…”

Section: Discussionmentioning

confidence: 99%

Bacterial communities in temperate and polar coastal sands are seasonally stable

Miksch

Meiners

Meyerdierks

et al. 2021

ISME Communications

View full text Add to dashboard Cite

Coastal sands are biocatalytic filters for dissolved and particulate organic matter of marine and terrestrial origin, thus, acting as centers of organic matter transformation. At high temporal resolution, we accessed the variability of benthic bacterial communities over two annual cycles at Helgoland (North Sea), and compared it with seasonality of communities in Isfjorden (Svalbard, 78°N) sediments, where primary production does not occur during winter. Benthic community structure remained stable in both, temperate and polar sediments on the level of cell counts and 16S rRNA-based taxonomy. Actinobacteriota of uncultured Actinomarinales and Microtrichales were a major group, with 8 ± 1% of total reads (Helgoland) and 31 ± 6% (Svalbard). Their high activity (frequency of dividing cells 28%) and in situ cell numbers of >10% of total microbes in Svalbard sediments, suggest Actinomarinales and Microtrichales as key heterotrophs for carbon mineralization. Even though Helgoland and Svalbard sampling sites showed no phytodetritus-driven changes of the benthic bacterial community structure, they harbored significantly different communities (p < 0.0001, r = 0.963). The temporal stability of benthic bacterial communities is in stark contrast to the dynamic succession typical of coastal waters, suggesting that pelagic and benthic bacterial communities respond to phytoplankton productivity very differently.

show abstract

Section: Discussionmentioning

confidence: 99%

Bacterial communities in temperate and polar coastal sands are seasonally stable

Miksch

Meiners

Meyerdierks

et al. 2021

ISME Communications

View full text Add to dashboard Cite

show abstract

“…In contrast, sediments outside the seeps are impoverished in organic substrates for most of the year and depend on benthic-pelagic coupling (Gooday, 1988). Thus, the benthic communities in the Arctic, which experience low food are likely more sensitive to food input from primary production (e.g., Gooday, 1988Gooday, , 1993Sander and van der Zwaan, 2004;Nomaki et al, 2005;Schönfeld and Numberger, 2007;Braeckman et al, 2018). After the episode of strong food pulses, a population of specific opportunistic species increased, which can quickly utilize large amounts of detritus (e.g., Gooday, 1988;Nomaki et al, 2005;Braeckman et al, 2018).…”

Section: Foraminiferal Faunamentioning

confidence: 99%

“…Thus, the benthic communities in the Arctic, which experience low food are likely more sensitive to food input from primary production (e.g., Gooday, 1988Gooday, , 1993Sander and van der Zwaan, 2004;Nomaki et al, 2005;Schönfeld and Numberger, 2007;Braeckman et al, 2018). After the episode of strong food pulses, a population of specific opportunistic species increased, which can quickly utilize large amounts of detritus (e.g., Gooday, 1988;Nomaki et al, 2005;Braeckman et al, 2018). In fact, samples from GHP5 are dominated by M. barleeanus, an opportunistic species well adapted to high organic content (e.g., Wollenburg and Mackensen, 1998;Alve et al, 2016) and shows a relatively high number of E. excavatum.…”

Section: Foraminiferal Faunamentioning

confidence: 99%

Effectiveness of Fluorescent Viability Assays in Studies of Arctic Cold Seep Foraminifera

Melaniuk

2021

Front. Mar. Sci.

View full text Add to dashboard Cite

Highly negative δ13C values in fossil foraminifera from methane cold seeps have been proposed to reflect episodes of methane release from gas hydrate dissociation or free gas reservoirs triggered by climatic changes in the past. Because most studies on live foraminifera are based on the presence of Rose Bengal staining, that colors the cytoplasm of both live and recently dead individuals it remains unclear if, and to what extent live foraminifera incorporate methane-derived carbon during biomineralization, or whether the isotopic signature is mostly affected by authigenic overgrowth. In this paper, modern foraminiferal assemblages from a gas hydrate province Vestnesa Ridge (∼1,200 m water depth, northeastern Fram Strait) and from Storfjordrenna (∼400 m water depth in the western Barents Sea) is presented. By using the fluorescent viability assays CellTrackerTM Green (CTG) CMFDA and CellHunt Green (CHG) together with conventional Rose Bengal, it was possible to examine live and recently dead foraminifera separately. Metabolically active foraminifera were shown to inhabit methane-enriched sediments at both investigated locations. The benthic foraminiferal faunas were dominated by common Arctic species such as Melonis barleeanus, Cassidulina neoteretis, and Nonionellina labradorica. The combined usage of the fluorescence probe and Rose Bengal revealed only minor shifts in species compositions and differences in ratios between live and recently dead foraminifera from Storfjordrenna. There was no clear evidence that methane significantly affected the δ13C signature of the calcite of living specimens.

show abstract

“…Prokaryotes provide a link between the abiotic and biotic realms, such that prokaryotic community structure reflects environmental gradients in, for example, OM deposition. Studies conducted in the Norwegian Arctic suggest that prokaryotic community structure shifts with varying quality and quantity of OM inputs, with possible consequences for ecosystem function (Hoffmann et al, 2017;Braeckman et al, 2018). Certain taxonomic groups have been strongly correlated with environmental parameters, such as Chl-a and bathymetry, measured along natural environmental gradients (Bienhold et al, 2012;Jacob et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Patterns in Benthic Microbial Community Structure Across Environmental Gradients in the Beaufort Sea Shelf and Slope

2021

View full text Add to dashboard Cite

The paradigm of tight pelagic-benthic coupling in the Arctic suggests that current and future fluctuations in sea ice, primary production, and riverine input resulting from global climate change will have major impacts on benthic ecosystems. To understand how these changes will affect benthic ecosystem function, we must characterize diversity, spatial distribution, and community composition for all faunal components. Bacteria and archaea link the biotic and abiotic realms, playing important roles in organic matter (OM) decomposition, biogeochemical cycling, and contaminant degradation, yet sediment microbial communities have rarely been examined in the North American Arctic. Shifts in microbial community structure and composition occur with shifts in OM inputs and contaminant exposure, with implications for shifts in ecological function. Furthermore, the characterization of benthic microbial communities provides a foundation from which to build focused experimental research. We assessed diversity and community structure of benthic prokaryotes in the upper 1 cm of sediments in the southern Beaufort Sea (United States and Canada), and investigated environmental correlates of prokaryotic community structure over a broad spatial scale (spanning 1,229 km) at depths ranging from 17 to 1,200 m. Based on hierarchical clustering, we identified four prokaryotic assemblages from the 85 samples analyzed. Two were largely delineated by the markedly different environmental conditions in shallow shelf vs. upper continental slope sediments. A third assemblage was mainly comprised of operational taxonomic units (OTUs) shared between the shallow shelf and upper slope assemblages. The fourth assemblage corresponded to sediments receiving heavier OM loading, likely resulting in a shallower anoxic layer. These sites may also harbor microbial mats and/or methane seeps. Substructure within these assemblages generally reflected turnover along a longitudinal gradient, which may be related to the quantity and composition of OM deposited to the seafloor; bathymetry and the Mackenzie River were the two major factors influencing prokaryote distribution on this scale. In a broader geographical context, differences in prokaryotic community structure between the Beaufort Sea and Norwegian Arctic suggest that benthic microbes may reflect regional differences in the hydrography, biogeochemistry, and bathymetry of Arctic shelf systems.

show abstract

Carbon and nitrogen turnover in the Arctic deep sea: in situ benthic community response to diatom and coccolithophorid phytodetritus

Cited by 24 publications

References 103 publications

Bacterial communities in temperate and polar coastal sands are seasonally stable

Bacterial communities in temperate and polar coastal sands are seasonally stable

Effectiveness of Fluorescent Viability Assays in Studies of Arctic Cold Seep Foraminifera

Patterns in Benthic Microbial Community Structure Across Environmental Gradients in the Beaufort Sea Shelf and Slope

Contact Info

Product

Resources

About