Density and distribution of megafauna at the Håkon Mosby mud volcano (the Barents Sea) based on image analysis

Rybakova, Elena; Galkin, Sergey; Bergmann, Melanie; Soltwedel, Thomas; Gebruk, Andrey

doi:10.5194/bg-10-3359-2013

Cited by 34 publications

(44 citation statements)

References 49 publications

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“…Cold seeps, where hydrocarbons and reduced gases emerge from the seafloor, are ubiquitous in the world's oceans and despite being discovered only a few decades ago (Paull et al, 1984), they have been studied intensively in a variety of settings around the world (Levin, 2005;Levin et al, 2016;Sibuet and Olu, 1998;Sibuet and Olu-Le Roy, 2002). However, cold seeps in the Arctic Ocean have received less attention and the literature on Arctic seep communities is limited to a few studies in the Barents and Beaufort seas (Åström et al, 2016, 2017aGebruk et al, 2003;Lösekann et al, 2008;Paull et al, 2015;Pimenov et al, 2000;Rybakova (Goroslavskaya) et al, 2013). The most well studied seep site in the Arctic is the Håkon Mosby mud volcano (HMMV), which has practically become synonymous with Arctic seep biology.…”

Section: Introductionmentioning

confidence: 99%

Geophysical and geochemical controls on the megafaunal community of a high Arctic cold seep

et al. 2018

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Abstract. Cold-seep megafaunal communities around gas hydrate mounds (pingos) in the western Barents Sea (76∘ N, 16∘ E, ∼400 m depth) were investigated with high-resolution, geographically referenced images acquired with an ROV and towed camera. Four pingos associated with seabed methane release hosted diverse biological communities of mainly nonseep (background) species including commercially important fish and crustaceans, as well as a species new to this area (the snow crab Chionoecetes opilio). We attribute the presence of most benthic community members to habitat heterogeneity and the occurrence of hard substrates (methane-derived authigenic carbonates), particularly the most abundant phyla (Cnidaria and Porifera), though food availability and exposure to a diverse microbial community is also important for certain taxa. Only one chemosynthesis-based species was confirmed, the siboglinid frenulate polychaete Oligobrachia cf. haakonmosbiensis. Overall, the pingo communities formed two distinct clusters, distinguished by the presence or absence of frenulate aggregations. Methane gas advection through sediments was low, below the single pingo that lacked frenulate aggregations, while seismic profiles indicated abundant gas-saturated sediment below the other frenulate-colonized pingos. The absence of frenulate aggregations could not be explained by sediment sulfide concentrations, despite these worms likely containing sulfide-oxidizing symbionts. We propose that high levels of seafloor methane seepage linked to subsurface gas reservoirs support an abundant and active sediment methanotrophic community that maintains high sulfide fluxes and serves as a carbon source for frenulate worms. The pingo currently lacking a large subsurface gas source and lower methane concentrations likely has lower sulfide flux rates and limited amounts of carbon, insufficient to support large populations of frenulates. Two previously undocumented behaviors were visible through the images: grazing activity of snow crabs on bacterial mats, and seafloor crawling of Nothria conchylega onuphid polychaetes.

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Section: Introductionmentioning

confidence: 99%

Geophysical and geochemical controls on the megafaunal community of a high Arctic cold seep

et al. 2018

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“…HMMV has been a focus of biogeochemical and geophysical studies documenting the fate of venting methane from the seabed (Milkov et al 1999;L€ osekann et al 2008;. The benthic environment around the caldera of HMMV consists of three main habitats; microbial mats, siboglinid (pogonophoran) worm fields and plain light-colored sediments, each possessing different faunal community patterns influenced by seafloor methane emissions (Gebruk et al 2003;Rybakova et al 2013). Megafaunal densities and taxa richness varied significantly in relation to these different habitats, (Rybakova et al 2013) and methane derived carbon is incorporated into the faunal communities via trophic interactions (Gebruk et al 2003;.…”

Section: Introductionmentioning

confidence: 99%

“…The benthic environment around the caldera of HMMV consists of three main habitats; microbial mats, siboglinid (pogonophoran) worm fields and plain light-colored sediments, each possessing different faunal community patterns influenced by seafloor methane emissions (Gebruk et al 2003;Rybakova et al 2013). Megafaunal densities and taxa richness varied significantly in relation to these different habitats, (Rybakova et al 2013) and methane derived carbon is incorporated into the faunal communities via trophic interactions (Gebruk et al 2003;. Å str€ om et al (2016) described macrofaunal benthic communities associated with cold seeps around western Svalbard and the northwest Barents Sea shelf (75-798 N).…”

Section: Introductionmentioning

confidence: 99%

Methane cold seeps as biological oases in the high‐Arctic deep sea

Åström

Carroll

Ambrose

et al. 2017

Limnology & Oceanography

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Cold seeps can support unique faunal communities via chemosynthetic interactions fueled by seabed emissions of hydrocarbons. Additionally, cold seeps can enhance habitat complexity at the deep seafloor through the accretion of methane derived authigenic carbonates (MDAC). We examined infaunal and megafaunal community structure at high-Arctic cold seeps through analyses of benthic samples and seafloor photographs from pockmarks exhibiting highly elevated methane concentrations in sediments and the water column at Vestnesa Ridge (VR), Svalbard (798 N). Infaunal biomass and abundance were five times higher, species richness was 2.5 times higher and diversity was 1.5 times higher at methane-rich Vestnesa compared to a nearby control region. Seabed photos reveal different faunal associations inside, at the edge, and outside Vestnesa pockmarks. Brittle stars were the most common megafauna occurring on the soft bottom plains outside pockmarks. Microbial mats, chemosymbiotic siboglinid worms, and carbonate outcrops were prominent features inside the pockmarks, and high trophic-level predators aggregated around these features. Our faunal data, visual observations, and measurements of sediment characteristics indicate that methane is a key environmental driver of the biological system at VR. We suggest that chemoautotrophic production enhances infaunal diversity, abundance, and biomass at the seep while MDAC create a heterogeneous deep-sea habitat leading to aggregation of heterotrophic, conventional megafauna. Through this combination of rich infaunal and megafaunal associations, the cold seeps of VR are benthic oases compared to the surrounding highArctic deep sea.

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“…Frenulate siboglinid worms are the dominant fauna of cold seeps in northern latitude regions (Åstrom, Carroll, Ambrose, & Carroll, ; Åström et al, ; Decker et al, , p. 1; Decker & Olu, ; Gebruk et al, ; Hovland & Svensen, ; Paull et al, ; Rybakova (Goroslavskaya), Galkin, Bergmann, Soltwedel, and Gebruk, ; Savvichev et al, ; Sen et al, ; Sen, Åström, et al, ; Sen, Duperron, et al, ). They are also the only confirmed chemosynthesis‐based animals of the communities at nearly all high latitude seeps (Sen, Åström, et al, ; Sen, Duperron, et al, ) and therefore integral to the functioning of these ecosystems.…”

Section: Introductionmentioning

confidence: 99%

Frenulate siboglinids at high Arctic methane seeps and insight into high latitude frenulate distribution

Sen

Didriksen

Hourdez

et al. 2020

Ecology and Evolution

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Frenulate species were identified from a high Arctic methane seep area on Vestnesa Ridge, western Svalbard margin (79°N, Fram Strait) based on mitochondrial cytochrome oxidase subunit I (mtCOI). Two species were found: Oligobrachia haakonmosbiensis, and a new, distinct, and undescribed Oligobrachia species. The new species adds to the cryptic Oligobrachia species complex found at high latitude methane seeps in the north Atlantic and the Arctic. However, this species displays a curled tube morphology and light brown coloration that could serve to distinguish it from other members of the complex. A number of single tentacle individuals were recovered which were initially thought to be members of the only unitentaculate genus, Siboglinum. However, sequencing revealed them to be the new species and the single tentacle morphology, in addition to thin, colorless, and ringless tubes indicate that they are juveniles. This is the first known report of juveniles of northern Oligobrachia. Since the juveniles all appeared to be at about the same developmental stage, it is possible that reproduction is either synchronized within the species, or that despite continuous reproduction, settlement, and growth in the sediment only takes place at specific periods. The new find of the well‐known species O. haakonmosbiensis extends its range from the Norwegian Sea to high latitudes of the Arctic in the Fram Strait. We suggest bottom currents serve as the main distribution mechanism for high latitude Oligobrachia species and that water depth constitutes a major dispersal barrier. This explains the lack of overlap between the distributions of northern Oligobrachia species despite exposure to similar current regimes. Our results point toward a single speciation event within the Oligobrachia clade, and we suggest that this occurred in the late Neogene, when topographical changes occurred and exchanges between Arctic and North Atlantic water masses and subsequent thermohaline circulation intensified.

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Density and distribution of megafauna at the Håkon Mosby mud volcano (the Barents Sea) based on image analysis

Cited by 34 publications

References 49 publications

Geophysical and geochemical controls on the megafaunal community of a high Arctic cold seep

Geophysical and geochemical controls on the megafaunal community of a high Arctic cold seep

Methane cold seeps as biological oases in the high‐Arctic deep sea

Frenulate siboglinids at high Arctic methane seeps and insight into high latitude frenulate distribution

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