Cold-seep fossil macrofaunal assemblages from Vestnesa Ridge, eastern Fram Strait, during the past 45 000 years

Thomsen, Elsebeth; Rasmussen, Tine L.; Sztybor, Kamila; Hanken, Nils‐Martin; Tendal, Ole Secher; Uchman, Alfred

doi:10.33265/polar.v38.3310

Cited by 12 publications

(14 citation statements)

References 79 publications

(124 reference statements)

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“…L. Rasmussen et al, 1996b). At Vestnesa Ridge methane seep sites, the presence of vesicomyid/solemyid bivalves at HS1 has also been suggested as the result of higher BWT (Hansen et al, 2020;Sztybor & Rasmussen, 2017;Thomsen et al, 2019). In our core, the relative abundance of the "Atlantic species" group is high in HS1 (ca.…”

Section: Heinrich Stadials and Greenland Stadialssupporting

confidence: 50%

Millennial‐Scale Changes in Bottom Water Temperature and Water Mass Exchange Through the Fram Strait 79°N, 63‐13 ka

Altuna

Ezat

Greaves

et al. 2021

Paleoceanog and Paleoclimatol

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During the last glacial period, the climate of the northern hemisphere was affected by abrupt millennial-scale climate changes called Dansgaard-Oeschger (D-O) events (Dansgaard et al., 1982, 1993; Johnsen et al., 1992). Greenland ice cores record ∼25 sudden atmospheric warmings in the order of 8°C-16°C from cold stadials (Greenland Stadials, GS) to warm interstadials (Greenland Interstadials, GI) occurring within a few decades (

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Section: Heinrich Stadials and Greenland Stadialssupporting

confidence: 50%

Millennial‐Scale Changes in Bottom Water Temperature and Water Mass Exchange Through the Fram Strait 79°N, 63‐13 ka

Altuna

Ezat

Greaves

et al. 2021

Paleoceanog and Paleoclimatol

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“…1 b). Previous paleo-studies from ‘Lomvi’ pockmark revealed chemosymbiotic fossil macrofaunal communities related to the different types of seep environments 26 (and references therein), and studies of fossil foraminifera showed diagenetic alterations of their tests 12 , 18 . Biological investigations from this pockmark documented the presence of species-rich live macro- and megafaunas 27 , 28 , carbonate outcrops 12 , 29 , and heterogeneous environmental conditions associated with methane release.…”

Section: Study Areamentioning

confidence: 98%

Influence of methane seepage on isotopic signatures in living deep-sea benthic foraminifera, 79° N

Melaniuk

Sztybor

Treude

et al. 2022

Sci Rep

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Fossil benthic foraminifera are used to trace past methane release linked to climate change. However, it is still debated whether isotopic signatures of living foraminifera from methane-charged sediments reflect incorporation of methane-derived carbon. A deeper understanding of isotopic signatures of living benthic foraminifera from methane-rich environments will help to improve reconstructions of methane release in the past and better predict the impact of future climate warming on methane seepage. Here, we present isotopic signatures (δ13C and δ18O) of foraminiferal calcite together with biogeochemical data from Arctic seep environments from c. 1200 m water depth, Vestnesa Ridge, 79° N, Fram Strait. Lowest δ13C values were recorded in shells of Melonis barleeanus, − 5.2‰ in live specimens and − 6.5‰ in empty shells, from sediments dominated by aerobic (MOx) and anaerobic oxidation of methane (AOM), respectively. Our data indicate that foraminifera actively incorporate methane-derived carbon when living in sediments with moderate seepage activity, while in sediments with high seepage activity the poisonous sulfidic environment leads to death of the foraminifera and an overgrowth of their empty shells by methane-derived authigenic carbonates. We propose that the incorporation of methane-derived carbon in living foraminifera occurs via feeding on methanotrophic bacteria and/or incorporation of ambient dissolved inorganic carbon.

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“…Methane seep ecosystems are unique, because they host chemosynthesis-based communities resulting in an "oasis effect" on the seafloor, due to enhanced macrofaunal biomass and diversity in comparison to nearby nonseep environments (Åström et al, 2018;Levin, 2005;Levin et al, 2016;Sibuet & Olu, 1998;Sibuet & Olu-Le Roy, 2002;Thomsen et al, 2019). At the crater area, numerous frenulate siboglinid worms, the dominant chemosymbiotrophic megafauna in high latitude seeps, and chemosynthetic bacterial mats are recorded (Sen, Duperron, et al, 2018).…”

Section: The Effect Of Methane On Productivity and Lpf Biomassmentioning

confidence: 99%

Development, Productivity, and Seasonality of Living Planktonic Foraminiferal Faunas and Limacina helicina in an Area of Intense Methane Seepage in the Barents Sea

et al. 2020

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Although the plankton communities in the Barents Sea have been intensely studied for decades, little is known about the living planktonic foraminiferal (LPF) and pteropod faunas, especially those found at methane seep sites. Along a repeated transect in the “crater area” (northern Barents Sea, 74.9°N, 27.7°E) in spring and summer 2016 the flux of LPF and of the pteropod species Limacina helicina showed a high degree of variability. The LPF had low concentration (0–6 individuals m−3) and small tests (x̄ = 103.3 μm) in spring and a 53‐fold increase (43–436 individuals m−3) and larger tests (x̄ = 188.6 μm) in summer. Similarly, the concentration of L. helicina showed a tenfold increase between spring and summer. The LPF species composition remained stable with the exception of the appearance of subtropical species in summer. No relationship was observed between the spatial distribution of LPF, L. helicina, and methane concentrations in the area. The methane plumes in April coincided with elevated dissolved inorganic carbon, low pH, and calcium carbonate saturation states, and the methane concentration seemed to be controlled by lateral advection. The δ13C and δ18O of Neogloboquadrina pachyderma and Turborotalita quinqueloba are comparable to previous observations in the Arctic and do not show any influence of methane in the isotopic signals of the shells. Although no evidence of direct impact of high methane concentrations on the LPF (size and concentration) were found, we speculate that methane could indirectly enhance primary productivity, and thus biomass, through several potential pathways.

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Cold-seep fossil macrofaunal assemblages from Vestnesa Ridge, eastern Fram Strait, during the past 45 000 years

Cited by 12 publications

References 79 publications

Millennial‐Scale Changes in Bottom Water Temperature and Water Mass Exchange Through the Fram Strait 79°N, 63‐13 ka

Millennial‐Scale Changes in Bottom Water Temperature and Water Mass Exchange Through the Fram Strait 79°N, 63‐13 ka

Influence of methane seepage on isotopic signatures in living deep-sea benthic foraminifera, 79° N

Development, Productivity, and Seasonality of Living Planktonic Foraminiferal Faunas and Limacina helicina in an Area of Intense Methane Seepage in the Barents Sea

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