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  1. Article: Decadal trend of plankton community change and habitat shoaling in the Arctic gateway recorded by planktonic foraminifera

    Greco, Mattia / Werner, Kirstin / Zamelczyk, Katarzyna / Rasmussen, Tine L. / Kucera, Michal

    Global change biology. 2022 Mar., v. 28, no. 5

    2022  

    Abstract: The Fram Strait plays a crucial role in regulating the heat and sea‐ice dynamics in the Arctic. In response to the ongoing global warming, the marine biota of this Arctic gateway is experiencing significant changes with increasing advection of Atlantic ... ...

    Abstract The Fram Strait plays a crucial role in regulating the heat and sea‐ice dynamics in the Arctic. In response to the ongoing global warming, the marine biota of this Arctic gateway is experiencing significant changes with increasing advection of Atlantic species. The footprint of this ‘Atlantification’ has been identified in isolated observations across the plankton community, but a systematic, multi‐decadal perspective on how regional climate change facilitates the invasion of Atlantic species and affects the ecology of the resident species is lacking. Here we evaluate a series of 51 depth‐resolved plankton profiles collected in the Fram Strait during seven surveys between 1985 and 2015, using planktonic foraminifera as a proxy for changes in both the pelagic community composition and species vertical habitat depth. The time series reveals a progressive shift towards more Atlantic species, occurring independently of changes in local environmental conditions. We conclude that this trend is reflecting higher production of the Atlantic species in the Nordic Seas, from where they are advected into the Fram Strait. At the same time, we observe the ongoing extensive sea‐ice export from the Arctic and associated cooling‐induced decline in density and habitat shoaling of the subpolar Turborotalita quinqueloba, whereas the resident Neogloboquadrina pachyderma persists. As a result, the planktonic foraminiferal community and vertical structure in the Fram Strait shift to a new state, driven by both remote forcing of the Atlantic invaders and local climatic changes acting on the resident species. The strong summer export of Arctic sea ice has so far buffered larger plankton transformation. We predict that if the sea‐ice export will decrease, the Arctic gateway will experience rapid restructuring of the pelagic community, even in the absence of further warming. Such a large change in the gateway region will likely propagate into the Arctic proper.
    Keywords Retaria ; advection ; community structure ; decline ; exports ; habitats ; heat ; plankton ; sea ice ; summer ; time series analysis ; Arctic Ocean ; Arctic region
    Language English
    Dates of publication 2022-03
    Size p. 1798-1808.
    Publishing place John Wiley & Sons, Ltd
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 1281439-8
    ISSN 1365-2486 ; 1354-1013
    ISSN (online) 1365-2486
    ISSN 1354-1013
    DOI 10.1111/gcb.16037
    Database NAL-Catalogue (AGRICOLA)

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  2. Article ; Online: Decadal trend of plankton community change and habitat shoaling in the Arctic gateway recorded by planktonic foraminifera.

    Greco, Mattia / Werner, Kirstin / Zamelczyk, Katarzyna / Rasmussen, Tine L / Kucera, Michal

    Global change biology

    2021  Volume 28, Issue 5, Page(s) 1798–1808

    Abstract: The Fram Strait plays a crucial role in regulating the heat and sea-ice dynamics in the Arctic. In response to the ongoing global warming, the marine biota of this Arctic gateway is experiencing significant changes with increasing advection of Atlantic ... ...

    Abstract The Fram Strait plays a crucial role in regulating the heat and sea-ice dynamics in the Arctic. In response to the ongoing global warming, the marine biota of this Arctic gateway is experiencing significant changes with increasing advection of Atlantic species. The footprint of this 'Atlantification' has been identified in isolated observations across the plankton community, but a systematic, multi-decadal perspective on how regional climate change facilitates the invasion of Atlantic species and affects the ecology of the resident species is lacking. Here we evaluate a series of 51 depth-resolved plankton profiles collected in the Fram Strait during seven surveys between 1985 and 2015, using planktonic foraminifera as a proxy for changes in both the pelagic community composition and species vertical habitat depth. The time series reveals a progressive shift towards more Atlantic species, occurring independently of changes in local environmental conditions. We conclude that this trend is reflecting higher production of the Atlantic species in the Nordic Seas, from where they are advected into the Fram Strait. At the same time, we observe the ongoing extensive sea-ice export from the Arctic and associated cooling-induced decline in density and habitat shoaling of the subpolar Turborotalita quinqueloba, whereas the resident Neogloboquadrina pachyderma persists. As a result, the planktonic foraminiferal community and vertical structure in the Fram Strait shift to a new state, driven by both remote forcing of the Atlantic invaders and local climatic changes acting on the resident species. The strong summer export of Arctic sea ice has so far buffered larger plankton transformation. We predict that if the sea-ice export will decrease, the Arctic gateway will experience rapid restructuring of the pelagic community, even in the absence of further warming. Such a large change in the gateway region will likely propagate into the Arctic proper.
    MeSH term(s) Arctic Regions ; Ecosystem ; Foraminifera/physiology ; Ice Cover ; Plankton
    Language English
    Publishing date 2021-12-31
    Publishing country England
    Document type Journal Article
    ZDB-ID 1281439-8
    ISSN 1365-2486 ; 1354-1013
    ISSN (online) 1365-2486
    ISSN 1354-1013
    DOI 10.1111/gcb.16037
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Thesis ; Online: Holocene variability of surface and seep water advection to the Arctic Ocean - a multiproxy perspective from the aastern Fram Strait

    Werner, Kirstin

    2011  

    Abstract: Micropaleontological, geochemical, and sedimentological parameters of two sediment cores from the eastern Fram Strait have been studied to reconstruct the variability of surface and deep water advection and related fluctuations of the marginal ice zone ... ...

    Abstract Micropaleontological, geochemical, and sedimentological parameters of two sediment cores from the eastern Fram Strait have been studied to reconstruct the variability of surface and deep water advection and related fluctuations of the marginal ice zone during the past ca ∼9,000 years with multidecadal resolution. The Fram Strait between Greenland and Svalbard is the only deep connection between the Arctic and adjacent subpolar oceans and is often referred to as the ‘Arctic Gateway’. Fram Strait thus plays a crucial role for the energy budget and density pattern of the Arctic Ocean. Large amounts of warm and saline Atlantic Water derived from the North Atlantic Drift transport most of the heat through eastern Fram Strait to the Arctic basin, resulting in year-round ice-free conditions. Arctic sea ice and cold and fresh waters exit the western part of the strait southward along the Greenland shelf. Compared to the ice-covered Arctic Ocean, the strong east-west temperature gradient results in higher bioproductivity and sedimentation rates in the eastern Fram Strait which allows for suitably tracking Holocene variations of the heat flux to the Arctic Ocean in continuous high-resolution sediment sequences. The multiproxy results presented in this thesis suggest that the Holocene climate and oceanographic development in the Fram Strait and possibly the Arctic Ocean was much more variable than previously assumed. The variation and interaction between warm and saline advection of Atlantic Water at the surface to subsurface into the Arctic Ocean and a correspondingly fluctuating sea ice margin characterise the eastern Fram Strait throughout the Holocene. The data imply that the transition from deglacial/Early Holocene to modern-like conditions occurred stepwise. Inferred from the high relative abundance of the subpolar planktic foraminifer species Turborotalia quinqueloba, intense advection of warm Atlantic Water to the Arctic Ocean marks the Early and Mid-Holocene interval (~9,000 to 5,000 years before present), ...
    Subject code 551 ; 550
    Language English
    Publishing country de
    Document type Thesis ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Early Holocene planktic foraminifers record species-specific 14 C reservoir ages in Arctic Gateway

    Sarnthein, Michael / Werner, Kirstin

    2017  

    Abstract: Highlights • Planktic foraminifera species show an Early Holocene 14C plateau analogous to the atmospheric 14C plateau at 10.2–9.6 cal ka. • Age-calibrated Early Holocene 14C plateau boundaries provide precise age control in 3 sediment cores on a 900 km ... ...

    Abstract Highlights • Planktic foraminifera species show an Early Holocene 14C plateau analogous to the atmospheric 14C plateau at 10.2–9.6 cal ka. • Age-calibrated Early Holocene 14C plateau boundaries provide precise age control in 3 sediment cores on a 900 km long transect. • Differences between planktic foraminiferal and atmospheric 14C ages reveal the 14C reservoir age of local surface waters. • Different planktic species document different 14C reservoir ages characteristic of different surface and subsurface waters. To trace spatial variations in Holocene reservoir ages of surface and subsurface waters we studied narrowly spaced 14C records of planktic foraminifera in three high-sedimentation rate cores from the Nordic Seas, the Barents Sea continental margin and eastern Fram Strait. The two northern cores reveal a distinct Early Holocene 14C plateau in dates on the subsurface dweller Neogloboquadrina pachyderma at 9.3–9.1 14C ka. The plateau was tuned to an atmospheric 14C plateau at 9.0–8.7 14C ka that spans 10.2–9.6 calendar ka. These two plateau boundaries provide robust age control points to estimate short-term changes in sedimentation rate and to correlate paleoceanographic signals over 900 km along the West Spitsbergen Current. The difference between planktic and atmospheric 14C plateau ages suggests local 14C reservoir ages of 370–400 yr. Planktic foraminifera species that inhabit different water masses document different reservoir ages. By comparison, the subpolar N. incompta reveals a reservoir age of 150 yr, probably formed in well-mixed Atlantic-sourced waters during winter. The near-surface dweller Turborotalita quinqueloba shows an age of 290 yr in the Fram Strait, but one of 720 yr at the Barents Sea continental margin. The latter age suggests a calcification within old, meltwater-enriched Arctic surface waters admixed by the East Spitsbergen Current. Likewise, we assign an elevated reservoir age of 760 yr on mixed species at a Norwegian Sea site near 71°N to Preboreal meltwaters that spread from ...
    Language English
    Publisher Elsevier
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Book ; Online ; Thesis: Holocene Variability of Surface and Deep Water Advection to the Arctic Ocean - A Multiproxy Perspective from the Eastern Fram Strait

    Werner, Kirstin [Verfasser]

    2011  

    Author's details Kirstin Werner
    Keywords Geowissenschaften ; Earth Sciences
    Subject code sg550
    Language English
    Publisher Universitätsbibliothek Kiel
    Publishing place Kiel
    Document type Book ; Online ; Thesis
    Database Digital theses on the web

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  6. Article ; Online: Paleoceanographic Conditions in High Northern Latitudes During Quaternary Interglaciations

    Kandiano, Evgenia / Werner, Kirstin / Müller, Juliane / Cronin, Thomas M.

    2019  

    Language English
    Publishing date 2019-08-21
    Publisher Frontiers
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Book ; Online ; Thesis: Holocene Variability of Surface and Deep Water Advection to the Arctic Ocean - A Multiproxy Perspective from the Eastern Fram Strait

    Werner, Kirstin / Frank, Martin

    2011  

    Author's details Kirstin Werner
    Language English
    Size Online-Ressource
    Document type Book ; Online ; Thesis
    Thesis / German Habilitation thesis Univ., Diss.--Kiel, 2011
    Database Former special subject collection: coastal and deep sea fishing

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  8. Book ; Online ; Thesis: Holocene Variability of Surface and Deep Water Advection to the Arctic Ocean - A Multiproxy Perspective from the Eastern Fram Strait

    Werner, Kirstin / Frank, Martin

    2011  

    Author's details Kirstin Werner
    Language English
    Size Online-Ressource
    Document type Book ; Online ; Thesis
    Thesis / German Habilitation thesis Univ., Diss.--Kiel, 2011
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

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  9. Conference proceedings ; Online: Deglacial/Early Holocene to modern-like variability of heat transport to the Arctic Ocean inferred from planktic foraminifer fauna and stable isotope data of N. pachyderma and T. quinqueloba - multiproxy results from eastern Fram Strait sediments

    Werner, Kirstin / Spielhagen, Robert F.

    2012  

    Abstract: Northward advection of relatively warm and saline Atlantic Water masses keeps the eastern Fram Strait ice-free all year while the western part - occupied by cold and fresh Arctic water - is perennially ice-covered. The Fram Strait, often referred to as ... ...

    Abstract Northward advection of relatively warm and saline Atlantic Water masses keeps the eastern Fram Strait ice-free all year while the western part - occupied by cold and fresh Arctic water - is perennially ice-covered. The Fram Strait, often referred to as the Arctic Gateway, is the only deep-water passage for Atlantic-derived water masses to enter the Arctic Ocean. It therefore plays a crucial role for the heat budget of the Arctic Ocean. Two high resolution sediment sequences from the Western Svalbard margin covering the last ca. 10.000 years have been studied in order to derive information on Holocene variability of the heat transport to the Arctic Ocean. Planktic foraminifer fauna imply a stepwise transition from deglacial/Early Holocene to modern-like conditions in the eastern Fram. Repeated short-term advances of the sea ice margin are superimposed on the generally strong heat transport to the Arctic Ocean during the Early to Mid-Holocene until ca 5 cal ka BP. Strong fluctuations in stable isotope data of the subpolar planktic foraminifer species Turborotalita quinqueloba infer strong variability of summer sea surface conditions probably caused by variable extent of the upper mixed layer and the sea ice margin. The Late Holocene Neoglacial phase was characterized by the dominance of the cold water-indicating planktic foraminifer species Neogloboquadrina pachyderma. Consistent with the decreasing solar insolation, cooler (sub-)surface conditions established after ca 5 cal ka BP most likely related to a weakening of the Atlantic Water advection and strong export of Arctic sea ice through Fram Strait. During that time, N. pachyderma most likely migrated to the subsurface layer due to enhanced freshwater available at the surface. Cool Late Holocene conditions are reversed by a strong warming event likely caused by a significant strengthening of Atlantic heat advection to the Arctic during the present, anthropogenically influenced period.
    Subject code 551 ; 550
    Publisher University of Oulu and Thule Institute
    Publishing country de
    Document type Conference proceedings ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Conference proceedings ; Online: Holocene episodes of warm conditions in the eastern Fram Strait - a multiproxy perspective on the variability of Atlantic Water inflow

    Werner, Kirstin / Spielhagen, Robert F.

    2011  

    Abstract: EGU2011-2455 The current interglacial has gone through a variety of warmer and colder periods. Consistent with the decreasing solar insolation during the Holocene, warmest conditions have occurred particularly within its earliest phase. We studied high- ... ...

    Abstract EGU2011-2455 The current interglacial has gone through a variety of warmer and colder periods. Consistent with the decreasing solar insolation during the Holocene, warmest conditions have occurred particularly within its earliest phase. We studied high-resolution sediment sequences from the Western Svalbard margin covering the last ca 10,000 years in order to reconstruct the variations of Atlantic Water advection to the Arctic, the sea ice extent, and the structure of the water column on the Westspitsbergen continental margin. The Fram Strait, often referred to as the Arctic Gateway, is the only deep-water passage for Atlantic-derived water masses to enter the Arctic Ocean. Northward advection of relatively warm and saline Atlantic Water masses keeps the eastern part of the Fram Strait ice-free all year. It therefore plays a crucial role for the heat budget of the Arctic. A multiproxy data set including geochemical, micropaleontological, and sedimentological parameters was established with centennial to multidecadal time resolution. Records of foraminiferal oxygen and carbon isotopes, planktic foraminifer assemblages, and the amount of ice rafted debris clearly reveal distinct variations between climatically warmer and colder intervals throughout this period. Planktic foraminifer assemblages reveal warmest conditions for the early Holocene period (ca 10-8 ka). A second warming pulse is detected between 5 and 6 ka. In the second half of the Holocene, increased IRD contents are indicative of a significant cooling trend. Despite of the decreasing solar insolation planktic foraminiferal assemblages suggest a return of slightly strengthened Atlantic Water advection around 3 to 2 ka and a strong warming event in the present, anthropogenically influenced period.
    Subject code 551 ; 550
    Language English
    Publisher Copernicus
    Publishing country de
    Document type Conference proceedings ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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