Sea surface temperatures in Disko Bay during the Little Ice Age – caution needs to be exercised before assigning Thalassiosira kushirensis resting spore as a warm-water indicator in palaeoceanographic studies

Weckström, Kaarina; Miettinen, Arto; Caissie, Beth; Pearce, Christof; Ellegaard, Marianne; Krawczyk, Diana; Witkowski, Andrzej

doi:10.1016/j.quascirev.2014.07.015

Cited by 10 publications

(12 citation statements)

References 25 publications

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“…The exception to this is T. kushirensis which was classified as a warm/temperate water species [ Krawczyk et al , ]. More recently, T. kushirensis has been described both as an Arctic species [ Weckström et al ] and as a species associated with slightly warmer summer waters [ Krawczyk et al , ; Moros et al , ].…”

Section: Resultsmentioning

confidence: 99%

Quantitative reconstruction of Holocene sea ice and sea surface temperature off West Greenland from the first regional diatom data set

et al. 2017

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Holocene oceanographic conditions in Disko Bay, West Greenland, were reconstructed from high‐resolution diatom records derived from two marine sediment cores. A modern data set composed of 35 dated surface sediment samples collected along the West Greenland coast accompanied by remote sensing data was used to develop a diatom transfer function to reconstruct April sea ice concentration (SIC) supported by July sea surface temperature (SST) in the area. Our quantitative reconstruction shows that oceanographic changes recorded throughout the last ~11,000 years reflect seasonal interplay between spring (April SIC) and summer (July SST) conditions. Our records show clear correlation with climate patterns identified from ice core data from GISP2 and Agassiz‐Renland for the early to middle Holocene. The early Holocene deglaciation of western Greenland Ice Sheet was characterized in Disko Bay by initial strong centennial‐scale fluctuations in April SIC with amplitude of over 40%, followed by high April SIC and July SST. These conditions correspond to a general warming of the climate in the Northern Hemisphere. A decrease in April SIC and July SST was recorded during the Holocene Thermal Optimum reflecting more stable spring‐summer conditions in Disko Bay. During the late Holocene, high April SIC characterized the Medieval Climate Anomaly, while high July SST prevailed during the Little Ice Age, supporting previously identified antiphase relationship between surface waters in West Greenland and climate in NW Europe. This antiphase pattern might reflect seasonal variations in regional oceanographic conditions and large‐scale fluctuations within the North Atlantic Oscillation and Atlantic Meridional Overturning Circulation.

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Section: Resultsmentioning

confidence: 99%

Quantitative reconstruction of Holocene sea ice and sea surface temperature off West Greenland from the first regional diatom data set

et al. 2017

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“…In particular, the sample is dominated by sequences assigned to Skeletonema, Thalassiosira and Pseudo-nitzschia granii. Thalassiosira angulata, a species associated with low sea-ice concentrations (Oksman et al, 2019) and temperate water masses (Weckström et al, 2014), displays peak proportions in this sample. Lower proportions of sympagic diatoms in this sample are in accordance with the sea-ice retreat reconstructed from low IP25 and high brassicasterol concentrations (Müller and Stein, 2014) and high proportions of the subpolar planktic foraminifers…”

Section: Temporal Change Of Taxonomic Richness and Compositionmentioning

confidence: 83%

“…Pseudo-nitzschia granii (Lovejoy et al, 2002)) alongside the temperate to warm-water species Detonula pumila (Hasle, 1976) and Thalassiosira angulata (Krawczyk et al, 2013;Luddington et al, 2016;Weckström et al, 2014) and some cosmopolitans (Minidiscus trioculatus and Cerataulina pelagica (Hasle, 1976)). Beyond marine diatoms, sequences are also assigned to species preferring fresh to brackish water (e.g.…”

Section: Temporal Change Of Taxonomic Richness and Compositionmentioning

confidence: 99%

Changes in the composition of marine and sea-ice diatoms derived from sedimentary ancient DNA of the eastern Fram Strait over the past 30,000 years

Zimmermann¹,

Stoof‐Leichsenring²,

Kruse³

et al. 2019

Preprint

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Abstract. The Fram Strait is an area with a relatively low and irregular distribution of diatom microfossils in surface sediments, and thus microfossil records are underrepresented, rarely exceed the Holocene and contain sparse information about past diversity and taxonomic composition. These attributes make the Fram Strait an ideal study site to test the utility of sedimentary ancient DNA (sedaDNA) metabarcoding. By amplifying a short, partial rbcL marker, 95.7 % of our sequences are assigned to diatoms across 18 different families with 38.6 % of them being resolved to species and 25.8 % to genus level. Independent replicates show high similarity of PCR products, especially in the oldest samples. Diatom richness is highest in the Late Weichselian and lowest in Mid- and Late-Holocene samples. Taxonomic composition is dominated by cold-water and sea-ice associated diatoms and shows two re-organizations – one after the Last Glacial Maximum and another after the Younger Dryas. Different sequences assigned, amongst others, to Chaetoceros socialis indicate the detectability of intra-specific diversity using sedaDNA. We detect no clear pattern between our diatom sedaDNA record and the previously published IP25 record of this core, although proportions of pennate diatoms increase with higher IP25 concentrations and proportions of Nitzschia cf. frigida exceeding 2 % of the assemblage point towards past sea-ice presence.

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“…Significant percentages (3-18%) of diatom species Thalassiosira aff kushirensis Takano were present in sediments of the late RWP and the late MCA. This species has, according to different reports, an alternative habitat in warmer, temperate Atlantic (Krawczyk et al 2012) or cold Arctic (Weckström et al 2014) water so that we hesitate to use it as a reliable palaeoenvironmental proxy. Typical sea-ice species like Fragilariopsis cylindrus (Grunow) Helmcke & Krieger and F. oceanica (Cleve) Hasle were not found.…”

Section: Resultsmentioning

confidence: 99%

Warm-water events in the eastern Fram Strait during the last 2000 years as revealed by different microfossil groups

et al. 2018

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The environmental system of the northern Nordic Seas is very sensitive to oceanographic and climatic changes at the contact of cold Arctic and warmer North Atlantic waters. These contrasts are reflected in the associations of marine microorganisms and archived in the bottom sediments. A microfossil study (diatoms, coccoliths) of late Holocene sediments in core MSM5/5-712-1 from the eastern Fram Strait provides a better understanding of marine ecosystems and palaeoenvironments during Arctic warming events of the last two millennia. Indicative diatom species and groups of species revealed a high variability of sea-surface conditions. Based on the diatom distribution, three warming periods could be detected, corresponding to the time intervals of 0 to 440 CE (the later part of the Roman Warm Period), 1200 to1420 CE (the final part of the Medieval Climate Anomaly) and 1730 CE to present (including the Recent Warming). The various micropalaeontological proxies used in this study and other publications describe the Roman Warm Period and, especially, the Recent Warming as the most pronounced warm events in the area during the last 2000 years. A comparison of data from the different microfossil groups, indicators of seasurface and subsurface conditions, reveals variable, complicated and non-simultaneous palaeoenvironmental signals within the warm periods. This can potentially be explained by changes in the surface/subsurface water structure during the events (variations in the cold/ warm water advection, stratification, availability of nutrients, seasonal succession of bioproductivity, etc.), which are reflected by changes in the microplankton communities.

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Sea surface temperatures in Disko Bay during the Little Ice Age – caution needs to be exercised before assigning Thalassiosira kushirensis resting spore as a warm-water indicator in palaeoceanographic studies

Cited by 10 publications

References 25 publications

Quantitative reconstruction of Holocene sea ice and sea surface temperature off West Greenland from the first regional diatom data set

Quantitative reconstruction of Holocene sea ice and sea surface temperature off West Greenland from the first regional diatom data set

Changes in the composition of marine and sea-ice diatoms derived from sedimentary ancient DNA of the eastern Fram Strait over the past 30,000 years

Warm-water events in the eastern Fram Strait during the last 2000 years as revealed by different microfossil groups

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