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  • European Marine Science
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  • PANGAEA - Data Publisher for Earth and Environmental Science

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  • Open Access English
    Authors: 
    Michaud, Alexander B; Laufer, Katja; Findlay, Alyssa; Pellerin, Andre; Antler, Gilad; Turchyn, Alexandra V; Røy, Hans; Wehrmann, Laura Mariana; Jørgensen, Bo Barker;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | MICROENERGY (294200)

    In the summer of 2016, we collected sediment cores from three fjords (Smeerenburgfjorden, stn. J; Kongsfjorden, stn. P; and Van Keulenfjorden, stn. AC). These cores were both long cores (~80 cm) and short (~25 cm) where we conducted porewater geochemistry and incubation experiments to quantify the rate of sulfide oxidation and changes to the reactive Fe(III)-oxide pool over time. All coordinates of sampling sites are in the data file. The methods are included in the manuscript doi:10.1016/j.gca.2019.12.033.

  • Other research product . Other ORP type . Collection . 2020
    Open Access English
    Authors: 
    Heuer, Verena B; Inagaki, F; Morono, Yuki; Kubo, Y; Spivack, Arthur J; Viehweger, Bernhard; Treude, Tina; Beulig, F; Schubotz, Florence; Tonai, S; +32 more
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science

    This data set documents data for a publication currently under consideration at Science. It documents data obtained for IODP Site C0023 during IODP Expedition 370. The data include: concentration of microbial cells and concentration of endospores in sediments, concentration and isotopic composition of methane and acetate in interstitial waters.

  • Open Access English
    Authors: 
    Maturilli, Marion; Kayser, Markus;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science

    Radiosonde measurements obtained at the Arctic site Ny-Ålesund (78.9°N, 11.9°E), Svalbard, from 1993 to 2014 have been homogenized accounting for instrumentation discontinuities by correcting known errors in the manufacturer provided profiles. From the homogenized data record, the first Ny-Ålesund upper-air climatology of wind, temperature and humidity is presented, forming the background for the analysis of changes during the 22-year period. Particularly during the winter season, a strong increase in atmospheric temperature and humidity is observed, with a significant warming of the free troposphere in January and February up to 3 K per decade. This winter warming is even more pronounced in the boundary layer below 1 km, presumably amplified by mesoscale processes including e.g. orographic effects or the boundary layer capping inversion. Though the largest contribution to the increasing atmospheric water vapour column in winter originates from the lowermost 2 km, no increase in the contribution by specific humidity inversions is detected. Instead, we find an increase in the humidity content of the large-scale background humidity profiles. At the same time, the tropospheric flow in winter is found to occur less frequent from northerly directions and to the same amount more frequent from the South. We conclude that changes in the atmospheric circulation lead to an enhanced advection of warm and moist air from lower latitudes to the Svalbard region in the winter season, causing the warming and moistening of the atmospheric column above Ny-Ålesund, and link the observations to changes in the Arctic Oscillation.

  • Open Access English
    Authors: 
    Nürnberg, Dirk; Fütterer, Dieter K; Niessen, Frank; et al.;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science

    Marine geological investigations were performed across the Laptev Sea continental shelf and slope. Thirty sampling sites were selected covering a depth range of ca 3500 m. Maximum core recovery was 9 m. PARASOUND sub-bottom profiling was used for site surveying and provided important information on the depositional environment of the continental margin together with sedimentological and stratigraphical investigations. Undisturbed horizontal layering of the sea-floor sediments is a common feature for the Laptev Sea shelf. There is no indication for glaciation of the broad shelf region during the Last Glacial, since moraine deposits are missing. However, a high number of plough marks in places points to recent to sub-recent ice-erosion which has led to an intensive sediment reworking on the shelf. Several broadly incised river channels recorded near the shelf edge are related to Pleistocene drainage systems of large Siberian rivers which cut into the dry shelves during the Last Glacial Maximum and were subsequently filled during the Holocene. During the Last Glacial we therefore suspect a significant freshwater contribution from the Eurasian continent to the Arctic Oceans. The composition of the normally consolidated core sediments indicates a strong flux of terrigenous material, which is mainly provided by the Siberian rivers. Currents distributing the suspension load and sea ice are supposedly major agents transporting sediments across the shelf to the central arctic deep sea basin. Sediment cores from the upper and middle continental slope exhibit only minor lithological changes. Bioturbated, fine-grained sediments with high organic carbon contents dominate. The presence of free hydrogen sulphide gas within the sediment column indicates that an intense decay of organic matter under reducing conditions is taking place. Sedimentation rates are estimated to be ca. 50 cm/1000 years at the upper slope of the western Laptev Sea, being approximately 10 times higher than at the continental rise. The suboxic to anoxic environment diminishes at deep sea sites of the western Laptev Sea, where sedimentation rates and influx of organic matter are reduced.

  • Open Access English
    Authors: 
    Binczewska, Anna; Risebrobakken, Bjørg; Polovodova Asteman, Irina; Moros, Matthias; Tisserand, Amandine; Jansen, Eystein; Witkowski, A;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science

    We present results from two sediment cores from the central (EMB046/20-3GC) and western (EMB046/10-4GC) Skagerrak. Both cores were dated by Hg pollution records and AMS 14C and analysed for palaeoproductivity proxies such as total organic carbon, δ13C, total planktonic foraminifera, benthic foraminifera (total assemblages as well as abundance of Brizalina skagerrakensis and other palaeoproductivity taxa) and palaeothermometers such as Mg/Ca and δ18O. Our results reveal two periods with changes in productivity in the Skagerrak region: i) a moderate productivity at ~ CE 900 – 1700 and ii) a high productivity at ~ CE 1700 – present.

  • Open Access English
    Authors: 
    Stumpp, Meike; Wren, J; Melzner, Frank; Thorndyke, Mike; Dupont, Sam;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | EPOCA (211384)

    Anthropogenic CO2 emissions are acidifying the world's oceans. A growing body of evidence is showing that ocean acidification impacts growth and developmental rates of marine invertebrates. Here we test the impact of elevated seawater pCO2 (129 Pa, 1271 µatm) on early development, larval metabolic and feeding rates in a marine model organism, the sea urchin Strongylocentrotus purpuratus. Growth and development was assessed by measuring total body length, body rod length, postoral rod length and posterolateral rod length. Comparing these parameters between treatments suggests that larvae suffer from a developmental delay (by ca. 8%) rather than from the previously postulated reductions in size at comparable developmental stages. Further, we found maximum increases in respiration rates of + 100 % under elevated pCO2, while body length corrected feeding rates did not differ between larvae from both treatments. Calculating scope for growth illustrates that larvae raised under high pCO2 spent an average of 39 to 45% of the available energy for somatic growth, while control larvae could allocate between 78 and 80% of the available energy into growth processes. Our results highlight the importance of defining a standard frame of reference when comparing a given parameter between treatments, as observed differences can be easily due to comparison of different larval ages with their specific set of biological characters.

  • Open Access English
    Authors: 
    Niemeyer, Bastian; Klemm, Juliane; Herzschuh, Ulrike; Pestryakova, Luidmila A;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science

    Pollen productivity estimates (PPE) are used to quantitatively reconstruct variations in vegetation within a specific distance of the sampled pollen archive. Here, for the first time, PPEs from Siberia are presented. The study area (Khatanga region, Krasnoyarsk territory, Russia) is located in the Siberian Sub-arctic where Larixis the sole forest-line forming tree taxon. Pollen spectra from two different sedimentary environments, namely terrestrial mosses (n=16) and lakes (n=15, median radius ~100 m) and their surrounding vegetation were investigated to extract PPEs. Our results indicate some differences in pollen spectra between moss and lake pollen. Larix and Cyperaceae for example obtained higher representation in the lacustrine than in terrestrial moss samples. This highlights that in calibration studies modern and fossil dataset should be of similar sedimentary origin. The results of the Extended R-Value model were applied to assess the relevant source area of pollen (RSAP) and to calculate the PPEs for both datasets. As expected, the RSAP of the moss samples was very small (about 10 m) compared to the lacustrine samples (about 25 km). Calculation of PPEs for the six most common taxa yielded generally similar results for both datasets. Relative to Poaceae (reference taxon, PPE=1) Betula nana-type (PPEmoss: 1.8, PPElake: 1.8) and Alnusfruticosa-type (PPEmoss: 6.4, PPElake: 2.9) were overrepresented while Cyperaceae (PPEmoss: 0.5, PPElake: 0.1), Ericaceae (PPEmoss: 0.3, PPElake <0.01), Salix (PPEmoss: 0.03, PPElake <0.01) and Larix (PPEmoss <0.01, PPElake: 0.2) were under-represented in the pollen spectra compared to the vegetation in the RSAP. The estimation for the dominant tree in the region, Larixgmelinii, is the first published result for this species, but need to be considered very preliminary. The inferred sequence from over- to under-representation is mostly consistent with results from Europe; however, still the absolute values show some differences. Gathering vegetation data was limited by flowering season and low resolute satellite imagery and accessibility of the remote location of our study area. Therefore, our estimate may serve as first reference to strengthen future vegetation reconstructions in this climate-sensitive region.

  • Open Access English
    Authors: 
    Lucey, Noelle M; Lombardi, Chiara; Florio, Maurizio; DeMarchi, Lucia; Nannini, Matteo; Rundle, Simon; Gambi, Maria Cristina; Calosi, Piero;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: NSERC

    Ocean acidification (OA) is likely to exert selective pressure on natural populations. Our ability to predict which marine species will adapt to OA, and what underlies this adaptive potential, are of high conservation and resource management priority. Using a naturally low pH vent site in the Mediterranean Sea (Castello Aragonese, Ischia) mirroring projected future OA conditions, we carried out a reciprocal transplant experiment to investigate the relative importance of phenotypic plasticity and local adaptation in two populations of the sessile, calcifying polychaete /Simplaria /sp. (Annelida, Serpulidae, Spirorbinae): one residing in low pH and the other from a nearby ambient (i.e. high) pH site. We measured a suite of fitness related traits (i.e. survival, reproductive output, maturation, population growth) and tube growth rates in laboratory-bred F2 generation individuals from both populations reciprocally transplanted back into both ambient and low pH /in situ/ habitats. Both populations showed lower expression in all traits, but increased tube growth rates, when exposed to low pH compared to high pH conditions, regardless of their site of origin suggesting that local adaptation to low pH conditions has not occurred. We also found comparable levels of plasticity in the two populations investigated, suggesting no influence of long-term exposure to low pH on the ability of populations to adjust their phenotype. Despite high variation in trait values among sites and the relatively extreme conditions at sites close to the vents (pH < 7.36), response trends were consistent across traits. Hence, our data suggest that, for /Simplaria /and possibly other calcifiers, neither local adaptations nor sufficient phenotypic plasticity levels appear to suffice in order to compensate for the negative impacts of OA on long-term survival. Our work also underlines the utility of field experiments in natural environments subjected to high level of /p/CO_2 for elucidating the potential for adaptation to future scenarios of OA. The first dataset includes data on the fitness traits assessed after the reciprocal transplant experiment, the second includes seawater (pH), temperature, and time of measurement, taken hourly at the low pH site (S2), during the reciprocal transplant experiment. The water parameters were taken hourly, from June 17, 2015 to July 6, 2015.

  • Open Access English
    Authors: 
    Schirrmeister, Lutz; Grigoriev, Mikhail N; Strauss, Jens; Grosse, Guido; Overduin, Pier Paul; Kholodov, Alexander L; Hubberten, Hans-Wolfgang;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science
    Project: EC | PETA-CARB (338335)

    We here present lithological, geochronological, and geochemical data from a core drilled in 1999 in the Ivashkina Lagoon on the Bykovsky Peninsula, Northeast Siberia.

  • Open Access English
    Authors: 
    Fischer, Gerhard; Karakas, Gökay;
    Publisher: PANGAEA - Data Publisher for Earth & Environmental Science

    The flux of materials to the deep sea is dominated by larger, organic-rich particles with sinking rates varying between a few meters and several hundred meters per day. Mineral ballast may regulate the transfer of organic matter and other components by determining the sinking rates, e.g. via particle density. We calculated particle sinking rates from mass flux patterns and alkenone measurements applying the results of sediment trap experiments from the Atlantic Ocean. We have indication for higher particle sinking rates in carbonate-dominated production systems when considering both regional and seasonal data. During a summer coccolithophorid bloom in the Cape Blanc coastal upwelling off Mauritania, particle sinking rates reached almost 570 m per day, most probably due the fast sedimentation of densely packed zooplankton fecal pellets, which transport high amounts of organic carbon associated with coccoliths to the deep ocean despite rather low production. During the recurring winter-spring blooms off NW Africa and in opal-rich production systems of the Southern Ocean, sinking rates of larger particles, most probably diatom aggregates, showed a tendency to lower values. However, there is no straightforward relationship between carbonate content and particle sinking rates. This could be due to the unknown composition of carbonate and/or the influence of particle size and shape on sinking rates. It also remains noticeable that the highest sinking rates occurred in dust-rich ocean regions off NW Africa, but this issue deserves further detailed field and laboratory investigations. We obtained increasing sinking rates with depth. By using a seven-compartment biogeochemical model, it was shown that the deep ocean organic carbon flux at a mesotrophic sediment trap site off Cape Blanc can be captured fairly well using seasonal variable particle sinking rates. Our model provides a total organic carbon flux of 0.29 Tg per year down to 3000 m off the NW African upwelling region between 5 and 35° N. Simple parameterisations of remineralisation and sinking rates in such models, however, limit their capability in reproducing the flux variation in the water column.