cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.1594/pangaea.848479
title: (Table 1) Sympagic meiofauna and amphipods inhabiting the meltponds in the Central Arctic sampled during POLARSTERN cruise ARK-XXII/2

description: Meltponds on Arctic sea ice have previously been reported to be devoid of marine metazoans due to fresh-water conditions. The predominantly dark frequently also green and brownish meltponds observed in the Central Arctic in summer 2007 hinted to brackish conditions and considerable amounts of algae, possibly making the habitat suitable for marine metazoans. Environmental conditions in meltponds as well as sympagic meiofauna in new ice covering pond surfaces and in rotten ice on the bottom of ponds were studied, applying modified techniques from sea-ice and under-ice research. Due to the very porous structure of the rotten ice, the meltponds were usually brackish to saline, providing living conditions very similar to sub-ice water. The new ice cover on the surface had similar characteristics as the bottom layer of level ice. The ponds were thus accessible to and inhabitable by metazoans. The new ice cover and the rotten ice were inhabited by various sympagic meiofauna taxa, predominantly ciliates, rotifers, acoels, nematodes and foraminiferans. Also, sympagic amphipods were found on the bottom of meltponds. We suggest that, in consequence of global warming, brackish and saline meltponds are becoming more frequent in the Arctic, providing a new habitat to marine metazoans.
description: +++ abundant and dominant, ++ abundant, + present in low abundance, - not observed. Taxa, which were found in level ice (bottom 5 cm) or sub-ice (layer 0 m) but not in meltponds are also listed (all cells "-").
description: Supplement to: Kramer, Maike; Kiko, Rainer (2011): Brackish meltponds on Arctic sea ice - a new habitat for marine metazoans. Polar Biology, 34(4), 603-608
DOI: 10.1594/pangaea.848503
title: (Tables 1-3) Amphipod species observed under Antarctic pack ice during POLARSTERN cruises ANT-XXI/4, ANT-XXII/2 and ANT-XXIII/6

description: During three Antarctic expeditions (2004, ANT XXI-4 and XXII-2; 2006, ANT XXIII-6) with the German research icebreaker R/V Polarstern, six different amphipod species were recorded under the pack ice of the Weddell Sea and the Lazarev Sea. These cruises covered Austral autumn (April), summer (December) and winter (August) situations, respectively. Five of the amphipod species recorded here belong to the family Eusiridae (Eusirus antarcticus, E. laticarpus, E. microps, E. perdentatus and E. tridentatus), while the last belongs to the Lysianassidea, genus Cheirimedon (cf. femoratus). Sampling was performed by a specially designed under-ice trawl in the Lazarev Sea, whereas in the Weddell Sea sampling was done by scuba divers and deployment of baited traps. In the Weddell Sea, individuals of E. antarcticus and E. tridentatus were repeatedly observed in situ during under-ice dives, and single individuals were even found in the infiltration layer. Also in aquarium observations, individuals of E. antarcticus and E. tridentatus attached themselves readily to sea ice. Feeding experiments on E. antarcticus and E. tridentatus indicated a carnivorous diet. Individuals of the Lysianassoid Cheirimedon were only collected in baited traps there. Repeated conventional zooplankton hauls performed in parallel to this study did not record any of these amphipods from the water column. In the Lazarev Sea, E. microps, E. perdentatus and E. laticarpus were regularly found in under-ice trawls. We discuss the origin and possible sympagic life style of these amphipods.
description: + = present, - = absent.
description: Supplement to: Krapp, Rupert H; Berge, Jørgen; Flores, Hauke; Gulliksen, Bjørn; Werner, Iris (2008): Sympagic occurrence of Eusirid and Lysianassoid amphipods under Antarctic pack ice. Deep Sea Research Part II: Topical Studies in Oceanography, 55(8-9), 1015-1023
DOI: 10.1594/pangaea.848509
title: (Table 2) Stable carbon and nitrogen isotope ratios and molar C/N ratio for euchaetid and aetideid copepods during POLARSTERN cruise ANT-XXIII/5

description: Stable isotope (SI) ratios of carbon (d13C) and nitrogen (d15N) were measured in omnivorous and carnivorous deep-sea copepods of the families Euchaetidae and Aetideidae across the Atlantic sector of the Southern Ocean to establish their trophic positions. Due to high and variable C/N ratios related to differences in lipid content, d13C was corrected using a lipid-normalisation model. d15N signals ranged from 3.0-6.9 per mil in mesopelagic species to 7.0-9.5 per mil in bathypelagic congeners. Among the carnivorous Paraeuchaeta species, the epi- to mesopelagic species Paraeuchaeta antarctica had lower d15N values than the mesopelagic P. rasa and bathypelagic P. barbata. The same trend was observed among omnivorous Aetideidae, but was not significant. In the most abundant species P. antarctica, individuals from the western Atlantic had higher d13C and d15N values than specimens at the eastern stations. These longitudinal changes in d13C and d15N values were attributed to regional differences in hydrography and sea surface temperature (SST), in particular related to a northward extension of the Antarctic Polar Front (APF) at the easternmost stations. The results indicate that even in a mesopelagic carnivorous species, the changes in surface stable isotope signatures are pronounced.
description: Supplement to: Laakmann, Silke; Auel, Holger (2009): Longitudinal and vertical trends in stable isotope signatures (d13C and d15N) of omnivorous and carnivorous copepods across the South Atlantic Ocean. Marine Biology, 157(3), 463-471
DOI: 10.1594/pangaea.848590
title: Phytoplankton pigment concentrations during POLARSTERN cruise ANT-XXVII/2

description: Photophysiological processes as well as uptake characteristics of iron and inorganic carbon were studied in inshore phytoplankton assemblages of the Western Antarctic Peninsula (WAP) and offshore assemblages of the Drake Passage. Chlorophyll a concentrations and primary productivity decreased from in- to offshore waters. The inverse relationship between low maximum quantum yields of photochemistry in PSII (Fv/Fm) and large sizes of functional absorption cross sections (sigma PSII) in offshore communities indicated iron-limitation. Congruently, the negative correlation between Fv/Fm values and iron uptake rates across our sampling locations suggest an overall better iron uptake capacity in iron-limited pelagic phytoplankton communities. Highest iron uptake capacities could be related to relative abundances of the haptophyte Phaeocystis antarctica. As chlorophyll a-specific concentrations of humic-like substances were similarly high in offshore and inshore stations, we suggest humic-like substances may play an important role in iron chemistry in both coastal and pelagic phytoplankton assemblages. Regarding inorganic carbon uptake kinetics, the measured maximum short-term uptake rates (Vmax(CO2)) and apparent half-saturation constants (K1/2(CO2)) did not differ between offshore and inshore phytoplankton. Moreover, Vmax(CO2) and K1/2(CO2) did not exhibit any CO2-dependent trend over the natural pCO2 range from 237 to 507 µatm. K1/2(CO2) strongly varied among the sampled phytoplankton communities, ranging between 3.5 and 35.3 µmol/L CO2. While in many of the sampled phytoplankton communities, the operation of carbon-concentrating mechanisms (CCMs) was indicated by low K1/2(CO2) values relative to ambient CO2 concentrations, some coastal sites exhibited higher values, suggesting down-regulated CCMs. Overall, our results demonstrate a complex interplay between photophysiological processes, iron and carbon uptake of phytoplankton communities of the WAP and the Drake Passage.
DOI: 10.1594/pangaea.848592
title: Underway water measurements of halocarbons during METEOR cruise M91
DOI: 10.1594/pangaea.848596
title: Halocarbons measured on water bottle samples during METEOR cruise M91
DOI: 10.1594/pangaea.848304
title: Snow thickness measurements at sea ice station PS89/030-5

description: Measurements were obtained using a MagnaProbe (Snow-Hydro, Fairbanks, Alaska, USA) during walking surveys on each ice station. The walks were randomly done on the entire floe. Geographic coordinates were corrected for ice drift motion.
DOI: 10.1594/pangaea.848615
title: Underway measurements of dissolved gases along POLARSTERN cruise track ANT-XXVII/2

description: We present measurements of pCO2, O2 concentration, biological oxygen saturation (Delta O2/Ar) and N2 saturation (Delta N2) in Southern Ocean surface waters during austral summer, 2010-2011. Phytoplankton biomass varied strongly across distinct hydrographic zones, with high chlorophyll a (Chla) concentrations in regions of frontal mixing and sea-ice melt. pCO2 and Delta O2 /Ar exhibited large spatial gradients (range 90 to 450 µatm and -10 to 60%, respectively) and co-varied strongly with Chla. However, the ratio of biological O2 accumulation to dissolved inorganic carbon (DIC) drawdown was significantly lower than expected from photosynthetic stoichiometry, reflecting the differential time-scales of O2 and CO2 air-sea equilibration. We measured significant oceanic CO2 uptake, with a mean air-sea flux (~ -20 mmol m-2 d-1) that significantly exceeded regional climatological values. N2 was mostly supersaturated in surface waters (mean Delta N2 of +2.5 %), while physical processes resulted in both supersaturation and undersaturation of mixed layer O2 (mean Delta O2phys = 2.1 %). Box model calculations were able to reproduce much of the spatial variability of Delta N2 and Delta O2phys along the cruise track, demonstrating significant effects of air-sea exchange processes (e.g. atmospheric pressure changes and bubble injection) and mixed layer entrainment on surface gas disequilibria. Net community production (NCP) derived from entrainment-corrected surface Delta O2 /Ar data, ranged from ~ -40 to &gt; 300 mmol O2 m-2 d-1 and showed good coherence with independent NCP estimates based on seasonal mixed layer DIC deficits. Elevated NCP was observed in hydrographic frontal zones and regions of sea-ice melt with shallow mixed layer depths, reflecting the importance of mixing in controlling surface water light and nutrient availability.
description: Supplement to: Tortell, Philippe Daniel; Bittig, Henry; Körtzinger, Arne; Jones, Elizabeth M; Hoppema, Mario (2015): Biological and physical controls on N2, O2, and CO2 distributions in contrasting Southern Ocean surface waters. Global Biogeochemical Cycles, 29(7), 994-1013
DOI: 10.1594/pangaea.848305
title: Snow thickness measurements at sea ice station PS89/032-1

description: Measurements were obtained using a MagnaProbe (Snow-Hydro, Fairbanks, Alaska, USA) during walking surveys on each ice station. The walks were randomly done on the entire floe. Geographic coordinates were corrected for ice drift motion.
DOI: 10.1594/pangaea.848306
title: Snow thickness measurements at sea ice station PS89/035-1

description: Measurements were obtained using a MagnaProbe (Snow-Hydro, Fairbanks, Alaska, USA) during walking surveys on each ice station. The walks were randomly done on the entire floe. Geographic coordinates were corrected for ice drift motion.
DOI: 10.1594/pangaea.848307
title: Snow thickness measurements at sea ice station PS89/040-1

description: Measurements were obtained using a MagnaProbe (Snow-Hydro, Fairbanks, Alaska, USA) during walking surveys on each ice station. The walks were randomly done on the entire floe. Geographic coordinates were corrected for ice drift motion.
DOI: 10.1594/pangaea.848308
title: Snow thickness measurements at sea ice station PS89/046-1

description: Measurements were obtained using a MagnaProbe (Snow-Hydro, Fairbanks, Alaska, USA) during walking surveys on each ice station. The walks were randomly done on the entire floe. Geographic coordinates were corrected for ice drift motion.
DOI: 10.1594/pangaea.848309
title: Snow thickness measurements at sea ice station PS89/032-1 (on ROV grid only)

description: Measurements were obtained using a MagnaProbe (Snow-Hydro, Fairbanks, Alaska, USA) during walking surveys in straight lines on the optical measurement field. Geographic coordinates were corrected for ice drift motion.
DOI: 10.1594/pangaea.848310
title: Snow thickness measurements at sea ice station PS89/040-1 (on ROV grid only)

description: Measurements were obtained using a MagnaProbe (Snow-Hydro, Fairbanks, Alaska, USA) during walking surveys in straight lines on the optical measurement field. Geographic coordinates were corrected for ice drift motion.
DOI: 10.1594/pangaea.848311
title: Snow thickness measurements at sea ice station PS89/046-1 (on ROV grid only)

description: Measurements were obtained using a MagnaProbe (Snow-Hydro, Fairbanks, Alaska, USA) during walking surveys in straight lines on the optical measurement field. Geographic coordinates were corrected for ice drift motion.
DOI: 10.1594/pangaea.848345
title: Snow density measurements at sea ice ice stations during Polarstern cruise PS89 (ANT-XXX/2)

description: Measurements were obtained doing classical snow pits at every (snow-covered) ice station during PS89. Snow pits were taken once per ice station at a representative location of the floe. Measurments were done on an undisturbed shaded working wall of the snow pit.
DOI: 10.1594/pangaea.848346
title: Snow density and liquid water content measurements at sea ice ice stations during Polarstern cruise PS89 (ANT-XXX/2)

description: Measurements were obtained doing classical snow pits at every (snow-covered) ice station during PS89. Snow pits were taken once per ice station at a representative location of the floe. Measurments were done on an undisturbed shaded working wall of the snow pit. Additional density and liquid water content measurements were performed with a Snow Fork (Toikka, Finland) twice per measuring level (only used for stations PS89/040-1, PS89/046-1, and PS89/050-1).
DOI: 10.1594/pangaea.848347
title: Snow grain size and type determination at sea ice ice stations during Polarstern cruise PS89 (ANT-XXX/2)

description: Measurements were obtained doing classical snow pits at every (snow-covered) ice station during PS89. Snow pits were taken once per ice station at a representative location of the floe. Measurments were done on an undisturbed shaded working wall of the snow pit.
DOI: 10.1594/pangaea.848348
title: Snow temperature measurements at sea ice ice stations during Polarstern cruise PS89 (ANT-XXX/2)

description: Measurements were obtained doing classical snow pits at every (snow-covered) ice station during PS89. Snow pits were taken once per ice station at a representative location of the floe. Measurments were done on an undisturbed shaded working wall of the snow pit.
DOI: 10.1594/pangaea.848966
title: (Table 1) Statistics of size measurements of Lagenoeca antarctica sp. n. and Salpingoeca abyssalis sp. n. (floating form) sampled during POLARSTERN cruise ANT-XXII/2 and METEOR cruise M63/2

description: Despite their high abundance and their high importance for the oceanic matter flux, heterotrophic nanoflagellates are only poorly studied in the deep-sea regions. Studies on the choanoflagellate distribution during two deep-sea expeditions, to the South Atlantic (5038 m) and Antarctica (Weddell Sea, 2551 m), revealed the deepest records of choanoflagellates so far. A new species, (Lagenoeca antarctica) with a conspicuous spike structure on the theca is described from deep Antarctic waters. Lagenoeca antarctica sp. n. is a solitary unstalked free living salpingoecid-like choanoflagellate. The protoplast is surrounded by a typical theca with unique spikes only visible in SEM micrographs. The ovoid cell nearly fills the whole theca and ranges in size from 4 to 6 µm. The collar measures 2-3 µm and the flagellum 3-5 µm. A second species, Salpingoeca abyssalis sp. n., was isolated from the abyssal plain of the South Atlantic (5038 m depth). Floating and attached forms were observed. The protoplast ranges from to 2 to 4 µm in length and 1 to 2 µm in width. The collar is about the same length as the protoplast and the flagellum has 2 to 2.5 × the length of the protoplast. Phylogenetic analyses based on a fragment of SSU rDNA revealed Salpingoeca abyssalis to cluster together with a marine isolate of Salpingoeca infusionum while Lagenoeca antarctica clusters separately from the other codonosigid and salpingoecid taxa. Salpingoeca abyssalis and an undetermined Monosiga species seems to be the first choanoflagellate species recorded from the abyssal plain.
description: n = 25
description: Supplement to: Nitsche, Frank; Weitere, Markus; Scheckenbach, Frank; Hausmann, Klaus; Wylezich, Claudia; Arndt, Hartmut (2007): Deep sea records of Choanoflagellates with a description of two new species. Acta Protozoologica, 46, 99-106
DOI: 10.1594/pangaea.849040
title: Total dissolved organic carbon and total dissolved nitrogen in sediment pore water of the central Arctic Ocean collected during POLARSTERN cruise ARK-XXVII/3 from August-September 2012

description: During the RV Polarstern cruise ARK-XXVII/3 to the Arctic Ocean in summer 2012, when sea ice declined to a record minimum bottom, water and sediment pore water samples were collected with a TV-guided multicorer at stations in the Nansen and Amundsen basin. 50 ml sediment pore water samples were collected from 0-1, 1-5 and 5-10 cm sediment depths from up to 4 parallel sediment cores at each station. Additionally, overlying bottom waters were carefully collected from undisturbed sediment cores. Acidified pore water samples (pH2) were used for analysis of DOC and TDN concentrations. The measurements were performed by hand injection via catalytic oxidation at high temperature on a TOC-V Shimadzu instrument.
description: This is a contribution to the European Research Council Advanced Investigator Grant 294757 to Antje Boetius.
DOI: 10.1594/pangaea.847788
title: Ammonium excretion data for the squat lobster Pleuroncodes monodon measured during METEOR cruise M93
DOI: 10.1594/pangaea.847789
title: Respiration rate data for the squat lobster Pleuroncodes monodon measured during METEOR cruise M93
DOI: 10.1594/pangaea.847835
title: Station list and links to master tracks in different resolutions of POLARSTERN cruise ANT-XVIII/1, Bremerhaven - Cape Town, 2000-09-29 - 2000-10-24
DOI: 10.1594/pangaea.848739
title: Color measurements on sediment core PS2623-4

description: The color reflectance of dried sediment was measured with an X-Rite spectrophotometer, Model 500 Series, using the CIE* system, with L* a measure of black to white, a* (blue to red) and b* (yellow to green. The prepared dry samples were tapped into a 2.5 cm dia. aluminum XRD holder, overlain by a clear glass slide, and measured. A Pantone Color Chip (4705) was measured repeatedly to evaluate instrument drift.
DOI: 10.1594/pangaea.848740
title: Color measurements on sediment core PS2629-2

description: The color reflectance of dried sediment was measured with an X-Rite spectrophotometer, Model 500 Series, using the CIE* system, with L* a measure of black to white, a* (blue to red) and b* (yellow to green. The prepared dry samples were tapped into a 2.5 cm dia. aluminum XRD holder, overlain by a clear glass slide, and measured. A Pantone Color Chip (4705) was measured repeatedly to evaluate instrument drift.
DOI: 10.1594/pangaea.848741
title: Color measurements on sediment core PS2630-5

description: The color reflectance of dried sediment was measured with an X-Rite spectrophotometer, Model 500 Series, using the CIE* system, with L* a measure of black to white, a* (blue to red) and b* (yellow to green. The prepared dry samples were tapped into a 2.5 cm dia. aluminum XRD holder, overlain by a clear glass slide, and measured. A Pantone Color Chip (4705) was measured repeatedly to evaluate instrument drift.
DOI: 10.1594/pangaea.848742
title: Color measurements on sediment core PS2631-5

description: The color reflectance of dried sediment was measured with an X-Rite spectrophotometer, Model 500 Series, using the CIE* system, with L* a measure of black to white, a* (blue to red) and b* (yellow to green. The prepared dry samples were tapped into a 2.5 cm dia. aluminum XRD holder, overlain by a clear glass slide, and measured. A Pantone Color Chip (4705) was measured repeatedly to evaluate instrument drift.
DOI: 10.1594/pangaea.848743
title: Color measurements on sediment core PS2640-6

description: The color reflectance of dried sediment was measured with an X-Rite spectrophotometer, Model 500 Series, using the CIE* system, with L* a measure of black to white, a* (blue to red) and b* (yellow to green. The prepared dry samples were tapped into a 2.5 cm dia. aluminum XRD holder, overlain by a clear glass slide, and measured. A Pantone Color Chip (4705) was measured repeatedly to evaluate instrument drift.
DOI: 10.1594/pangaea.848744
title: Color measurements on sediment core PS2641-4

description: The color reflectance of dried sediment was measured with an X-Rite spectrophotometer, Model 500 Series, using the CIE* system, with L* a measure of black to white, a* (blue to red) and b* (yellow to green. The prepared dry samples were tapped into a 2.5 cm dia. aluminum XRD holder, overlain by a clear glass slide, and measured. A Pantone Color Chip (4705) was measured repeatedly to evaluate instrument drift.
DOI: 10.1594/pangaea.848745
title: Grain-size analysis on sediment core PS2623-4

description: Grain-size analyses were undertaken on sediments from PS2623, PS2631, PS2640, and PS2641 using a Malvern model 2000 laser system for the range 2000 to 0.5 µm. Add 5mL of hydrogen peroxide again and repeat the process. Keep repeating the process until the organic is gone (there is no reaction occurring). When organic is removed and the beakers are cooled a little add 8-10mL of magnesium chloride to each beaker.
DOI: 10.1594/pangaea.848746
title: Grain-size analysis on sediment core PS2631-5

description: Grain-size analyses were undertaken on sediments from PS2623, PS2631, PS2640, and PS2641 using a Malvern model 2000 laser system for the range 2000 to 0.5 µm. Add 5mL of hydrogen peroxide again and repeat the process. Keep repeating the process until the organic is gone (there is no reaction occurring). When organic is removed and the beakers are cooled a little add 8-10mL of magnesium chloride to each beaker.
DOI: 10.1594/pangaea.848747
title: Grain-size analysis on sediment core PS2640-6

description: Grain-size analyses were undertaken on sediments from PS2623, PS2631, PS2640, and PS2641 using a Malvern model 2000 laser system for the range 2000 to 0.5 µm. Add 5mL of hydrogen peroxide again and repeat the process. Keep repeating the process until the organic is gone (there is no reaction occurring). When organic is removed and the beakers are cooled a little add 8-10mL of magnesium chloride to each beaker.
DOI: 10.1594/pangaea.848748
title: Grain-size analysis on sediment core PS2641-4

description: Grain-size analyses were undertaken on sediments from PS2623, PS2631, PS2640, and PS2641 using a Malvern model 2000 laser system for the range 2000 to 0.5 µm. Add 5mL of hydrogen peroxide again and repeat the process. Keep repeating the process until the organic is gone (there is no reaction occurring). When organic is removed and the beakers are cooled a little add 8-10mL of magnesium chloride to each beaker.
DOI: 10.1594/pangaea.848752
title: XRD mineralogy of sediment core PS2629-2

description: We employ the quantitative X-ray diffraction method developed by Eberl (2003, 2004). The sediment &lt; 2 mm are spiked by 10% by weight of zincite, milled, and the samples are scanned on a D5000 Siemens X-Ray Diffractometer between 5° and 65° 2-theta with a 0.02° step and a 2-sec count. The resulting 3000 data points are loaded into the Excel macro-program Rockjock v6 (Eberl, 2003) and the weight% of minerals in the sediment mixtures calculated against a suite of 124 "standard" mineral patterns (Eberl, 2003). Finally, the data are normalized to sum to 100%