Kohlbach, Doreen; Kunisch, Erin H; Graeve, Martin; Fahl, Kirsten; Müller, Anja; Müller, Juliane; Lunden, Jonas; Woll, Matthias; Leu, Eva: Relative proportions of sterols in Melosira assemblages, pelagic and ice-associated particulate organic matter (PPOM and IPOM) collected during the RV Kronprins Haakon Arctic Ocean cruise 2024 [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.987100 (dataset in review)
Abstract:
During the AO2024 expedition (19 July to 12 August 2024), Melosira assemblages were collected using a handheld net at two sampling sites in the Amundsen Basin. Pelagic particulate organic matter (PPOM) was sampled at 13 stations spanning the Amundsen and Nansen Basins as well as the Gakkel Ridge, using Niskin bottles mounted on a CTD rosette. Between 3 and 6.5 L of seawater were filtered through GF/F filters. Ice-associated POM was obtained using a Kovacs 9 cm ice corer at one station each in the Amundsen and Nansen Basins; the bottom 10 cm of each ice core were melted with the addition of filtered seawater and filtered onto GF/F filters.
Lipids were extracted from freeze-dried samples following the method of Folch et al. (1957), using a dichloromethane/methanol mixture (2:1, v/v) in a sonication bath. Thereafter, lipids were saponified with 20% potassium hydroxide in water/methanol (1:9). Sterols were extracted with hexane, purified by open-column chromatography with SiO2 and eluted with methanol. Sterol fractions were derivatized using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). Sterols were analyzed with gas chromatography–mass spectrometry (Agilent 7890B, Agilent Technologies), equipped with a DB-1ms column (30 m length, 0.25 mm internal diameter, 0.25 μm film thickness) and an Agilent 5977A MSD, following Stein et al. (2025). The temperature program ranged from 60°C to 320°C. Sterols were quantified using an internal standard (androstanol).
Sterol analysis was conducted to complement datasets on fatty acid proportions and fatty acid stable isotope compositions. Collectively, the datasets enable a detailed characterization of the biochemical composition of different algal assemblages across the central Arctic Ocean.
Supplement to:
Kohlbach, Doreen; Kunisch, Erin H; Graeve, Martin; Fahl, Kirsten; Müller, Anja; Müller, Juliane; Lunden, Jonas; Woll, Matthias; Leu, Eva (submitted): Melosira arctica: algal superfood or nutritional dead-end for Arctic grazers? Elementa - Science of the Anthropocene
Related to:
Dodd, Paul Anthony; Wold, Anette; Ahmed, Fowzia; Darecki, Miroslaw; Duncan, Rebecca J; Fossan, Kristen; Goraguer, Lucie; Granskog, Mats A; Itkin, Polona; Kern, Yannick; Koenig, Zoé; Kohlbach, Doreen; Kovacs, Kit Maureen; Kowalczuk, Piotr; Christensen, Jakob; Leu, Eva; Lydersen, Christian; Muilwijk, Morven; Nowak, Benia; Randelhoff, Achim; Stürzinger, Vegard; Søreide, Janne E; Widera, Sara; Sviggum Helgerud, Trine Lise (2024): Arctic Ocean 2024 - Cruise Report. Norwegian Polar Institute, Tromsø, Norway, AO2024_cruise_report.pdf
References:
Folch, Jordi; Lees, M; Sloane Stanley, G H (1957): A simple method for the isolation and purification of total lipides from animal tissues. Journal of Biological Chemistry, 226(1), 497-509, https://doi.org/10.1016/S0021-9258(18)64849-5
Stein, Ruediger; Frederichs, Thomas; Fahl, Kirsten; Geibert, Walter; Matthiessen, Jens; Niessen, Frank; Vogt, Christoph; Sassenroth, Cynthia; Bazhenova, Evgenia A (2025): A 430 kyr record of ice-sheet dynamics and organic-carbon burial in the central Eurasian Arctic Ocean. Nature Communications, 16(1), 3822, https://doi.org/10.1038/s41467-025-59112-7
Project(s):
Funding:
Helmholtz Association of German Research Centres (HGF), grant/award no. VH-NG-20-09: Resilience and vulnerability of the central Arctic Ocean food web to cumulative stress by warming and anthropogenic pollution (Double-Trouble)
Horizon Europe (HorizonEU), grant/award no. 101136875: Ocean and coastal waters carbon- and biodiversity-rich ecosystems and habitats in Europe and the Polar Regions - HORIZON-CL6-2023-CLIMATE-01-3
Coverage:
Median Latitude: 85.386094 * Median Longitude: 1.560512 * South-bound Latitude: 81.823100 * West-bound Longitude: -34.800100 * North-bound Latitude: 87.794600 * East-bound Longitude: 30.169800
Date/Time Start: 2024-07-23T11:05:54 * Date/Time End: 2024-08-10T05:14:44
Minimum DEPTH, water: 15 m * Maximum DEPTH, water: 45 m
Event(s):
AO2024_IPOM_17 * Latitude: 83.941000 * Longitude: 22.125200 * Date/Time: 2024-08-06T12:40:09 * Location: Central Arctic Ocean * Campaign: AO2024 (2024007009) * Basis: Kronprins Haakon * Method/Device: Ice drilling corer (Kovacs) * Comment: Kovacs 9 cm ice corer
AO2024_IPOM_37 * Latitude: 86.576100 * Longitude: -4.877900 * Date/Time: 2024-07-31T06:21:20 * Elevation: -4232.0 m * Location: Central Arctic Ocean * Campaign: AO2024 (2024007009) * Basis: Kronprins Haakon * Method/Device: Ice drilling corer (Kovacs) * Comment: Kovacs 9 cm ice corer
AO2024_MA1 * Latitude: 86.719700 * Longitude: -34.121300 * Date/Time: 2024-07-23T11:05:54 * Elevation: -3608.0 m * Location: Central Arctic Ocean * Campaign: AO2024 (2024007009) * Basis: Kronprins Haakon * Method/Device: Hand net (HN)
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Event label | Event | Kohlbach, Doreen | |||
| 2 | Latitude of event | Latitude | Kohlbach, Doreen | |||
| 3 | Longitude of event | Longitude | Kohlbach, Doreen | |||
| 4 | Elevation of event | Elevation | m | Kohlbach, Doreen | ||
| 5 | Station label | Station | Kohlbach, Doreen | |||
| 6 | Device type | Device | Kohlbach, Doreen | |||
| 7 | Sample code/label | Sample label | Kohlbach, Doreen | |||
| 8 | DATE/TIME | Date/Time | Kohlbach, Doreen | Geocode | ||
| 9 | DEPTH, water | Depth water | m | Kohlbach, Doreen | Geocode | |
| 10 | Sample comment | Sample comment | Kohlbach, Doreen | |||
| 11 | Genus, unique identification | Genus UID | Kohlbach, Doreen | Reference in WoRMS (WoRMS) | ||
| 12 | Genus, unique identification (Semantic URI) | Genus UID (Semantic URI) | Kohlbach, Doreen | Reference in WoRMS (WoRMS) | ||
| 13 | Genus, unique identification (URI) | Genus UID (URI) | Kohlbach, Doreen | Reference in WoRMS (WoRMS) | ||
| 14 | 24-Methylcholesta-5,22E-dien-3beta-ol | Brassicasterol | % | Kohlbach, Doreen | see abstract | |
| 15 | 24-methylcholest-5-en-3beta-ol | Campesterol | % | Kohlbach, Doreen | see abstract | |
| 16 | 3beta-Stigmast-5-en-3-ol | b-Sitosterol | % | Kohlbach, Doreen | see abstract | |
| 17 | Cholesta-5,24-dien-3beta-ol | Desmosterol | % | Kohlbach, Doreen | see abstract |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0) (License comes into effect after moratorium ends)
Status:
Curation Level: Enhanced curation (CurationLevelC)
Size:
334 data points