Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Akvaplan-niva https://www.akvaplan.niva.no/ https://ror.org/03nrps502 Šupraha Luka 0000-0003-2613-945X Norwegian Institute for Water Research NIVA https://ror.org/03hrf8236 Graeve Martin martin.graeve@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/martin-graeve.html 0000-0002-2294-1915 Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven AWI https://www.awi.de/ https://ror.org/032e6b942 Fahl Kirsten kirsten.fahl@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/kirsten-fahl.html 0000-0001-9317-4656 Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven AWI https://www.awi.de/ https://ror.org/032e6b942 Müller Anja anja.mueller@awi.de Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven AWI https://www.awi.de/ https://ror.org/032e6b942 Müller Juliane juliane.mueller@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/juliane-mueller.html 0000-0003-0724-4131 Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven AWI https://www.awi.de/ https://ror.org/032e6b942 Lunden Jonas jonas.lunden@awi.de Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven AWI https://www.awi.de/ https://ror.org/032e6b942 Woll Matthias Matthias.Woll@awi.de Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven AWI https://www.awi.de/ https://ror.org/032e6b942 Kohlbach Doreen 0000-0002-9245-2500 Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven AWI https://www.awi.de/ https://ror.org/032e6b942 2026 Relative proportions of sterols in Melosira assemblages, and subsequently isolated unialgal cultures collected in June 2023 during the RV Kronprins Haakon cruise 2023-1 in Fram Strait dataset https://doi.org/10.1594/PANGAEA.987865 2026-01-07T12:45:39 During the AO2023-1 expedition (1-21 June 2023), Melosira assemblages were collected using a handpump at a sampling site in Fram Strait. In addition to performing physiological measurements and filtering the material for trophic markers (fatty acids, stable isotope ratios of fatty acids, sterols and highly branched isoprenoids (HBIs), living material was brought back to Akvaplan-niva in Oslo and two strains were established as unialgal cultures. The cultures are maintained in artificial seawater-based L1 medium at 4°C and 25 µmol m-2 s-1 light with a 16:8 L:D cycle. 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 Melosira arctica-dominated algal assemblages from the Arctic Ocean, and a comparison with a unialgal culture of this important species. Kohlbach Doreen 0000-0002-9245-2500 Kunisch Erin H erin.kunisch@ntnu.no 0000-0002-9877-4930 Graeve Martin martin.graeve@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/martin-graeve.html 0000-0002-2294-1915 Fahl Kirsten kirsten.fahl@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/kirsten-fahl.html 0000-0001-9317-4656 Müller Anja anja.mueller@awi.de Müller Juliane juliane.mueller@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/juliane-mueller.html 0000-0003-0724-4131 Lunden Jonas jonas.lunden@awi.de Woll Matthias Matthias.Woll@awi.de Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 submitted Melosira arctica: algal superfood or nutritional dead-end for Arctic grazers? Elementa - Science of the Anthropocene Folch Jordi Lees M Sloane Stanley G H 1957 A simple method for the isolation and purification of total lipides from animal tissues journal article Journal of Biological Chemistry 226(1) https://doi.org/10.1016/S0021-9258(18)64849-5 497-509 Stein Ruediger ru_st@uni-bremen.de https://www.awi.de/en/about-us/organisation/staff/single-view/ruediger-stein.html 0000-0002-4453-9564 Frederichs Thomas frederichs@uni-bremen.de 0000-0003-0976-0332 Fahl Kirsten kirsten.fahl@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/kirsten-fahl.html 0000-0001-9317-4656 Geibert Walter walter.geibert@awi.de http://www.awi.de/ueber-uns/organisation/mitarbeiter/walter-geibert.html 0000-0001-8646-2334 Matthiessen Jens jens.matthiessen@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/jens-matthiessen.html 0000-0002-6952-2494 Niessen Frank frank.niessen@awi.de https://www.awi.de/en/about-us/organisation/staff/single-view/frank-niessen.html 0000-0001-6453-0594 Vogt Christoph cvogt@uni-bremen.de 0000-0002-5376-9011 Sassenroth Cynthia cynthia.sassenroth@phd.unipi.it Bazhenova Evgenia A evgeniabazhenova@gmail.com 0000-0002-8092-702X 2025 A 430 kyr record of ice-sheet dynamics and organic-carbon burial in the central Eurasian Arctic Ocean journal article Nature Communications 16(1) https://doi.org/10.1038/s41467-025-59112-7 3822 -2.1387 -2.1387 78.9397 78.9397 -2.1387 78.9397 2023-06-18T00:00:00 2023-06-18T00:00:00 0.0 0.0 Horizon Europe HorizonEU https://research-and-innovation.ec.europa.eu/funding/funding-opportunities/funding-programmes-and-open-calls/horizon-europe_en https://doi.org/10.13039/100018693 101136875 Ocean and coastal waters carbon- and biodiversity-rich ecosystems and habitats in Europe and the Polar Regions - HORIZON-CL6-2023-CLIMATE-01-3 https://doi.org/10.3030/101136875 The FRAM Centre https://doi.org/10.13039/501100022349 2551323 Sustainable Development of the Arctic Ocean (SUDARCO) AO2023-1_MA1 78.9397 -2.1387 2023-06-18T00:00:00 Fram Strait http://en.wikipedia.org/wiki/Fram_Strait AO2023-1 2024007009 Steen, Harald 2023-06-01 2023-06-21 Longyearbyen, Svalbard Longyearbyen, Svalbard Kronprins Haakon https://npolar.no/en/kronprins-haakon/ 3YYQ 9739587 Hand pump HP 171 CC-BY-4.0 Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ Event label Event Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Event Station label Station Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Station Type of study Study type type Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Study type Sample code/label Sample label Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Sample label DEPTH, water Depth water m depth http://purl.obolibrary.org/obo/PATO_0001595 water http://purl.obolibrary.org/obo/CHEBI_15377 Length L http://dbpedia.org/resource/Length Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Depth water [m] Depth comment Depth comm Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Depth comm Genus, unique identification Genus UID Reference in WoRMS WoRMS https://www.marinespecies.org Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Genus UID Genus, unique identification (Semantic URI) Genus UID (Semantic URI) Reference in WoRMS WoRMS https://www.marinespecies.org Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Genus UID (Semantic URI) Genus, unique identification (URI) Genus UID (URI) Reference in WoRMS WoRMS https://www.marinespecies.org Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Genus UID (URI) 24-Methylcholesta-5,22E-dien-3beta-ol Brassicasterol % Dimensionless Ratio ψ Gas chromatograph-mass spectrometer GC-MS Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Brassicasterol [%] 24-methylcholest-5-en-3beta-ol Campesterol % 24-methylcholest-5-en-3beta-ol https://pubchem.ncbi.nlm.nih.gov/compound/12358784 Dimensionless Ratio ψ Gas chromatograph-mass spectrometer GC-MS Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Campesterol [%] 3beta-Stigmast-5-en-3-ol b-Sitosterol % Dimensionless Ratio ψ Gas chromatograph-mass spectrometer GC-MS Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 b-Sitosterol [%] Cholesta-5,24-dien-3beta-ol Desmosterol % Dimensionless Ratio ψ Gas chromatograph-mass spectrometer GC-MS Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Desmosterol [%] Date/time start, experiment Date/time start exp Unialgal cultures cultivation Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Date/time start exp Date/time end, experiment Date/time end exp Unialgal cultures cultivation Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Date/time end exp Experimental treatment Exp treat Unialgal cultures cultivation Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 Exp treat Treatment: temperature T:temp °C treatment Temperature Θ http://dbpedia.org/resource/Temperature Unialgal cultures cultivation Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 T:temp [°C] Treatment: salinity T:sal treatment Unialgal cultures cultivation Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 T:sal Treatment: nitrate T:[NO3]- µmol/l treatment nitrate http://purl.obolibrary.org/obo/CHEBI_17632 Molar Concentration Unialgal cultures cultivation Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 as NaNO3 T:[NO3]- [µmol/l] Treatment: silicate T:[Si(OH)4] µmol/l treatment Molar Concentration Unialgal cultures cultivation Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 as Na2SiO3 T:[Si(OH)4] [µmol/l] Treatment: phosphate T:[PO4]3- µmol/l treatment phosphate http://purl.obolibrary.org/obo/CHEBI_26020 Molar Concentration Unialgal cultures cultivation Leu Eva eva.leu@akvaplan.niva.no 0000-0002-5328-3396 as K2HPO4 T:[PO4]3- [µmol/l] CurationLevelC Enhanced curation https://wiki.pangaea.de/wiki/Curation_levels citable Arctic microalgae Melosira Standard cultivation Sterols trophic markers author100938 author10649 author109870 author113173 author113174 author118 author24521 author35356 author36311 author42270 author437 author451 author517 author625 author64180 author76932 author87525 author87526 author87527 author90 author92317 award4437 award4440 basis5396 campaign52892 curlevel30 event3317507 funder21271 funder21808 geocode1599 geocode1600 geocode1601 geocode1619 inst1095 inst1107 inst32 journal16656 journal16865 journal8201 license21 method11132 method12210 method18505 method9144 param102005 param105163 param129507 param16090 param185511 param185520 param515267 param516119 param516120 param519843 param534018 param534019 param550809 param550810 param550811 param790 param82404 pi42270 ref111974 ref131948 ref135832 term1073131 term1073482 term1073484 term20369 term2606205 term41013 term43794 term43863 term43972 term44030 term49174 term49506 term50040 term69398 term76775 term76776 term76885