bb4b1e74-d5af-4a73-9174-62a01807c641 eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2023-12-14 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 Fatty acid composition of 32 cold-water algal strains cultured under different conditions to support the interpretation of in situ algal FA data from the MOSAiC expedition 2019/2020 2023-12-14 creation 2023-12-14 revision 2023-12-14 publication 2023-12-14 released 1.0 https://doi.org/10.5285/bb4b1e74-d5af-4a73-9174-62a01807c641 doi GB/NERC/BAS/PDC/01808 https://data.bas.ac.uk/ NE/S002502/1 award NE/R017050/1 award Please cite this item as: Schmidt, K., Graeve, M., Hoppe, C., Rokitta, S., Welteke, N., Menendez, C., Probert, I., Brenneis, T., Belt, S., & Atkinson, A. (2023). Fatty acid composition of 32 cold-water algal strains cultured under different conditions to support the interpretation of in situ algal FA data from the MOSAiC expedition 2019/2020 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/bb4b1e74-d5af-4a73-9174-62a01807c641 A seasonal cycle of the FA composition of particulate organic matter from surface waters, Chlorophyll-a maximum layer and bottom sea ice, sampled during the MOSAiC expedition in the Central Arctic Ocean (2019-2020), suggests the importance of phylogenetic and environmental drivers. To improve our understanding of these different drivers, we conducted culture experiments with 32 cold-water algal strains where temperature, light intensity, and nutrient supply were manipulated individually or in combination. The culture experiments were carried out at the Culture Collection of Algae and Protozoa (CCAP; Oban, Scotland), the Roscoff Culture Collection (RCC; Roscoff, France) and the Alfred-Wegener-Institute-Helmholtz-Centre for Polar and Marine Research (AWI; Bremerhaven, Germany). The strains were part of the culture collections, had been isolated in the Arctic (25 strains), Southern Ocean (2 strains) or North Atlantic (5 strains), and included diatoms, chlorophytes, haptophytes, cryptophytes, chrysophytes, dinoflagellates and cyanobacteria. Some of the species are Arctic sea ice diatoms (e.g. Nitzschia frigida, Attheya spp.) or pelagic diatoms (e.g. Thalassiosira gravida), while others are non-diatom species that are becoming increasingly prominent in the Arctic, e.g. the coccolithophore Emiliania huxleyi (synonym Gephyrocapsa huxleyi), the prymnesiophyte Phaeocystis pouchetii, the chlorophyte Micromonas spp. and the cyanobacterium Synechococcus spp.. The experiments can be divided into three groups: First, those that tested a low light-low temperature setting, second, those that tested a low light-low temperature and a higher light-higher temperature setting and, third, those that tested the effect of nutrient (nitrate, phosphate and silicate) shortage in combination with low and high light intensity. The first set of experiments was conducted with all 32 strains, the second set with all strains grown at CCAP and AWI, and the third set focuses on the keystone under-ice diatom Melosira arctica. The experiments were run for 4-7 weeks to accumulate sufficient biomass for biomarker extractions (FA and sterols), C:N analysis and light-microscopy of cell size and cell concentration. At the end of the experiments, the algae were filtered onto GF/F filters and deep frozen until analysis. After addition of internal standards for FA and sterols, the filters were saponified with KOH. Thereafter, non-saponifiable lipids (sterols) were extracted with hexane and purified by open column chromatography on silica gel. FA were obtained by adding concentrated HCl to the saponified solution and re-extracted with hexane. Samples were converted into fatty acid methyl esters (FAME) and analysed using an Agilent 6890N gas chromatograph with FID detector. The Clarity chromatography software system (DataApex, Czech Republic) was used for chromatogram data evaluation. FAME were quantified via the internal standard, Tricosanoic acid methyl ester (23:0) (Supelco, Germany) to provide the total amount of FA (TFA) per filter. These FA datasets of cultured algae are presented in a manuscript together with the FA pattern seen in sea ice- and water column POM in the CAO during the MOSAiC expedition and in previously published data from Arctic shelf regions. The manuscript focusses mainly on two important long-chain omega-3 FA (eicosapentaenoic acid and docosahexaenoic acid) that are considered essential for the nutrition of higher trophic levels, including humans, and their production to decline with global temperature rise. Contributions by KS were funded by the UK's Natural Environment Research Council MOSAiC Thematic project SYM-PEL: 'Quantifying the contribution of sympagic versus pelagic diatoms to Arctic food webs and biogeochemical fluxes: application of source-specific highly branched isoprenoid biomarkers'/ (NE/S002502/1). CRM was funded by the NERC National Capability Services and Facilities Programme (NE/R017050/1). No credit. completed Schmidt, Katrin University of Plymouth Researcher author Graeve, Martin Alfred Wegener Institute Researcher author Hoppe, Clara Alfred Wegener Institute Researcher author Rokitta, Sebastian Alfred Wegener Institute Researcher author Welteke, Nahid Alfred Wegener Institute Researcher author Menendez, Cecilia Rad Scottish Association For Marine Science Researcher author Probert, Ian Sorbonne University Researcher author Brenneis, Tina Alfred Wegener Institute Researcher author Belt, Simon T. University of Plymouth Researcher author Atkinson, Angus Plymouth Marine Laboratory Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Biosphere > Plant Taxonomy > Algae EARTH SCIENCE > Oceans > Ocean Chemistry > Nutrients EARTH SCIENCE > Oceans > Ocean Temperature > Water Temperature EARTH SCIENCE > Oceans > Sea Ice theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher Arctic DHA EPA MOSAiC Melosira arctica cultured algae fatty acids light intensity lipid biomarker nutrients sea ice temperature theme Isolated from the Arctic, Southern Ocean and North Atlantic, Laboratory facilities of the culture collection sites (CCAP, RCC or AWI) place Habitats and biotopes Oceanographic geographical features theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license Open Government Licence v3.0 otherRestrictions Data released under Open Government Licence V3.0: otherRestrictions No restrictions apply. url url largerWorkCitation url url crossReference url url crossReference url url crossReference url url crossReference url url crossReference doi doi crossReference textTable eng utf8 biota oceans -180.0 180.0 -90.0 90.0 2021-07-04 2022-05-05 It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor text/csv text/plain bytes 38912 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=bb4b1e74-d5af-4a73-9174-62a01807c641 WWW:LINK-1.0-http--link Get Data Download data download bytes 38912 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=bb4b1e74-d5af-4a73-9174-62a01807c641 WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: Microalgae cultures: In 2022, we conducted FA analysis on 32 cold-water strains that were isolated in the Arctic (25 strains), Southern Ocean (2 strains) or North Atlantic (5 strains), and included diatoms, chlorophytes, haptophytes, cryptophytes, chrysophytes, dinoflagellates and cyanobacteria. These strains were either obtained from commercial culture collections (CCAP or RCC) or provided by the AWI. The CCAP cultures were inoculated in 50 ml Erlenmeyer conical flasks with 25 ml of F/2 medium and added 60 micromol L-1 silicate for diatoms (Guillard and Ryther 1962). The algal strains were grown for four weeks at either low temperature - low light intensity (3-4 degrees Celsius, 10 micromol m-2 s-1) or higher temperature - higher light intensity (8 degrees Celsius, 20 micromol m-2 s-1) and a light:dark cycle of 12:12 hrs. The culturing conditions at RCC resembled those at CCAP, but only for the low temperature - low light intensity (3-4d degrees Celsius, 10 micromol m-2 s-1). The algae growth rates were not monitored, but with these culture conditions and time span, the strains usually reach late exponential-early stationary growth (C. Rad-Menendez, I. Probert, pers. comm.). From each strain, two 5 ml technical replicates were filtered via a vacuum pump (-20 kPA) onto pre-combusted (12 h, 450 degrees Celsius) 25 mm Whatman GF/F filters, freeze dried and stored in aluminium foil at -20 degrees Celsius until FA analysis. Note: Three of the strains from CCAP (CCAP-1023/3, CCAP-1029/29, CCAP-1029/30) were obtained and analysed as 'Fragilariopsis sp.' but subsequently identified as 'Grammonema sp.'. Experiments with Melosira arctica: The experiments with Melosira arctica were carried out at the AWI in 2021 and 2022, using a strain that was isolated in the Central Arctic Ocean in 2015 (79.56 degrees N, 4.84 degrees W; strain PS93.1_030). The strain was grown as semi-continuous batch cultures under 6 different environmental conditions including the species' natural range of temperature, light and nutrient availability (Spilling and Markager 2008, Fernandez-Mendez et al. 2014). Therefore, low temperatures (0-1 dgrees Celsius) were combined with high and low light intensity (10 and 100 micromol m-2 s-2), each with high and low nutrient supply (details below), and higher temperatures (3 and 6 degrees Celsius) with high light and nutrient availability. Experiments were performed with 4 biological replicates in sterile 1-L Schott bottles in temperature-controlled rooms, with bottles at 3 and 6 degrees Celsius being immersed in water-filled aquaria for additional temperature stability. Day light lamps (Biolux T8, 6500K, Osram) provided continuous light and irradiance levels were adjusted with a black mesh fabric and measured using a 4 pi spherical sensor (Li-Cor) and data logger (ULM-500, Walz). Cells were cultivated in 0.2 micrometerm sterile-filtered Arctic seawater (salinity 33.5), with or without added macronutrients, vitamins and trace metals according to F/2 or F/20 media (Guillard and Ryther, 1962). Initial nutrient concentrations in set-ups with F/20 media were 10.4 +/-0.24 micromol L-1 nitrate-and-nitrite, 18.1 +/-1.36 micromol L-1 silicate and 1.2 +/- 0.19 micromol L-1 phosphate. In set-ups without added medium, initial nutrient concentrations were 1.8+/-0.07 micromol L-1 nitrate-and-nitrite, 14.4 +/-2.3 micromol L-1 silicate and 0.4 +/-0.01 micromol L-1 phosphate. To minimize changes in carbonate chemistry and to remain close to natural population densities, cultures were diluted every 1-2 weeks with Arctic seawater, with or without medium. Sufficient algal biomass for subsequent lipid analysis was grown after 4 weeks for cultures that received media, and after 7 weeks for those without media. At the end of the experiment, 2 technical replicates were taken from each biological replicate, filtered onto pre-combusted (12 h, 450 degre...(24) Data collection: Fatty acid analysis: FAME were quantified using an Agilent 6890N gas chromatograph (Agilent Technologies, USA) with a DB-FFAP capillary column (60 m, 0.25 mm I.D., 0.25 micrometer film thickness, Agilent Technologies, USA) supplied with a splitless injector and a flame ionization detector using temperature programming. Chromatogram data evaluation: Clarity chromatography software system (version 8.8.0, DataApex, Czech Republic) Data quality: The fatty acid profiles were compared to several commercial- and self-produced standards (e.g. Arctic algae standard, Bacteria standard, Calanus spp. standard), and fatty acid peaks were identified accordingly. In a few cases, samples were also analysed with the mass spectrometer and peaks were identified via (1) the mass of the compound, (2) the retention time of the compound and (3) the equivalent chain length method. Unusual peaks were also compared with published FA profiles from related species (e.g. Leblond et al. 2006 for cold-adapted dinoflagellates). asNeeded completed