Data_Sheet_1_Multiple Trophic Markers Trace Dietary Carbon Sources in Barents Sea Zooplankton During Late Summer.docx

• Main Authors: Doreen Kohlbach, Haakon Hop, Anette Wold, Katrin Schmidt, Lukas Smik, Simon T. Belt, Amalia Keck Al-Habahbeh, Matthias Woll, Martin Graeve, Anna Maria Dąbrowska, Agnieszka Tatarek, Angus Atkinson, Philipp Assmy
• Format: Dataset
• Language: unknown
• Published: 2021
• Subjects: Oceanography; Marine Biology; Marine Geoscience; Biological Oceanography; Chemical Oceanography; Physical Oceanography; Marine Engineering; food web; Barents Sea; sea ice; carbon sources; trophic markers; fatty acids; highly branched isoprenoid (HBI) lipids; sterols; Clione limacina; ice algae; Sea ice; Themisto libellula; Copepods
• Online Access: https://doi.org/10.3389/fmars.2020.610248.s001; https://figshare.com/articles/dataset/Data_Sheet_1_Multiple_Trophic_Markers_Trace_Dietary_Carbon_Sources_in_Barents_Sea_Zooplankton_During_Late_Summer_docx/13572422

We investigated diets of 24 Barents Sea zooplankton taxa to understand pelagic food-web processes during late summer, including the importance of sea ice algae-produced carbon. This was achieved by combining insights derived from multiple and complementary trophic marker approaches to construct individual aspects of feeding. Specifically, we determined proportions of algal-produced fatty acids (FAs) to reflect the reliance on diatom- versus dinoflagellate-derived carbon, highly branched isoprenoid (HBI) lipids that distinguish between ice-associated and pelagic carbon sources, and sterols to indicate the degree of carnivory. Copepods had the strongest diatom signal based on FAs, while a lack of sea ice algae-associated HBIs (IP 25 , IPSO 25 ) suggested that they fed on pelagic rather than ice-associated diatoms. The amphipod Themisto libellula and the ctenophores Beroë cucumis and Mertensia ovum had a higher contribution of dinoflagellate-produced FAs. There was a high degree of carnivory in this food web, as indicated by the FA carnivory index 18:1(n−9)/18:1(n−7) (mean value < 1 only in the pteropod Clione limacina), the presence of copepod-associated FAs in most of the taxa, and the absence of algal-produced HBIs in small copepod taxa, such as Oithona similis and Pseudocalanus spp. The coherence between concentrations of HBIs and phytosterols within individuals suggested that phytosterols provide a good additional indication for algal ingestion. Sea ice algae-associated HBIs were detected in six zooplankton species (occurring in krill, amphipods, pteropods, and appendicularians), indicating an overall low to moderate contribution of ice-associated carbon from late-summer sea ice to pelagic consumption. The unexpected occurrence of ice-derived HBIs in pteropods and appendicularians, however, suggests an importance of sedimenting ice-derived material at least for filter feeders within the water column at this time of year.