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Lookup NU author(s): Dr Matthew CobainORCiD, Emeritus Professor Nick Polunin
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND).
© 2023 The Authors. Limnology and Oceanography published by Wiley Periodicals LLC on behalf of Association for the Sciences of Limnology and Oceanography. A rapidly warming Arctic Ocean and associated sea-ice decline is resulting in changing sea-ice protist communities, affecting productivity of under-ice, pelagic, and benthic fauna. Quantifying such effects is hampered by a lack of biomarkers suitable for tracing specific basal resources (primary producers and microorganisms) through food webs. We investigate the potential of δ13C values of essential amino acids (EAAs) (δ13CEAA values) to estimate the proportional use of diverse basal resources by organisms from the under-ice (Apherusa glacialis), pelagic (Calanus hyperboreus) and benthic habitats (sponges, sea cucumber), and the cryo-pelagic fish Boreogadus saida. Two approaches were used: baseline δ13CEAA values, that is, the basal resource specific δ13CEAA values, and δ13CEAA fingerprints, or mean-centred baseline δ13CEAA values. Substantial use of sub-ice algae Melosira arctica by all studied organisms suggests that its role within Arctic food webs is greater than previously recognized. In addition, δ13CEAA fingerprints from algae-associated bacteria were clearly traced to the sponges, with an individually variable kelp use by sea cucumbers. Although mean-centred δ13CEAA values in A. glacialis, C. hyperboreus, and B. saida tissues were aligned with microalgae resources, they were not fully represented by the filtered pelagic- and sea-ice particulate organic matter constituting the spring diatom-dominated algal community. Under-ice and pelagic microalgae use could only be differentiated with baseline δ13CEAA values as similar microalgae clades occur in both habitats. We suggest that δ13CEAA fingerprints combined with microalgae baseline δ13CEAA values are an insightful tool to assess the effect of ongoing changes in Arctic basal resources on their use by organisms.
Author(s): Vane K, Cobain MRD, Trueman CN, Vonnahme TR, Rokitta S, Polunin NVC, Flores H
Publication type: Article
Publication status: Published
Journal: Limnology and Oceanography
Year: 2023
Pages: Epub ahead of print
Online publication date: 09/02/2023
Acceptance date: 18/01/2023
Date deposited: 23/02/2023
ISSN (print): 0024-3590
ISSN (electronic): 1939-5590
Publisher: John Wiley and Sons Inc.
URL: https://doi.org/10.1002/lno.12315
DOI: 10.1002/lno.12315
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