Stable isotopic composition of top consumers in Arctic cryoconite holes: revealing divergent roles in a supraglacial trophic network

0542850 - BC 2022 RIV DE eng J - Journal Article
Novotná Jaroměřská, T. - Trubač, J. - Zawierucha, K. - Vondrovicová, L. - Devetter, Miloslav - Žárský, J.D.
Stable isotopic composition of top consumers in Arctic cryoconite holes: revealing divergent roles in a supraglacial trophic network.
Biogeosciences. Roč. 18, č. 4 (2021), s. 1543-1557. ISSN 1726-4170. E-ISSN 1726-4189
Institutional support: RVO:60077344
Keywords : microbial communities * organic-matter * ablation zone * food-web * bacterial communities * natural-abundance * carbon isotopes * glaciers * nitrogen * soil
OECD category: Biodiversity conservation
Impact factor: 5.092, year: 2021
Method of publishing: Open access
https://bg.copernicus.org/articles/18/1543/2021/bg-18-1543-2021.pdf

Arctic cryoconite holes represent highly biologically active aquatic habitats on the glacier surface characterized by the dynamic nature of their formation and functioning. The most common cryoconite apex consumers are the cosmopolitan invertebrates tardigrades and rotifers. Several studies have highlighted the potential relevance of tardigrades and rotifers to cryoconite holes' ecosystem functioning. However, due to the dominant occurrence of prokaryotes, these consumers are usually out of the major scope of most studies aimed at understanding biological processes on glaciers. The aim of this descriptive study is to present pioneering data on isotopic composition of tardigrades, rotifers and cryoconite from three High Arctic glaciers in Svalbard and discuss their role in a cryoconite hole trophic network. We found that tardigrades have lower δ15N values than rotifers, which indicates different food requirements or different isotopic fractionation of both consumers. The δ13C values revealed differences between consumers and organic matter in cryoconite among glaciers. However, the mechanistic explanation of these variations requires further investigation focused on the particular diet of cryoconite consumers and their isotopic ratio. Our study introduces the first observation of carbon and nitrogen stable isotopic composition of top consumers in cryoconite holes analysed by an improved method for cryoconite sample processing, paving the way for further studies of the supraglacial trophic network.
Permanent Link: http://hdl.handle.net/11104/0324684