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

Abstract. Arctic cryoconite holes represent highly biologically active aquatic habitats on the glacier surface characterized by dynamic nature of their formation and functioning. The most common apex consumers are cosmopolitan invertebrates – tardigrades rotifers. Several studies have highlighted potential relevance rotifers to holes' ecosystem However, due dominant occurrence prokaryotes, these usually out major scope aimed at understanding biological processes glaciers. aim this descriptive study is present pioneering data isotopic composition tardigrades, from three High glaciers in Svalbard discuss role a hole trophic network. We found that lower ?15N values than rotifers, which indicates different food requirements or fractionation both consumers. ?13C revealed differences between organic matter among mechanistic explanation variations requires further investigation focused particular diet ratio. Our introduces first observation carbon nitrogen stable top analysed an improved method for sample processing, paving way supraglacial