Snapshot of micro-animals and associated biotic and abiotic environmental variables on the edge of the south-west Greenland ice sheet

Krzysztof Zawierucha,Michał Bogdziewicz,Jakub Buda,Mirosława Pietryka,Nicoletta Makowska,Edyta Łokas,Dorota Richter,Sara Lehmann-Konera

doi:10.1007/s10201-017-0528-9

Abstract

Microinvertebrates play a role as top consumers on glaciers. In this study we tested what kind of cryoconite material the animals inhabit (mud vs granules) on the edge of the Greenland ice sheet (GrIS) in the south-west. We also tested the links between the densities of micro-fauna in cryoconite material and selected biotic (algae, cyanobacteria, bacterial abundances) and abiotic (water depth, pH, ion content, radionuclides) factors. We collected 33 cryoconite samples. Tardigrada and Rotifera were found in 18 and 61% of samples, respectively. Invertebrates in this study were considerably less frequent and less abundant in comparison with High Arctic glaciers. The highest density of tardigrades and rotifers constituted 53 and 118 ind./ml, respectively. Generalized linear models showed no relationship between the densities of fauna and biotic and abiotic factors. The densities of animals were significantly higher in granules than in mud. The difference in the densities of animals between granules and mud reflects a simple mechanistic removal of invertebrates from the sediment during its erosion by flushing which leads to mud formation. These processes may influence a random distribution of micro-fauna without clear ecological interactions with biotic and abiotic variables at the edge of the GrIS.

Highlights

Glaciers and ice sheets constitute an important element of the biosphere in terms of freshwater and carbon cycle (Hodson et al 2008; Cook et al 2015b)
In this study we tested what kind of cryoconite material the animals inhabit on the edge of the Greenland ice sheet (GrIS) in the south-west
We tested the links between the densities of micro-fauna in cryoconite material and selected biotic and abiotic factors

Summary

Introduction

Glaciers and ice sheets constitute an important element of the biosphere in terms of freshwater and carbon cycle (Hodson et al 2008; Cook et al 2015b). Cyanobacteria produce extracellular polymeric substances (EPS) which stick together mineral and organic matter to form granules (Takeuchi et al 2001a, b; Hodson et al 2010b; Langford et al 2014; Cook et al 2015b) These granules are a key component of glacial ecosystems (Hodson et al 2008; Cook et al 2015b), and together with dust and ice algae, they reduce surface albedo and increase the melting of glaciers (Wharton et al 1985; Takeuchi et al 2001a, b, 2010). Data on the biggest organisms in glacial ecosystems, micro-animals, are scarce and mainly restricted to taxonomical snapshots (Dastych et al 2003; Zawierucha et al 2016a)

Methods

Results

Conclusion