Inter fjord variations as a key contributor in the meiobenthic faunal distribution in the Arctic Kongsfjord, Svalbard

Abstract

The community pattern of meiobenthos in an inner and outer glacial fjord of Kongsfjord was analysed during this study. This study examined the hypothesis that there is a significant difference in the distribution of total meiofauna and the major meiofaunal groups between the inner and outer fjords and it also looked into the effect of environmental variables on their distribution. Meiofaunal abundance and diversity was higher in the inner fjord, indicating that meiofauna can be less sensitive to sediment disturbances caused by glacial activity. Average abundance and biomass of the major meiofaunal groups, namely nematodes (54%) and foraminiferans (37%) were higher in the outer region. 45 species of nematodes representing 20 families were identified during the study, in which Dorylaimopsis sp. (39.55%) and Terschellingia longicaudata (12.53%) had the highest relative abundance. Out of the 56 foraminiferan species belonging to 5 suborders, Nonionellina labradorica (18.30%) and Cassidulina teretis (8.85%) had the highest relative abundance. There are clear and significant changes (ANOSIM) in the assemblage of meiofauna with increasing distance from the glacial front which correlates to environmental variables. Species contributing to differences between inner and outer basins (SIMPER) were also determined. Among nematodes, Chromadorids and Araeolaimids had a tendency to distribute in the inner fjord while Enoplids and Monhysterids were more prevalent in the outer fjord. Sediment organic matter, silt content and pH were the best matching variables (BEST) for the distribution of both nematodes and foraminiferans. The Principal Component Analysis (PCA) revealed that environmental variations have significant patterns in the faunal distribution in Kongsfjord. From this study it can be inferred that the inner fjord has the maximum numerical abundance of meiofauna but the foraminiferans and nematodes were numerically abundant in the outer fjord and there is also significant difference in the distribution of species between the two fjords.