Meiofauna Biodiversity and Community Structures in the Barents Sea and Nansen Basin Are Influenced by Benthic Spatiotemporal Heterogeneity

Sammendrag

Meiobenthic metazoans occur worldwide and are a cornerstone of aquatic ecosystems. Here, we investigate the composition of meiobenthic communities along a transect in the Barents Sea and Nansen Basin and provide the first meiobenthos dataset for this region to combine seasonal resolution with high taxonomic fidelity. We identified 12 higher meiobenthic taxa and provide identifications of 143 nematode genera, 37 copepod genera, 11 species of kinorhynchs, the meiobenthic hydrozoan Plotocnide , and the first loriciferan records for the region. Nematodes dominated communities (47%–90% of abundances), followed by copepods (3%–24%) and kinorhynchs (≤ 10%), and we provide a comprehensive taxonomic dataset of these groups along with analyses of structuring environmental and spatiotemporal factors. We observed a general decrease in abundances and biodiversity with increasing water depth, and high richness of several taxa around the northern shelf and continental slope. Community structuring appears to be driven primarily by spatial effects on small and large scales in addition to variation across the four seasons, while granulometric properties and organic carbon levels of the sediment also have a demonstrable effect on nematode, copepod and kinorhynch communities. Based on our analyses, we draw the conclusion that these spatiotemporal and environmental factors coalesce to influence community structures of meiobenthic metazoans in the Barents Sea. While our synthesis of environmental and biodiversity data represents a contribution to the knowledge of current Arctic metazoan meiobenthos communities, they are vulnerable to alterations resulting from drastic climate‐driven changes in the near future and require further study.