Macrobenthic communities in water bodies and streams of Svalbard,Norway

Diversity of macrobenthic communities was studied from water bodies and streams of Spitsbergen, Svalbard archipelago, Norway. In total 162 quantitative samples from different regions of Spitsbergen were analysed in relation to environmental variables. Macrobenthic communities were found on all kinds of substrates (except for the periglacial zone), representing a wide range of biological communities: solid-bottom, soft-bottom, macrophytes and small brook associated. However, taxonomical structure is very simplified, with particular dominance of the Chironomidae family. Chironomid larvae dominated highly in diversity, abundance and biomass. Overall macrobenthic communities were characteristic, with remarkable dominance of one species and general omnipresent taxonomical scarcity (average 2.8 species per sample). In total we found 30 taxa. We distinguished 16 types of macrobenthis communities, with characteristic dominance of different taxa: chironomids (11 types), oligochaete Enchytraeidae family (3), caddisfly Apatania zonella (1) and gammarid amphipod Gammarus setosus (1). Regarding environmental variables, temperature and pH had the most significant influence on the abundance of macrobenthic organisms. It is hypothesized that the structural convergence of different types of communities is their common response to extreme high Arctic living conditions. On the other hand, different chironomids may dominate in the same habitats and water bodies. This gives the effect of lower average similarity of communities and high β-diversity.     

Freshwater harpacticoids (Crustacea: Copepoda: Harpacticoida) in Norway – a comprehensive contribution from G.O. Sars,and a provisional checklist

Since the pioneering works of the Norwegian biologist G.O. Sars, little attention has been given to the freshwater harpacticoids in Norway. The prime purpose of this paper is to present the state of current knowledge about the Norwegian freshwater harpacticoid fauna based on all known published and unpublished literature and archive material. We highlight the contribution of G.O. Sars to the knowledge of this group by presenting his remaining unpublished archive material. We present two Norwegian species checklists – one for freshwater harpacticoids (16 species) and another for freshwater-associated/brackish-water harpacticoids (nine species). Four of the freshwater harpacticoid species are described by G.O. Sars. Original unpublished plates with drawings of those species are included in the paper. In addition, an overview of species distributions throughout the country is given.