European Diatom Database-Svalbard pH dataset

The top 0.5 cm of short sequences taken by gravity corer were analysed for diatoms, 500 diatoms per sample were counted for these surface sediment samples. Over 180 taxa were found but generally samples are taxon poor, with the majority of sites dominated by benthic genera such as Fragilaria, Navicula and Achnanthes.

Planktonic Cyclotella species occur at only 3 sites. Current relationships between diatom abundance and water chemistry and other environmental variables were explored numerically and a preliminary transfer function for pH was constructed. Lakes fall into three groups on the basis of their diatom assemblages from (1) high pH, high cation, high conductivity sites characterised by Amphora libyca, (2) shallow sites with relatively high nutrient values characterised by Fragilaria species and (3) more acid and dilute sites with higher snow cover in the catchments characterised by small Achnanthes species and Navicula digitulus.