Diatoms in bottom sediments of the arctic lake in the pechora river delta (Nenets Autonomous Okrug, Russia)

Abstract

© 2020 International Multidisciplinary Scientific Geoconference. All rights reserved. Diatoms are widely used for paleoindication, through which the main stages of life of lakes against the background of changing environmental conditions determined by both natural and anthropogenic factors can be reconstructed. The results of the diatom analysis of a 96 cm long continuous sediment core from the artic lake in the Pechora River delta (Nenets Autonomous Okrug, Russia) were presented. The arctic lake under study is characterized by low conductivity and nutrients content. In 33 samples taken from the lake, 113 diatom taxa belonging to 44 genera were identified. The prevalence of holarctic, alkaliphilic, and benthic species with the abundance growth under moderate temperatures was established. The dominance of Eunotia genera and acidophilic Tabellaria flocculosa indicates the presence of peat bogs in the study area. Diatom stratigraphy was divided into three diatom zones on the basis of changes in the diatom abundance and taxa composition. The mass development and diversity of diatoms was noted in the lower part of the core, thereby reflecting the high water level and the formation of a deep and less mineralized water body in a humid climate. Diatoms were absolutely absent or present in small number in the middle layers of the core. The upper layers of the core are characterized by an increase in the number of diatoms in the sediments. In addition, re-deposited frustules of Tabellaria fenestrata, Сymbella sp. were found in this zone.