Phytoplankton community structure of thermokarst lakes from Khatanga River Basin (Krasnoyarsk Region, Russia).

Abstract

Planktonic algae - phytoplankton - is a key component of water systems, actively involved in the formation of the water quality, and a sensitive indicator of the state of aquatic ecosystems and the water body as a whole. We have studied phytoplankton of several thermokarst lakes of northern areas of Krasnoyarsk region. Samples for phytoplankton analysis were selected during the comprehensive limnological and palaeolimnological Russian-German expedition in August 2013, from 18 lakes. This report presents qualitative and quantitative indicators of phytoplankton, as well as evaluation of the current ecological status of water by the parameters phytoplankton of several thermokarst lakes of the Khatanga river basin. During the observation period, we found 164 planktonic algae taxa in phytoplankton of the investigated water bodies. Quantitative indicators of the phytoplankton of the studied lakes are low, the total abundance and biomass of phytoplankton varies from 31.50-2,331.50 thousand Cl./L and 0.05-1.01 mg/L. The most prevalent in number are green-blue algae, and in biomass - dinoflagellate, green and golden algae. Water of most thermokarst lakes of the Khatanga river basin during the observation period corresponds to oligotrophic type, and only of two lakes - to mesotrophic. Water quality in the nine of the eighteen lakes is considered as mesosaprobic, the other nine - as oligosaprobic.