Physicochemical characteristics of the Dombrovska pit lake (Ukraine) formed in an opencast potassium salt mine and the genome response ofChironomus salinariusKieffer (Chironomidae, Diptera) to these conditions

摘要

This study focuses on the Dombrovska pit lake, near the city of Kalush in Ukraine, which is a former potassium salt mine filled with brine and freshwater. The water level is still increasing and as a result the salinity is decreasing. We analyzed the benthic fauna communities and the genome instability by assessing the rearrangements in the polytene chromosomes ofChironomus salinariusand the physicochemical parameters of the near-bottom water (pH, conductivity, mineralization, major ions, NO3-, NH4+, metals Cd, Pb, Cu, Mn, and Fe) and sediment (pH, organic matter and metals Cd, Pb, Cu, Zn, Mn, and Fe) at four sites. The water mineralization ranged from 17.3 to 26.2 g dm(-3)which are classified as mesohaline and polyhaline waters, respectively. The biodiversity of the benthic fauna was low, and the dominant species wasC. salinarius.The density ofC. salinariusvaried spatially and changed from 637 ind./m(2)at a depth of 5 m to 8167 ind./m(2)at a depth of 2.5 m. The genome instability was analyzed by examining the structural and functional changes in the salivary gland chromosomes ofC. salinarius. The exposure ofC. salinariusdamaged the chromosomes and the activities of key structures, such as the Balbiani ring and nucleolar organizer, were partially or completely suppressed.