Natural evolution of artificial lakes formed in lignite excavations based on diatom, geochemical and isotopic data

Abstract

TR-31 and TR-33 are post-mining lakes located within the Łuk Mu_ zakowa Geopark (western Poland). They were created after the end of lignite exploitation in the second half of the nineteenth century. Although they are located in neighbouring excavations and currently have neutral pH levels, they developed differently. Based on the diatom communities, elemental analyses and isotopic data, TR-33 experienced a natural neutralization process from an acidic state to nearly neutral due to the presence of lignite residuum at the bottom of the excavation. Pyrite is common in lignite deposits and gangue, and its oxidation causes acidity in aquatic ecosystems. The primordial state of the acidic water in TR-33 was confirmed by the development of diatoms belonging to the Eunotia genus, which can tolerate acidic environments. The excavation in TR-31 was filled by rain and groundwater, and the pH of the water was neutral or nearly neutral from the beginning of lake's existence. This is indicated by the diatom assemblages during the initial phase of lake formation and the reconstruction of the water pH. The relatively low values of the C/N ratio in the deep layers of the core indicate the lack of lignite deposits at the bottom of TR-31.

Geometric Morphometrics of Bilateral Asymmetry in Eunotia bilunaris (Eunotiales, Bacillariophyceae) as a Tool for the Quantitative Assessment of Teratogenic Deviations in Frustule Shapes

“…The valves of E. bilunaris are typical for arcuate isopolar outlines with rounded polar ends that are slightly tapered (Figure 1). Interestingly, in the specimens of this species, teratogenic deformations of valvar outlines have been repeatedly reported [3,6,7,9,10,13]. These deformities were largely linked to adverse environmental conditions, such as heavy metal pollution [6,7] or low pH [9,10].…”

“…The incidence of such morphological deformations in the sedimentary record has frequently been used as proxy data for the identification of historical changes in the anthropogenic loading of various aquatic ecosystems [3,5,6,13]. In these studies, the stress rate is usually quantified as the proportion of deformed frustules relative to the "standard" shapes.…”

Geochemical Variability of Surface Sediment in Post-Mining Lakes Located in the Muskau Arch (Poland) and Its Relation to Water Chemistry

“…coal versus clay mining), the age of the lake (Pukacz et al 2018), hydrogeological and geological conditions, presence of lignite, pyrite content (Labus and Skoczyńska 2013), and ore geometry. This results in high variability in lake water and sediment chemistry, even when comparing closely located sites (Sienkiewicz and Gąsiorowski 2019). Moreover, the complex geological structure of glaciogenic sediments containing lignite makes the changes in the chemistry of the studied lakes difficult to model and predict (Sienkiewicz and Gąsiorowski 2016).…”

“…The negative correlation with pH and weak negative correlation with DOC (r = − 0.37) suggest that in neutral and alkaline lakes, which are more productive (e.g. sites 31 or 68), at least part of the Si budget is consumed by diatoms (Sienkiewicz and Gąsiorowski 2019) and subsequently deposited into sediments. This process results in a higher concentration of Si in lakes with low pH and a simple food web, characterised by sediments rich in iron hydroxides (Fig.…”

Water quality and spatial and seasonal dynamics in the largest water supply reservoir in Brazil and implications for diatom assemblages

“…The understanding of structure and function of biological communities permit the assessment of an ecosystem's status (Tilman et al, 1997), and especially for diatoms, it is an important tool for environmental monitoring and sustainable exploitation of natural resources (Ndiritu et al, 2003). The diatom community is widely associated with water quality (Liang et al, 2020;Pandey et al, 2018;Poulicková et al, 2004), pH variations (Razumovskii and Razumovskii, 2019;Sienkiewicz and Gąsiorowski, 2019;Dixit et al, 1992), and trophic status (Costa-Böddeker et al, 2012;Besse-Lototskaya et al, 2011;Belling et al, 2006;Bennion, 1995;Fritz et al, 1993). However, other factors may also be important to understand the organization of these communities.…”