A new charophyte habitat with a stabilized good ecological potential of mine water

Abstract

Each newly-created pond which is supplied with mine water gives the opportunity to study a unique ecosystem in context of possible conditions for biotic live. Therefore, this research aimed to assess a phytoplankton-based ecological potential against the trophic conditions and the risk of contamination with trace elements, and demonstrate the possibility to stabilize at least good water quality of a clarification pond. The gradual decrease in turbidity-related variables (including suspended solids and iron) and nutrients, on the one hand, and an increase in phytoplankton-related indicators, on the other hand, were the most evident. Besides, relative stability in trace elements (the best water quality class), trophic level (slightly eutrophic level) and ecological potential (maximum potential), and relative instability in sulfates and calcium were also recorded. The final stabilization of water habitat resulted in abundant growth of charophyte Nitella mucronata. This all suggested a new ecological opportunity for settlement of a rare species and important for biodiversity enhancement. Furthermore, the study revealed that a clarification pond did not pose any toxic risk from the elevated content of trace elements or the growth of toxic or potentially toxic cyanobacteria which is essential for proper functioning and management of water ecosystems.

Abiotic–Biotic Interrelations in the Context of Stabilized Ecological Potential of Post-Mining Waters

“…The development of plankton may be limited by the large amount of suspended solids, including mechanical aspects of creating aggregates and causing its sinking, as well as limiting access to light [40,41]. Similar observations were demonstrated in studies of other reservoirs supplied with mine water [8]. Furthermore, the flocculation process involving both the phytoplankton and zooplankton is one of the key factors in suspension sedimentation [42,43].…”

“…The positive correlations between phytoplankton and TSS, turbidity, and color compounds indicated its influence on the water quality, connected with the shading conditions in water, and such relationships were opposite to those described for other mine waters [7,8]. Such close relations were not observed either for zooplankton or planktivorous fish, and their role in the flocculation process is not well known yet.…”

“…However, the second most dominant group was euglenoids belonging to codon W1, which is typical of ponds, even temporary, rich in organic matter from husbandry or sewages, suggesting a more fertile environment. These two groups were not recorded as dominant groups in the other ponds fed with water of the same origin, and, on the contrary, phytoplankton were dominated primarily by diatoms [7,8]. Large-sized diatoms, which are important for the flocculation process of mineral particles in sedimentation ponds [45], dominated only in 2015 (Kamie ń sedimentation pond).…”

“…Phosphate's affinity for calcium, iron, and manganese ions under stable aerobic conditions and in alkaline water limits primary production. Such relations and increases in the concentrations of calcium and sulfate ions were noted by identifying the hydrochemical properties of the mine water [7,8]. The development of plankton may be limited by the large amount of suspended solids, including mechanical aspects of creating aggregates and causing its sinking, as well as limiting access to light [40,41].…”

“…The other roles of such reservoirs concern the technical function, e.g., for the sedimentation of suspended particles in the pretreatment of mine water [7,8]. These reservoirs offer, however, new habitats for aquatic organisms, including planktonic and benthic organisms, macrophytes, and fish, supporting the European Union Biodiversity Strategy for 2030 [9] and the Green Deal [10].…”