Molluscs of Subsidence Basins in the Karviná Region

The study assesses water-filled subsidence basins in the Karviná region using ecological and faunistic characteristics, with freshwater molluscs as bioindicators. Two sites—subsidence lake Kozinec and Doubrava basins—differing in size, salinity, and vegetation, were examined. A malacological survey identified 16 mollusc species, with invasive species dominating Kozinec due to high salinity from mine water discharge, while native species prevailed in Doubrava basins. The study analysed the impact of shoreline zones on mollusc communities, measured physicochemical water parameters (e.g., salinity, pH, nitrites), and evaluated anthropogenic influences. Proposed measures include raising the dam to prevent salinisation of Kozinec’s isolated section, supporting ecological succession, and protecting littoral zones, highlighting the potential for revitalising post-mining sites.