Macroinvertebrates as bioindicators of water quality in the Skawa River and Mucharskie Lake (Southern Poland)

Aquatic macroinvertebrates are organisms’ sensitive to changes in the environment in which they function and are therefore used to assess the quality of surface waters. This study aimed to assess the water quality of the Skawa River and Mucharskie Lake based on benthic macroinvertebrates, using the BMWP-PL index. Water samples from six research sites were utilised for the study – three on the Skawa River and three on Mucharskie Lake. Various macroinvertebrates were identified in water samples from the study sites, such as mayflies, caddisflies, stoneflies, beetles, crustaceans, snails, and leeches. The assessment of the water quality of the Skawa River and Mucharskie Lake, taking into account the BMWP-PL index, indicates a generally poor condition of the studied waters. The BMWP-PL indices obtained at the studied sites ranged from 3 to 93 points. Such a score corresponds to four water quality classes – II, III, IV, and V. Points S1, S2 and S6 on the Skawa River were characterized by good and moderate water quality (II and III class). On the other hand, bad water quality was characterized by sites S3 (Dabrówka) and S4 (Mucharz) on Mucharskie Lake.