Ecological Assessment of Macrozoobenthos in the Mountain Lake Šator (Bosansko Grahovo, Bosnia and Herzegovina)
Mountain lakes are sensitive ecosystems that serve as natural indicators of ecological change and conservation needs. This study presents the first ecological assessment of Lake Šator (Bosansko Grahovo, Bosnia and Herzegovina), a glacial lake situated at 1,488 m a.s.l. Field research in July and November 2021 included measurements of physicochemical parameters, water sampling, and analysis of littoral and sublittoral macrozoobenthos. The lake showed oligotrophic conditions with high oxygen saturation (101–134%), low organic load, and stable conductivity (208 µS/cm). Nitrate concentrations increased in November, reflecting seasonal dynamics. The macrozoobenthic community comprised 10 taxa in July (26 individuals) and 11 taxa in November (19 individuals). Characteristic taxa included Sympetrum flaveolum, Asellus aquaticus, Erpobdella octoculata, Limnephilus rhombicus, Limnephilus flavicornis, Tubificidae, and water mites (Hydracarina). Functional Feeding Groups analysis revealed dominance of predators (42–46%), followed by collectors, shredders, and scrapers, indicating a balanced trophic structure. Saprobic Index values (2.24 in July; 2.14 in November) correspond to β-mesosaprobic conditions, while Shannon–Weaver Index indicated stable but seasonally variable diversity. These findings confirm the good ecological status of Lake Šator with preserved littoral dynamics. Given its sensitivity and limited prior research, the lake should be considered a priority for long-term monitoring and conservation in the Dinaric karst.