Influence of Natural Barriers on Small Rivers for Changes in Water Quality Parameters

The occurrence of the protected species Castor fiber L., which creates a network natural barriers for its own needs, may affect changes in water quality parameters. This study shows parameters (EC, BOD5, COD, TN, N-NH4, N-NO3, N-NO2, TP, P-PO4, Cl−, SO42−) small rivers eastern Poland. results were analysed using one-way and three-way ANOVA Tukey’s HSD post hoc test to identify significance habitats, seasons, land use. All parameters, with exception met standards good ecological status. average values P-PO4 exceeded threshold status summer meadows. annual are characterised by decrease pollution. highest concentration 57% was found 45% TP at sites after barriers. lowest 5% EC. In case increase 33%. situation completely different removing barriers, where an pollutants about 30% found. Changes significantly influenced season Due various construction, age, removal beaver habitats positively or negatively impact quality. It is crucial improvement ensure durability functioning proper use land.