Impacts of small hydro power plant and fish pond on diatom community (Prištavica River, Serbia)

Abstract

The mountain streams are under increasing pressure due to the construction of small hydro power plants (SHPs) and fish ponds (FPs). About 90 SHPs have been built in Serbia so far, and a total of 850 are planned. Objective of this study was to investigate the influence of SHP and FP on the spatial and temporal distribution of diatom assemblages in the Prištavica River. Epilithic samples were collected in July and October 2019 from 4 sites. SHP is located between the sites 3 and 4 and FP between 1 and 2. Permanent slides were made, and then qualitative and quantitative analysis of diatoms was performed. The results suggest that construction of SHP and FP have significant impact on physical and chemical water parameters which varied among the sampling sites. A total of 78 diatom taxa belonging to 28 genera were identified. Impact of SHP on diatom species diversity was noticed in summer, when observed species diversity was significantly lower at site 4 compared to others. Sites directly after the FP and SHP (sites 2 and 4) were distinguished by the same dominant species. Achnanthidium minutissimum and Cocconeis euglypta were dominant taxa at these sites in summer and Nitzschia amphibia in autumn. This indicates that both constructions built on the Prištavica River have a similar impact on the diatom community structure and thus probably on the water quality. Further research is necessary to improve management strategies which will enable sustainability and diversity of diatoms community as well as other aquatic organisms.