Effects of run‐of‐river hydropower plants on fish communities in montane stream ecosystems in Serbia

Abstract

Small run-of-river hydropower plants (RRHPs) have revealed strong harmful effects worldwide on stream habitats (e.g., fragmentation and destruction) and decreased fish species, especially anadromous species abundance. Recently, RRHPs have rapidly been installed in Serbia. Most were installed on montane streams because their steep slopes are most convenient for hydropower energy production at minimal costs.Brown trout Salmo trutta are prominent in the fish communities of this rarest type of aquatic ecosystems. Their native molecular diversity reflects a biodiversity hotspot in the Balkans, and they provide attractive fishing opportunities. Records from fishery management plans for highland stream fisheries where RRHPs were installed revealed reduced brown trout biomass compared with streams without RRHPs.Research on six streams with operational RRHPs revealed severe deterioration of habitat, for example, increased water temperature, reduced dissolved oxygen, and increased nutrient contents. Effects on fish communities were evident from a change in their structure. Resident, stream-dwelling brown trout were the most affected species with steep declines in abundance, biomass, and productivity. Fragmentation owing to damming was also reflected by deterioration of their age structure. Unique native brown trout stocks susceptible to adverse effects are difficult to restore by stocking, and fish passages commonly supplied as compensation to overcome the disruption of habitats cannot mitigate the threat posed to the fish.

Designing Hydropower Flows to Balance Energy and Environmental Needs (HydroWIRES Topic A Final Project Report)

“…Hydropeaking can amplify these impacts and make them much less predictable as flow vortices and intensities rapidly change. Reduced flow and sedimentation also increase water temperature, reduce dissolved oxygen levels, and reshape nutrient flow and food web structures (Ibàñez et al, 1996;Fantin-Cruz et al, 2016;Kennedy et al, 2016;Simonović et al, 2021).…”

Heterogenisation of riverine ichthyofauna diversity by small hydropower dams

“…(2014), SHPs can cause ecosystem problems comparable to those of large hydropower plants, despite generating fewer megawatts (MW). Research on the ecological impacts of small run‐of‐the‐river dams has focused on their effects on ichthyofauna (Cella‐Ribeiro et al., 2017; Gibeau et al., 2017; Robson, 2013) and habitat fragmentation, and degradation (Nilsson et al., 2005; Santucci et al., 2005; Simonovi et al., 2021). All three have negative consequences for hydrology and biodiversity (Carvajal‐Quintero et al., 2017; Reidy et al., 2012).…”

Potencijali i prepreke za transnacionalizaciju suvremenih ekoloških borbi u Srbiji

“…The consequences of the piping of the rivers, especially if the investors did not adhere to the standards, were devastating. They threatened both the natural environment(Ristić et al, 2018;Crnobrnja-Isailović et al, 2021;Simonović et al, 2021), and the local communities whose daily livelihoods depended on the access to fresh water, as the population is mainly engaged in agriculture, animal husbandry or agricultural Therefore, the environmental and social costs of SHPPs exceeded the potential economic gains(Ristić et al, 2018), deepening already existing social inequalities.…”