Stocking to offset negative effects of dam construction and balance the ecosystem

Abstract

An ecohydraulic model system was developed to evaluate the effects of the Da‐Wei dam construction and possible fish restoration strategies. The ecohydraulic model system consists of a hydrodynamic model, a hydromorphology model, a habitat model, and the logistic and matrix population models. The effects of dam construction and fish stocking strategy on fish habitat and population status were studied in the Jiao‐Mu River, providing the modeled ecological status of Schizothorax prenanti and Schizothorax plagiostomus heckel populations within the river segment. The two fish species richness, fish age structures, and fish density distributions were predicted. Based on the fish number prediction, the optimal number of fish to stock was evaluated with the population models, and an optimal fish stocking proposition was worked out. The results indicated that the two fish species habitat quality and fish richness would decrease due to the hydropower dam construction, and the fish stocking strategy could make up the fish species ecological status. The findings could facilitate the quantity and quality assessment of a dam development plan and increase the success rate of fish restoration.

Application of a fish habitat model to assess habitat fragmentation using high flow and sediment transport in the Rumei Dam in Lancang River (China)

“…The solid wall boundary condition was set on the riverbank. More detailed information can be found Yao and Chen (2018), Yao (2023) and Wang, Yang, et al (2023). Lancang River, variables like water discharge, temperature and velocity and other physico-chemical parameters such and conductivity could play a major role in influencing fish species richness in the respective habitat type (Fan et al, 2015;Yao et al, 2021).…”

“…Other fish species such as S. davidi (Q. and Schizothorax yunnanensis taliensis (Chen et al, 2016) are endangered, and some are already extinct over the last 20 years, indicating that the degrading ecological circumstances for a typical upper Lanchang River (Zhang et al, 2018;Zhu et al, 2018). Habitat degradation has a particularly significant and detrimental effect on endangered fish species (Yao, 2023). Two fish species, S. prenanti and S. davidi, were selected as target fish species for this study.…”

“…During the last two decades, studies focused on the effects of ecological flow and the natural discharge on ecosystems Yao, 2023); however, only a few studies examined how the modified high flows would directly impact on fish habitats (Benjankar et al, 2018;Li, Chen, Tonina, & Cai, 2015;Quan et al, 2021).…”

Assessment of Fish Habitats and Suitable Ecological Flow under Hydropower Operation

“…However, despite the social and economic benefits, water conservancy projects like reservoirs inevitably disrupt river connectivity, modifying hydrological conditions, including water level, flow, temperature, turbidity, and more [3][4][5]. These changes result in a decrease in the habitat suitability for fish, notably impacting the existing fish community structure and distribution within the watershed [6,7]. Preserving appropriate ecological flow and habitat conditions is a prerequisite for ensuring the reproduction of fish [8,9].…”