Research progress on impact of cascade hydropower development in lower Jinsha River on early-life resources of Coreius guichenoti

Abstract

[Objective] To investigate the effects of cascade hydropower development in the lower Jinsha River on the distribution of spawning grounds and early-life resources of Coreius guichenoti. [Methods] Based on literature review and field survey data recorded from 1981 to 2023, combined with the progression of hydropower project construction, the spatiotemporal variation characteristics of the spawning scale, early-life resources, and spawning grounds of C.guichenoti and their driving factors were analyzed. [Results] The result showed that current spawning activities were primarily distributed in river reaches including Pingdi Town, Yuanmou County, and Jiaopingdu, with only sporadic spawning remaining in areas such as Qiaojia, Huidong, and Wuding, indicating a continuous reduction in overall scale. Following the operation of the second-phase projects, spawning grounds in Qiaojia, Jiaopingdu, and Yuanmou County may further disappear, and the major spawning grounds were projected to shift towards the tributaries and mainstem upstream of the Wudongde Dam. Under the combined influence of environmental factors such as water temperature, discharge, flow velocity, and physical barriers, the age at first sexual maturity of C.guichenoti was delayed, the reproductive period was shortened, the spawning frequency decreased, and both spawning quantity and hatching rate declined, leading to a year-by-year decreasing trend in early-life resource abundance. [Conclusion] It is recommended to adopt ecological regulation and habitat substitution technologies to improve spawning habitat conditions. Furthermore, artificial proliferation and release should be enhanced, and fish passage facilities should be constructed to enhance the reproductive population size and genetic diversity, thereby mitigating the negative impact of cascade hydropower development on C.guichenoti population resources.

Keywords

Lower Jinsha River / hydropower development / cascade hydropower stations / Coreius guichenoti / spawning ground / early-life resources / species protection / influencing factors

Funding

National Key R&D Program of China(2022YFC3203903)

National Natural Science Foundation of China(52179083)

National Natural Science Foundation of China(42206214)