Dispersal Limitation Dominates Riverine Fish Communities in the Areas of the Water Diversion Project in the Western Sichuan Plateau, China

Animals, Journal Year: 2025, Volume and Issue: 15(5), P. 730 - 730

Published: March 4, 2025

The riverine fish species are highly vulnerable and responsive to large-scale water diversion projects. These adverse impacts more pronounced in the plateau river ecosystems, which may change environmental conditions of habitats community structure. We investigated effects various factors on diversity seven rivers Western Sichuan Plateau, is planned area China's South-to-North Water Diversion Project. Twenty-two species, including eight exotic were collected during September 2023 (Autumn) May 2024 (Spring). communities exhibited no significant difference between seasons but had prominent variations among different rivers. heterogeneity was significantly positively correlated with geographical distance sampling sites (based a projected coordinate system). Furthermore, canonical correspondence analysis (CCA) illustrated that altitude contributed distribution than other physicochemical factors, such as channel width, conductivity, temperature. Rivers at low altitudes likely be invasion fish. Our results demonstrated dispersal limitation by altitudinal gradient primary regulatory spatial differentiation study area, reflected high dependence local habitats. As project implemented, attention expected paid protecting regime shifts communities. Additionally, risk assessment biological under inter-basin transfers human activities should carried out soon possible.

Language: Английский

Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key Drivers

Animals, Journal Year: 2025, Volume and Issue: 15(7), P. 1068 - 1068

Published: April 7, 2025

Understanding spatiotemporal patterns of fish density and their environmental drivers is critical for managing river-lake ecosystems, yet dynamic interactions in heterogeneous habitats remain poorly quantified. This study combined hydroacoustic surveys, spatial autocorrelation analysis (Moran's I), generalized additive models (GAMs) to investigate seasonal distribution, aggregation characteristics, regulatory mechanisms China's Zhelin Reservoir. The results reveal pronounced fluctuations, with summer peaking at 13.70 ± 0.91 ind./1000 m3 declining 1.95 0.13 winter. Spatial heterogeneity was evident, the Xiuhe region sustaining highest (15.69 1.09 m3) persistent hotspots upstream bays. Transient high-density clusters (90-99% confidence) near Dam during suggested thermal or hydrodynamic disturbances. GAM (R2adj = 0.712, 78.5% deviance explained) identified transitions (12.26% variance), water depth (16.54%), conductivity (13.75%), dissolved oxygen (13.29%) as dominant drivers, nonlinear responses bimodal conductivity/oxygen. These findings demonstrate that hydrological seasonality habitat jointly govern aggregation, underscoring ecological priority bays core habitats. provides a mechanistic framework guiding reservoir management, including targeted conservation, dam operation adjustments mitigate impacts, integrated strategies balancing needs similar ecosystems.

Language: Английский