Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key Drivers
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),...
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MDPI AG
2025-04-01
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| author | Zihao Meng Feifei Hu Miao Xiang Xuejun Fu Xuemei Li |
| author_facet | Zihao Meng Feifei Hu Miao Xiang Xuejun Fu Xuemei Li |
| author_sort | Zihao Meng |
| collection | DOAJ |
| description | 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), and generalized additive models (GAMs) to investigate seasonal and spatial fish distribution, aggregation characteristics, and regulatory mechanisms in China’s Zhelin Reservoir. The results reveal pronounced seasonal fluctuations, with summer fish density peaking at 13.70 ± 0.91 ind./1000 m<sup>3</sup> and declining to 1.95 ± 0.13 ind./1000 m<sup>3</sup> in winter. Spatial heterogeneity was evident, with the Xiuhe region sustaining the highest density (15.69 ± 1.09 ind./1000 m<sup>3</sup>) and persistent hotspots in upstream bays. Transient high-density clusters (90–99% confidence) near the Zhelin Dam during summer suggested thermal or hydrodynamic disturbances. GAM analysis (R<sup>2</sup>adj = 0.712, 78.5% deviance explained) identified seasonal transitions (12.26% variance), water depth (16.54%), conductivity (13.75%), and dissolved oxygen (13.29%) as dominant drivers, with nonlinear responses to depth and bimodal patterns for conductivity/oxygen. These findings demonstrate that hydrological seasonality and habitat heterogeneity jointly govern fish aggregation, underscoring the ecological priority of Xiuhe and upstream bays as core habitats. This study provides a mechanistic framework for guiding reservoir management, including targeted conservation, dam operation adjustments to mitigate hydrodynamic impacts, and integrated strategies for balancing hydrological and ecological needs in similar ecosystems. |
| format | Article |
| id | doaj-art-1b67050cfd0143acbb6c1e875b26d31c |
| institution | DOAJ |
| issn | 2076-2615 |
| language | English |
| publishDate | 2025-04-01 |
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| spelling | doaj-art-1b67050cfd0143acbb6c1e875b26d31c2025-08-20T03:08:43ZengMDPI AGAnimals2076-26152025-04-01157106810.3390/ani15071068Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key DriversZihao Meng0Feifei Hu1Miao Xiang2Xuejun Fu3Xuemei Li4Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, ChinaYangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, ChinaYangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, ChinaAquatic Conservation and Rescue Center of Jiangxi Province, Nanchang 330096, ChinaYangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, ChinaUnderstanding 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), and generalized additive models (GAMs) to investigate seasonal and spatial fish distribution, aggregation characteristics, and regulatory mechanisms in China’s Zhelin Reservoir. The results reveal pronounced seasonal fluctuations, with summer fish density peaking at 13.70 ± 0.91 ind./1000 m<sup>3</sup> and declining to 1.95 ± 0.13 ind./1000 m<sup>3</sup> in winter. Spatial heterogeneity was evident, with the Xiuhe region sustaining the highest density (15.69 ± 1.09 ind./1000 m<sup>3</sup>) and persistent hotspots in upstream bays. Transient high-density clusters (90–99% confidence) near the Zhelin Dam during summer suggested thermal or hydrodynamic disturbances. GAM analysis (R<sup>2</sup>adj = 0.712, 78.5% deviance explained) identified seasonal transitions (12.26% variance), water depth (16.54%), conductivity (13.75%), and dissolved oxygen (13.29%) as dominant drivers, with nonlinear responses to depth and bimodal patterns for conductivity/oxygen. These findings demonstrate that hydrological seasonality and habitat heterogeneity jointly govern fish aggregation, underscoring the ecological priority of Xiuhe and upstream bays as core habitats. This study provides a mechanistic framework for guiding reservoir management, including targeted conservation, dam operation adjustments to mitigate hydrodynamic impacts, and integrated strategies for balancing hydrological and ecological needs in similar ecosystems.https://www.mdpi.com/2076-2615/15/7/1068fish distributionschooling behaviorenvironmental gradientsgeneralized additive modelsacoustics monitoringZhelin Reservoir |
| spellingShingle | Zihao Meng Feifei Hu Miao Xiang Xuejun Fu Xuemei Li Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key Drivers Animals fish distribution schooling behavior environmental gradients generalized additive models acoustics monitoring Zhelin Reservoir |
| title | Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key Drivers |
| title_full | Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key Drivers |
| title_fullStr | Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key Drivers |
| title_full_unstemmed | Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key Drivers |
| title_short | Spatiotemporal Dynamics of Fish Density in a Deep-Water Reservoir: Hydroacoustic Assessment of Aggregation Patterns and Key Drivers |
| title_sort | spatiotemporal dynamics of fish density in a deep water reservoir hydroacoustic assessment of aggregation patterns and key drivers |
| topic | fish distribution schooling behavior environmental gradients generalized additive models acoustics monitoring Zhelin Reservoir |
| url | https://www.mdpi.com/2076-2615/15/7/1068 |
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