Fish swimming hydrodynamics serves as a critical foundation for aquatic ecological conservation,with recent research extending from 2D to 3D perspectives.This study employs 3D high-fidelity modeling with dynamic mesh ...Fish swimming hydrodynamics serves as a critical foundation for aquatic ecological conservation,with recent research extending from 2D to 3D perspectives.This study employs 3D high-fidelity modeling with dynamic mesh technology to investigate how cylindrical obstacles at varying positions affect Carassius auratus locomotion.Analysis of nine configurations reveals bidirectional flow interactions between fish and cylinders,with cylinder wake influence persisting at 1-2 times the total length intervals but diminishing at 3times.Compared with swimming in uniform flow,the mechanical benefit of C.auratus located 2 times the total length directly behind the cylinder is the largest,and its value reaches 4.19 times.Wavelet analysis of 30-cycle mechanical data demonstrates closer intervals enhance benefit magnitude,whereas greater distances accelerate benefit realization.These 3D computational findings corroborate 2D studies while providing new spatial interaction insights,offering theoretical foundations for fish conservation strategies related to hydraulic structures.展开更多
The determinants of local differences in species and functions matter for reservoir management but have seldom been investigated.To this aim,we explored fish taxonomic,and functional beta diversity between local assem...The determinants of local differences in species and functions matter for reservoir management but have seldom been investigated.To this aim,we explored fish taxonomic,and functional beta diversity between local assem-blages in a large Chinese reservoir.Taxonomicβdiversity was primarily driven by species richness differences(54%–72%),while functionalβdiversity was almost equally driven by turnover and nestedness components.Environmental characteristics of the sites were significant predictors of all facets of fishβdiversity.Additionally,site contributions to taxonomic(LCBD)and functional(XLCBD)βdiversity were significantly associated with human activity variables,suggesting that there is a pressing need to mitigate human-induced disturbances for the conservation of biodiversity.Species contributions to taxonomic(SCBD)and functional(XSCBD)βdiversity exhibited positive correlations primarily with species occupancy and abundance,suggesting the potential uniqueness of certain common species.Priority conservation areas in the upstream area and rare but key species such as Tachysurus and Siniperca were identified based on site and species contributions.We thus propose to focus on habitat restoration actions to upstream areas by restricting sand mining,as the current mining activities in the river channel can directly alter riverbed morphology and damage the spawning grounds of fish.We also emphasize the necessity for increased conservation efforts through the development of sustainable recreational fishing policies and stock recovery programs for sensitive species such as Pelteobagrus vachelli and Acheilognathus macropterus.These species have lower SCBD or XLCBD values than others and possess unique feeding habits or high economic value,making them primary targets for recreational fishing.This research highlights the impor-tance of integrating taxonomic and functionalβdiversity to effectively evaluate biodiversity changes and develop more comprehensive and sustainable conservation strategies for fish diversity conservation.展开更多
Although China has established more than 600 wetland nature reserves, conservation gaps still exist for many species, especially for freshwater fishes. Underlying this problem is the fact that top-level planning is mi...Although China has established more than 600 wetland nature reserves, conservation gaps still exist for many species, especially for freshwater fishes. Underlying this problem is the fact that top-level planning is missing in the construction of nature reserves. To promote the development of nature reserves for fishes, this study took the middle and lower reaches of the Yangtze River basin(MLYRB) as an example to carry out top-level reserve network planning for fishes using approaches of systematic conservation planning. Typical fish species living in freshwater habitats were defined and considered in the planning. Based on sample data collected from large quantities of literatures, continuous distribution patterns of 142 fishes were obtained with species distribution modeling and subsequent processing, and the distributions of another eleven species were artificially designated. With the distribution pattern of species, Marxan was used to carry out conservation planning. To obtain ideal solutions with representativeness, persistence, and efficiency, parameters were set with careful consideration regarding existing wetland reserves, human disturbances, hydrological connectivity, and representation targets of species. Marxan produced the selection frequency of planning units(PUs) and a best solution. Selection frequency indicates the relative protection importance of a PU. The best solution is a representative of ideal fish reserve networks. Both of the PUs with high selection frequency and those in the best solution have low proportions included in existing wetland nature reserves, suggesting that there are significant conservation gaps for fish species in MLYRB. The best solution could serve as a reference for establishing a fish reserve network in the MLYRB. There is great flexibility for replacing selected PUs in the solution, and such flexibility facilitates the implementation of the solution in reality in case of unexpected obstacles. Further, we suggested adopting a freshwater management framework in the implementation of such solution.展开更多
基金National Key Research and Development Program of China,Grant/Award Number:2022YFC3204202National Natural Science Foundation of China,Grant/Award Number:52122904Ministry of Water Resources,Grant/Award Number:SKS-2022121。
文摘Fish swimming hydrodynamics serves as a critical foundation for aquatic ecological conservation,with recent research extending from 2D to 3D perspectives.This study employs 3D high-fidelity modeling with dynamic mesh technology to investigate how cylindrical obstacles at varying positions affect Carassius auratus locomotion.Analysis of nine configurations reveals bidirectional flow interactions between fish and cylinders,with cylinder wake influence persisting at 1-2 times the total length intervals but diminishing at 3times.Compared with swimming in uniform flow,the mechanical benefit of C.auratus located 2 times the total length directly behind the cylinder is the largest,and its value reaches 4.19 times.Wavelet analysis of 30-cycle mechanical data demonstrates closer intervals enhance benefit magnitude,whereas greater distances accelerate benefit realization.These 3D computational findings corroborate 2D studies while providing new spatial interaction insights,offering theoretical foundations for fish conservation strategies related to hydraulic structures.
基金supported by the China Agriculture Research System of MOF and MARA(CARS-46)the Central Public-interest Scientific Institution Basal Research Fund,CAFS(grant 2023TD61,YFI20240102 and YFI202418)the Key Research and Development Program of Jiangxi Province,China(grant 20223BBF61010).
文摘The determinants of local differences in species and functions matter for reservoir management but have seldom been investigated.To this aim,we explored fish taxonomic,and functional beta diversity between local assem-blages in a large Chinese reservoir.Taxonomicβdiversity was primarily driven by species richness differences(54%–72%),while functionalβdiversity was almost equally driven by turnover and nestedness components.Environmental characteristics of the sites were significant predictors of all facets of fishβdiversity.Additionally,site contributions to taxonomic(LCBD)and functional(XLCBD)βdiversity were significantly associated with human activity variables,suggesting that there is a pressing need to mitigate human-induced disturbances for the conservation of biodiversity.Species contributions to taxonomic(SCBD)and functional(XSCBD)βdiversity exhibited positive correlations primarily with species occupancy and abundance,suggesting the potential uniqueness of certain common species.Priority conservation areas in the upstream area and rare but key species such as Tachysurus and Siniperca were identified based on site and species contributions.We thus propose to focus on habitat restoration actions to upstream areas by restricting sand mining,as the current mining activities in the river channel can directly alter riverbed morphology and damage the spawning grounds of fish.We also emphasize the necessity for increased conservation efforts through the development of sustainable recreational fishing policies and stock recovery programs for sensitive species such as Pelteobagrus vachelli and Acheilognathus macropterus.These species have lower SCBD or XLCBD values than others and possess unique feeding habits or high economic value,making them primary targets for recreational fishing.This research highlights the impor-tance of integrating taxonomic and functionalβdiversity to effectively evaluate biodiversity changes and develop more comprehensive and sustainable conservation strategies for fish diversity conservation.
基金supported by fund of State Forestry Administration of China-United Nations Development Program/Global Environment Facility(83911 NP-2014-007)
文摘Although China has established more than 600 wetland nature reserves, conservation gaps still exist for many species, especially for freshwater fishes. Underlying this problem is the fact that top-level planning is missing in the construction of nature reserves. To promote the development of nature reserves for fishes, this study took the middle and lower reaches of the Yangtze River basin(MLYRB) as an example to carry out top-level reserve network planning for fishes using approaches of systematic conservation planning. Typical fish species living in freshwater habitats were defined and considered in the planning. Based on sample data collected from large quantities of literatures, continuous distribution patterns of 142 fishes were obtained with species distribution modeling and subsequent processing, and the distributions of another eleven species were artificially designated. With the distribution pattern of species, Marxan was used to carry out conservation planning. To obtain ideal solutions with representativeness, persistence, and efficiency, parameters were set with careful consideration regarding existing wetland reserves, human disturbances, hydrological connectivity, and representation targets of species. Marxan produced the selection frequency of planning units(PUs) and a best solution. Selection frequency indicates the relative protection importance of a PU. The best solution is a representative of ideal fish reserve networks. Both of the PUs with high selection frequency and those in the best solution have low proportions included in existing wetland nature reserves, suggesting that there are significant conservation gaps for fish species in MLYRB. The best solution could serve as a reference for establishing a fish reserve network in the MLYRB. There is great flexibility for replacing selected PUs in the solution, and such flexibility facilitates the implementation of the solution in reality in case of unexpected obstacles. Further, we suggested adopting a freshwater management framework in the implementation of such solution.
