Research on the spatial and temporal distribution of shrimp mariculture can provide a reference for the optimization of the spatial distribution and sustainable development of the shrimp mariculture industry.In recent...Research on the spatial and temporal distribution of shrimp mariculture can provide a reference for the optimization of the spatial distribution and sustainable development of the shrimp mariculture industry.In recent years,most of the domestic shrimp research focuses on biological characteristics,shrimp breeding,and environmental factors,with limited studies on the overall distribution patterns of large-scale marine shrimp farming.11 provinces along the coast of China were selected as the study area to investigate the spatial and temporal evolution characteristics of the four types of shrimp marine aquaculture production and their spatial differences in driving factors over the past 20 years.The results showed that:(1)The production and farming area of Litopenaeus vannamei(LV)were the highest among the four types of shrimp and increased exponentially over time.The farming area of the other three shrimp species showed a decreasing trend;(2)The farming centers of LV and Penaeus monodon(PM)are located in the southern regions,while those of Fenneropenaeus chinensis(FC)and Marsupenaeus japonicus(MJ)are in the northern regions.The farming centers of all four types of shrimp have shifted to varying degrees,with farming area being the main factor influencing the movement of these centers;(3)Regarding driving factors,wild catch,farming area,and extension personnel are the leading factors in the spatial differences in production,and the interaction between the factors ultimately led to spatial differences in shrimp production;(4)Comparison of different sea areas revealed that shrimp in the South China Sea region is mainly farmed in sea water,while the northern regions rely more on freshwater farming.The yield of shrimp per unit area in the South China Sea can reach up to 14 t/ha,which is significantly higher than that in the northern region;(5)Using the established regression model to predict the production and area of LV,its production and area in the next five years to maintain a sustained growth trend.The results can provide support for the formulation of relevant government policies,thus promoting the healthy development of shrimp mariculture.展开更多
Recreational beaches are widely distributed in coastal cities.Investigating the coupling mechanisms between anthropogenic interventions and natural coastal processes on sediment grain-size distribution is critical for...Recreational beaches are widely distributed in coastal cities.Investigating the coupling mechanisms between anthropogenic interventions and natural coastal processes on sediment grain-size distribution is critical for maintaining and enhancing recreational beach functionality and value.This study examines three major recreational beaches within Zhanjiang Bay,conducting comparative analyses of surface sediment characteristics including representative grain-size metrics,granulometric composition,and statistical parameters.Key findings include:(a)significant variations in mode size(0.87-1.89φ)and D10 values(-0.80 to-0.09φ)among the three beaches,contrasted with limited differences in D50 and D90 metrics;(2)dominance of medium sand(26.16-39.14%)and coarse sand(26.75-31.43%)fractions,supplemented by fine and very coarse sand components,with central transects exhibiting higher medium-coarse sand concentrations than southern/northern sections;(3)sorting coefficient gradients(0.90-1.21)ranking central>northern>southern beaches,while mean grain size(0.83-1.21φ),skewness(-0.12 to-0.02),and kurtosis(0.87-1.18)show no distinct spatial patterns.Sediment grain-size distribution patterns are governed by four primary mechanisms:artificial nourishment inputs,anthropogenic sediment modification(harvesting/excavation),natural sediment supply processes,and hydrodynamic forcing.This research establishes a typical framework for characterizing recreational beach sediments,advancing understanding of multi-factor controlled grain-size distribution patterns and sediment transport dynamics.展开更多
Mangrove forests possess significant ecological and aesthetic values.Investigating the spatial distribution characteristics of beach sediments in mangrove habitats and their relationships with hydrodynamic conditions ...Mangrove forests possess significant ecological and aesthetic values.Investigating the spatial distribution characteristics of beach sediments in mangrove habitats and their relationships with hydrodynamic conditions and vegetation dynamics is crucial for sustaining the health and sustainability of mangrove ecosystems.This study aims to explore the spatial distribution characteristics of sediments in the mangrove beach of Xiashan Sea-viewing Promenade,Zhanjiang,and their relationship with hydrodynamics and mangrove vegetation.A total of 59 surface sediment samples were collected from 6 transects in the study area.The elevation of the sampling points,as well as wave and current data during the sampling period,were measured.The sediment transport trends of the 6 transects were also analyzed.The results show that the average grain size of surface sediments in the study area ranges from-0.75 to 5.15φ;the average sorting coefficient is 1.26,indicating poor sediment sorting;the average skewness is 0.19,with positively skewed and extremely positively skewed sediments widely distributed in the study area;the kurtosis values range from 0.36 to 2.31,with an average of 1.14,and narrow kurtosis is observed on the seaward side of the southern and northern parts of the study area.The significant wave height in the study area ranges from 0.05 to 0.17 m,the wave period ranges from 1.44 to 3.38 s,and the current velocity ranges from 1.44 to 7.44 cm·s^(−1).The surface sediment types include gravel,sand,silt,and clay,with sand being the most abundant,followed by silt,while gravel and clay are present in small amounts,with gravel only found in small quantities near the shore in the northern part of the study area.The sand content decreases from the shore to the sea,while the spatial distribution of silt shows the opposite trend.The clay content is relatively low,with a higher concentration in the seaward area.The wave action in the study area is significantly stronger than the current action,with the strongest hydrodynamic forces occurring during the early flood tide and late ebb tide,leading to an onshore sediment transport trend.This process can increase beach elevation and stability,which is beneficial for the growth and development of mangroves.展开更多
High-level pond aquaculture,as a typical aquaculture model along the South China coast,poses potential threats to coastal ecosystems due to beach topographic changes induced by its tailwater discharge.Supported by dro...High-level pond aquaculture,as a typical aquaculture model along the South China coast,poses potential threats to coastal ecosystems due to beach topographic changes induced by its tailwater discharge.Supported by drone technology,this study employed a combined method of DJI Matrice 300 RTK UAV LiDAR surveying and ground GNSS RTK measurements to collect data from the beach area affected by high-level pond tailwater discharge in northern Longhaitian,eastern Leizhou Peninsula.The study aims to investigate the impact of high-level pond tailwater discharge on beach topography using DSM generated from UAV LiDAR data.The results show:(1)By verifying the accuracy of UAV LiDAR data(RMSE of 8.05 cm,99%confidence interval[6.59,8.09]cm),confirmed the reliability and applicability of UAV LiDAR for monitoring beach topography affected by high-level pond tailwater discharge,with credible measurement data;(2)The beach exhibits significant spatial differentiation characteristics:the beach berm is eroded by aquaculture tailwater,with the central beach berm completely eroded away;(3)Compared to unaffected profiles,those influenced by high-level pond tailwater discharge show greater elevation change ranges,with maximum erosion depths exceeding 4 m and maximum sedimentation thickness approaching 2 m.The affected beach area demonstrates berm erosion,sedimentation in erosion gullies,and scarp erosion in the southern section,with maximum scarp erosion reaching approximately 5 m.The combined effects of tides and aquaculture tailwater discharge are the primary factors causing these phenomena.These research findings can provide technical support for the quantitative assessment of beach topography changes induced by high-level pond tailwater discharge.展开更多
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2022 A1515240023)the Key Laboratory of Tropical Marine Ecosystem and Bioresource,Ministry of Natural Resources(2023QN04).
文摘Research on the spatial and temporal distribution of shrimp mariculture can provide a reference for the optimization of the spatial distribution and sustainable development of the shrimp mariculture industry.In recent years,most of the domestic shrimp research focuses on biological characteristics,shrimp breeding,and environmental factors,with limited studies on the overall distribution patterns of large-scale marine shrimp farming.11 provinces along the coast of China were selected as the study area to investigate the spatial and temporal evolution characteristics of the four types of shrimp marine aquaculture production and their spatial differences in driving factors over the past 20 years.The results showed that:(1)The production and farming area of Litopenaeus vannamei(LV)were the highest among the four types of shrimp and increased exponentially over time.The farming area of the other three shrimp species showed a decreasing trend;(2)The farming centers of LV and Penaeus monodon(PM)are located in the southern regions,while those of Fenneropenaeus chinensis(FC)and Marsupenaeus japonicus(MJ)are in the northern regions.The farming centers of all four types of shrimp have shifted to varying degrees,with farming area being the main factor influencing the movement of these centers;(3)Regarding driving factors,wild catch,farming area,and extension personnel are the leading factors in the spatial differences in production,and the interaction between the factors ultimately led to spatial differences in shrimp production;(4)Comparison of different sea areas revealed that shrimp in the South China Sea region is mainly farmed in sea water,while the northern regions rely more on freshwater farming.The yield of shrimp per unit area in the South China Sea can reach up to 14 t/ha,which is significantly higher than that in the northern region;(5)Using the established regression model to predict the production and area of LV,its production and area in the next five years to maintain a sustained growth trend.The results can provide support for the formulation of relevant government policies,thus promoting the healthy development of shrimp mariculture.
基金supported by the Innovation Driven Development Foundation of Guangxi(Grant No.AD22080035)the open project funding of the Key Laboratory of Tropical Marine Ecosystem and Bioresource,Ministry of Natural Resources(2023QN04)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(2022 A1515240023)the Program for Scientific Research Start-up Funds of Guangdong Ocean University(No.060302022312).
文摘Recreational beaches are widely distributed in coastal cities.Investigating the coupling mechanisms between anthropogenic interventions and natural coastal processes on sediment grain-size distribution is critical for maintaining and enhancing recreational beach functionality and value.This study examines three major recreational beaches within Zhanjiang Bay,conducting comparative analyses of surface sediment characteristics including representative grain-size metrics,granulometric composition,and statistical parameters.Key findings include:(a)significant variations in mode size(0.87-1.89φ)and D10 values(-0.80 to-0.09φ)among the three beaches,contrasted with limited differences in D50 and D90 metrics;(2)dominance of medium sand(26.16-39.14%)and coarse sand(26.75-31.43%)fractions,supplemented by fine and very coarse sand components,with central transects exhibiting higher medium-coarse sand concentrations than southern/northern sections;(3)sorting coefficient gradients(0.90-1.21)ranking central>northern>southern beaches,while mean grain size(0.83-1.21φ),skewness(-0.12 to-0.02),and kurtosis(0.87-1.18)show no distinct spatial patterns.Sediment grain-size distribution patterns are governed by four primary mechanisms:artificial nourishment inputs,anthropogenic sediment modification(harvesting/excavation),natural sediment supply processes,and hydrodynamic forcing.This research establishes a typical framework for characterizing recreational beach sediments,advancing understanding of multi-factor controlled grain-size distribution patterns and sediment transport dynamics.
基金supported by the Key Laboratory of Tropical Marine Ecosystems and Biological Resources,Ministry of Natural Resources(Grant No.2021QN02)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2022A1515240023)+1 种基金the Scientific Research Start-up Fund of Guangdong Ocean University(Grant No.060302112104)the Guangxi Zhuang Autonomous Region Youth Fund Project(Grant No.2022GXNSFBA035566).
文摘Mangrove forests possess significant ecological and aesthetic values.Investigating the spatial distribution characteristics of beach sediments in mangrove habitats and their relationships with hydrodynamic conditions and vegetation dynamics is crucial for sustaining the health and sustainability of mangrove ecosystems.This study aims to explore the spatial distribution characteristics of sediments in the mangrove beach of Xiashan Sea-viewing Promenade,Zhanjiang,and their relationship with hydrodynamics and mangrove vegetation.A total of 59 surface sediment samples were collected from 6 transects in the study area.The elevation of the sampling points,as well as wave and current data during the sampling period,were measured.The sediment transport trends of the 6 transects were also analyzed.The results show that the average grain size of surface sediments in the study area ranges from-0.75 to 5.15φ;the average sorting coefficient is 1.26,indicating poor sediment sorting;the average skewness is 0.19,with positively skewed and extremely positively skewed sediments widely distributed in the study area;the kurtosis values range from 0.36 to 2.31,with an average of 1.14,and narrow kurtosis is observed on the seaward side of the southern and northern parts of the study area.The significant wave height in the study area ranges from 0.05 to 0.17 m,the wave period ranges from 1.44 to 3.38 s,and the current velocity ranges from 1.44 to 7.44 cm·s^(−1).The surface sediment types include gravel,sand,silt,and clay,with sand being the most abundant,followed by silt,while gravel and clay are present in small amounts,with gravel only found in small quantities near the shore in the northern part of the study area.The sand content decreases from the shore to the sea,while the spatial distribution of silt shows the opposite trend.The clay content is relatively low,with a higher concentration in the seaward area.The wave action in the study area is significantly stronger than the current action,with the strongest hydrodynamic forces occurring during the early flood tide and late ebb tide,leading to an onshore sediment transport trend.This process can increase beach elevation and stability,which is beneficial for the growth and development of mangroves.
基金Guangdong Basic and Applied Basic Research Foundation(2022A1515240023)Open Fund of Key Laboratory of Tropical Marine Ecosystem and Biological Resources,Ministry of Natural Resources(2023QN04)the Program for Scientific Research Start-up Funds of Guangdong Ocean University(No.060302112304).
文摘High-level pond aquaculture,as a typical aquaculture model along the South China coast,poses potential threats to coastal ecosystems due to beach topographic changes induced by its tailwater discharge.Supported by drone technology,this study employed a combined method of DJI Matrice 300 RTK UAV LiDAR surveying and ground GNSS RTK measurements to collect data from the beach area affected by high-level pond tailwater discharge in northern Longhaitian,eastern Leizhou Peninsula.The study aims to investigate the impact of high-level pond tailwater discharge on beach topography using DSM generated from UAV LiDAR data.The results show:(1)By verifying the accuracy of UAV LiDAR data(RMSE of 8.05 cm,99%confidence interval[6.59,8.09]cm),confirmed the reliability and applicability of UAV LiDAR for monitoring beach topography affected by high-level pond tailwater discharge,with credible measurement data;(2)The beach exhibits significant spatial differentiation characteristics:the beach berm is eroded by aquaculture tailwater,with the central beach berm completely eroded away;(3)Compared to unaffected profiles,those influenced by high-level pond tailwater discharge show greater elevation change ranges,with maximum erosion depths exceeding 4 m and maximum sedimentation thickness approaching 2 m.The affected beach area demonstrates berm erosion,sedimentation in erosion gullies,and scarp erosion in the southern section,with maximum scarp erosion reaching approximately 5 m.The combined effects of tides and aquaculture tailwater discharge are the primary factors causing these phenomena.These research findings can provide technical support for the quantitative assessment of beach topography changes induced by high-level pond tailwater discharge.
