Current Articles
2025, Volume 47, Issue 1
Display Method:
2025,
47(1):
1-12.
doi: 10.12284/hyxb2025009
Abstract:
Saline water intrusion at the Changjiang (Yangtze) River Estuary severely affects the security of upstream water supply, agricultural irrigation, and ecological environmental health. The distance of saline water intrusion upstream, influenced by the interaction between runoff and tidal forces, has received considerable attention. However, research on the extent of this intrusion under the influence of the runoff-tide interaction remains insufficient. This paper establishes a three-dimensional hydrodynamic and salinity mathematical model of the Changjiang River Estuary using the MIKE 3 hydrodynamic model. The model is validated against field measurements of water levels, flow velocities, flow directions, and salinity from the Changjiang River Estuary in 2016. The validation results show a good agreement between the simulated and measured values, indicating that the three-dimensional hydrodynamic and salinity mathematical model of the Changjiang River Estuary established in this study can effectively simulate the hydrodynamic and salinity characteristics in the vicinity of the estuary. To investigate the impact of upstream runoff on the extent of saltwater intrusion in the Changjiang River Estuary, this study sets up eight different flow rates ranging from15000 m3/s to 50000 m3/s for the upstream section of the Changjiang River Estuary. The simulations focus on the effects of these varying upstream flow rates on the saltwater intrusion distances in three navigation channels: the South Branch-North Port, the South Branch-South Port-North Channel, and the South Branch-South Port-South Channel. The simulation results indicate that the degree of saltwater intrusion in all three channels is significantly dependent on tidal dynamics. During spring tides, when tidal forces are stronger, both saltwater intrusion from the open sea and saltwater backflow from the North Branch are more pronounced compared to neap tides, resulting in longer saltwater intrusion distances overall during spring tides. When the upstream discharge is low, backflow from the North Branch also contributes to increased saltwater intrusion distances. The vertical distribution of salinity and stratification phenomena in the three channels under different flow conditions were also analyzed, and the relationships between upstream flow rates and the distances of saltwater intrusion in the three channels were established. The findings of this study provide valuable references for research on “salinity control and freshwater supplementation” in the Changjiang River Estuary, as well as studies on material transport.
Saline water intrusion at the Changjiang (Yangtze) River Estuary severely affects the security of upstream water supply, agricultural irrigation, and ecological environmental health. The distance of saline water intrusion upstream, influenced by the interaction between runoff and tidal forces, has received considerable attention. However, research on the extent of this intrusion under the influence of the runoff-tide interaction remains insufficient. This paper establishes a three-dimensional hydrodynamic and salinity mathematical model of the Changjiang River Estuary using the MIKE 3 hydrodynamic model. The model is validated against field measurements of water levels, flow velocities, flow directions, and salinity from the Changjiang River Estuary in 2016. The validation results show a good agreement between the simulated and measured values, indicating that the three-dimensional hydrodynamic and salinity mathematical model of the Changjiang River Estuary established in this study can effectively simulate the hydrodynamic and salinity characteristics in the vicinity of the estuary. To investigate the impact of upstream runoff on the extent of saltwater intrusion in the Changjiang River Estuary, this study sets up eight different flow rates ranging from
2025,
47(1):
13-24.
doi: 10.12284/hyxb2025012
Abstract:
Understanding the distribution and relevant controlling factors of organic carbon in the ocean is of great significance to study the global carbon cycle and tackle climate change. Here, surface sediment samples were collected from the Bohai Sea and the Yellow Sea. For illustrating the source composition, distribution pattern, and their constraints, material characterization such as specific surface area, total organic carbon, nitrogen, sulfur contents and their isotopes (TOC, TN, TS, S2‒, δ13C, δ15N, and δ34S), as well as pigment biomarkers and thermos-gravimetric analysis were conducted. The results showed that the TOC and TN contents were lower in the nearshore but higher in the offshore region due to stronger hydrodynamics nearshore. The specific surface area had significant impacts on the distribution of organic carbon. The sediments contain a mixture of organic carbon from land plants, soil, and marine algae. Three-endmember mixing model suggested that sediments near the Huanghe River mouth and the shallower region along the Liaodong Peninsula in the Bohai Sea were dominated by soil-derived organic carbon with a smaller carbon reactivity index, while marine phytoplankton contributed mostly to the southern Yellow Sea with increasing carbon reactivity index. Significant correlation between TOC and TS in the Bohai Sea and northern Yellow Sea indicated significant linkages between organic carbon degradation and sulfate reduction. The negative δ34S indicated the process of sulfate reduction-sulfide oxidation-seawater sulfate diffusion at the sediment-water interface, which hinted the oxidation of organic carbon from oxic to anoxic condition. Pigment degradation potentially resulted in its weak correlation with the TOC content. As the risk of harmful algal bloom and hypoxia is becoming more severe, it is essential to monitor the coupling relationship of water chemistry and elemental cycling in the sediment to comprehensively understand the role of the continental shelf on organic carbon burial.
Understanding the distribution and relevant controlling factors of organic carbon in the ocean is of great significance to study the global carbon cycle and tackle climate change. Here, surface sediment samples were collected from the Bohai Sea and the Yellow Sea. For illustrating the source composition, distribution pattern, and their constraints, material characterization such as specific surface area, total organic carbon, nitrogen, sulfur contents and their isotopes (TOC, TN, TS, S2‒, δ13C, δ15N, and δ34S), as well as pigment biomarkers and thermos-gravimetric analysis were conducted. The results showed that the TOC and TN contents were lower in the nearshore but higher in the offshore region due to stronger hydrodynamics nearshore. The specific surface area had significant impacts on the distribution of organic carbon. The sediments contain a mixture of organic carbon from land plants, soil, and marine algae. Three-endmember mixing model suggested that sediments near the Huanghe River mouth and the shallower region along the Liaodong Peninsula in the Bohai Sea were dominated by soil-derived organic carbon with a smaller carbon reactivity index, while marine phytoplankton contributed mostly to the southern Yellow Sea with increasing carbon reactivity index. Significant correlation between TOC and TS in the Bohai Sea and northern Yellow Sea indicated significant linkages between organic carbon degradation and sulfate reduction. The negative δ34S indicated the process of sulfate reduction-sulfide oxidation-seawater sulfate diffusion at the sediment-water interface, which hinted the oxidation of organic carbon from oxic to anoxic condition. Pigment degradation potentially resulted in its weak correlation with the TOC content. As the risk of harmful algal bloom and hypoxia is becoming more severe, it is essential to monitor the coupling relationship of water chemistry and elemental cycling in the sediment to comprehensively understand the role of the continental shelf on organic carbon burial.
2025,
47(1):
25-35.
doi: 10.12284/hyxb2025020
Abstract:
The 210Bi-210Pb radionuclide pair is considered to be a new radiotracer for particulate carbon dynamics. Due to the very short half-life of 210Bi and the difficulty of determination, we have very few knowledge about the biogeochemical behavior of 210Bi in the ocean and whether there is a 210Bi-210Pb activity disequilibrium. This paper reported the observation results of dissolved and particulate 210Po, 210Bi, and 210Pb and their activity ratios in seawaters in the East China Sea close to the Changjiang River Estuary during a red tide event on the spring scientific cruise organized by National Natural Science Foundation of China from May 5 to 15, 2017. The results showed that the 210Po/210Pb activity ratio varied from 0.20 to 2.08, with an average of 0.82±0.58 (n=15) and the 210Bi/210Pb activity ratio changed between 0.31 and 3.72, showing an average of 1.38±0.79 (n=15). This phenomenon indicates that the activity disequilibrium of 210Po-210Pb and 210Bi-210Pb was ubiquitous in the seawater. More specifically, there is an obvious excess of 210Po and 210Bi relative to 210Pb in deep seawater, which implied that 210Po and 210Bi might be released from sinking particles in the middle and deep layer of water column. By calculating the distribution coefficients and fractionation factors of 210Po, 210Bi, and 210Pb, it was found that suspended particles in seawater tended to preferentially scavenge and remove 210Po and 210Bi, comparing with 210Pb. Similar to 210Po, 210Bi showed a stronger particle affinity for marine suspended particles than 210Pb, and the increase of phytoplankton biomass can promote the fractionation behavior between 210Bi and 210Pb, supporting the idea that 210Bi-210Pb can be used to trace particle processes in the ocean.
The 210Bi-210Pb radionuclide pair is considered to be a new radiotracer for particulate carbon dynamics. Due to the very short half-life of 210Bi and the difficulty of determination, we have very few knowledge about the biogeochemical behavior of 210Bi in the ocean and whether there is a 210Bi-210Pb activity disequilibrium. This paper reported the observation results of dissolved and particulate 210Po, 210Bi, and 210Pb and their activity ratios in seawaters in the East China Sea close to the Changjiang River Estuary during a red tide event on the spring scientific cruise organized by National Natural Science Foundation of China from May 5 to 15, 2017. The results showed that the 210Po/210Pb activity ratio varied from 0.20 to 2.08, with an average of 0.82±0.58 (n=15) and the 210Bi/210Pb activity ratio changed between 0.31 and 3.72, showing an average of 1.38±0.79 (n=15). This phenomenon indicates that the activity disequilibrium of 210Po-210Pb and 210Bi-210Pb was ubiquitous in the seawater. More specifically, there is an obvious excess of 210Po and 210Bi relative to 210Pb in deep seawater, which implied that 210Po and 210Bi might be released from sinking particles in the middle and deep layer of water column. By calculating the distribution coefficients and fractionation factors of 210Po, 210Bi, and 210Pb, it was found that suspended particles in seawater tended to preferentially scavenge and remove 210Po and 210Bi, comparing with 210Pb. Similar to 210Po, 210Bi showed a stronger particle affinity for marine suspended particles than 210Pb, and the increase of phytoplankton biomass can promote the fractionation behavior between 210Bi and 210Pb, supporting the idea that 210Bi-210Pb can be used to trace particle processes in the ocean.
2025,
47(1):
36-50.
doi: 10.12284/hyxb2025036
Abstract:
The freshwater discharges of the Changjiang (Yangtze) River into the sea largely control the extension range of the Changjiang Diluted Water in the estuary and the inherent biogeochemical behaviors of biogenic elements. In July 2023, a summer drought event occurred in the Changjiang River basin, with extremely lower river discharge. In order to study the distribution characteristics of nutrients in the Changjiang River Estuary in response to this drought, samples were collected from 32 stations in the Changjiang River Estuary that month, and the results were further compared with those obtained before and after the arrivals of the Changjiang River watershed floods occurring in the summers of 2016 and 2020. Under the drought condition in July 2023, the estuarine mixing area of freshwater and seawater greatly shrank, and the time and space for the occurrences of non-conservative processes of\begin{document}${{\rm {NO}}_3^-} $\end{document} ![]()
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The freshwater discharges of the Changjiang (Yangtze) River into the sea largely control the extension range of the Changjiang Diluted Water in the estuary and the inherent biogeochemical behaviors of biogenic elements. In July 2023, a summer drought event occurred in the Changjiang River basin, with extremely lower river discharge. In order to study the distribution characteristics of nutrients in the Changjiang River Estuary in response to this drought, samples were collected from 32 stations in the Changjiang River Estuary that month, and the results were further compared with those obtained before and after the arrivals of the Changjiang River watershed floods occurring in the summers of 2016 and 2020. Under the drought condition in July 2023, the estuarine mixing area of freshwater and seawater greatly shrank, and the time and space for the occurrences of non-conservative processes of
2025,
47(1):
51-62.
doi: 10.12284/hyxb2025022
Abstract:
Investigating the impact of high-level pond aquaculture effluent discharge on the response mechanisms of sandy coastlines to typhoons is of significant importance for promoting the sustainable use and value enhancement of coastal resources. This study conducts a comparative analysis of sediment characteristics, including particle size, grain size distribution, and grain size parameters, before and after Typhoon No. 2203, Chaba, focusing on the influence of effluent discharge from high-level ponds on the coastal sediment distribution at Donghai Island in western Guangdong, as well as on normal coastal areas. The research findings indicate the following: (1) After the typhoon, the sediment in normal coastal areas exhibited poorer sorting, with finer sediments nearshore and coarser sediments offshore. (2) The sorting coefficient of sediment from the affected coastal area remained stable post-typhoon, while other parameters (characteristic particle size, grain size composition, and grain size parameters) did not show a consistent pattern of change. (3) The average changes in characteristic particle sizes (D10, D50, and D90) and mean particle size of the affected coastal sediments were significantly greater than those of the normal coastal sediments after the typhoon. The intense wave action and rising water levels induced by the typhoon are critical factors influencing the sediment response in normal coastal areas. In contrast, the response of sediments in the affected coastal areas is more complex, resulting from the interplay between the gully topography created by effluent discharge and sediment redistribution processes, coupled with storm surge dynamics during the storm. This study provides a case for understanding the sediment grain size response characteristics of coastal areas influenced by high-level pond effluent during typhoon events, contributing to a better understanding of the interaction mechanisms between extreme events and aquaculture activities in coastal geomorphological evolution.
Investigating the impact of high-level pond aquaculture effluent discharge on the response mechanisms of sandy coastlines to typhoons is of significant importance for promoting the sustainable use and value enhancement of coastal resources. This study conducts a comparative analysis of sediment characteristics, including particle size, grain size distribution, and grain size parameters, before and after Typhoon No. 2203, Chaba, focusing on the influence of effluent discharge from high-level ponds on the coastal sediment distribution at Donghai Island in western Guangdong, as well as on normal coastal areas. The research findings indicate the following: (1) After the typhoon, the sediment in normal coastal areas exhibited poorer sorting, with finer sediments nearshore and coarser sediments offshore. (2) The sorting coefficient of sediment from the affected coastal area remained stable post-typhoon, while other parameters (characteristic particle size, grain size composition, and grain size parameters) did not show a consistent pattern of change. (3) The average changes in characteristic particle sizes (D10, D50, and D90) and mean particle size of the affected coastal sediments were significantly greater than those of the normal coastal sediments after the typhoon. The intense wave action and rising water levels induced by the typhoon are critical factors influencing the sediment response in normal coastal areas. In contrast, the response of sediments in the affected coastal areas is more complex, resulting from the interplay between the gully topography created by effluent discharge and sediment redistribution processes, coupled with storm surge dynamics during the storm. This study provides a case for understanding the sediment grain size response characteristics of coastal areas influenced by high-level pond effluent during typhoon events, contributing to a better understanding of the interaction mechanisms between extreme events and aquaculture activities in coastal geomorphological evolution.
2025,
47(1):
63-73.
doi: 10.12284/hyxb2025010
Abstract:
To investigate the effect of low temperature stress on juvenile cobia (Rachycentron canadum), the fish were reared under normal temperature [(30.5 ± 1.0)℃] and low temperature [(20.0 ± 0.5)℃] for 7 days, followed by genome-based transcriptome sequencing of there liver tissues. Each group included 3 biological replicates. The results showed that a total of approximately 243 694 134 raw reads were obtained from the 6 sequencing samples, with Q30 scores exceeding 94% for all samples and GC content raging between 47.65% and 48.16%. A total of 4 362 differentially expressed genes (DEGs) were identified, including 2 793 up-regulated and 1 569 down-regulated genes. KEGG pathway enrichment analysis revealed that in lipid metabolism, a significant number of DEGs were enriched in biological processes such as lipid metabolism, lipid biosynthesis, glycerophospholipid metabolism, phospholipid metabolism and glycerideid metabolism. Key lipid metabolism-related genes, including pparα, pparβ, scd1, cpt1, and cpt2 in the PPAR signaling pathway, played crucial roles in the response of juvenile cobia to low temperature stress. In glucose metabolism, numerous genes were enriched in pathways such as glycolysis/gluconeogenesis, galactose metabolism, starch and sucrose metabolism, and pentose and glucuronate interconversions. Among these, genes such as g6pc and eno were found to play important roles in the adaptation of juvenile cobia to low temperature stress.
To investigate the effect of low temperature stress on juvenile cobia (Rachycentron canadum), the fish were reared under normal temperature [(30.5 ± 1.0)℃] and low temperature [(20.0 ± 0.5)℃] for 7 days, followed by genome-based transcriptome sequencing of there liver tissues. Each group included 3 biological replicates. The results showed that a total of approximately 243 694 134 raw reads were obtained from the 6 sequencing samples, with Q30 scores exceeding 94% for all samples and GC content raging between 47.65% and 48.16%. A total of 4 362 differentially expressed genes (DEGs) were identified, including 2 793 up-regulated and 1 569 down-regulated genes. KEGG pathway enrichment analysis revealed that in lipid metabolism, a significant number of DEGs were enriched in biological processes such as lipid metabolism, lipid biosynthesis, glycerophospholipid metabolism, phospholipid metabolism and glycerideid metabolism. Key lipid metabolism-related genes, including pparα, pparβ, scd1, cpt1, and cpt2 in the PPAR signaling pathway, played crucial roles in the response of juvenile cobia to low temperature stress. In glucose metabolism, numerous genes were enriched in pathways such as glycolysis/gluconeogenesis, galactose metabolism, starch and sucrose metabolism, and pentose and glucuronate interconversions. Among these, genes such as g6pc and eno were found to play important roles in the adaptation of juvenile cobia to low temperature stress.
2025,
47(1):
74-83.
doi: 10.12284/hyxb2025008
Abstract:
Bigeye grunt Brachydeuterus auritus is an important economic species in the waters off Sierra Leone in West Africa, with great ecological value. Based on bottom trawl survey data from six voyage samples collected between 2019 and 2021, the body weight-length relationship (WLR) and relative weight were analyzed using logarithm-transformed body length measurements and their corresponding mean body weight values. This study fitted the WLR of bigeye grunt by gender, calculated its fullness, and analyzed the influence of environmental factors. The results showed that month and gender had a significant impact on body length and weight distribution (P < 0.01). There was a highly significant negative correlation (P < 0.01) between value a and value b in the WLR, and salinity significantly affects value b (P < 0.05). The (lg a)/b ratio was less affected by environmental factors which may be related to the body size and density of the fish. The difference in b between male and female populations was highly significant (P < 0.01). The relative weight had significant seasonal variation characteristics, with highly significant effects of sex and body length (P < 0.01). Negative allometric growth was observed in September, October, and December, while positive allometric growth occurred in January, April, and May. With increasing body length, the relative weight showed two types of changes, continuously increasing and firstly increasing then decreasing, with salinity and b significantly affecting the type of change (P < 0.05) and depth having a highly significant effect (P < 0.01). The bigeye grunt off the coast Sierra Leone exhibited significant seasonal growth characteristics, with significant differences in growth characteristics between male and female individuals. This study suggested that salinity may be the main factor affecting its growth and development. In addition, this study hypothesised that the peak breeding season may occur during the dry season, beginning in December and ending before April of the following year. The study provides updated and more comprehensive insights into the biology and ecology of the bigeye grunt offshore Sierra Leone in West Africa, which can provide scientific basis for its resource assessment, development and utilization, and resource management.
Bigeye grunt Brachydeuterus auritus is an important economic species in the waters off Sierra Leone in West Africa, with great ecological value. Based on bottom trawl survey data from six voyage samples collected between 2019 and 2021, the body weight-length relationship (WLR) and relative weight were analyzed using logarithm-transformed body length measurements and their corresponding mean body weight values. This study fitted the WLR of bigeye grunt by gender, calculated its fullness, and analyzed the influence of environmental factors. The results showed that month and gender had a significant impact on body length and weight distribution (P < 0.01). There was a highly significant negative correlation (P < 0.01) between value a and value b in the WLR, and salinity significantly affects value b (P < 0.05). The (lg a)/b ratio was less affected by environmental factors which may be related to the body size and density of the fish. The difference in b between male and female populations was highly significant (P < 0.01). The relative weight had significant seasonal variation characteristics, with highly significant effects of sex and body length (P < 0.01). Negative allometric growth was observed in September, October, and December, while positive allometric growth occurred in January, April, and May. With increasing body length, the relative weight showed two types of changes, continuously increasing and firstly increasing then decreasing, with salinity and b significantly affecting the type of change (P < 0.05) and depth having a highly significant effect (P < 0.01). The bigeye grunt off the coast Sierra Leone exhibited significant seasonal growth characteristics, with significant differences in growth characteristics between male and female individuals. This study suggested that salinity may be the main factor affecting its growth and development. In addition, this study hypothesised that the peak breeding season may occur during the dry season, beginning in December and ending before April of the following year. The study provides updated and more comprehensive insights into the biology and ecology of the bigeye grunt offshore Sierra Leone in West Africa, which can provide scientific basis for its resource assessment, development and utilization, and resource management.
2025,
47(1):
84-90.
doi: 10.12284/hyxb2025004
Abstract:
The Trachurus murphyi is affected by the environment, and the environment itself changes with time, with short-term seasonal changes and long-term regime shifts. Based on the data on jack mackerel stock and the environment from 1970 to 2017, this paper analyzes the relationship between the environment and jack mackerel stock from month to year using integral regression, regime shifts analysis, and all-subsets regression analysis. The month-on-month analysis results show that the influence of Sea Surface Temperature (SST) on stock biomass changes most obviously with time. Chilean jack mackerel is more dependent on SST in spawning and overwintering seasons. Followed by the Pacific Decadal Oscillation (PDO), the effects of Sea Surface Salinity (SSS) and Oceanic Niño Index (ONI) vary less in different months. The impact of Sea Surface Height (SSH) hardly changes from month to month. The annual analysis revealed four distinct regime shifts in Chilean mackerel resources over a long-time scale, with each regime characterized by unique dominant factor combinations. Notably, with the escalation of global climate change in recent years, a broader array of environmental factors has potentially influenced fishery resources, leading to significant changes in the patterns of environmental impact on fisheries.
The Trachurus murphyi is affected by the environment, and the environment itself changes with time, with short-term seasonal changes and long-term regime shifts. Based on the data on jack mackerel stock and the environment from 1970 to 2017, this paper analyzes the relationship between the environment and jack mackerel stock from month to year using integral regression, regime shifts analysis, and all-subsets regression analysis. The month-on-month analysis results show that the influence of Sea Surface Temperature (SST) on stock biomass changes most obviously with time. Chilean jack mackerel is more dependent on SST in spawning and overwintering seasons. Followed by the Pacific Decadal Oscillation (PDO), the effects of Sea Surface Salinity (SSS) and Oceanic Niño Index (ONI) vary less in different months. The impact of Sea Surface Height (SSH) hardly changes from month to month. The annual analysis revealed four distinct regime shifts in Chilean mackerel resources over a long-time scale, with each regime characterized by unique dominant factor combinations. Notably, with the escalation of global climate change in recent years, a broader array of environmental factors has potentially influenced fishery resources, leading to significant changes in the patterns of environmental impact on fisheries.
2025,
47(1):
91-103.
doi: 10.12284/hyxb2025024
Abstract:
To better understand the community patterns and their interconnections between different habitats in coastal areas, it is essential to explore the potential factors influencing species distribution and ecological connectivity between artificial and natural habitats. This study conducted a comprehensive survey of fish and invertebrate communities across four typical habitats in Haizhou Bay, Jiangsu Province: artificial reef area (ARA), nori culture area (NCA), oyster culture area (OCA), and natural area (NA). The results showed significant differences in species abundance among the four habitats (P < 0.05), with some important species occurring across multiple habitats, and some endemic species restricted to a single habitat. The biomass of Oratosquilla oratoria in ARA was significantly higher compared to other habitats, and the body length of Chaeturichthys stigmatias in ARA, NCA, and OCA was significantly greater than in NA (P < 0.05), which was strongly associated with the distribution of prey organisms. Differences in body length distributions of fish with different life habits indicate that species migration behavior plays an important role in species distribution and habitat connectivity. Migratory fish species, such as Larimichthys polyactis and Sardinella zunasi, exhibited significantly greater body lengths in artificial habitats compared to natural habitats (P < 0.05). Resident fish species, such as Chaeturichthys stigmatias, exhibited significantly larger body lengths in OCA compared to ARA and NCA (P < 0.05), while Cynoglossus joyneri exhibited a significantly greater body length in NCA than in ARA and OCA (P < 0.05). This study demonstrates that artificial habitats, by enhancing habitat complexity, provide favorable environmental conditions for the restoration of marine biological resources and the development of individuals. The distribution of prey organisms and species migration characteristics are likely associated with connectivity between different habitats.
To better understand the community patterns and their interconnections between different habitats in coastal areas, it is essential to explore the potential factors influencing species distribution and ecological connectivity between artificial and natural habitats. This study conducted a comprehensive survey of fish and invertebrate communities across four typical habitats in Haizhou Bay, Jiangsu Province: artificial reef area (ARA), nori culture area (NCA), oyster culture area (OCA), and natural area (NA). The results showed significant differences in species abundance among the four habitats (P < 0.05), with some important species occurring across multiple habitats, and some endemic species restricted to a single habitat. The biomass of Oratosquilla oratoria in ARA was significantly higher compared to other habitats, and the body length of Chaeturichthys stigmatias in ARA, NCA, and OCA was significantly greater than in NA (P < 0.05), which was strongly associated with the distribution of prey organisms. Differences in body length distributions of fish with different life habits indicate that species migration behavior plays an important role in species distribution and habitat connectivity. Migratory fish species, such as Larimichthys polyactis and Sardinella zunasi, exhibited significantly greater body lengths in artificial habitats compared to natural habitats (P < 0.05). Resident fish species, such as Chaeturichthys stigmatias, exhibited significantly larger body lengths in OCA compared to ARA and NCA (P < 0.05), while Cynoglossus joyneri exhibited a significantly greater body length in NCA than in ARA and OCA (P < 0.05). This study demonstrates that artificial habitats, by enhancing habitat complexity, provide favorable environmental conditions for the restoration of marine biological resources and the development of individuals. The distribution of prey organisms and species migration characteristics are likely associated with connectivity between different habitats.
2025,
47(1):
117-122.
doi: 10.12284/hyxb2025002
Abstract:
During an investigation of marine diatom flora in the sand samples from Guangxi, three species were identified as new records in China, which were Halamphora woelfeliae Stachura-Suchoples, Enke, Schlie, Schaub, Karsten & R.Jahn, Psammodiscus calceatus Tsuy.Watanabe, Nagumo & Ji.Tanaka and Ehrenbergiulva granulosa (Grunow) A.Witkowski, Lange-Bertalot & Metzeltin. Their morphological features, ecological habitats and geographical distribution were described in detail. This study enriched the biodiversity of marine diatoms in China.
During an investigation of marine diatom flora in the sand samples from Guangxi, three species were identified as new records in China, which were Halamphora woelfeliae Stachura-Suchoples, Enke, Schlie, Schaub, Karsten & R.Jahn, Psammodiscus calceatus Tsuy.Watanabe, Nagumo & Ji.Tanaka and Ehrenbergiulva granulosa (Grunow) A.Witkowski, Lange-Bertalot & Metzeltin. Their morphological features, ecological habitats and geographical distribution were described in detail. This study enriched the biodiversity of marine diatoms in China.
2025,
47(1):
104-116.
doi: 10.12284/hyxb2025028
Abstract:
Dissolved oxygen concentration is one of the important indexes to measure seawater quality. In order to grasp the change of seawater quality in time and reduce the risk and loss of seawater pollution, it is very important to establish the prediction mechanism of marine water quality parameters. Therefore, this paper proposes a prediction model of dissolved oxygen concentration in seawater based on temporal and spatial information fusion of buoy Networks and Generative Adversarial Networks (GAN), which aims to integrate topological information of buoy networks in the monitoring area and realize multi-feature fusion of buoy sensors. The model uses the Graph Attention Mechanism (GAT) to mine the influence of different nearest neighbor points on the target node and calculate the weights of the adjacent nodes, so as to capture the spatio-temporal characteristics of the buoy data. The two-head attention mechanism and the two-time-scale Update Rule (TTUR) were used to optimize the GAN prediction network and the network training process, improve the training speed balance of the generated adversarial network, and improve the fitting effect of the generator network. The mean squared error, root mean squared error, mean absolute error and R-Square are used as evaluation indexes to compare the model prediction performance. The results show that the evaluation indexes of the proposed model are superior to other models, and can effectively mine the spatial information of multiple buoys. It overcomes the shortcomings of traditional methods in the prediction of dissolved oxygen concentration in seawater, such as low accuracy, inability to flexibly use historical spatial data, poor training stability and slow speed, and can provide important technical support for marine water quality monitoring and prediction.
Dissolved oxygen concentration is one of the important indexes to measure seawater quality. In order to grasp the change of seawater quality in time and reduce the risk and loss of seawater pollution, it is very important to establish the prediction mechanism of marine water quality parameters. Therefore, this paper proposes a prediction model of dissolved oxygen concentration in seawater based on temporal and spatial information fusion of buoy Networks and Generative Adversarial Networks (GAN), which aims to integrate topological information of buoy networks in the monitoring area and realize multi-feature fusion of buoy sensors. The model uses the Graph Attention Mechanism (GAT) to mine the influence of different nearest neighbor points on the target node and calculate the weights of the adjacent nodes, so as to capture the spatio-temporal characteristics of the buoy data. The two-head attention mechanism and the two-time-scale Update Rule (TTUR) were used to optimize the GAN prediction network and the network training process, improve the training speed balance of the generated adversarial network, and improve the fitting effect of the generator network. The mean squared error, root mean squared error, mean absolute error and R-Square are used as evaluation indexes to compare the model prediction performance. The results show that the evaluation indexes of the proposed model are superior to other models, and can effectively mine the spatial information of multiple buoys. It overcomes the shortcomings of traditional methods in the prediction of dissolved oxygen concentration in seawater, such as low accuracy, inability to flexibly use historical spatial data, poor training stability and slow speed, and can provide important technical support for marine water quality monitoring and prediction.
2025,
47(1):
123-132.
doi: 10.12284/hyxb2025026
Abstract:
Biological monitoring of marine microplastic pollution based on mussel indicator is a monitoring method with broad application prospects. However, the current pretreatment process includes a variety of mussel tissue digestion and microplastic density separation technologies, and the scientific nature of pretreatment technology has yet to be verified, which makes it difficult to guarantee the accuracy of marine microplastic pollution monitoring results obtained by this method and the data are difficult to compare. In order to comprehensively evaluate the accuracy of multiple mussel tissue digestion and microplastic density separation operations and to obtain a cost-effective and reliable pretreatment technology, comparison tests of 4 common digestion methods (mixed acid digestion, potassium hydroxide digestion, Fenton digestion and protease K digestion) and density separation tests of 3 microplastic flotation fluids (sodium chloride saturated solution, sodium iodide saturated solution and potassium formate saturated solution) were carried out. The effects of different digestion methods on the digestion efficiency of mussel tissue and on the morphology, spectral characteristics and recovery rate of common microplastic in the ocean, as well as the separation effect of microplastic in different flotation fluids were evaluated, and the digestion conditions were optimized by single factor and response surface tests. The results showed that the Fenton digestion method had both efficient digestion of mussel tissue and low destructive effect on microplastic, and could be used as the optimal method for digestion of mussel tissue. After optimization, under the conditions of H2O2 (30%) volume 40 mL, Fe2+ concentration 0.020 mol/L, temperature 59℃, pH 3.7 and digestion time 24 h, the digestion rate of 10 g mussel tissue reached 96.7%. At the same time, this study confirmed that potassium formate saturated solution could replace sodium chloride and sodium iodide saturated solution as the flotation fluid with high efficiency. The development of the above research provides a reference for the improvement and standardization of the pretreatment technology for biological monitoring of marine microplastic pollution based on mussel indicator.
Biological monitoring of marine microplastic pollution based on mussel indicator is a monitoring method with broad application prospects. However, the current pretreatment process includes a variety of mussel tissue digestion and microplastic density separation technologies, and the scientific nature of pretreatment technology has yet to be verified, which makes it difficult to guarantee the accuracy of marine microplastic pollution monitoring results obtained by this method and the data are difficult to compare. In order to comprehensively evaluate the accuracy of multiple mussel tissue digestion and microplastic density separation operations and to obtain a cost-effective and reliable pretreatment technology, comparison tests of 4 common digestion methods (mixed acid digestion, potassium hydroxide digestion, Fenton digestion and protease K digestion) and density separation tests of 3 microplastic flotation fluids (sodium chloride saturated solution, sodium iodide saturated solution and potassium formate saturated solution) were carried out. The effects of different digestion methods on the digestion efficiency of mussel tissue and on the morphology, spectral characteristics and recovery rate of common microplastic in the ocean, as well as the separation effect of microplastic in different flotation fluids were evaluated, and the digestion conditions were optimized by single factor and response surface tests. The results showed that the Fenton digestion method had both efficient digestion of mussel tissue and low destructive effect on microplastic, and could be used as the optimal method for digestion of mussel tissue. After optimization, under the conditions of H2O2 (30%) volume 40 mL, Fe2+ concentration 0.020 mol/L, temperature 59℃, pH 3.7 and digestion time 24 h, the digestion rate of 10 g mussel tissue reached 96.7%. At the same time, this study confirmed that potassium formate saturated solution could replace sodium chloride and sodium iodide saturated solution as the flotation fluid with high efficiency. The development of the above research provides a reference for the improvement and standardization of the pretreatment technology for biological monitoring of marine microplastic pollution based on mussel indicator.
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