10 April 2024, Volume 46 Issue 2

    

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• Research Papers
• Three-dimensional dynamic sea surface modeling and ocean echo simulation

  WANG Wenchao, YANG Hua, ZHANG Hao, CHEN Yujie, WANG Xue

  2024, 46(2): 1-7. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.001

  Abstract ( ) PDF ( )

  The research and development of radar systems generally require repeated tests. In order to solve the problem of wasting a lot of manpower and material resources in field tests, this paper established an echo simulator mainly based on sea clutter, which was used for radar tests to reduce costs. Based on the Elfouhaily spectrum, the nonlinear dynamic sea surface was established by using the Choppy wave model,and the sea surface was divided into different resolution units by using the grid mapping method. This paper combined the gridded sea surface with the backscatter characteristics of the echo to generate a simulated echo for the first time. And in the simulation process, an algorithm for correcting the grazing angle based on the characteristics of the waves was proposed. Finally, the simulated echo was analyzed and fitted with the measured and theoretical data, which proved the effectiveness of the simulated echo.
• Study on return value calculation of extreme wave height induced by typhoon

  ZHANG Jian, PANG Liang, DONG Sheng

  2024, 46(2): 8-14. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.002

  Abstract ( ) PDF ( )

  Return value calculation of extreme marine environmental parameters induced by typhoon is of great significance for engineering disaster prevention. The rationality of the calculation depends on the sampling method and probability distribution model. In this paper, the sampling method of typhoon process was combined with exponentiated Weibull distribution model. A Poisson-exponentiated Weibull compound extreme value distribution model was established based on the compound extreme value distribution theory. This new distribution model was applied to the probability prediction of extreme marine environmental parameters under typhoon, and the corresponding return values were calculated. The study showed that the annual typhoon frequency at the selected calculation points conformed to Poisson distribution, and the exponentiated Weibull distribution fitted the sequence of extreme wave height induced by typhoon well. It was reliable to calculate the return values by using Poisson-exponentiated Weibull compound distribution model. This compound model was more perfect in physical and statistical sense, and the calculation results were stable and reasonable.
• The measured heat transfer coefficients and numerical simulation of temperature rise change in superheated water bodies

  YANG Jie, XIONG Congbo, SUN Huifeng, LIU Yanling, ZHOU Tao, CHI Wanqing

  2024, 46(2): 15-21. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.003

  Abstract ( ) PDF ( )

  In the design phase of a coastal power plant, numerical simulation is usually used to predict the influence scope of thermal water discharge needing the realistic heat transfer coefficients. The coefficient was almost judged based on experience and lack of systematic research actually so far. To solve this problem, this paper analyzed the comprehensive heat dissipation of the Meizhou bay power plant, and proposed a method for measuring the coefficients. The measured data showed that heat transfer coefficients fluctuated dramatically during high and low tides, so the empirical constant was not completely reliable with deviation. Conversely, the model results could reflect the temperature rise change more accurately caused by external factors, which was more consistent with the measured. This simulation method increased the accuracy of the heat transfer coefficients, and it had an important progress in rationally determining the influence of thermal water drainage.
• Climatic evolution characteristics of the coupled main mode of the sea surface temperature and net sea surface heat flux in the tropical Indian Ocean

  YANG Mengxi, HU Ruijin, LIU Mei, ZHANG Yinyi, SHI Dawei

  2024, 46(2): 22-31. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.004

  Abstract ( ) PDF ( )

  Based on a total of 49a sea surface temperature (SST) data of SODA and net sea surface heat flux data of ECMWF from January 1960 to December 2008, the climatic evolution characteristics of the coupled main mode of the two anomalies were studied in the tropical Indian Ocean by using moving SVD method. The main results were as follows: (1) The coupling effect was gradually strengthened in the evolution process, the correlations between the two fields maintain well. (2) The sea surface net heat flux anomaly can better explain the basin variations of the SSTA field itself in most periods with the largest variations locating in the coastal area of Sumatra-Java and the sea area south of 20°S. And under its influence, the sea basin showed a warming trend in most periods. (3) The spatial distribution of the two fields of the coupled main mode changed significantly once from 1961~1970 to 1962~1971, under the significant influence of the year 1971. (4) The SSTA field changed significantly in the northeast Indian Ocean and the South China Sea with obvious positive change areas, while the sea area south of 20°S showed obvious negative changes. The net sea surface heat flux anomaly filed showed significant positive and negative changed in the South China Sea, the equatorial eastern Indian Ocean and somewhere east of Madagascar, respectively.
• Analysis of seabed dome and fracture formation induced by gas

  TANG Haoru, YANG Bin, GUO Xiujun, LEI Shiyun, XING Cheng, SUN Hao

  2024, 46(2): 32-40. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.005

  Abstract ( ) PDF ( )

  When gas from a deep source in sediments breaks through surface fine-grained sediments, different gas source pressures and stratum structures may lead to different degrees of seabed dome, and then cause different deformation and failure processes of fine-grained sediments, leading to different scale and types of geological disasters. To study the evolution characteristics of this process, the gas injection laboratory experiment and numerical simulation analysis of fine-grained sediments were carried out to observe the typical process of gas-induced soil heave, the change of excess pore water pressure in sediments, and the stress and strain changes under different degrees of sediments dome. Combined with previous studies on sediments deformation and gas-induced fracture theory, the experimental data were analyzed. It was found that (1) The elastic plate bending deformation theory could well describe the deformation process of fine sediment under constant pressure and uniform gas distribution; (2) After gas domed fine-grained sediments, the location of cracks was related to the critical pressure to form cracks and the size of the gas pocket at the bottom of the sediments. The dumper and fatter the gas pocket were, the more prone the edge of the gas pocket were to be failed with tensile; otherwise, the top of the fine sediments of the gas pocket was more likely to produce fracture.
• Complex model of interaction between seawater and underground brine in muddy tidal flat

  ZHANG Yufeng, XING Cheng, GUO Xiujun, SHAO Shuai, FU Tengfei, WU Hanfu

  2024, 46(2): 41-50. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.006

  Abstract ( ) PDF ( )

  In the world, many coastal underground brine resources are distributed in the muddy tidal flat area, but the research on the subterranean estuary in this area is only in the primary stage, and the model has not been established. In this paper, the southern bank of Laizhou bay was selected as a typical study area. Electrical resistivity tomography monitoring, pore water conductivity monitoring, seawater and groundwater conductivity measurement were carried out in the areas with different vertical permeability coefficients of surface sediments. The sediment-physical relationship of muddy tidal flat was clarified. A standard for the division of seawater-groundwater mixed zones was established. This standard combined with the electrical resistivity tomography monitoring results at each tidal time to analyze the complex exchange mode of seawater-groundwater and its influencing factors, and to reveal the temporal and spatial distribution of the mixing zone. The research results showed that the biological channels clustered in the silt layer were the main ways of seawater-groundwater exchange during the tidal cycles. The formation mechanism of "upper saline plume" and "groundwater discharge tunnel" in the muddy tidal flat subterranean estuary and the seawater-groundwater exchange process were different from those of sandy tidal flats. Decreasing the permeability of tidal flat sediments would cause the direct exchange rate of seawater-groundwater through sediments to decrease, leading the main exchange path to shift to high-permeability channels. The flow rate of intrusion and excretion in the channels would increase.
• Analysis of characteristics of excess pore water pressure changes in the process of gasbag formation in marine sediments

  LEI Shiyun, LIU Huifang, GUO Xiujun, SUN Hao, XING Cheng

  2024, 46(2): 51-61. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.007

  Abstract ( ) PDF ( )

  Under the action of external factors, the deep gas in seafloor sediments moves upward, which is easy to accumulate at the interface of shallow coarse-fine sediments and form gasbags. When the gas in the gasbag escapes, it will induce a variety of submarine geological disasters and bring harm to human engineering construction. Therefore, real-time monitoring of the formation-growth-dissipation process of gasbags is of great significance for effectively judging its development law and predicting the occurrence of follow-up potential disasters. In this study, the multi-point pore water pressure monitoring technique was used to simulate and monitor the forming and dissipation of gasbags in saturated fine-grained sediments by mathematical simulation and physical simulation experiments. The variation characteristics and mechanism of typical excess pore water pressure of fracture formation, gasbag formation and gas release were discussed in detail. According to the results of mathematical simulation and physical simulation experiments, combined with theoretical analysis, the formation-growth-dissipation process of gasbag was divided into three stages: transverse crack generation, gasbag longitudinal expansion and oblique or vertical crack generation, and its corresponding excess pore water pressure was concave. The formation of gasbag began with the transverse cracks at the interface of coarse and fine sediments, and excess pore water pressure attenuated rapidly. The gasbag showed the expansion of longitudinal cavity, and excess pore water pressure remained almost unchanged; oblique or vertical cracks appeared at the end of the evolution of gasbag, and excess pore water pressure accumulated and dissipated again. The variation curve of excess pore water pressure in gas release stage had obvious saw-tooth fluctuation characteristics, and it could be used to distinguish whether the gas was released intermittently or continuously. The accumulated extreme value of excess pore water pressure could be reduced during gas reinjection, which meant that a lower pressure could create cracks and reopen the gas channel, destroying the sediment and causing the gas to escape.
• Pore pressure response of silt seabed during storms- taking Zhoushan Zhujiajian sea area as an example

  HOU Yankai, XUE Liang, LIANG Tianyang, SHAN Hongxian

  2024, 46(2): 62-70. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.008

  Abstract ( ) PDF ( )

  The pore water pressure in seabed sediments is sensitive to hydrodynamic changes, and investigating the response of pore water pressure in sediments under different sea conditions is of great significance to the study of seabed instability and dynamic evolution of seabed boundary layer. In the sea area of Zhoushan Zhujiajian, Zhejiang Province, the dynamic changes of the hydrodynamic conditions and the pore water pressure of seabed sediments at 1m, 3m, 5m and 7m below the sea bed before and after typhoon Lekima were recorded by using the pore water pressure monitoring system. The monitoring data showed that the variation of pore water pressure in seabed sediments was affected by hydrostatic pressure and sediment properties, and had obvious response to wave action in short term. During the typhoon, the hydrodynamic force was greatly enhanced, and the effective wave height could reach more than 5 times of that under the calm sea condition. The oscillation amplitude of the excess pore water pressure in the sediment at the shallow 1m layer could reach 1-2 kPa, and the change of the excess pore pressure value was strong consistently with the wave strength. In the process of wave load acting on seabed sediment, the wave pressure had obvious amplitude attenuation, and the attenuation could reach more than 70% at the shallow layer of 1 meter. The influence of waves could be almost ignored below 1 meter. The influence of rod stop plate was an important reason for the attenuation of pore pressure amplitude. The presence of gas in seabed sediments and the interaction between shallow active silt layer and waves could significantly reduce the influence of wave load on seabed pore water pressure, which was an important factor of wave energy consumption.
• Analysis of tidal dynamic characteristics in the sea area adjacent to Liuheng island

  SUN Yongzhao, JI Qiyan, SU Yu, ZHANG Jie, PENG Tengteng, ZUO Juncheng

  2024, 46(2): 71-81. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.009

  Abstract ( ) PDF ( )

  Based on the FVCOM ocean model, a high-resolution three-dimensional ocean numerical model was established for the adjacent sea area of Liuheng island. The main characteristics of tides and tidal currents in the adjacent sea area of Liuheng island were simulated in detail. The results of the model were in good agreement with the observation data of one tide station and two current stations, which could reflect the movement characteristics of tides and tidal currents in the adjacent sea area of Liuheng island. Meanwhile, main tidal components, such as M₂, S₂, K₁, O₁, M₄ and M₆, and the elliptical spatial distribution of surface tidal currents as well as two shallow water tidal components were given. Finally, the surface flow field and the spatial distribution of residual current in the surface layer, 0.6 layer and bottom layer were analyzed. The results showed that M₂, S₂ and O₁ were high in the south and low in the north, and the amplitudes of M₂, S₂ and O₁ were 115-145 cm, 15-30 cm and 19-24 cm, respectively. K₁ was 20-30 cm, and the main tidal components propagated in the same direction. At the same time, the spatial distribution and propagation direction were opposite to the main tidal components. Based on the results of harmonic analysis, the tidal pattern coefficient and the maximum possible tidal range were calculated. The whole sea area was characterized by regular semidiurnal tide, and the maximum possible tidal range could reach 600-650 cm in the southern sea area and 450-550 cm in the northern sea area. According to the calculation of tidal asymmetry, the ebb tide speed in the south of Liuheng was higher than that in the north. Under the four tidal conditions, the maximum velocity of the ebb flow field was 22 cm/s, and the maximum velocity of the four main tidal components was 160 cm/s, 60 cm/s, 22 cm/s and 12 cm/s, respectively. The spatial distribution of the ebb flow field was characterized by offshore rotating current and inshore reciprocating current. In the distribution of residual current, the maximum of surface layer, 0.6h layer and bottom layer could reach 25 cm/s at the headland, but the residual current gradually weakened with the increase of water depth.
• Numerical investigation of the hydrodynamic characteristics in Zhoushan sea area based on wave-current coupling model

  ZHENG Sheng, ZHU Ye, CHEN Xinping, GAO Yangyang, WANG Lizhong, ZHOU Peiyuan

  2024, 46(2): 82-90. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.010

  Abstract ( ) PDF ( )

  Three-dimensional wave-current coupling numerical model was established based on the FVCOM (Finite-Volume Community Ocean Model) circulation model and wave model. Numerical simulation on the hydrodynamic environment characteristics of Zhoushan island sea area was performed. The tidal current and wave characteristics of Zhoushan island sea area were mainly investigated. The results showed that the reciprocating current was dominate in the nearshore area and the rotating current was dominant in the offshore area of Zhoushan islands. The ebb tide was stronger than the flood tide in most areas of the Zhoushan islands. The vertical current velocity in the bottom layer was about 59%~70% of that in the surface layer. The significant wave height during the spring tide was higher than that during the neap tide, and the significant wave height gradually decreased from the offshore to nearshore area. The effect of wave on the tidal current velocity was related to the water depth, where the current velocity in the nearshore area at small water depth was mostly affected by waves.
• A study on the relationship between typhoon distance and optimum storm surge factors based on SVR

  ZHANG Xiaoqi, LIU Qiang

  2024, 46(2): 91-97. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.011

  Abstract ( ) PDF ( )

  Storm surge usually causes huge disasters and losses, and it is great practical significant for disaster mitigation departments to prevent disaster. Eight kinds of data, such as last hour storm surge, the straight line distance between the tide stations and three typhoons, were collected about Yongxing island tide station, and a support vector regression prediction model for storm surge was built. The experimental results showed that the best combination of influencing factors of the prediction model was affected to a certain extent by the straight line distance between tide station and typhoon. When the tide station was located on the edge and outside of the typhoon circle radius, and the typhoon position had a great influence on the prediction model. The accuracy of the prediction model can be improved by 32.76%.
• Relationship between spatial and temporal distribution of jumbo flying squid Dosidicus gigas off Peru and sea surface temperature

  LU Xinyi, WU Xiaoci, XU Lijie, YU Wei

  2024, 46(2): 98-108. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.012

  Abstract ( ) PDF ( )

  Jumbo flying squid Dosidicus gigas is a pelagic and economically important squid species widely distributed off Peru. The purposes of this study were to understand the relationship between spatio-temporal fishing grounds of D. gigas and environmental conditions, and to provide a scientific basis for the sustainable utilization and management of D. gigas resources. Based on the fisheries data of D. gigas in the southeast Pacific Ocean off Peru from September to December, 2006 thorough 2015 provided by National Data Center of Distant-water Fisheries of China, in this study, we determined the position of longitudinal and latitudinal gravity center of fishing ground, and quantified the temporal and spatial changes of fishing ground. In addition, the cluster analysis on the fishing ground gravity centers was performed. The relationship between fishing effort and sea surface temperature (SST) was examined based on frequency distribution analysis and the influence of SST on the changes of fishing ground gravity centers was further evaluated. The responses of fishing ground gravity centers to the La Niña and El Niño events were finally explored. Significant monthly and interannual variations were found in the longitudinal and latitudinal gravity centers of the fishing ground. Cluster analysis divided the fishing ground gravity centers into three categories. The fishing effort distribution in the longitude, latitude and SST showed a large difference from month to month. Compared with the El Niño year (2015), the SST on the fishing ground in the La Niña year (2007) was lower, leading to the northwestward shift of the most preferred temperature front for D. gigas. Therefore, the gravity centers of fishing ground in 2007 moved northwestward. The results indicated that spatio-temporal distribution of D. gigas was closely related to large-scale climate variability-induced SST change.
• Research Report
• Evaluation of seawater intrusion in Tangshan based on entropy-weight attribute recognition model

  YANG Jianxin, ZHANG Longji, SUN Jinpeng, GAO Xiaoli, CAO Xiangyue, LIN Guoqing, LI Faju

  2024, 46(2): 109-115. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.013

  Abstract ( ) PDF ( )

  Widespread intrusion of saline seawater in Tangshan posed significant challenges to the sustainable utilization of groundwater resources. By analyzing monitoring data of groundwater chemistry, characteristic indicators including Cl^-, TDS, SO^2-₄, A (salinization coefficient), and SAR (sodium adsorption ratio) were selected. Utilizing an entropy-weighted attribute recognition model, the degree of saline seawater intrusion in Tangshan was evaluated. The results indicated that the mildly invaded area by saline seawater in Tangshan was approximately 1.98 × 10³ km², while the severely invaded area was about 1.87 × 10³ km². The maximum intrusion distance of saline seawater in Tangshan was 41.4 km, along the Dongyutuo-Xiaoshuangtuo village line. A comparison between the entropy-weighted attribute recognition model and the single-index method for intrusion assessment demonstrated a 70.8% consistency. However, the entropy-weighted attribute recognition model better reflected the transition zone between saline and fresh water, the ion exchange phenomena and the water quality variations caused by historical saline water intrusion, making the results more precise and reliable.
• Studies on the applications of Trichoderma and compound microbial agents in the restoration of Scirpus mariqueter wetland

  WANG Qinyi, ZHANG Shengle, ZHANG Bolun , ZHOU Zhijie, HE Peimin, FANG Shubo

  2024, 46(2): 116-124. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.014

  Abstract ( ) PDF ( )

  In this study, the feasibility of promoting wetland restoration using the Trichoderma and the microbial agents was investigated. The analysis focused on the effects of different concentrations of Trichoderma and composite microbial agents on the characteristics of Scirpus mariqueter inhabiting Dongtan, Nanhui, which include plant number, plant height growth rate, rhizosphere soil physical and chemical properties, and enzyme activities. Two types of soils, A and B, representing the typical soil conditions were collected. The results indicated that the microbial preparations from two soil samples had a positive impact on the growth of S. mariqueter. The optimal density of Trichoderma in soils A and B was 44.78 kg/ha and 29.85 kg/ha, respectively. For the compound microbial preparations, the optimal concentrations were found to be 7.46 L/ha and 14.93 L/ha, respectively. The corresponding plant growth rate was observed to be 669%, 200%, 846% and 288% while the plant height growth rate was 186%, 180%, 136% and 280%, respectively. The addition of microbial preparations influenced the content of ammonium nitrogen, nitrate nitrogen and total phosphorus in the soil. The influenced included also the activities of soil urease and alkaline phosphatase. These changes contributed to the promotion of plant growth. Overall, our findings demonstrated that the application of suitable microbial agents can effectively enhance the number and height of S. mariqueter. What we found provided a practical and efficient approach to the artificial restoration of S. mariqueter wetlands, proved the potential of wetland conservation and restoration effort.
• Effects of salinity and nitrogen and phosphorus concentrations on water quality and growth of Sesuvium portulacastrum

  HAO Mingmei, Li Bin, LI Huanjun, QIAO Peng, ZHANG Mingliang, XIANG Zhiwei, NI Zhijie, SUN Yanqing, Li Meng, HU Shunxin, SUN Chunxiao, CHEN Lizhu

  2024, 46(2): 125-133. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.015

  Abstract ( ) PDF ( )

  Saline tolerant plant plays an important role in marine aquaculture wastewater treatment and seawater agriculture development. In order to explore the salt tolerance and nitrogen and phosphorus purification ability of S. portulacastrum, in this study, we carried out the indoor hydroponic experiments of S. portulacastrum salinity treatment and nitrogen and phosphorus concentration treatment. S. portulacastrum plants were grown in Hoagland nutrient solution at salinities of 0, 10, 20, 30 and 35, respectively, in salinity experiment, and were cultured in artificial seawater with N∶0 (P∶0.5) mg/L, N∶1 (P∶0.1) mg/L, N∶5 (P∶0.5) mg/L, N∶20 (P∶2) mg/L, N∶50 (P∶5) mg/L, respectively. The treatment period was 20 days. We found that 1) the absorption effect of nitrogen and phosphorus was obvious under the condition of medium and low salinities (0～20) while the absorption effect was significantly weaker than that of the low-medium salinity groups under the condition of high salinities (30～35) (P<0.05); 2) the Na⁺ content in S. portulacastrum tissues increased continuously with the increase of salinity while the K⁺ content showed a decreasing trend; and the effect of nitrogen and phosphorus concentration on the content of Na⁺ and K⁺ was not obvious; 3) under the conditions of all nitrogen and phosphorus treatments, S. portulacastrum grew normally and showed a high nitrogen and phosphorus removal ability, significantly reduced the nitrogen and phosphorus concentrations in the water. S. portulacastrum had a strong salt-tolerance ability and effectively alleviated the eutrophication, which can be used to purify the aquaculture wastewater and improve the aquaculture environment.
• Effect of bivalent copper ion on the growth and antioxidant enzyme activity of Halophila ovalis

  LI Qianru, ZENG Siqin, HU Jiefei, HUANG Jun, Zhang Yulei, ZENG Qitao, LUO Xiaoxia, HUANG Xianghu

  2024, 46(2): 134-142. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.016

  Abstract ( ) PDF ( )

  To determine the effect of seawater bivalent copper ion (Cu²⁺) at different concentrations on the growth of Halophila ovalis, seagrass H. ovalis was planted in door and in seawater containing different amounts of Cu²⁺. After 2 weeks culture, the biomass, pigment content, soluble protein content, three antioxidant enzyme activities of H. ovalis and copper content in its tissues were measured. The results showed that the increase of Cu²⁺ content significantly affected the biomass and relative growth rate (RGR) (P<0.05). The content of Cu²⁺ had no significant effect on the pigment content (P>0.05). The soluble protein content increased with the increase of Cu²⁺ content. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) decreased with the increase of Cu²⁺ content. The amount of copper in above ground tissues was higher than that in underground parts. Moreover, with the increase of Cu²⁺ content in seawater, more copper was enriched in plant tissues. We found also that the growth rate and the antioxidant enzyme activities of H. ovalis were decreased significantly when the Cu²⁺ was high than 0.1 mg/L in seawater. The high concentrations of Cu²⁺ caused the degradation of seagrass bed. Copper was enriched in the leaves of H. ovalis, leading to the rapid defoliation of H. ovalis and affecting the ecological function of seagrass bed.
• Characteristics and evaluation of spatial variation of water quality in Bosten lake

  Saimire TUOHETI, Dilinuer AJI, ZHANG Min, LI Ruxia, WANG Xiaolan

  2024, 46(2): 143-150. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.017

  Abstract ( ) PDF ( )

  Methods such as spatial interpolation, principal component analysis, and the Nemero pollution index were used to analyze and evaluate the water pollution of Bosten lake. According to the result, the total nitrogen (TN), total phosphorus (TP), ammonia nitrogen (NH₃-N), potassium permanganate index (COD_Mn), suspended solids (SS) and turbidity of Bosten lake water quality indicators indicated an obvious spatial difference, with the concentration of the southwest shore and the northeast shore of the lake being higher than that of central lake. the dissolved oxygen (DO) showed decreasing from east to west, and the pH value increasing from the southwest shore of the lake to the center and the middle zone of the north shore. There was a strong correlation between the water quality indicators. The DO and TN, TP, NH₃-N, COD_Mn and turbidity were significantly negatively correlated while TP and TN, NH₃-H, COD_Mn, turbidity, NH₃-N and COD_Mn and turbidity. COD_Mn and turbidity were significantly positively correlated. Organic matters such as DO, TN, TP, NH₃-N polluted the waterfront in the lake area heavily, with the pollution level of the south shore being the highest, then the north shore, the west shore, lake centre, followed by the east shore. The results of the pollution assessment showed that the east shore, centre and west bank of Bosten lake were lightly polluted with class III water quality, and the north shore and the south shore of the lake were medium pollution with class IV water quality. The spatial variation characteristics of water quality could reflect the main pollution factors and the pollution level of lake water quality, thus providing a reference for the protection and treatment of water resources in inland lakes in arid areas.
• Analysis of species and taxonomic diversities of fish inhabiting Dongping Lake, downstream of Yellow River

  LI Xian, WANG Guanhan, DONG Wen, DONG Jun, LIU Feng

  2024, 46(2): 151-157. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.018

  Abstract ( ) PDF ( )

  In order to describe the species composition and taxonomic diversity of fish inhabiting Dongping Lake, downstream of Yellow River, the species composition was analyzed and the taxonomic diversity and G-F diversity indexes were calculated based on the survey data of fish resources from 1979 to 1980 and the survey data of fish from 2020 to 2021. In total, 55 species belonging to 39 genera, 15 families and 8 orders of fish were recorded from 1979 to 1980, and 41 species belonging to 39 genera, 15 families and 7 orders of fish were recorded from 2020 to 2021, among them fish species in Cypriniformes were absolutely dominant. From 1979 to 1980 and from 2020 to 2021, the average taxonomic difference index (Δ⁺) of fish inhabiting Dongping Lake was 77.19 and 79.39, the taxonomic difference variation index (Λ⁺) was 581.9 and 561.5, the family diversity index (F index) was 5.05 and 4.15, the genus diversity index (G index) was 3.70 and 3.65, and the standardized G-F index was 0.27 and 0.12 respectively. Fish diversity of Dongping Lake displayed an overall downward trend. Fish germplasm resources protection and habitat restoration of Dongping Lake should be strengthened.
• Research Review
• Measurement and difference analysis of high-quality development level of ocean economy of China

  GUAN Hongjun, FENG Min

  2024, 46(2): 158-168. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.019

  Abstract ( ) PDF ( )

  Based on the panel data of 11 coastal provinces (municipalities directly under the governance of central government) in China from 2011 to 2020, we constructed an indicator system for high-quality development of ocean economy from six dimensions including comprehensive economic strength, degree of scientific and technological innovation, level of coordinated development, capacity for sustainable development, level of opening to the outside world and improvement of people's livelihood. We used the AHP-entropy weight TOPSIS method to calculate the high-quality development level index of the ocean economy, and discussed the current situation of the high-quality development of the marine economy of China. On this basis, the Theil index and Moran index were used to discuss the regional differences and spatial correlations of high-quality development of the ocean economy. We found that the high-quality development level of the ocean economy of China shows a fluctuating upward trend. The main source of the overall difference in the high-quality development of ocean economy was the regional difference, of which the difference in the southern ocean economic circle was the most significant. There was a significant spatial positive correlation between the high-quality development level of the ocean economy of China, and the provinces and cities with the same high-quality development level showed a certain degree of agglomeration in space.
• A comparative study on management strategies basing on fuel cost of Ommastrephes bartramii in north Pacific Ocean

  SU Xue, CHEN Xinjun

  2024, 46(2): 169-176. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.020

  Abstract ( ) PDF ( )

  Ommastrephes bartramii is an important economic species of the pelagic fishery of China, and the sustainable use of fish resources is an important part of the research. In this study, basing on the Gordon-Schaefer bioeconomy model, the bio-economic social synthesis was established by considering the impact of biology, economy and society. We used the production and related economic data of the north Pacific Ocean from 1995 to 2019 to analyze the impact of the change in fuel cost on the sustainable use of fish resources. Up to 9 fishing scenarios were drawn to simulate the accumulative stock biomass variation, accumulative catch and accumulative profit changes under different scenarios of fuel cost for short-term (1-5 years), medium-term (10 years) and long-term (20 years) resources. The results showed that both scenarios 6 (2.5% reduction in fuel cost) and scenarios 7 (5% reduction in fuel cost) obtained not only considerable fishery profits but also protected soft fish resources from overfishing. Considering the influence of biological, economic, social and ecological factors, they can be used as the optimal scenarios to realize the optimal allocation of resources.
• Application of eco-concrete in rocky reef ecosystem restoration and associating prospects

  YANG Haijie, WANG Xiaokang, QIN Junqi, XU Kang, ZHAO Peng

  2024, 46(2): 177-185. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.021

  Abstract ( ) PDF ( )

  Rocky reef habitat is an essential part of marine ecosystems because it boasts complex plant and animal communities, high biomass, stable material cycles and energy flows. However, human activities and frequent weather disasters have caused rocky reef habitat loss and biodiversity loss. Therefore, restoring degraded rocky reef habitats is considered a top-priority action. In this paper, we applies ecological theories such as ecological niche theory, succession theory, edge effect theory and disturbance-stability theory to restore the concrete rock reef ecosystem. As eco-concrete has a complex pore structure, rough surface and high strength, its application can offer an attachment base and habitat for marine organisms. Therefore, eco-concrete can be used to restore oyster reefs, algal reefs, coral reefs and ecological seawalls, to build an ecosystem with engineering values, to purify water, to provide biological habitat, to maintain biodiversity and to resist wave erosion and to achieve sustainable development. We aimed to protect and restore ecology by conducting research on eco-concrete in terms of its design, production, and construction technology. By doing so, the reef ecosystem survey technology, and an eco-concrete reef ecosystem modular restoration technology system were established, which should improve the management of the eco-concrete reef ecosystem.
• Progresses in detecting shellfish toxins with hydrophilic interaction chromatography -mass spectrometry

  ZHENG Xuying, SUN Xiaojie, LI Zhaoxin, XING Lihong, JIANG Wanfeng

  2024, 46(2): 186-191. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.022

  Abstract ( ) PDF ( )

  Shellfish toxins are toxic macromolecular compounds produced by toxic algae in the ocean. Shellfish accumulate in their body by ingesting toxic algae, which seriously threatens the health of consumers. In this paper, we reviewed the classification of shellfish toxins and the retention mechanism and characteristics of hydrophilic interaction chromatography (HILIC). The application of hydrophilic interaction chromatography-mass spectrometry (HILIC-MS) in determining shellfish toxins was introduced, and the development trend of HILIC-MS in the detection and analysis of shellfish toxins was put forward.
• Studies on the governance of the ecological environment of marine fishing villages from the perspective of social capital

  ZHENG Jianming, HU Min, LIU Jingzhou

  2024, 46(2): 192-200. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.023

  Abstract ( ) PDF ( )

  Marine fishing villages are the unit form in overall rural area. Strengthening studies on the ecological environment management should prompt the implementation of rural revitalization strategy. By combing the current practicing effect of the ecological environment management of marine fishing villages, we found that the social capital plays a significant role. Selecting S Village of Shanwei City and K Village of Jiangmen City as the case sites, we compared the degree of social capital participation in environmental governance, the mechanism of action, and the difference in effectiveness through questionnaires and in-depth interviews. The results showed that the environmental governing ability and quality of governors, and the difference in social capital stock of fishing village communities are the main reasons for the obvious differences in governance effectiveness. It is believed that the follow-up of the ecological environment management of marine fishing villages should focus on improving the governance capabilities and political literacy of local governments and fishing village leaders, cultivating and making good use of the social capital of marine fishing villages to encourage the endogenous role of multi-participation, and promoting the modernization of marine fishing village ecological environmental governance.
• Studies on the social adaptation of the fishermen retreated from Yangtze River fishing from the respective of empowerment

  ZHANG Zuping, SHEN Nana

  2024, 46(2): 201-208. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.024

  Abstract ( ) PDF ( )

  The fishmen retreated from Yangtze River fishing have been facing many difficulties in adapting society, among them losing power is particularly prominent. Enhancing their rights is a key factor to their social adaptation and an important guarantee for the effective implementation of fishing banning. Based on the analysis of the field surveying findings, in this article, we concluded that the withdrawal of fishermen is mainly reflected in economic loss of power, social environmental loss of power and psychological loss of power. Therefore, the fishermen should be assisted as soon as possible from three perspectives, system empowerment, organizational empowerment and individual empowerment, which should aid to realizing social adaptation and finally the goals of retirement, stability and prosperity.
• Risk assessment of coastal geological hazards in Jiaodong peninsula, China based on analytic hierarchy process

  ZHU Hongye, WU Wen, YU Jing, CHEN Wenyue, MA Chen

  2024, 46(2): 209-216. https://doi.org/10.13984/j.cnki.cn37-1141.2024.02.025

  Abstract ( ) PDF ( )

  The coastal zone is a fragile area affected by the global ecological environment and is extremely sensitive to global changes. Due to the change of climate environment and the excessive exploitation of groundwater, coastal geological hazards such as coastal erosion and seawater intrusion in Jiaodong peninsula have gradually become a serious threat to the sustainable economic development and people’s property security in this region. In this paper, based on the relevant data of coastal geological hazards in the coastal zone of Jiaodong peninsula, the qualitative analysis was carried out to determine that the main coastal geological hazards in this region were seawater intrusion and coastal erosion. On this basis, the risk assessment index system was established by selecting representative indicators. The quantitative risk assessment and GIS-based zoning of seawater intrusion and coastal erosion in Jiaodong peninsula were then carried out. The results showed that the comprehensive risk level of seawater intrusion in Jiaodong peninsula was ranked from high to low as Qingdao, Weihai, south Yantai and north Yantai. The comprehensive risk level of coastal erosion was ranked from high to low as Qingdao, north Yantai, Weihai and south Yantai. Accordingly, this paper proposed to rationally exploit groundwater in Weihai city and Yantai city, to protect coastal sand mines and vegetation in north Yantai and to move sand making beaches, to strengthen coastal defense projects in Qingdao and to pay attention to the pre-disaster investment.