10 February 2023, Volume 45 Issue 1

    

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• Research Papers
• Laboratory model tests on lateral bearing capacity of U-shaped steel sheet pile

  LYU Peng, DONG Sheng, YAN Zhen, WANG Long

  2023, 45(1): 1-9. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.001

  Abstract ( ) PDF ( )

  Large scale tests were conducted to investigate the displacement and soil pressure responses and failure mode of an U-shaped steel sheet pile subjected to lateral loading. Effects of dry and wet conditions, loading rate, penetrating depth and loading height on the displacement and soil pressures were analyzed. Test results show that when the U-shaped steel sheet pile was loaded on the convex surface, the displacement increased with increasing loading height, buried depth, loading magnitudes, and the displacement in the dry sand was greater than that in the wet sand. When on the concave surface, the displacement decreased with increasing buried depth, increased with increasing loading magnitudes, and remain almost constant in different loading height and different soil dry and wet conditions. The distribution of earth pressure on the loading side of U-shaped steel sheet pile was R-shaped, which increased with increasing buried depth and soil moisture content. Tilting failure was triggerred for the U-shaped steel sheet pile with the increase of loading force, and the pile bends approximately 1/3 of buried depth from the bottom of the pile.
• Research on horizontal bearing capacity of umbrella suction anchor in saturated silt under cyclic load

  SHENG Tengfei, LIU Hongjun, LIU Can

  2023, 45(1): 10-17. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.002

  Abstract ( ) PDF ( )

  The bearing performance of the umbrella suction anchor was studied using the ABAQUS finite element software to construct model. The horizontal cyclic load was applied to the umbrella suction anchor. Under the condition of fixed load size, the displacement of the anchor and the stress and strain of the soil at different positions are investigated. According to the analysis, under the action of horizontal cyclic load, the maximum plastic strain of the soil appears at the position of the tube skirt. The combination of the tube skirt and the anchor support played a major role in the bearing performance. The load conditions were changed to study the effect of different load sizes on the umbrella suction anchor. The research found that with the increase of the intensity of the cyclic wave load, the stability effect of skirt was more obvious, and this effect was more prominent in the later stage of cyclic wave load.
• Prediction of evaporation duct height based on BP neural network optimized by mind evolutionary algorithm

  LI Yaohao, LI Xingfei, DING Lele, YANG Shaobo

  2023, 45(1): 18-22. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.003

  Abstract ( ) PDF ( )

  It is very important to predict the evaporation duct height parameters at sea, but it is difficult to detect or predict duct parameters accurately. In this paper, measured data from evaporation duct detection platforms in the South China Sea and the ERA-Interim data set were used to extract point data of relevant hydrological and meteorological elements. The NPS model was used to calculate the height of evaporation duct to form the data set. The model of MEA-BP was then used to predict the height of the evaporation duct. The optimized BP neural network can avoid falling into the local minimum point, and the prediction results have a high accuracy rate. Moreover, MEA has a relatively fast convergence rate when calculating the optimal individual. Finally, this paper provides a method for predicting the height of horizontally uniform evaporative duct.
• Experimental study on scour protection of submarine pipeline by permeable spoiler

  GAO Feng, SHI Bing, XIAO Yanan, CONG Xiaohong, YU Xida

  2023, 45(1): 23-29. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.004

  Abstract ( ) PDF ( )

  Based on the complex flow field around a submarine pipeline, there are many characteristics such as scour and suspension failure in the process of operation. According to the scour protection mechanism of submarine pipeline under the action of spoiler, we put forward a scour prevention measure combining the permeable spoiler and submarine pipeline. The dimensionless formula that affects the scour depth of submarine pipeline is obtained by dimensional analysis. Through physical model test, the influence of the permeable spoiler on the scour protection of submarine pipeline is studied under the condition of different velocity, different pipe hole ratio and different water permeability ratio. It is found that due to the existence of the permeable spoiler, the pushing force of the sediment is reduced, resulting in sediment deposition. The scour depth of the submarine pipeline is less than that of the pipeline without the protection of the spoiler. The maximum scour depth of the pipeline with the protection of the permeable spoiler is 0.3D in front of the pipe axis, and the scour depth under the pipe line is significantly reduced. Based on the analysis of the test data, the calculation formula of the equilibrium scour depth is obtained by fitting. The formula fits well with the measured data, which shows that the formula has good applicability.
• The influence of sea level variability on the surface circulation in the Japan Sea

  DU Kailun, GUO Xinyu, YANG Haiyan, ZHENG Junyong, MAO Xinyan

  2023, 45(1): 30-37. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.005

  Abstract ( ) PDF ( )

  A three-dimensional hydrodynamics model in the Japan Sea was established by POM, changing the topography conditions and carrying out numerical experiments under different sea levels, to study the responses of surface circumfluence field of the Japan Sea as the sea level dropped. With the decrease of sea level, the TWC (Tsushima Warm Current) and its branches gradually weaken in southern Japan Sea. When the sea level drops to -90 m and -100 m, the East Korean Warm Current branch and Tsushima Current coastal branch almost disappear. While the intensity of the cold current in the northern part of the Japan Sea remains basically unchanged, the position of its principal axis moves northward. Moreover, the transport volume through the Tsushima Strait reduce gradually due to the decrease of the sea level, which leads to the weakening of the TWC and the shrinking of its influence scope. The results can be used as a reference for the change of surface circulation in the Japan Sea in the past.
• Experimental study on ice resistance properties of jack-up platform

  FAN Dunqiu, LIU Xuetao, ZHANG Lin

  2023, 45(1): 38-44. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.006

  Abstract ( ) PDF ( )

  The jack-up platform is generally designed without considering the effect of ice load. To realize the operation in ice area, it is necessary to investigate the anti-ice ability of such platform. This paper studies the ice load mechanism, ice-induced vibration and anti-ice method of jacket platform. The ice load acting on structure and vibration response are gradually increased with the ice thickness. The vibration mechanism of different ice thickness has not changed, by comparing the time series response with different ice thickness. It is found that the vibration response will show a quasi-static response at low ice speed and a random response at high ice speed. The occurrence of ice-induced vibration is the result of the inherent structural characteristics, ice speed, ice thickness, ice material parameters and other factors, and the mechanism of action is particularly complex. This study focuses on the research of ice-induced vibration characteristics of jacket platform in ice area.
• Water depth retrieval based on gradient boosting decision tree algorithm

  MENG Ran, SHEN Wei, LUAN Kuifeng, JI Qian, RAO Yali

  2023, 45(1): 45-50. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.007

  Abstract ( ) PDF ( )

  Traditional water depth measurement generally use on-site detection by shipboard sonar, which is less flexible and has a long update cycle. In some sea areas, it is often difficult for ships to get close to complete the measurement. This paper uses WorldView-2 multispectral remote sensing images near Qilianyu sea water to construct a water depth retrieval model based on the Gradient Boosting Decision Tree (GBDT) algorithm, and combines the water depth data combined with single beam and manual measurement. The water depth retrieval accuracy is compared with the water depth data of the traditional single-band model, dual-band model and BP neural network water depth retrieval model. The results show that the accuracy of the GBDT model is higher than other models in the 0-20 m deep sea area, and it is more in line with the actual water depth. The R² of the test point is 0.9664, RMSE is 0.94 m, MAE is 0.75 m, and RME is 19 %.
• Analysis of thermocline features in the deep water near Taiwan Island

  LI Maolin, LI Qinghong, ZHANG Lei, YAO Zhongshan

  2023, 45(1): 51-56. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.008

  Abstract ( ) PDF ( )

  Based on the temperature measurements from nearly 3600 CTD stations during 1992 to 2002 (excluding 1999) and the vertical gradient method, the thermocline features in the southwestern, southeastern and northeastern regions of Taiwan Island were investigated. Results indicated that the thermocline depth in the southwestern region is shallower than those in the southeastern and northeastern regions, whereas the thermocline thickness was in the middle of those in the southeastern and northeastern regions. Both thermocline depth and thickness in the southwestern and southeastern regions had seasonal variations: the thermocline depth reached the maximum in winter and minimum in summer, while the thermocline thickness reached the maximum in summer and minimum in winter. However, in the northeastern region, both thermocline depth and thickness exhibited oscillations during June to October. Moreover, the thermocline depths in the three regions reached the minimum in 1998, which may be attributed to the El Nino event.
• Morphological characteristics and nutrient composition of resident masu salmon Oncorhynchus masou inhabiting Mijiang River, Jilin Province

  SONG Bizeng, WANG Bing, LIANG Shan, CHONG Xiangyu, ZHENG Wei, YIN Xuwang

  2023, 45(1): 57-66. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.009

  Abstract ( ) PDF ( )

  Masu salmon (Oncorhynchus masou) has been listed as a national second-class protected species in China. The morphological characteristics and nutrient levels of masu salmon are critical for the protection of its biodiversity and fishery resources rationally. In the present work, we analyzed the morphological characteristics, amino acid and fatty acid of wild resident masu salmon population inhabiting Mijiang River and compared with the artificial resident masu salmon population. Wild resident masu salmon varied between 19.93 and 215.05 g in body weight and between 10.40 and 22.00 cm in body length. Wild resident masu salmon was 74.04±3.05% in water content of muscle, 1.84±0.33% in ash content, 19.73±2.42% in crude protein content and 3.18±0.04% in crude fat content. In total, 17 amino acids were detected in muscle, including 7 essential amino acids (accounting for 40.77% of the total) and 4 delicious amino acids (accounting for 37.54% of the total). Valine is the first limiting amino acid, and phenylalanine and tyrosine are the second two limiting amino acids when using the amino acid score (AAS) as the evaluation standard. In addition, 22 fatty acids were detected in muscle, including unsaturated fatty acids (59.36%), EPA (3.87%) and DHA (2.81%). The findings of this study will provide the basic information for the protection of fishery resources and biodiversity of masu salmon in Tumen River Basin.
• Breedinghigh phloroglucinol and optimization of medium

  MA Xiangjun, WANG Xiangfa, HOU Shiying, LI Yinta, TIAN Li

  2023, 45(1): 67-73. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.010

  Abstract ( ) PDF ( )

  his studymarine Pseudomonas LBF-96 isolated earlierphloroglucinol , and the fermentation medium of the mutant was optimized. UV for 60 s and microwave irradiation for 20 s. The yield of phloroglucinol 0.599 g / L cinnamaldehyde colorimetry, 159% higher than that of the original. The production time of phloroglucinol was advanced and the cost of fermentation was reduced.he mutant YLM96-01 showed good genetic stabilitysubculture. After the culture condition w optimized response surface methodology, the yield of phloroglucinol mutant YLM96-01 increased to 0.784 g / L, 31% higher than that . The high phloroglucinol-producing strain YLM96-01 bred potentialproduction.
• Research Repor
• Researches on the characteristics of tide and current in the coastal area of Dingzi Bay

  CAO Xuefeng, CHEN Zhaolin, YU Jiewen, SHI Wenqi, ZHANG Chong, WEN Wu

  2023, 45(1): 74-81. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.011

  Abstract ( ) PDF ( )

  Based on the latest observation data of Dingzi Bay in 2021, the basic characteristics of tide, current and residual current were studied. The type of tide is regularly semidiurnal. The maximum tide is 405 cm, the minimum tide is 69 cm, and the averaged tide is 248 cm. The duration of high tide is less than that of low tide. The tidal current is regularly semidiurnal. The maximum flood current velocity is 67cm/s and the maximum ebb current velocity is 72 cm/s. The duration of rising tide current is less than that of falling tide current. The current velocity decreased from top to bottom. The rotary spectrum analysis of the current showed that the spectral peak of M2 tidal constituent is the highest, and the motion form is counterclockwise. The amplitude of residual current is less than 10 cm/s, and decreases from top to bottom. In the observation period, the wind direction of long period is opposite to the direction of residual current. The wind is not the controlling factor of residual current.
• Spatial distribution characteristics of microplastics in the estuary of Duliujian River

  QIAN Hong, DAI Yuanyuan, ZhANG Xin, YANG Hongwei, ZhANG Shengnan, WANG Shuai, REN Ling, FANG Yuan, SUN Xueliang, WANG Ruonan, WU Jizhou, PENG Chu

  2023, 45(1): 82-89. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.012

  Abstract ( ) PDF ( )

  In order to explore the spatial distribution characteristics of microplastics in the Duliujian River estuary, in this study, we collected samples from different environments in this area in March 2021, and analyzed the types, abundances, particle size, and shapes of microplastics in the samples using digestion flotation and laser infrared imaging systems. The results showed that the concentrations of microplastics detected in the water samples ranged from 227 to 402 items/L. A total of 17 microplastics were detected, of them, the most abundant were polypropylene (PP), polyethylene (PE), polyamide (PA), polyethylene terephthalate (PET) and polymethyl methacrylate esters (PMMA). The abundance of microplastics in sediments was varied between 8 430 and 12 600 items/kg. A total of 18 microplastics were detected, of them, PE, PP, PET, PA and polyvinyl chloride (PVC) were the most abundant. In water samples and sediments, the particle size distribution showed a sharp increase in the number of microplastics as the particle size decreases. In the shape distribution, except for a small number of large particle sized PET, PA and PP that appeared as fibers, most microplastics were in granular form. During the transfer of microplastics from freshwater to seawater along the Duliujiang River, with the increase of salinity and density, the abundance of microplastics in the water body increased significantly. There were significant differences in the composition and structure of microplastics between water samples and sediments. It was revealed that the density and use of microplastics in water bodies and microplastics are important factors affecting the spatial distribution of microplastics in estuaries.
• Integrative assessment of ecosystem based on remote sensing ——Xiangshan Bay as a case

  LI Ting , HUANG Xiuqing, HUANG Xiaochen

  2023, 45(1): 90-97. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.013

  Abstract ( ) PDF ( )

  A coastal ecological evaluation index system is established based on the remote sensing information of coastal zone and the pollutant flux into Xiangshan Bay. In order to evaluate ecological value of the coast of Xiangshan Bay, a comprehensive index system was established in combination with factors of coastal beach and harbor marine ecology. It was found that the evaluation results of Port 1C and 4C areas have changed significantly considering the factors affecting the marine ecology of beach and harbor. Coastal ecological factors have negative and positive effects on the ecology of Xiangshan Bay, changing the ecology of zone 1C from good to better, and the ecology of zone 4C is generally better.
• Effects of land use patterns at different spatial scales on water quality of Kaidu River

  LI Ruxia, Dilinuer·Aji, Saimire Tuoheti, WANG Xiaolan, ZHANG Min

  2023, 45(1): 98-106. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.014

  Abstract ( ) PDF ( )

  To investigate the effects of land use of different scales practices on water quality in the Kaidu River, water samples were obtained from 15 sample sites in the Kaidu River in June and October 2021. Four water quality indicators, TDS, TN, TP, COD, were tested. With these test results and the data of land use in 2020, which is about the land use of buffer zones of 0 m to 100 m, 100 m to 200 m, 200 m to 500 m, 500m to 800 m, and 800 m to 1000 m created around from sample-taking sites, the redundancy analysis (RDA), correlation analysis and linear regression model were applied to reveal the influence of land use patterns of different scales on water quality. The results showed that the overall water quality of Kaidu River fallen into the category of Class II water standard, with TN and TP as its main potential pollutants, and agricultural waste water and grazing as its main source of pollution. RDA analysis finds buffer zones within 500 m has the largest the degree of explanation in the scale of land use pattern on water quality indexes. During water abundant seasons, TDS, TP, TN and COD were positively correlated with watershed and cropland, and negatively correlated with bare land and grassland; during normal water seasons, TP, TDS, TN were positively correlated with grassland, and negatively correlated with watershed and bare land, while COD was positively correlated with cropland and negatively correlated with bare land, watershed and grassland. The correlation between land use of different spatial scales and their water quality indexes was also different. During water abundant seasons, TN was significantly negatively correlated with grassland within buffer zone of 500~1000 m; during normal water seasons, COD was negatively correlated with grassland within the 1000 m buffer zone. During water abundant seasons and normal water seasons, TN and COD were significantly and positively correlated with cropland within buffer zone of 100~1000 m. The influence of land use pattern on water quality had a scaled effect, and the largest influence on water quality was the proportion of cropland area, followed by grassland.
• Research on marine PAHs pollution investigation and biological monitoring technology in Laizhou Bay

  CAO Yunhao, PAN Luqing, SUN Jiawei, LI Zeyuan

  2023, 45(1): 107-116. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.015

  Abstract ( ) PDF ( )

  This study carried out the PAHs pollution investigation and biological monitoring technology research in Laizhou Bay in March, May, August and October 2018. The results showed that the surface sediment ΣPAHs in Laizhou Bay ranged from 197.53 to 575.73 ng/g dw, the lowest was S4 site in March, and the highest was S2 site. October; the four-corner clam software department is 73.43-156.39 ng/g dw, the lowest is S4 site in March, and the highest is S2 site in August. The average value of PAHs in the surface sediments and the soft parts of the four-cornered clams showed a trend of S2> S3> S1> S4. Pearson correlation analysis showed that gill’s EROD, SOD, GPx, DNA damage, LPO and digestive glands’ CYP450, EROD, UGT, T-AOC, GPx, DNA damage, PC, LPO can be used as indicators of PAHs pollution in Laizhou Bay. The results of IBR analysis of gill and digestive glands were different. The average gill’s IBR scores show a trend of S2> S3> S4> S1, while the digestive glands were S2> S3> S1> S4. MPI showed that S2 was in a serious pollution level, S3 was in a light pollution level, S1 and S4 were similar between light and good levels, and the IBR and MPI results of gill and digestive glands showed good consistency. Among them, the average ranking of the digestive glands’ IBR scores was the same as the chemical monitoring results, and the index evaluation results of the digestive glands were significantly related to the PAHs content in the sediments of Laizhou Bay. Thus, the comprehensive biological index analysis method is an effective tool for assessing the pollution of the marine environment.
• Adsorption performance of new artificial reef materials for heavy metals in water

  WANG Hong, ZHANG Xue, GAO Yan, ZHANG Jingwei, XU Xiaofu, DAI Yuanyuan, FANG Enjun

  2023, 45(1): 117-121. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.016

  Abstract ( ) PDF ( )

  In order to prepare a functional artificial reef, oyster shells with different proportions were added into the experimental new artificial reef materials. The adsorption performance of the new artificial reef materials with different contents of oyster shells for Cu, Zn, Pb, Cd, Cr and As in water was investigated at different concentrations of heavy metals and different adsorption times. Oyster shell is used as heavy metal adsorption material to improve the adsorption capacity of artificial reef to repair the marine ecological environment, and fully realize the purpose of using waste to treat waste. The results showed that the concrete sample with 50% oyster shell particles has a higher removal rate of six heavy metal ions. The removal rate of the concrete sample to 6 kinds of heavy metal ions is almost similar. The removal rate increased significantly within 5min, and then the increasing trend tended to be gentle. The order of adsorption capacity of concrete samples to heavy metal ions is Zn>Cu>Pb>Cd>Cr>As.
• Water quality improvement measures and effect monitoring of the artificial bathing beach in the Muddy Coast——a case study of Jinshan City sand beach, Shanghai, China

  JI Yongxing, YIN Yue

  2023, 45(1): 122-128. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.017

  Abstract ( ) PDF ( )

  An artificial beach was proposed to build at the muddy coast located in the north side of the Hangzhou Bay. In order to deposit sediment and maintain water quality, several potential factors were investigated including tidal current, sediment transport, water quality and local organism. A general approach of water quality maintenance is presented following the procedure of submerged dike enclosure, sediment deposition, change water and ecosystem construction. The series of studies were carried out on effect of sediment deposition, feasibility of change water and the size of division and drainage system, ecological self-purification system construction, and a long period of water quality monitoring. The results show that: (1) The sediment is settled when the water body is enclosed by submerged dike. About 93% of suspension is settled out of water and the concentration of total phosphorus reduced more than 70% after two days. (2) The water in the enclosure region can be changed by pump station and culvert during the tide period. The size of them should be determined by the tidal characters. (3) The ecological self-purification system should be established based on the background investigation. The aquatic animal such as fish, shrimp, crab, shell, algae etc. should be dropped in proper quantity and in proper range following the principle of nutri-dynamics of food network. (4) On-site monitoring results indicate that during the long-term operation, with increased tourists, the water quality has tended to worse, and it changes in season. At last, the paper suggests that the division and drainage system should be maintenance, the water quality monitoring should be enhanced, the number of tourists in summer should be limited and the frequency of water changing should be increased.
• Study on area change and influencing factors of Tao-Ahaizi lake in the Bojiang Haizi river basin from 1979 to 2017

  CHEN Yue, DONG Shaogang, WANG Lei, HOU Qingqiu

  2023, 45(1): 129-137. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.018

  Abstract ( ) PDF ( )

  This paper takes the Tao-Ahaizi lake as research object. The Landsat remote sensing data are used to extract water image of nearly 40a from 1979 to 2017. The changes of lake boundary and lake area are obtained by water index method, and the climate and human factors affecting the changes are explained and analyzed. The results show that: (1) From 1979 to 2017, the area of Tao-Ahaizi lake decreased from 12.84 km² to 2.30 km², among which 2002—2003 was the inflection point of significant changes in the lake area. (2) The change of lake area showed a trend of periodic shrinkage, which was divided into three stages: the relatively stable stage (1979—1999), shrinking stage (2000—2015), and recovery stage (2015—2017). (3) Climatic factors with a warming and drying trend were the main influencing factors for the change of lake area before 2000. Human activities, such as water conservancy projects, ecological restoration projects and coal mining, make the lake unable to get effective water supply, which is the main factor that leads to the shrinking of the lake area after 2000.
• Ecological relationship among mudflat crab (Helice tientsinensis), microphytobenthos and salt marsh plant Suaeda heteroptera inhabiting red beach

  WANG Yan, LIU Guize, YU Guoxin, YANG Xiaolong, CAO Linquan, LIU Qing

  2023, 45(1): 138-145. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.019

  Abstract ( ) PDF ( )

  In order to explore the reasons of degradation of the salt marsh plant Suaeda heteroptera in Panjin Liaoning Red Beach, we studied the ecological relationship among microphytobenthos and mudflat crab (Helice tientsinensis) inhabiting surrounding plant ecosystem. In May and August, the three areas of unvegetated mudflat and areas with good and poor plant growth were selected, and microphytobenthos and crabs were collected from the surface sediment at the surface, slope and bottom of the tidal creeks in the same area. The height and wet weight of the plants were measured. The collected mudflat crabs were moved back to the laboratory and divided into three groups for feeding experiments of S. heteroptera. Results showed that the average density of red beach microphytobenthos in May (46.72±17.71 cells/cm² ) was significantly higher than that in August (6.47±4.98 cells/cm²) (p <0.05). The area with good growth is the lowest, and there was a significant difference with the mudflat soil and poor growth area (p<0.05). Results also showed that the average biomass of red beach microphytobenthos in May (0.057±0.023×10^-3mg/cm²) was higher than that in August (0.00±0.001×10^-3mg/cm²). The lowest biomass of microphytobenthos was found in the area with good plant growth, which was significant different from that of other two regions (p<0.05). The height of the plant was 10.61±2.10 cm in May and 20.53±2.79 cm in August, no significant difference was observed among three areas (p>0.05). The weight of the plant was 0.40±0.26g in May and 8.36±2.37g in August. There was a significant difference in weight among the area with poor growth in May and the other two areas (p<0.05). The crabs can eat Suaeda salsa, with increasing body weight. The average daily food intake of crabs increased. Individual difference in size was significant (p<0.05). The average daily diet of crabs was 22.1mg/g. The disturbance of crabs was one of the reasons for the degradation of Suaeda salsa on red beach. The findings of this study provided some references for the ecological relationship among crabs, microphytobenthos and plants in S. heteroptera ecosystem.
• Study on the impact of sewage disposal on marine environment

  CAI Dequan, LENG Xing, HU Hongzhi, JIANG Laixiang, GAO Guang, LIU Aijiang, ZHANG Xiaodong

  2023, 45(1): 146-155. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.020

  Abstract ( ) PDF ( )

  According to the results near the Weihai sewage outfall in 2021, the current situation of seawater quality was evaluated. Combined with the water quality monitoring results in 2007 and the continuous monitoring data from 2017 to 2021, the change trend of seawater quality before and after sewage discharge and in recent years were analyzed. Mike 3 model was used to predict the impact range and degree of COD, inorganic nitrogen and active phosphate on the marine environment after the increase of sewage discharge and the improvement of pollutant discharge standard. The results show that the seawater quality in the study area was slightly lower than that in 2007, but most stations met the class II standard of seawater quality. The seawater quality was relatively good. Weihai sewage treatment plant had a small impact on the regional marine environment due to the standard discharge of sewage in offshore deep water for many years. After the upgrading of the sewage treatment plant, only the diffusion range of inorganic nitrogen slightly exceeded the original mixed region. So the upgrading will not have a significant impact on the water quality environment of the study area.
• Research Review
• Comparative analysis of research status and hotspots on the coupling relationship between mangroves and climate change in China and USA based on bibliometrics

  JIANG Lu, YU Jing, WANG Quanbin

  2023, 45(1): 156-163. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.021

  Abstract ( ) PDF ( )

  The study of mangrove-climate change coupling is a research hotspot in the field of climate change as well as mangroves. In this study, we used bibliometric analysis to compare the current status and hotspots of mangrove-climate change coupling research in China and the United States, and explored the similarities and differences of research characteristics between the two countries in this field. The results show that (1) the United States, with the highest number of publications, has the strongest academic influence; China has the third highest number of publications in the world, but there is a gap with the United States in terms of academic influence. The number of publications in this field in both China and the U.S. shows a trend of continuous growth. (2) China and the U.S. have maintained a strong cooperative relationship in this field, and each has formed a more extensive international cooperation network. (3) Both Chinese and American scientists have shown a strong interest in the vulnerability of mangrove ecosystems in the context of climate change and the role of mangroves as nature based solution in addressing climate change. However, due to the late start, there is still a gap between the breadth and depth of mangrove-climate change research in China and the United States, and there is a need to further expand international cooperation, strengthen research output, and enhance academic influence. The results of this study will provide information reference for scientific research, policy formulation and management practices in the field of mangroves and climate change in China.
• Study on the suitability of small-scale marine spatial planning ——using Jinpu new district, Dalian as an example

  GAO Jinzhu, ZHANG Kuncheng, HE Guangshun, TIAN Shizheng, ZHAO Yuhan

  2023, 45(1): 164-173. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.022

  Abstract ( ) PDF ( )

  The present research of marine spatial planning is mainly from the perspective of nation and province. Marine spatial planning usually chooses the sea areas under the jurisdiction of province or a large scale of key sea areas. But in the process of compiling our country's small-scale marine spatial planning, it is found that there is still a lack of systematic research on theories and technical methods. This paper draws on the suitability evaluation method of territorial space development to construct a zoning suitability evaluation method suitable for small-scale Marine space. This paper divides marine space into "three areas and one line" (marine ecological space, marine biological resource utilization space, construction sea space and marine ecological red line). Using Jinpu new district as an example, carrying out the "three districts" suitability evaluation analysis, proposing the "three districts and one line" zoning plan. Finally, checking the conformity with the upper plan, the marine functional zoning layout is delineated. This paper provides strategic guidance and management reference for the marine comprehensive management, and theoretical and technical basis for the regional study of small-scale marine spatial planning.
• Realization of incentive compatibility principle in individual transferable quota and input control system

  KONG Fanhong, CHEN Ya

  2023, 45(1): 174-182. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.023

  Abstract ( ) PDF ( )

  Individual transferable quota (ITQ) and input control systems are two models of marine fishery resource management. The logical starting point of their construction is consistent with the management goal they intend to achieve. Focusing on the four management objectives of controlling fishing effort, restoring fishery resources, improving fisheries economic efficiency and optimizing resource allocation, after comparing the ITQ system with the input control system according to the principle of incentive compatibility, due to the particularity of the specific design, we found that ITQ system contains more incentive effects, which can basically unify the individual fishermen′s motivation to pursue the maximization of interests with the goal of the conservation and sustainable development of fishery resources, thus has a higher incentive compatibility. At the same time, ITQ system also has real dilemmas that need to be resolved. These dilemmas include, for example, the difficulty in setting the total allowable catch, the fairness of quota allocation, the excessive concentration and monopoly of quotas, the adverse selection of bycatch and optimizing catches, and the difficulties of supervision. Supplementary supporting institutional arrangements should aid to deal with these difficulties. Due to the comparative advantages of the ITQ system in terms of incentive compatibility, when conditions are mature, the implementation of ITQ system for specific fish species in specific sea areas is applicable as an alternative mode for controlling the input.
• Studies on the correlation between the spatial distribution of aquaculture facilities and the influence of typhoon in southeast China

  JIANG Yuqing, ZHANG Junbo, GUO Zhixing, WAN Rong

  2023, 45(1): 183-192. https://doi.org/10.13984/j.cnki.cn37-1141.2023.01.024

  Abstract ( ) PDF ( )

  In this study, we presented and analyzed the distribution characteristics of typhoons and three kinds of aquaculture facilities in southeast coastal provinces of China from 2015 to 2018. Based on Chi-square and rank sum tests and with regional center of gravity method, the correlation between the distributed pattern of aquaculture facilities and the wind speed and frequency of typhoons were determined. The results showed that the provinces with the most typhoon landings in the southeast coastal areas of China were Guangdong, Fujian and Hainan in the past four years, and their respective frequencies were more than 5 times. The distribution of traditional cage was linearly correlated with the wind speed and frequency of typhoon. The distribution is more affected when the typhoon reaches 8 (wind speed>17.1 m/s) and higher levels. The distribution of deep-water cage was only affected by the wind speed of typhoon, especially by the high-speed (wind speed>24.4 m/s) typhoon. According to the comprehensive index of typhoon, the center of gravity of raft culture was found to be the farthest away from the center of gravity of typhoon, indicating that its distribution is affected most considerably by typhoon. When the typhoon reaches level 6 (wind speed>10.8 m/s), its disaster status would be more significant. Raft culture is suitable to be distributed in the sea area where typhoon reaches up to level 6. Tradition is widely distributed, which can be set in the sea area with level 8 wind force such as inner bay. Deep cage is suitable to be distributed in the open sea area. According to the distribution of aquaculture facilities each province, it is suggested that Fujian and Guangdong should reduce the raft culture while the compound-fishery should be actively developed in Haina and Zhejiang. Northern coastal provinces are less affect by the typhoon disaster. With the advantage of raft culture varieties, we can actively build recreational fishery relying on marine ranching. However, in general, the suitableness of the aquaculture facilities distribution should be further discussed. The findings in this study will be helpful to make the future planning of aquaculture facilities reasonably.