10 October 2023, Volume 45 Issue 5

    

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• Research Papers
• Comparison of Tropical Cyclone Paths Between El Nino Years and La Nina Years in the Western Pacific

  GUI Xinwei, LI Ziqiang, ZHANG Shuiping, MENG Zhaoyi, GAO Shumin, WANG Shicheng, HAN Shuzong

  2023, 45(5): 1-7. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.001

  Abstract ( ) PDF ( )

  Typhoon is a very destructive natural disaster, China is located in the west coast of the Pacific Ocean is one of the countries most affected by the typhoon, so the study of the distribution of tropical cyclone path in the western Pacific Ocean is of great significance to the typhoon prediction. In this paper, using the data of tropical cyclone best path data sets, studied in 1949—2017 el nino and la Nina years the number of tropical cyclones in the western Pacific and path distribution, the following main conclusions: el nino years less than the number of tropical cyclones year average produce la Nina years, but the strength of development to the typhoon and the proportion of tropical cyclones over higher; El nino and la Nina years of tropical cyclone path are mainly distributed in the low latitude region of 10~20°N, but el nino years of tropical cyclone path in the east of the Philippine islands waters more concentrated , more concentrated in the west side of the Philippine island waters of la Nina years; The distribution pattern of tropical cyclone paths with typhoon intensity and above is similar to that of all tropical cyclone intensities, but is more northerly, especially in el nino years. The distribution of tropical cyclone intensification zones is basically the same as that of tropical cyclone paths.
• Application of machine learning-based methods to short-term forecasting of typhoon waves

  LUO Feng, ZHANG Jie, QUAN Xiufeng, WANG Yi

  2023, 45(5): 8-16. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.002

  Abstract ( ) PDF ( )

  Based on the third-generation wave model SWAN, a numerical wave model was established for the East China Sea to simulate the wave fields during the transit of typhoons 1509 “ Chan-hom”, 1909 “Lekima” and 2106 “In-Fa”. The results were used as the dataset for the multilayer perceptron, random forest and support vector regression forecasting typhoon wave models. The spatial features were introduced to improve the algorithm input and to compare the training speed of different models. The results showed that the model forecasting accuracy was improved by adding spatiality features. The RMSE of multilayer perceptron was reduced by 40% running the fastest. The RMSE of random forest was reduced by 25% running the slowest, and the RMSE of support vector regression was reduced by 8% running between the first two. It was shown that the improved model effectively improves the forecast accuracy and was a feasible application of machine learning-based methods for short-term forecasting of typhoon waves.
• A comparative study on offshore CCMP and two reanalyzing wind speed data of China

  QI Hao, MA Gengxue, ZHANG Xiuzhi

  2023, 45(5): 17-22. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.003

  Abstract ( ) PDF ( )

  In this study, we selected the satellite wind speed data CCMP as the main data to compare these data with the reanalyzing wind speed data ERA and ICOADS to verify the rationality of the offshore satellite remote sensing data of China, and provide a data support for drawing the offshore wind speed climate zoning map of China. We found that the CCMP is generally less than ERA by about 1.0 m/s. In comparison with ICOADS, it was 10~20% smaller. In Taiwan Strait region, the difference is over 40%. The CCMP satellite remote sensing wind speed data are closer to the ocean surface observation data ICOADS, and these data aid to overcome the lack of data of the non-ship routes of ICOADS. Unfortunately, unreasonable spatial distribution was also found in Bohai Sea, Taiwan Strait among others.
• Temporal-spatial pattern of precipitation in Shandong Province in recent 60 years and its response to different circulation factors

  ZHUANG Guangyuan, SHI Bing, WANG Junjie

  2023, 45(5): 23-31. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.004

  Abstract ( ) PDF ( )

  To reveal the temporal and spatial pattern of precipitation in Shandong Province and its response to different circulation factors according to the daily precipitation data documented from 1959 to 2017 at 61 weather stations in Shandong Province, the trend, spatiotemporal evolution and multi-scale characteristics of precipitation were studied with the methods including Mann-Kendall trend analysis, CEEMDAN, EOF and cross wavelet transform, and the resonance period and coherence between precipitation and different atmospheric circulation factors in different time frequency domain were investigated. (1) In the past 60 years, the monthly precipitation in Shandong Province had significant seasonal, interannual and interdecadal scale characteristics, of which the inter-annual scale oscillation cycle was the main. The cumulative variance contribution rate reached 48.2%; and the overall precipitation showed a decreasing trend. (2) The cumulative variance contribution rate of the first three modes was 68.1%. The first mode showed the consistency of the precipitation changing trend in the whole province, and the second and third modes showed the west-east and north-south “+, -” reverse distribution. (3) The atmospheric circulation factors MEI and PDO were closely related to the precipitation, and strongly influenced the interannual cycle scale of precipitation.
• Long-term remote sensing observation and analysis of upwelling around Zhoushan Islands in summer

  ZHOU Nan, WEI Yongliang, XIA Wusong, TANG Zeyan, YUAN Xinzhe

  2023, 45(5): 32-37. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.005

  Abstract ( ) PDF ( )

  The upwelling exists in Zhoushan year round in summer, and its intensity and range change interannually. In this study, sea surface temperature and chlorophyll a concentration from July to August during a period from 2002 to 2011 were used to study the physical characteristics and interannual changes of the Zhoushan upwelling region in summer. In addition, the upwelling boundary was defined using the difference of SST between the upwelling area and the outer waters and the corresponding distribution range of chlorophyll a concentration. The results showed that the summer sea surface temperature of Zhoushan sea area was significantly lower than that of the outer waters, ranging from 29°N to 31°N and from 122°E to 123°E, and the average temperature difference in the center was 1.5 ℃. The average chlorophyll a concentration in July reached 6.6 mg/m³, and the chlorophyll a concentration difference between the upwelling area and the non-upwelling area was large, indicating that the upwelling was in a strong period. The average chlorophyll a concentration in August reached 6.4 mg/m³, but the difference between the years was large, with obvious interannual variation characteristics. Combining the chlorophyll a concentration distribution characteristics and the sea surface temperature difference data, it can be defined that the Zhoushan upwelling boundary temperature threshold in July is 0.75 ℃, and the threshold in August is 0.5 ℃.
• A study on the coastal sea level variation of Tianjin in last 40 years

  ZHANG Qi, CHEN Yanzhen, NIU Fuxin, LI Xibin, WANG Luning, JIN Yudan

  2023, 45(5): 38-43. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.006

  Abstract ( ) PDF ( )

  In this study, the sea level variation along the coast of Tianjin was investigated using the documented tide observations at Tanggu Station and the Sea Level Anomaly (SLA) data from the Archiving Validation and Interpretation of Satellite Oceanographic. The results showed that the average tide level, the highest and the lowest tide level all presented rising trends in last 40 years. The lowest tide level changed most obviously, reaching 1.35cm/a. The average tide range and the highest tide range all presented decreasing trends. The power spectrum analysis showed that the tides along the coast of Tianjin changed periodically each 10 years. At the same time, the analysis by combining with the satellite altimeter data showed that the sea level height along the coast of Tianjin continued to rise.
• Isolation, identification and pathogenicity analysis of pathogenic bacterium P5W in Sebastes schlegelii

  CHEN Yuzhen, WANG Tengteng, HAN Huizong, CUI Guangxin, WANG Fei, ZHANG Mingliang, JIANG Haibin

  2023, 45(5): 44-52. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.007

  Abstract ( ) PDF ( )

  Sebastes schlegelii is the main fish for proliferation and release and deep-water cage aquaculture in the coastal areas of northern China. In recent years, with the expansion of the scale of S. schlegelii farming and the limitations of disease prevention and control techniques, aquaculture diseases occur frequently. To find out the cause of the disease and death of S. schlegelii during culture, a dominant strain P5W was isolated from the focus of diseased S. schlegelii in Yantai aquaculture area. Through morphological characteristics observation, mitochondrial 16S rDNA sequence comparison and phylogenetic evolutionary identification, the strain P5W was identified as Vibrio harveyi. The artificial infection experiment, histopathological observation, extracellular product enzymatic and hemolytic activity analysis, physiological biochemical and susceptibility testing were further carried out. Healthy S. schlegelii was then challenged with the strain P5W through intraperitoneal injection. The results confirmed that P5W was the pathogenic bacterium of S. schlegelii, causing ulceration and congestion on the surface of challenged S. schlegelii. The median lethal dose of P5W was 5.7×10⁶ CFU/mL. Histopathological analysis revealed that the liver, spleen, kidney and muscle showed different degrees of lesions and necrosis. For example, hepatocytes were obviously vacuolized, blood cells diffused in spleen, kidney tubule partial epithelial were shed and necrotic and muscle fiber fractured. The extracellular products of the bacterium had the activities of protease, lipase, lecithin, amylase, urease and gelatinase, and the hemolytic activity of sheep erythrocytes. P5W could survive at temperatures ranging from 15 to 35℃, acidities varying between pH 5 and 10, NaCl content (w/v%) ranging from 1 to 8. The best condition for P5W was 25℃, pH 7, and NaCl content varying between 2 and 4. The susceptibility testing showed that P5W was particularly sensitive to 13 drugs including cefotaxime, ceftriaxone, levofloxacin, tetracycline and cotrimoxazole. The research results provided a theoretical and practical guidance for the prevention and control of vibriosis during the culture of S. schlegelii. As a strong pathogenic strain of V. harveyi, P5W can be used to selecting and breeding anti-disease seedlings and developing a V. harveyi vaccine for S. schlegelii.
• Three dimensional numerical simulation analysis of seepage and stability of sea retaining dam of the Muguandao bay reservoir

  CAO Tonggang, ZHU Chenghao, LIU Hongjun, WANG Zhipeng

  2023, 45(5): 53-60. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.008

  Abstract ( ) PDF ( )

  The construction of the bay reservoir at the estuary of river is an important measure to solve the shortage of water resources at home and abroad, which is of great significance to the full utilization of water resources. Based on Muguandao bay reservoir project, considering marine hydrological factors and geological conditions, this paper established a large-scale three-dimensional seepage and stability simulation finite element model by using the finite element analysis software ABAQUS. The simulation calculation of pore water pressure, seepage velocity and vertical settlement of the sea retaining dam under various tide level conditions were carried out, and the seepage and stability of Muguandao sea retaining dam were analyzed. The analysis showed that under the tide level with a return period of 20 years, the anti-seepage performance of the sea blocking dam was good, and it played a role in blocking seawater and fresh water. When the tide level occurred once every 50 or 100 years, the seepage velocity occurred in the impervious wall, which was the result of the excessive water pressure difference and the increase of seepage intensity. The uneven settlement of the sea retaining dam was well controlled, and the cracking of the dam body, especially the core wall, would not occur. The reinforcement measures of cut-off wall were put forward to provide reference basis for seepage prevention of dam foundation, stability design and safety guarantee of subsequent construction and use of sea retaining dam.
• Wind energy resource and availability assessment in the Philippines

  JIANG Dong, WANG Zhifeng, LI Qingjie

  2023, 45(5): 61-72. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.009

  Abstract ( ) PDF ( )

  Long-term wind characteristics and wind energy potential along the Philippines coast from 1987-2016 were investigated based on 30-year hindcast data. The data of Cross-Calibrated Multi-Platform (CCMP) (1987~2016) wind field was the background wind field to reconstruct the wind field in the Philippines for 30 years. By comparison, the observed wind field and the reconstructed wind field were in good agreement. Based on the reconstructed data, the spatio-temporal patterns of annual, seasonal, and monthly averaged wind speed and wind energy in the Philippines were analyzed. The results showed that the maximum values of the mean annual wind speed and wind energy were in the northwest part of the Philippines. Wind energy were abundant in January, February and December and scarce in June, July, August and September. Twelve representative points along the Philippine coast were selected to draw wind and wind energy roses. A directional analysis showed that the dominant wind speed and wind energy directions were in NNE, NE, and ENE. Through the analysis of gale frequency, it was found that the frequency of wind speed above grade 6 the northwest Philippines was the highest (about 30%). In addition, the utilization efficiency of wind energy converts in north and east of Philippines was higher.
• Numerical analysis of bearing characteristics of umbrella suction anchor foundation under combined loading

  LIU Can, LIU Hongjun, YU Peng, LENG Hao

  2023, 45(5): 73-82. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.010

  Abstract ( ) PDF ( )

  According to the loading characteristics of umbrella suction anchor foundation (USAF) used for offshore wind turbine under actual conditions, a numerical calculation model was built using numerical simulation method based on ABAQUS. The bearing characteristics of USAF in H-V, H-T, V-T loading spaces and H-V-T non-coplanar composite loading mode were analyzed, and the mathematical expressions of failure envelopes were deduced. The fixed displacement ratio loading method was used to combined loading and the bucket head displacement was taken as the failure criterion. The elliptic equation curves of stress normalized composite loading failure envelopes suggested can simulate the failure envelope forms of USAF with different aspect ratios in different load spaces precisely. With the increase of aspect ratios, the combined bearing capacity of USAF in H-T loading space increased while the changes in H-V and V-T loading spaces were not obvious. The 3D failure envelope of USAF in H-V-T loading space was drawn, and the stability of umbrella suction anchor foundation can be evaluated according to the relative position relationship between actual loading state and the computed 3D failure envelope.
• Study on fishery resources community structure of the Huanghua port

  LIU Dong, LV Zhenbo, LI Min, ZHANG Jingjing, GAO Yanjie, REN Zhonghua, WANG Yibin, SONG Mingyi

  2023, 45(5): 83-90. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.011

  Abstract ( ) PDF ( )

  In order to comprehensive understand the composition and structure of the fishery resources and to provide a scientific basis for their conservation in the coastal water of Huanghua port in Bohai bay, data collected in May and October 2014 using the bottom trawl in this area were analyzed. The index of relative importance (IRI), Margalef index (d), Shannon-Winner index (H'), Pielou index (J') and multivariate analysis were used to evaluate the species composition, distribution, dominance, and community structure of fishery resources in the coastal water of Huanghua port. The results showed that: 1) 48 species including 26 fish species, 18 crustacean species and 4 siphonopods species were collected in May and October; 2) The crustaceans such as Oratosquilla oratoria were dominant species in May, while it was Gobiidae in October; 3) The seasonal distribution of fishery resources was not uniform in May and October, the average density of fishery resources was 13.16 kg/h in May and 14.87 kg/h in October, respectively; 4) Biodiversity of fishery resources was higher in October while the community structure was more stable in May. The research results revealed the structural characteristics of fishery resources in Huanghua port, which could provide theoretical basis for the restoration and conservation of fishery resources and provide scientific support for the construction of port engineering.
• Research Report
• Environmental effects of continuous mining from phreatic aquifers in coastal plain areas: a group drilling pumping test in Gongkou peninsula, Zhangzhou city

  WU Chengcheng, GUO Xin, LIN Jiquan, GAO Zenwen, ZHENG Xilai

  2023, 45(5): 91-97. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.012

  Abstract ( ) PDF ( )

  Group drilling pumping test is one of the effective technical means to find out hydraulic connection of different aquifers, to evaluate quantity of groundwater resources and to simulate actual exploitation ability. This paper simulated the change law of groundwater level and water quality using sustained group drilling pumping test through choosing a typical vegetable cultivated zone in the coastal plain area of Gongkou peninsula, Zhangzhou city. The results showed that the pumping test area formed a water level negative values zone. Each pumping hole produced mutual interference during group drilling pumping test. Unit water inflow of each pumping hole had decrease with a variation range from 13.0% to 31.2%. The chloride concentration of four pumping holes, which was L5K2-E, L5K2-S, L5K2-W and L5K2-N, rised by 163.65, 93.94, 37.77 and 126.65 mg/L. Meanwhile, the mineralization degree of the four pumping holes rose by 266.30, 65.34, 76.44 and 313.70 mg/L. Along with the continuous pumping, the range of groundwater depression cone was expanding constantly. The peripheral groundwater transferred to pumping holes constantly. Therefore, this test produced significant environmental negative effect. The experimental results could provide some references for rational utilization of groundwater resources, local ecological environment protection and drinking water supply virtuous circle in rural area.
• Experimental studies on coconut fiber reinforcement effect on calcium sand and analysis of mechanism underlining such effect

  KOU Hailei, HUANG Jiaming, YUAN Jingquan, ZHANG Peng, HONG Bo, LIU Jiahui

  2023, 45(5): 98-103. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.013

  Abstract ( ) PDF ( )

  It is of great significance to increase the shear strength of the South China Sea calcareous sand through fiber reinforcement for the safety and stability of the South China Sea Island Reef coastal zone slope protection. In this study, the stress-strain relationship and the effect of coconut fiber content on the peak strength and deformation modulus of South China Sea calcareous sand with different contents (0.2%, 0.5%, 0.8%, 1.1%, 1.4% and 1.7%) of coconut fiber reinforced calcium were analyzed by laboratory triaxial test. The results showed that the shear strength and deformation modulus of reinforced calcareous sand increased first and then decreased with coconut content. When the fiber content was 1.4%, the peak strength and deformation modulus of reinforced calcareous sand were 293kpa and 2.85mpa, respectively, and the fiber content was the best. When the content of coconut fiber was 1.1%, the strain corresponding to the peak strength of reinforced calcareous sand was the largest, coconut fibers were more evenly distributed in the sand, and the ductility effect was the best. Our findings provided the experimental data and a theoretical basis for the application of the fiber reinforced calcareous sand in the South China Sea.
• Effects of nitrogen, phosphorus fertilizer and their combined application on the growth and amino acid content and composition of Pyropia yezoensis

  LI Mingchuan, CUI Xiangyu, LI Xinshu, HE Peimin, XU Juntian, FU Guanghui, CHEN Baiyao

  2023, 45(5): 104-110. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.014

  Abstract ( ) PDF ( )

  This paper investigated the effects of nitrogen and phosphorus fertilizer application in seawater on the growth, total protein amino acids and free amino acids (FAA) content and composition of Pyropia yezoensis. Four treatments were designed to culture P. yezoensis: natural seawater as a control, nitrogen application alone,phosphorus application alone and a combination of nitrogen and phosphorus. The results indicated that nitrogen application alone slightly promoted the growth of P. yezoensis, and significantly increases the total amino acid content and FAA content. Phosphorus application alone significantly promoted the growth of P. yezoensis, but decreased the total amino acid content. Additionally the FAA content was significantly lower compared to nitrogen application alone and a combination of nitrogen and phosphorus. The combined application of nitrogen and phosphorus showed the highest relative growth rate of P. yezoensis. It also significantly increased the total amino acid content and FAA content, leading to an increase in the number of flavoring amino acids. This improvement in quality enhanced the edibility of P. yezoensis. Therefore, the combined application of nitrogen and phosphorus fertilizer had a mutually beneficial effect on the growth and quality improvement of P. yezoensis.
• Studies on ocean environment influences of disinfection by-products of ship ballast water management system

  ZHANG Wenting, ZHANG Li, YANG Yi, SHAO Minghao, XIE Junpeng

  2023, 45(5): 111-118. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.015

  Abstract ( ) PDF ( )

  The disinfection by-products of drinking water treatment have been studied intensively; however, the studies on the safety hazards of disinfection by-products from the ballast water treatment are scarce. Such scenario has been receiving more and more attentions of the experts from different countries and International Maritime Organization (IMO). Disinfectants, organic matters in water and salinity as the main factors associate with the generation of disinfection by-products, and their influences on the generation of disinfection by-products have been studying actively. The 45 ballast water management systems approved by IMO use different active substances and different treating technologies, producing different amounts and different types of disinfection by-products. The total amount of disinfection by-products produced each systems varies greatly even these systems use the same techniques. It is true that the ballast water management system using active substances must pass the risk assessment of IMO completely. However, the risk assessment of some materials with the models available currently may not be acceptable at some ports. The complexity of the geography and water quality conditions of various ports, the lack of toxicological data, and the limitations of related testing technologies are all the limitations to execute the assessment standards. With the intensification of relative studies and the continuous attention from IMO, we believe that more stringent restrictions will be established in near future. The implementation of the Convention will foster rich orders of ballast water management system installations, and accordingly, the problems associating with the disinfection by-products from ballast water treatment will be further highlighted. Therefore, shipowners must pay attention to the technology when installing ballast water management systems. It is particularly critical to adapt greener and safer ballast water treatment technologies, and implement these technologies in ballast water treatment.
• Studie of the integrated navigation of underwater glider using Kalman filter method

  WEI Peng, LI Baoyu, ZHANG Runfeng, FENG Dengxue, ZHANG Lianhong, CHEN Yibo, LAN Shiquan

  2023, 45(5): 119-125. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.016

  Abstract ( ) PDF ( )

  The improvement of the positioning and navigating accuracies of an underwater glider is very important for its underwater task. The traditional positioning method of the underwater glider is based on the dead reckoning of GPS information, which has a low positioning accuracy and does not meet the navigation requirement of sailing along the given path. Therefore, an integrated navigation method based on Kalman filter was proposed in this study. Based on the traditional dead reckoning technology, this method used the Kalman filter to fuse INS data and depth gauge data to obtain the best Kalman estimation value of depth, thus replaced the direct measurement value of depth meter in traditional dead reckoning technology, and improved the accuracy of dead reckoning. Using this method, the simulation analysis and the pool experiment were carried out. The results verified the effectiveness of the method.
• Characteristics of community structure of phytoplankton in the Datong lake in summer and bioassessment of water quality in 2019

  LIANG Ting, XU Jing, QIN Kunming, WANG Nianyao, LI Chunhua, ZHENG Ye, LIU Xiaoshou

  2023, 45(5): 126-133. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.017

  Abstract ( ) PDF ( )

  In order to reveal the community structure of phytoplankton and water quality in the Datong lake, field sampling of phytoplankton was conducted in June 2019. The eutrophication status of lake water was assessed using the algae biological index and biodiversity index. Results showed that a total of 204 species belonging to 8 classes were identified in this study. The dominant species were Cryptomonas erosa, Cryptomonas ovate, Cryptomonas rostrate, Aphanocapsa delicatissima, Phorimidium tenus, Anabaena oscillarioides, Anabaena circinalis, Anabaena flos-aquae, Cyclotella meneghiniana, Synedra acus, Synedra ulna and Ulothrix tenerrima. The average abundance and biomass of phytoplankton in the Datong lake in summer of 2019 were 1.02×10⁶ ind./L and 0.87mg/L, respectively. The values of Shannon-Wiener index, Pielou index, and Margalef index were 1.83 to 2.64, 0.45 to 0.59, and 4.09 to 6.79, respectively, indicating that the phytoplankton in the Datong lake was evenly distributed during the survey period, with high species number and high diversity. With strong ability of automatic adjustment, phytoplankton community structure in the Datong lake was stable overall. Comprehensive assessement of the Datong lake water quality based on algae biological index and community structure showed that the study area was a medium-eutrophic lake.
• Effects of multiple environmental factors such as nutrients and heavy metals on phytoplankton inLaizhou Bay

  QIN Huawei, TAO Huimin, ZHANG Juan, ZHANG Xiaowen, SONG Xin, GU Weili, WANG Kai, Gai Yunyun

  2023, 45(5): 134-141. https://doi.org/10.13984/j.cnki.cn37-1141.20231011.001

  Abstract ( ) PDF ( )

  Laizhou Bay (LB) is a typical bay of the Bohai Sea. The existence of coastal industrial zones produces a large number of nutrients, heavy metals and other substances flowing into LB along with the Huanghe River, Xiaoqinghe River and other rivers, which has impacts on the growth of phytoplankton. In this paper, a marine survey was carried out in LB in August 2020, and the distribution of environmental factors such as nutrients and heavy metals, and their effects on phytoplankton growth in LB were studied. The results showed that the runoff input from the Huanghe River and Xiaoqinghe River along the coast led to eutrophication in the estuary of the Huanghe River (E=1.25 at L1) and the southwest area of LB (E=16.96 and 1.14 at L5 and 20, respectively). About 95% of the stations in the whole investigated area had potential phosphorus limitation. The corresponding eutrophic area was the high value area of phytoplankton biomass, with a higher proportion of dinoflagellate species and red tide species (Skeletonema costatum, Noctiluca scintillans and Prorocentrum micans). Heavy metals (Pb and As) were at concentrations that could theoretically inhibit phytoplankton growth, but high nutrient loads may mask heavy metal toxicity, resulting in a positive correlation between phytoplankton biomass and heavy metals Pb and As.
• An observational study on the near shore dissolved oxygen concentration around the northeastern Shandong Peninsula in Sept., 2018

  FAN Siqi, ZHAI Fangguo, LIU Zizhou, GU Yanzhen, WU Wenfan

  2023, 45(5): 142-151. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.019

  Abstract ( ) PDF ( )

  Based on the data obtained from the marine survey on Sept. 28, 2018, in this study, we analyzed the spatial distribution characteristics of dissolved oxygen in the northeastern sea of Shandong Peninsula, and explored the possible effects of temperature, salinity, stratification, current and chlorophyll a on dissolved oxygen concentration in seawater. The spatial distribution of dissolved oxygen concentration in seawater was characterized by a decrease from the surface to the bottom, an increase first and then a decrease from the open sea to the nearshore in water more shallow than 25 m and decrease from the open sea to the nearshore in water deeper than 25 m in the horizontal direction. During the observation period, there were three obvious centers of high dissolved oxygen concentration, which were in the upper layer offshore, and the upper layer and the deep layer off the coast, and were affected by different factors. The first one is corresponding to higher chlorophyll concentration, and therefore may be affected by phytoplankton photosynthesis that produce oxygen, the second one could be related to Lubei coastal current which transports dilute water of low salt and high oxygen of the Yellow River, and the third one is in the cold water under the stratification and may be controlled by the yellow sea cold water mass. The low concentration of dissolved oxygen in water deeper than 25 m in the middle of the observed sea area may be caused by the combined effects of seawater stratification which inhibit the turbulent diffusion of dissolved oxygen and the consumption of oxygen in the bottom biochemical process.
• Ecological characteristics of macro- and meso-zooplankton in north coastal areas of Zhejiang Province in spring and summer, 2018, and their relationship with environmental factors

  BIAN Jiayin, WANG Pingbo, SHEN Dandi, LIU Tao, CHENG Fangping

  2023, 45(5): 152-162. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.020

  Abstract ( ) PDF ( )

  To document the ecological characteristics and main influencing factors of macro- and meso-zooplankton community in the north coastal areas of Zhejiang Province, the large and medium-sized zooplankton were investigated in spring (May) and summer (August), 2018 (collected by shallow water type I and type II plankton networks), and the relevant environmental factors were monitored. The results showed that the average zooplankton abundance in August is slightly higher than that in May, which is consistent with the seasonal variation trend of the average biomass. The zooplankton diversity index in the east of the investigated sea area in August was significantly higher than that in Hangzhou Bay. Overall, environmental factors had a certain impact on the ecological characteristics of zooplankton community. In August, when upwelling was strong, zooplankton abundance was positively correlated with dissolved oxygen (DO) although DO did not reach the hypoxia threshold. The Spearman correlation analysis showed that low DO had a certain impact on zooplankton community and reduced zooplankton abundance. However, DO had no significant effect on biomass and diversity index (H′). The pH was negatively correlated with zooplankton abundance and biomass in May, but positively in August.
• Research Review
• The approach and factors of the Kuroshio intrusion and its influence on the South China Sea

  GAO Shumin, HAN Shuzong, Ni Yuhuai, WU Kejian, LIU Zenghong, XU Jianping

  2023, 45(5): 163-172. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.021

  Abstract ( ) PDF ( )

  This article focused on reviewing the main research achievements of domestic and foreign scholars on the path, influence mechanism, seasonal and interannual variability of the Kuroshio intrusion into the South China Sea, as well as its impact on the South China Sea circulation, water mass properties and mesoscale eddies in the past two decades. The path of Kuroshio's intrusion from the Luzon Strait into the South China Sea could be divided into three forms, and the transportation in the Luzon Strait presented a “sandwich structure”. Kuroshio intrusion was influenced by monsoon, sea pressure gradient, mesoscale vortex, β effect, sea pressure gradient, ENSO, PDO, typhoon and other factors. Due to the influence of the Kuroshio's own intensity and the East Asian monsoon, the intensity of the Kuroshio's intrusion into the South China Sea was greater in winter than in summer. Interannual variability depended on El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). ENSO and PDO controlled the kuroshio's intrusion intensity by affecting the location of North Equatorial Current bifurcation. Kuroshio water, as part of Indonesian throughflow, brought high-temperature salty water to the South China Sea, or shed anti-cyclonic eddies to affect the South China Sea mesoscale eddy structure.
• Challenges and prospects formanagement of marine genetic resources in areas beyond national jurisdiction

  ZOU Leilei, HAO Zhijian

  2023, 45(5): 173-181. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.022

  Abstract ( ) PDF ( )

  The issue of marine genetic resources (MGR), one of the important topics of negotiations on marine biodiversity beyond areas of national jurisdiction (ABNJ), encounters varieties of challenges like unclear management scope, unrecognized management subject, undefined legal status, and unresolved access and benefit-sharing patterns arising from utilization of MGR. Inspired by the management of fisheries resources and mineral resources in ABNJ, the paper presented some suggestions for the management of MGR in ABNJ. The scope of management should be clarified to coordinate with the existing management framework. The cooperation should be encouraged between countries. A global agency should be established or empowered to be responsible for coordinating the management. MGR should be identified as the "common heritage of mankind". The precautionary approach should be applied to the management of MGR. Mandatory provisions for non-party should be incorporated in the agreement. Different types of benefit-sharing patterns should be defined in accordance with the different procedures in the utilization of MGR.
• Study on fishery development in recent ten years ——a visual analysis based on CiteSpace

  WANG Xiaojun, HU Xiao

  2023, 45(5): 182-191. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.023

  Abstract ( ) PDF ( )

  In order to promote the sustainable development of fisheries, on the basis of systematical combing the research results of Chinese scholars on fishery development in the past ten years, the themes, hot spots, trends and other related issues were clarified. Using "fishery development" as the key word, the documents from 2010 to 2020 were collected taking the China National Knowledge Resources Database (CNKI) as data samples. The CiteSpace software was used for author, institution cooperation, and keyword co-occurrence analysis. The results showed that: (1) Four main author research teams were formed; (2) Nine medium and high-yield institutions were formed; (3) Research themes focused on fisheries, recreational fisheries, marine fisheries, countermeasures, modern fisheries, aquatic products, fishery resources, aquaculture, fishery production, etc. In view of the shortcomings in the existing achievements in the adjustment of fishery structure and the construction of new fishing villages, suggestions were put forward to vigorously develop offshore fisheries, to learn from Japan's "6th industrialization" experience, and to build shared fishing villages.
• Hot topics and evolutionary logic of global coastal zone disaster management research since 1972

  WANG Jiangbo, XU Mingming, GOU Aiping

  2023, 45(5): 192-199. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.024

  Abstract ( ) PDF ( )

  Global coastal zone disaster management research is of great significance to ensure the safety and sustainable development of coastal areas. It is important to clarify the hot spot directions in the process of coastal zone disaster management, to grasp the historical development logic of coastal zone disaster management research, and to explore the driving factors of disaster management, in order to meet a realistic need for coastal zone governance. Coastal zone disaster management research has gone through three development stages: foundation stage, practical exploration stage and rapid development stage. The change of research hot spots showed a law of cognition-practice-recognition. It is concluded that coastal disaster management was developed and evolved under the three factors of laws and policies, natural disaster events and economic society. This conclusion provides reference for coastal disaster management in coastal provinces and cities across the country.
• Study on integrated marine management in the Gulf of Mexico based on ecosystem

  CHU Xiaolin, YU Liang

  2023, 45(5): 200-207. https://doi.org/10.13984/j.cnki.cn37-1141.2023.05.025

  Abstract ( ) PDF ( )

  Integrated marine management based on ecosystem is an important concept of global large-scale marine ecosystem management at present. The Gulf of Mexico is one of the large marine ecosystems in the United States of America (USA), and it is also one of the typical cases of integrated marine ecosystem based on marine management in USA. The integrated management of the Gulf of Mexico based on ecosystem was facing double pressure at home and abroad. Domestic: ecological restoration policies and regulations were not perfect, and the federal government and local government were constrained by each other; abroad: due to the great difference in ideology and economic level between USA, Mexico and Cuba, it was difficult to coordinate the cooperation of the three countries to manage the marine ecosystem of the Gulf of Mexico. Despite the dual pressures at home and abroad, the integrated marine management of the Gulf of Mexico based on the ecosystem had also made some achievements, such as the formulation of relevant policies and regulations, the establishment of ecological assessment system, the implementation of marine spatial planning. In the future, USA should continue to promote special legislation on marine ecosystem restoration, improve sectoral coordination mechanism, and strengthen cooperation among the three Gulf countries, so as to promote theoretical improvement and practical development of integrated marine management based on ecosystems.