10 December 2024, Volume 46 Issue 6

    

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• Research Papers
• Study on wave design parameters in sea ice melting zone of the eastern Barents Sea

  LIAO Zhenkun, ZHANG Zefei, DONG Sheng

  2024, 46(6): 1-8. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.001

  Abstract ( ) PDF ( )

  The eastern part of the Barents Sea is rich in oil and gas but covered by sea ice. With climate change, the sea ice continues to melt, making the eastern region maintain open water for longer, and wave characteristics will also change accordingly. It is necessary to carry out corresponding research for the design, construction and operation of marine engineering structures serving in this sea area. In this paper, the sea ice concentration data from the National Snow and Ice Data Center (NSIDC) were collected to drew the sea ice edge lines and analyzed the changes of sea ice extent. According to ice edge lines, one representative point was selected in the eastern sea ice melting zone. The wave data from the ERA5 dataset of the European Center for Medium-Range Weather Forecasts (ECMWF) were collected to study the basic wave characteristics and wave design parameters. The annual and seasonal extreme values of wave height were extract to estimate the return values of significant wave height by the GEV, Gumbel, Weibull and Maximum entropy distribution models, respectively. The results showed that with the reduction of sea ice, the frequency without wave at representative point had decreased significantly, and wave existence was throughout the year in recent years. According to the results of the return values, summer was the most suitable operating season.
• Experimental analysis of the double-plate type and twin-arc plate permeable breakwater in force characteristics

  PENG Jing, XIU Chunyi, LI Xueyan, WANG Qing, DUAN Chen

  2024, 46(6): 9-16. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.002

  Abstract ( ) PDF ( )

  To explore the similarities and differences of different permeable plate breakwaters in terms of structural forces, this paper investigated a physical model tests of twin-flat-plate (TFP) and twin-arc-plate (TAP) permeable breakwaters in a wave flume. Under different diving depth conditions, the results indicated that the wave pressure distribution characteristics of the upper and lower plate of the TAP breakwater were markedly different. Except for the upper surface of the upper plate, the positive wave pressure on the TAP breakwater was less than the TFP breakwater for the 77.8% cases. Under the different submergence condition, the negative wave pressures on the upper surface of the upper plate of the TAP breakwater was greater than the TFP breakwater. The lower surface of the lower plate in the emerged state (h/d=-0.05) and at the still water level (h/d=0), except for the upper surface of the upper plate in the submerged state (h/d=0.05), the negative pressure on the twin-arc-plate breakwater was less than those on the TFP breakwater. The positive and negative vertical wave forces on the twin-arc-plate breakwater were less than those of the TFP breakwater, and the differs notably between the negative vertical wave forces. The results of this study could be used as a reference for the application of plate permeable breakwaters in engineering.
• Design and stability analysis of Ruban lock-type artificial reef

  JI Zhipeng, DONG Kun, JIANG Jitong, DU Derun

  2024, 46(6): 17-23. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.003

  Abstract ( ) PDF ( )

  A prefabricated artificial reef connected with Ruban lock was designed in view of the large size and low transportation efficiency of the cast-in-place concrete artificial reef. The small size rod could be assembled into large empty space bodies by mortise and tenon, which could effectively save transportation and delivery costs. The stability calculation was made according to the sea conditions of an artificial reef area near Rizhao, Shandong province. The results showed that under the joint action of waves and flow, the maximum force was 7.252 kN and the maximum moment of action was 8.702 kN·m. The anti-slip safety coefficient of the reef was 3.4 and the anti-overturning safety coefficient of the reef was 4.5, which met the reef stability conditions, and the reef would not slip and overturn in this area. This study provided an important reference value for designing prefabricated artificial reefs suitable for the environmental characteristics of China's offshore waters.
• The impact of typhoon Lekima on the marine dynamic environment in Dongjiakou harbor

  LI Songlin, QI Xin, NIU Fuxin, TAO Yijun, JIANG Wanjun, YU Huaming

  2024, 46(6): 24-31. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.004

  Abstract ( ) PDF ( )

  The finger piers of Dongjiakou protrude out of the open ocean and are vulnerable to extreme sea state without the protection of breakwater. In this study, the abnormal changes and mechanism of hydrodynamic environment caused by typhoon Lekima captured by ADCP and bathythermograph at the front of Dongjiakou finger pier were analyzed, which could provide important reference for the prediction of berthing environment. It was found that the residual water level showed a "V" symmetric distribution with the maximum water reduction as the symmetry center, and its variation was dominated by wind. When the typhoon was close to Dongjiakou, the lag response time for storm surge was short. When the typhoon center was far away, it was the opposite. The observed residual current was generally less than 20 cm/s during typhoon Lekima, the coastal current had little threat to the port. The forehead swell reached the pier 12 h ahead of the extreme wind speed, and the wave spectrum peak period of forehead swell was in the rolling resonance region of 300 000 ton crude oil carrier and 400 000 ton ore carrier berthed at the jetty which needed to be prevented in advance. Due to the mixing effect of typhoon waves, the bottom water temperature of the observation point rose about 1℃, and the thermocline was destroyed. Even after the typhoon, the bottom water temperature dropped slowly, with a cooling trend of 0.15 ℃/day.
• Evaluating the impacts of El Niño intensity on interannual variation in spatio-temporal distribution of potential habitat for jumbo flying squid Dosidicus gigas in Southeast Pacific Ocean

  YANG Ruiqi, CHEN Bingjian, YU Wei

  2024, 46(6): 32-40. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.005

  Abstract ( ) PDF ( )

  The jumbo flying squid (Dosidicus gigas) is one of the largest cephalopods with high economical values, which is an important fishing target by Chinese squid-jigging fisheries. According to the sea surface temperature (SST) and sea surface height anomaly (SSHA) data obtained from 8°-20°S,95°-75°W off Peru from Sept, to Dec. during a period from 2006 to 2015, the weighted habitat suitability index model (HSI) was developed, and the optimal HSI model was selected and validated. Furthermore, the optimal HSI model was used to predict the habitat suitability for D. gigas, the differences of spatial and temporal distribution in potential habitat of D. gigas in the years with El Niño events at different intensity were further examined. The fisheries data from Sept. to Dec., 2015, were used to validate the optimal model, and the model outputs exhibited a good prediction performance. The environmental conditions combined with spatial and temporal variations of potential habitats of D. gigas were compared between year 2006 with weak El Niño event and year 2015 with very strong El Niño event. The results showed that relative to year 2015 with strong El Niño event, year 2006 with weak El Niño event experienced colder SST, lower SSH, and wider range of suitable SST and SSH. The environments in 2006 were favorable for squid survival, leading to a significant increase in suitable habitat in 2006. Our findings suggested that the impacts of El Niño events at different intensity on habitat suitability of D. gigas are dramatically different. The studies on evaluating climate variability on squid species in the future should consider the characteristics each anomalous climatic event.
• Analysis of tidal current characteristics and seasonal variation inHaitan strait

  WANG Jianfeng, ZHAO Jianli, QIUJufei, SHA Wei, JIANG Yunyun

  2024, 46(6): 41-46. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.006

  Abstract ( ) PDF ( )

  Based on the monthly tide level data and the hydrological synchronous survey data in spring and neap tides in Haitan strait in spring, summer, autumn and winter, characteristics of the tide and tidal current in sea area near Haitan strait were analyzed, and the influencing factors of residual current variation characteristics in Haitan strait were discussed. The results showed that the tide in the sea area near Haitan strait belonged to the regular semi-diurnal tide, and the ebb tide duration was generally slightly longer than the flood tide duration. The tidal current belonged to the regular semi-diurnal tidal current, the shallow water sub tidal current was relatively significant, and the main direction of the ebb and flow tidal current was obvious, which was a reciprocating current. The tidal waves in Haitan strait were standing waves. The seasonal variation of residual current was significantly affected by the coastal current of Fujian and Zhejiang in the East China Sea and monsoon, the residual current was generally southward in winter and northward in summer.
• Studies on early developmental pattern of Oplegnathus punctatus digestive system

  CHEN Xiao, LI Jun, JI Guanglei, WANG Yufu, MA Yuting, XIAO Zhizhong, LIU Xiangquan, LIAN Chang, LIAN Yaming, YANG Lizhong

  2024, 46(6): 47-54. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.007

  Abstract ( ) PDF ( )

  To systematically reveal the change of organs of Oplegnathus punctatus at its early stage of digestive system development, continuous histological sections of O. punctatus aged from 1 to 49 days were analyzed. The results showed that the digestive tract of 1-day-old O. punctatus was located inside the yolk sac and was only a simple tubular structure. The development of the digestive system of O. punctatus can be roughly divided into three stages. At 1~3 days of age, the digestive system was still in the primitive stage. At this age, the mouth fissure was closed, and only the yolk sac was used as the nutrient source, thus presented a complete endogenous nutrition. At 4~20 days of age, the digestive system was preliminarily developed, and it was in the transition stage with basic feeding, digestion and absorption capacity. At this stage, the mouth fissure opened, the yolk sac gradually disappeared, and the hepatopancreas developed rapidly. The fish gradually developed the ability to digest food. The transition to exogenous nutrition began. Tt 21 to 35 days of age, the digestive system developed further and the gastric glands appeared, forming a complete digestive system. After that, the tissues and organs of the digestive system only increased in cell scale rather than structural changes.
• Studies on infectious hypodermal and hematopoietic necrosis virus (IHHNV) infection in different organs of adult Penaeus vannamei

  YANG Ning, WANG Jingjing, XU Jiahui, YU Jiyue, LI Ting, YAN Dongchun, CHANG Linrui

  2024, 46(6): 55-60. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.008

  Abstract ( ) PDF ( )

  Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is one of the main viruses affecting shrimp culture. It is generally believed that IHHNV mainly infects organs originating from ectoderm and mesoderm, and does not infect endoderm organs, such as hepatopancreas. In this study, Penaeus vannamei was artificially infected by feeding challenge, and PCR method was used to analyze the infection of IHHNV to different organs such as gill, hepatopancreas, pleopods and muscle. The results showed that the hepatopancreas of P. vannamei was more susceptible to IHHNV, and the positive infection rate was 86.7%. The virus load of IHHNV was 9.8copies/μL DNA. The infection rate of gill was 46.7%. The viral load of gill IHHNV was 3.0copies/μL DNA. Muscles and pleopods had a similar sensitivity to IHHNV, and the infection rate was 13.3%. The viral load of them was 0.8copies/μL and 0.3copies/μL DNA, respectively. Our findings showed that the hepatopancreas can also be infected with IHHNV, and the degree of IHHNV infection was higher compared with other organs. These results provided a new perspective for the study of the mechanism of IHHNV infection. Due to only the small amount of tissue samples were taken, the histopathological examination of the different organs each shrimp was not carried out. Therefore, the study of IHHNV on the different organs of P. vannamei, especially the organs from the endoderm, appreciates further researches in combination with histopathology and other molecular biological tools.
• Numerical simulation of seawater intrusion caused by groundwater extraction inlayered heterogeneous aquifers

  ZHANG Zhuangzhuang, WU Yajie, WU Xiaoqiang

  2024, 46(6): 61-69. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.009

  Abstract ( ) PDF ( )

  In coastal areas with layered heterogeneous aquifers, over-exploitation of the groundwater resource has led to serious seawater intrusion. Based on previous physical model tests in coastal areas with layered heterogeneous aquifers, a two-dimensional numerical model of saltwater rising caused by pumping wells was established by applying the scientific modelling package OpenGeoSys to investigate the behavior of seawater intrusion. With the verified model, the heterogeneity of layered heterogeneous aquifer, the thickness of lower permeability aquifer and the influence of pumping well location on critical pumping rate and seawater intrusion were analyzed. The numerical results indicated that the critical pumping rate of the pumping well in heterogeneous aquifers was lower than that in homogeneous aquifers, and the difference of the critical pumping rate between the two types of aquifers was larger for deep wells and wells near the seawater boundary. In layered heterogeneous aquifer, the influence of seawater intrusion was greater when the thickness of low permeability aquifer was thicker. With the increase of pumping rate of pumping wells, the influence of seawater intrusion was more obvious. The horizontal distance between the pumping well and the seawater boundary was closer, the pumping well depth was deeper and the critical pumping rate was lower. Furthermore, the critical pumping rate of the pumping well was more sensitive to the change of the well depth. This research provided scientific theoretical basis for rational exploitation and planning of groundwater resources in coastal areas with layered heterogeneous aquifers.
• Spatial-temporal evolution and prediction of coastal landscape pattern and habitat quality based on MCE-CA -Markov and InVEST model

  ZHANG Bin, HAN Zhen

  2024, 46(6): 70-79. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.010

  Abstract ( ) PDF ( )

  Under the background of rapid urbanization, this paper analyzed the temporal and spatial distribution changes of landscape pattern and habitat quality in Nanhui Dongtan coastal zone of Shanghai, so as to provide a theoretical basis for ecological environment protection and policy planning in the coastal zone. Based on the land use data of Nanhui Dongtan coastal zone interpreted by remote sensing in the years of 2013, 2015, 2017 and 2019, the landscape pattern of Nanhui Dongtan coastal zone in 2021 and 2023 was predicted by MCE-CA-Markov model combined with the actual environment, and the spatio-temporal evolution characteristics of habitat quality in the study area from 2013 to 2023 were analyzed by InVEST model. From 2013 to 2019, the main landscape types in the study area were construction land and tidal flat. The area of sea water, forest land and cultivated land decreased year by year. The part of cultivated land decreased was mainly transformed into construction land, and the area of sea water decreased was mainly transformed into tidal flat. The index of habitat quality in the study area decreased year by year, and the overall habitat quality decreased, and a large number of high habitat areas in the east changed to medium habitat. From 2019 to 2023, the landscape pattern and habitat quality of Nanhui Dongtan coastal zone continued to maintain the change trend from 2013 to 2019, mainly reflected in the increase of construction land area and the decline of habitat quality. The main reason for the decline of habitat quality and the change of landscape pattern in the study area was the economic activities of human society, in which the development of urbanization was an important factor in the landscape ecological change of Nanhui Dongtan coastal zone.
• Description of health status of coral reef ecosystem of Wenchang, Hainan and analysis of its influencing factors

  LANG Shangkun, PANG Qiaozhu, LUO Lizhen, XU Buxin, ZHANG Jan, LI Yuanchao

  2024, 46(6): 80-88. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.011

  Abstract ( ) PDF ( )

  Based on coral reef survey in Wenchang waters with line transect method and historical data collected in 2012 and 2018, and using the semi-quantitative coral reef health index (hereafter as CI), the health status of coral reef ecosystem in Wenchang waters, the change trend and its main influencing factors were analyzed. A total of 79 species of hermatypic corals belonging to 11 families and 31 genera were identified, of them the dominants were the environmentally-tolerant massive ones, i.e., Porites lutea, Favia speciosa, Favites abdita, and Platygyra daedalea. However, Acroporidae, the environmental stress sensitive, were less observed, which had a low coverage. Despite the excellent water quality conditions of Wenchang waters, macroalgae were abundant with mean coverage up to 16%. The community structure of hermatypic corals have obviously changed. The CI value estimated ranged from -0.44 to 0.95, suggesting that the whole coral reef ecosystem was poor in Wenchang waters. Coastal engineering construction and aquaculture sewage discharge were perhaps the two driving factors leading to coral reef degradation in the region. However, compared with 2018, the health status of coral reefs in the region recovered significantly as were revealed by increased CI values from -0.59 in 2018 to -0.06 in 2020. Moreover, in this survey, the mean coverage of hermatypic corals was 12.73% and coral recruitment was 0.9 ind./m², displaying a slight increase compared with historical data. More importantly, little short-term dead corals and coral diseases were found in this survey. These signals indicated that the coral reef ecosystem in this area has a good potential for recovery. It was suggested that the ecological control should be strengthened, and coral reef restoration should be carried out to accelerate its natural recovery.
• Analysis of spatiotemporal variations of the turbidity maximum zone in the Jiaojiang estuary

  YAO Yanming, CHEN Xueqian, YUAN Jinxiong , LI Li

  2024, 46(6): 89-98. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.012

  Abstract ( ) PDF ( )

  In this paper, the characteristics of the turbidity maximum zone (TMZ) in the Jiaojiang estuary before and after channel dredging and the influence of the TMZ on channel siltation were studied. Firstly, the hydrodynamic and sediment of the Jiaojiang estuary was numerically simulated, and the model could simulate the complex terrain and hydrodynamic sediment conditions well. Secondly, the mechanism of suspended sediment transport in the Jiaojiang estuary, the movement process of the TMZ and the changes after dredging were analyzed. The calculation of net sediment fluxes showed that the tidal pumping dominated the suspended sediment transport near the outer channel of the Jiaojiang estuary. The net sediment fluxes near sea side of channel were mainly in the sea direction, while that in the near land side were in the land direction. The TMZ moved back and forth with spring-neap tide and flood-ebb tide near the outer channel. The suspended sediment concentration (SSC) in the TMZ was the highest at the flood peak in a tidal cycle. After channel dredging, the position of the TMZ and SSC changed little, and there was always a high siltation area in upstream of the dredged channel.
• Studies on ecological water level of Dongping Lake

  LIU Xinyang, LIU He, SU Qiang, JI Jianhong, YU Xiaolong, XU Hongzeng, CHEN Hao, LU Min

  2024, 46(6): 99-107. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.013

  Abstract ( ) PDF ( )

  The Mann-Kendall method, moving t-test technique, and wavelet analysis were used to determine the water level mutation point of Dongping Lake, analyze the trend of the annual average water level change, and characterize the daily water level change based on the daily water level sequence of Dongping Lake from 1960 to 2020. The impact of water level change on the spatial evolution of Dongping Lake wetland was discussed. The ecological water level of Dongping Lake was studied using the annual spreading method and the variability range method (RVA) in combination. The results showed that (1) the abrupt change of water level occurred in 1989, and the rise of the water level has caused a significant evolution in the wetland space at the entrance and exit of Dongping Lake; (2) the monthly ecological water levels calculated with the annual spreading methods 1 and 2 before the water level mutation varied between 38.11 and 39.46 m and between 36.94 and 38.24 m, respectively,the monthly protection degree of the ecological water level before the mutation was relatively high, and the water level remained high for a long time after the water level mutation; (3) the ecological water level of Dongping Lake was calculated based on the water level sequence after the abrupt change, the monthly ecological water level calculated by the annual spreading methods 1 and 2 within the year ranged from 39.83 to 40.55 m and from 37.59 to 38.27 m, and the duration of high and low water levels varies greatly in different years; (4) the ecological water level of Dongping Lake calculated with annual spreading method 1 during the year ensured that the wetland will not degrade, at the same time, by combining the underwater elevation of the wetland with the growth period of the reeds, the suitable water level of Dongping Lake can be determined; (5) by setting the dynamic water level of the Dongping Lake flood limit, the Dawen River flood can be resourced and the health of Dongping Lake ecosystem can be guaranteed.
• Research Report
• Distribution and assessment of heavy metals in the sea area of the proposed marineranching in Wailingding island in Zhuhai

  XIE Xiaoyan, CHEN Pimao, TONG Fei, YUAN Huarong, FENG Xue, YU Jing, SHU Liming, LIU Yan

  2024, 46(6): 108-116. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.014

  Abstract ( ) PDF ( )

  According to the investigation data of heavy metals in seawater and surface sediments of the proposed marine ranching of Wailingding island, Zhuhai in spring and autumn of 2020, single-factor evaluation method, comprehensive pollution index method and potential ecological risk index method were used to evaluate the quality level of heavy metals. The results showed that the Cu content of very few stations exceeded the class II seawater quality standard, the comprehensive evaluation index of heavy metals in surface seawater of each station was less than 1, the comprehensive evaluation degree of heavy metals in seawater at S16 station was slightly polluted, and the rest stations were clean. There was obvious homology between Hg and As in surface seawater, and obvious heterogeneity among Pb, Hg and As. The content of heavy metals in surface sediments all met the quality standards of class I marine sediments, and heavy metals in sediments had only slight potential ecological risks to marine ecosystems. There were slight potential ecological risks of heavy metals in surface sediments, and the construction of artificial reefs could form an upwelling and proliferating artificial reef system, which was conducive to eliminating the potential ecological impacts brought by heavy metals in surface sediments.
• Preliminary analysis on monitoring data of seawater intrusion and soil salinization in three coastal cities in Jiangsu

  HONG Chenfei, LI Yu, XIE Yixuan, FENG Sulan, LI Xiangyang, ZHU Wenjing, WANG Xue

  2024, 46(6): 117-122. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.015

  Abstract ( ) PDF ( )

  Seawater intrusion is a common disaster in coastal areas. It is usually associated with other natural disasters, such as deterioration of water quality and soil salinization, which affect normal industrial production, agricultural activities and human life. This study was conducted in three coastal cities in Jiangsu (Ganyu district of Lianyungang, Dafeng district of Yancheng, and Qidong city of Nantong) in November 2019 to determine the monitoring sections for sampling, to analyze the basic monitoring indicators of seawater intrusion and soil salinization, and to get a preliminary grasp. The current situation of seawater intrusion and soil salinization disasters in three coastal cities in Jiangsu were reviewed. The results showed that seawater intrusion and soil salinization disasters had occurred in three coastal cities in Jiangsu: severe seawater intrusion and heavy saline soil had occurred in Ganyu and Qidong parts of the survey area. The chloride ion concentration in Ganyu groundwater was as high as 2260.90 mg/L. The chloride ion concentration in the Qidong area was as high as 1472.30 mg/L. The soil salinization in Qidong and Ganyu was relatively large, and the degree of seawater intrusion and soil salinization in Dafeng was relatively light. Based on the current situation of seawater intrusion and soil salinization intrusion, and the analyzing the causes of intrusion in some regions, it would be helpful for follow-up research.
• Prediction and influencing factor analysis of harmful algal bloom species with random forest classification

  LUAN Qingshan, SUN Jianqiang

  2024, 46(6): 123-130. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.016

  Abstract ( ) PDF ( )

  Harmful algal blooms are frequently caused in the context of global change by phytoplankton, which lead to a series of problems with respect to fisheries, aquacultures, human health and social economy. By utilizing the random forest classification method of machine learning, in this study, we developed two models of shellfish toxic and fish kill basing on the common harmful algal bloom species around the waters of Zhangzi Island in the northern Yellow Sea. The response variable of shellfish toxic model was designated by the cell abundances of Alexandrium tamarense, Dinophysis spp., Gonyaulax spp., Prorocentrum spp. and Pseudo-nitzschia spp. whilst that of the fish kill model was setup by the Karenia mikimotoi, Noctiluca scintillans and Dictyocha fibula. The feature variables for the two models were transparency, temperature, salinity, pH value and dissolved oxygen. The classification performance showed that the accuracy of the shellfish toxic and fish kill models were 87.9% and 89.7%, respectively, while the precision all reached up to over 80%. The analysis of the feature importance indicated that temperature and dissolved oxygen were the key predictive variables for shellfish toxic model with MeanDecreaseGini being 15.4% and 14.3%, respectively, while pH value and salinity were the key variables for fish kill model with that values of 21.6% and 15.5%, respectively. Our findings could provide case study and basic information on discriminating key predictive variables for the harmful algal bloom species and establishing the early monitoring and warning system in the waters of fisheries, aquaculture and crucial habitats.
• Geological relics and resource evaluation of river capture ——take the upper reaches of the Chaiwen river in Yiyuan, Shandong province as an example

  YU Guangke, CHU Zhongxin, ZHU Xiaojie, HAN Mingxing, JIANG Jinfei, ZHU Longhai

  2024, 46(6): 131-138. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.017

  Abstract ( ) PDF ( )

  River capture is an important issue in Quaternary geology and geomorphology, which has been widely concerned by scholars at home and abroad. In the upper reaches of the Chaiwen River in Yiyuan, Shandong, a river capture event occurred in the late Pleistocene, and the typical and complete river capture geological remains are still preserved. On the basis of field investigation and high precision DEM data, this paper studies the types, characteristics and causes of typical river capture geological relics resources in this area, and makes a comprehensive quantitative evaluation of river capture geological relics resources by using analytic hierarchy process. The results show that there are 1 world-class, 4 national, 3 provincial and 2 local level geological relics in the upper reaches of The Chaiwen River in Yiyuan, Shandong province. The comprehensive quantitative evaluation of the geological relics resources captured by rivers in this area has reference value for correctly understanding the evolution of the geomorphology captured by rivers, protecting and developing the geological relics resources, and promoting the development of local tourism economy.
• Seasonal variation of tintinnid communities in Changjiang River estuary and DachenIsland sea area

  ZHU Linqing, FENG Meiping, ZHANG Shouyu, WANG Zhenhua, SONG Quanjian, XU Peng, CHENG Xiaopeng

  2024, 46(6): 139-147. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.018

  Abstract ( ) PDF ( )

  We investigated the variation of tintinnid communities in Changjiang River estuary in Jun., 2019 and Dec., 2020), and Dachen Island sea area in Nov., 2020 and Apr., 2021. A total of 83 samples were collected. (1) Eighteen tintinnid species belonging to 9 genera were observed, and the total abundance ranged from 0 to 618 ind./L. (2) Lorica oral diameter (LOD) of the 18 tintinnid species varied between 14.5 and 96.4 μm, and were grouped into 8 size classes. (3) Tintinnid abundance in Dachen Island sea area was significantly and positively correlated to temperature and chlorophyll a concentration (p<0.01) but significantly and negatively to salinity (p<0.01). (4) There were more redundant species and LOD size classes in Dachen Island sea area than in Changjiang River estuary. The existence of redundant species should increase the capability of a community to exploit changes in conditions, leading to the speculation of more stable tintinnid communities in Dachen Island sea area. Our findings provided basic data for further studies on the microbial ecology of Changjiang River estuary and its adjacent areas.
• Studies on quality evaluation system of Weihai coastal tourist beach based on AHP and Fishbein-Rosenberg Model

  WANG Liyang, JI Zezhou, LI Yongqing, LIU Zongyu, SHI Hongyuan, YOU Zaijin

  2024, 46(6): 148-155. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.019

  Abstract ( ) PDF ( )

  Weihai has rich beach resources which are very suitable for the development of coastal tourism. Beach quality evaluation is an important basis for the further development of coastal beaches. Based on analytic hierarchy process (AHP) and Fishbein-Rosenberg model, in this study, we established a quality evaluation system suitable for Weihai tourist beaches by collecting the data of 14 Weihai tourist beaches. The system consisted of three categories, beach tourism social factors, beach dynamic characteristics and safety, and beach natural resource conditions, included 22 evaluation factors, and was divided into five levels. The quality evaluation results of 14 beaches in Weihai showed that a good average score of social factors of beach tourism, 76.59, a excellent average score of beach dynamic characteristics and safety, 83.94, and an average score of beach natural resource conditions, 81.20, of 14 beaches, 9 excellent, 3 good and 2 qualified. The existing tourist beaches in Weihai have superior natural conditions and high safety. The existing problems are mainly social factors, such as low degree of supporting service facilities and less leisure and entertainment projects. According to the evaluation results, some suggestions on the development of tourist beaches in Weihai were put forward.
• Researches on constructing evaluation index system of recreational fishery competitiveness of China

  ZHAO Qilei, CHEN Xinjun, QI Siqiong, CHEN Guiying

  2024, 46(6): 156-164. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.020

  Abstract ( ) PDF ( )

  (Objectives) Recreational fisheries development is an important part of advancing the modern fishery construction, as well as an important measure to implement the strategy of rural revitalization and build a powerful marine economy. The evaluation of recreational fishery competitiveness is an important basis for guiding its development. (Methods) In this research, we draw on the relevant theories of economic competitiveness to analyze the concept of recreational fishery competitiveness using a combination of qualitative and quantitative analysis methods, and the process of building-optimizing-testing index system to construct an evaluation index system for the recreational fishery competitiveness of China. (Results) (1) The competitiveness of recreational fishery is a comprehensive reflection of the development strength and development potential of a regional recreational fishery, including the four core elements of economic growth, resource endowment, service industry development level, and consumer market; (2) Competing for fishery resources 11 indicators in four aspects, competitiveness, industrial competitiveness, service competitiveness, and leisure demand competitiveness, to construct a recreational fishery competitiveness evaluation index system; (3) According to correlation analysis, eliminate linearly related repeating indicators, and coefficient of variation analysis eliminates weak discriminative power. Qualitative analysis retains the characteristic indicators of the recreational fishery industry. This qualitative and quantitative method has good applicability in the evaluation of recreational fishery competitiveness. (Conclusion) In this study, we believe that the construction-optimization-testing process of recreational fishery competitiveness index system is reasonable. The optimized index system eliminates the repetitive index and the weakly identifiable index, the competitiveness evaluation result is more objective, and the index reflecting the characteristics of the recreational fishery industry is retained based on the qualitative evaluation.
• Research of fishery administration rangers incentive mechanism based on psychological contract theory

  ZHANG Zuping, YANG Yulin

  2024, 46(6): 165-173. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.021

  Abstract ( ) PDF ( )

  With the continuous increase in the number of fishery administration rangers in the Yangtze River basin, it has a bearing on the operation of the 10-year ban on fishing in the basin whether the corresponding supporting safeguard measures can provide an incentive for fishery administration rangers. Based on the psychological contract theory, combined with the results of the questionnaire survey, an incentive index system for fishery administration rangers was constructed. By comparing and analyzing the difference between the actual perceived value and expected value of each incentive element in the incentive index system, it was found that the e incentive effect exerted by the interpersonal dimension was obvious, the incentive effect exerted by the development dimension was average, and the incentive effect exerted by the normative dimension was not obvious. In particular, welfare benefits, wage levels, equipment configuration, promotion channels, and professional honor had a greater impact on the overall incentive effect. In view of the problems in the incentive mechanism for fishery administration rangers, it is suggested to build a psychological contract incentive model for fishery administration rangers, to establish a fair salary system, to optimize the configuration of patrol equipment, to improve leadership methods, to unblock promotion channels, to shape team culture, to establish an internal mutual aid system, and to innovate honor incentive methods.
• Reviews on “New Horizons in Meiobenthos Research: Profiles, Patterns and Potentials”

  HUA Er, LIU Xiaoshou

  2024, 46(6): 174-177. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.022

  Abstract ( ) PDF ( )

  Meiobenthology is an important component of benthology. In recent 20 years, meiobenthology has advanced rapidly with the development of new methods and amazing progresses in digitization. In 2023, a book entitled as ‘New Horizons in Meiobenthos Research: Profiles, Patterns and Potentials’ was published. It was edited by Olav Giere and Michaela Schratzberger, and over thirty authors with different backgrounds, perspectives and experiences participated writing. This book focuses on meiofauna and attempts to address and summarize recent progresses in various fields of forthcoming importance, emphasizes the role of meiofauna in the world of benthos, and seeks to outline new horizons for future meiobenthology. The content of this book is a summary of the current progresses in meiobenthology, and the prospect of the future meiobentholgy. It will play a substantial role in promoting the development and international exchanges of meiobenthology.
• Research Review
• Literature analysis of application of diatomite in photovoltaic wastewater treatment

  LV Zhifeng, BI Qingkun, LIU Peng, REN Shouguo, JIANG Xinchuang, XU Liuqing, AI Xin, GONG Bentao, HUANG Dajiang, YAN Xiaohong

  2024, 46(6): 178-183. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.023

  Abstract ( ) PDF ( )

  Research on the application of diatomite in the field of wastewater treatment is helpful for photovoltaic silicon wafer processing enterprises to find more efficient and economic methods to treat wastewater. Based on bibliometrics and according to the literature data provided by CNKI and Web of Science database, this paper collected and sorted the information of research papers on "diatomite, wastewater, photovoltaic". Citespace, VOSviewer, Excel and other software were used to analyze the number of publications, researchers, keywords and other information. The research trend of this topic was obtained. The results showed that the number of papers on this topic has increased steadily every year since 1998, and the keywords with high frequency included diatomite, adsorption, wastewater treatment, COD, modified, photocatalysis, heavy metals, composite, etc. Diatomite adsorption method was suitable for the pretreatment of photovoltaic wastewater.
• Research progresses in deep learning of ocean remote sensing and fishery

  XIE Mingyang, CHEN Xinjun, LIU Bin

  2024, 46(6): 184-192. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.024

  Abstract ( ) PDF ( )

  In the past 40 years, with the continuous development of space technology and sensor technology, ocean remote sensing and fishery have entered the era of big data. Accurate, efficient, and intelligent mining of useful information in these ocean remote sensing and fishery data is a challenging problem that needs to be solved. As a powerful technology emerging in the field of machine learning in recent years, deep learning has achieved good results in many industrial applications. Compared with traditional image information extraction algorithms based on physics or statistics, its advantages are more obvious. As the beginning to expand the application in ocean remote sensing and fishery, in this study, we introduced the key theories and methods of artificial intelligence into ocean remote sensing and fishery. In the direction of ocean remote sensing and fishery, we summarized the use of deep learning in marine environmental parameter inversion, remote sensing image classification and identification, marine phenomenon prediction, population identification, fishery biology and research progresses in fishery forecasts, and prospects for the future development of deep learning in ocean remote sensing and fishery.
• Researches on policy tools for water pollution prevention and control of China: A quantitative analysis based on policy text from 1984 to 2020

  WANG Qin, KONG Fanhong

  2024, 46(6): 193-202. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.025

  Abstract ( ) PDF ( )

  Since the "13^th Five-Year" Plan, the ecological civilization construction of China has achieved remarkably; however, the environmental problems are still serious. As one of the important contents of ecological civilization construction, water pollution prevention and control need to be further promoted and strengthened during the "14^th Five-Year" Plan period. Constructing an analysis framework by taking the water environment policy texts of China as the research object since 1984 is based on the basic types of water environment policy tools, and combines the three dimensions of water pollution policy, governance process, policy issuance time and policy actors. Through the collection, sorting, coding and quantitative analysis of water pollution prevention and control policy documents, it was found that the water pollution prevention and control policy system of China is relatively comprehensive. However, there are problems such as the imbalance in the use of policy tools, the weak governance links in the whole process of policy tools and the monotonous structure of the actors of policy tools. In the future, it is necessary to adjust the use proportion of flexible and rigid policy tools, strengthen the supply of the whole-process governance tools of water pollution control policies, promote the diverse participation of water pollution control policy actors, and improve existing policy tools and innovate new ones.
• Effects of rice-crab coculture on rice growth and paddy field ecosystem: A review

  LI Weijing, WANG Hongyuan, PAN Junting, XU Yang, LI Hao, JIN ke, LIU Hongbin

  2024, 46(6): 203-210. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.026

  Abstract ( ) PDF ( )

  The rice-crab coculture model, as a distinctive rice field cultivation and breeding mode in China, relies on mutual benefits between species and complementary utilization of resources in rice field. It plays a significant role in maintaining soil fertility and rice yield, improving nitrogen use efficiency, and controlling pests, diseases, and weeds. In this paper, we mainly summarizes and analyzes the impact of the rice-crab coculture model on rice field ecosystems from five aspects, rice growth, water quality, soil environment, system nitrogen loss and biodiversity. The main conclusion is that the rice-crab coculture model can stabilize or increase rice yield and improve rice quality although its impact on the rice field ecological environment is complex. Our findings provided a reference for the in-depth development and promotion of rice-crab co-culture model.
• Association of the scientific committee reports with the resolutions of Indian Ocean Tuna Commission on shark conservation and management

  CHU Xiaolin, LU Yuwei

  2024, 46(6): 211-220. https://doi.org/10.13984/j.cnki.cn37-1141.2024.06.027

  Abstract ( ) PDF ( )

  The Indian Ocean Tuna Commission, one of the world five largest regional fishery management organizations, has paid more and more attentions to the conservation and management of shark resources. From 2005 to 2020, the Indian Ocean Tuna Commission has adopted 15 scientific committee reports on shark data collection and reporting, stock resource assessment and conservation management recommendations. Simultaneously the Indian Ocean Tuna Commission adopted 12 resolutions on shark conservation and management, which covere scientific research, safe release and fin-cutting. These reports provided an important scientific basis for the corresponding resolutions on shark conservation and management, which is one of the key conditions for the formation and implementation of corresponding resolutions. In-depth studies on the correlation between the reports and the resolutions should aid us to grasp the development trend of shark maintenance management of Indian Ocean Tuna Commission. It is seeable that the reports and the resolution are progressively deepening. Understanding these reports and associating resolutions should facilitate maintaining our fishing rights and interests in Indian Ocean, and promote the sustainable exploitation of global shark resources.