In this paper Cheng Yanqiu’s personality,manliness and his hobbies are discussed.From the narration of his farming life in the 1940s and his founding of schools his view on life is to be seen.In the latter part of th...In this paper Cheng Yanqiu’s personality,manliness and his hobbies are discussed.From the narration of his farming life in the 1940s and his founding of schools his view on life is to be seen.In the latter part of the paper the artistic achievements of his masterpiece“The Lucky Purse”are explored.展开更多
This study applies the mass-spring system to model the dynamic behavior of a submerged net panel similar to the shooting process in actual purse seine fishing operation. Modeling indicates that there is insufficient s...This study applies the mass-spring system to model the dynamic behavior of a submerged net panel similar to the shooting process in actual purse seine fishing operation. Modeling indicates that there is insufficient stretching with the net panel under the floatline in the prophase of the shooting process. Sinkers at different locations along the leadline descend successively after submergence, and the sinking speed decreases gradually with elapsed time until attainment of a stable state. Designs with different current speeds and sinker weights are executed to determine the dimensional shape and sinking characteristics of the net. The net rigged with greater sinker weight gains significantly greater sinking depth without water flow. Compared with the vertical spread of the net wall in static water, the middle part of the netting presents a larger displacement along the direction of current under flow condition. It follows that considerable deformation of the netting occurs with higher current speed as the sinkers affected by hydrodynamic force drift in the direction of current. The numerical model is verified by a comparison between simulated results and sea measurements. The calculated values generally coincide with the observed ones, with the former being slightly higher than the latter. This study provides an implicit algorithm which saves computational loads for enormous systems such as purse seines, and ensures the accuracy and stability of numerical solutions in a repetitious iteration process.展开更多
Shepherd＇s purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Res...Shepherd＇s purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Results revealed that HB-1,HB-2,HB-3,HB-4,HB-6,HB-7,HB-17,HB-18,HB-19,HB-20,HB-21,and HB-22 populations were susceptible to tribenuron-methyl characterised by very low GR50 values of about 0.10 g a.i.ha-1.On the other hand,populations HB-15 and HB-16 had moderate resistance to tribenuron-methyl with resistance indices （RI） ranging from 10-100 folds,whilst populations HB-5,HB-8,HB-9,HB-10,HB-11,HB-12,HB-13,and HB-14 expressed high level of resistance to tribenuron-methyl with resistance indices over 100.The proportion of moderate resistance level was about 9.09%,and that of high resistance was about 36.36%.展开更多
In the Indian Ocean, bigeye tuna supports one of the most important fisheries in the world. This fishery mainly consists of two components: longline and purse seine fisheries. Evidence of overfishing and stock depleti...In the Indian Ocean, bigeye tuna supports one of the most important fisheries in the world. This fishery mainly consists of two components: longline and purse seine fisheries. Evidence of overfishing and stock depletion of bigeye tuna calls for an evaluation of alternative management strategies. Using an age-structured operating model, parameterize dwith the results derived in a recent stock assessment,we evaluated the effectiveness of applying constant fishing mortality (CF) and quasi-constant fishing mortality (QCF) strategies to reduce fishing effort of purse seining with fish aggregating devices (FADs) at different rates. Three different levels of productivity accounted for the uncertainty in our understanding of stock productivity. The study shows that the results of CF and QCF are similar. Average SSB and catchduring simulation years would be higher if fishing mortality of FAD-associated purse seiningwas reduced rapidly. The banning or rapid reduction of purse seining with FAD resulted in a mean catch, and catch in the last simulation year, higher than that of the base case in which no change was made to the purse seine fishery. This could be caused by growth overfishing by purse seine fisheries with FADs according to the per-recruit analysis. These differences would be more obvious when stock productivity was low. Transferring efforts of FAD-associated purse seining to longline fisheries is also not feasible.Our study suggests that changes are necessary to improve the performance of the current management strategy.展开更多
Fishing with artificial light has become one of the most advanced,efficient,and common methods for the night-time purse seining in Vietnam.This study evaluated the radiation spectrum,CIE chromaticity coordinates,corre...Fishing with artificial light has become one of the most advanced,efficient,and common methods for the night-time purse seining in Vietnam.This study evaluated the radiation spectrum,CIE chromaticity coordinates,correlated color temperature(CCT),catch rate,fuel consumption,and CO_(2)emissions when using Light emitting diode(LED)lamps(0.196 kW)in comparison with the use of metal halide(MH)lights(1 kW)in the offshore purse seine fishery in Quang Tri province,Vietnam.The fishing efficiency of the purse seine fishing boats using LED lamps has increased 1.58 times in catch rate than MH lights,although the energy consumption of LED lamp is 4 times smaller.Fuel consumption of boats per trip using LED lamps was one third of that using MH lights.The use of LED reduced the radiation spectrum,especially the intense UV radiation which negatively affects the health of fishermen.This study also showed the potential of CO_(2)emission reduction up to 1.09 tons of CO_(2)per trip per boat from the use of LED lamps in the offshore purse seine fishing boats.展开更多
EVER since Yang Yue got married six years ago, she has kept her husband, Liang Xiaoming, on a short financial leash, giving him about 2,500 yuan （$393） a month for his own personal use.
The Double Take column looks at a single topic from an African and Chinese perspective. This month we discuss whether husbands should surrender their salary within a family or not.
Understanding the catch composition of multispecies fisheries is fundamental to effective spatial fishery management.In the Equatorial Western and Central Pacific Ocean(EWCPO),the main catches of the tuna purse-seine ...Understanding the catch composition of multispecies fisheries is fundamental to effective spatial fishery management.In the Equatorial Western and Central Pacific Ocean(EWCPO),the main catches of the tuna purse-seine fishery include skipjack tuna(Katsuwonus pelamis),yellowfin tuna(Thunnus albacares),and bigeye tuna(Thunnus obesus).Studying the spatiotemporal distribution of the catch composition in the context of climate change contributes to the sustainable development of this fishery.Our study analyzed purse seine fishery data and environmental data from 1997 to 2019,using a random forest model to explore the changing mechanisms of catch composition under different El Niño-Southern Oscillation(ENSO)episodes with catch mean trophic level(CMTL)as the response variable.Emerging hot spot analysis was used to identify significant spatiotemporal hot(cold)spot areas.The results revealed two hot spot areas,namely the western hotspot area(WHA)and the eastern hotspot area(EHA),and two cold spot areas,namely the northern cold spot area(NCA)and the southern cold spot area(SCA).EHA spans the entire central Pacific east of 170°E among different ENSO episodes,expanding and contracting in tandem with the 28℃isotherm.WHA is mainly influenced by surface organic matter and the Western Boundary Currents and remains among different ENSO episodes.NCA is formed by the westerly anomalies and positive wind stress curl anomalies and exists only under La Niña episodes.SCA persists within the unproductive South Equatorial Current(SEC)and remains stable among different ENSO episodes.Our study contributes to revealing the spatiotemporal dynamics in tuna catch composition and their relationships with environmental factors and interspecies competition,providing valuable insights for ecosystem-based dynamic fishery management.展开更多
为了解中西太平洋金枪鱼围网渔业的渔获组成及其时空变化规律,根据1984—2020年中国、美国、西班牙围网作业渔船在中西太平洋海域的生产统计资料,对金枪鱼渔获量、单位捕捞努力量渔获量(catch per unit effort,CPUE)以及鲣(Katsuwonus p...为了解中西太平洋金枪鱼围网渔业的渔获组成及其时空变化规律,根据1984—2020年中国、美国、西班牙围网作业渔船在中西太平洋海域的生产统计资料,对金枪鱼渔获量、单位捕捞努力量渔获量(catch per unit effort,CPUE)以及鲣(Katsuwonus pelamis)、黄鳍金枪鱼(Thunnus albacares)和大眼金枪鱼(Thunnus obesus)3种金枪鱼渔获量比例等进行分析,重点研究了渔获率的年代间变化。结果表明:1)同一作业方式的不同船队鱼种渔获量比重相似;自由集群与人工集鱼装置(fish aggregation devices,FADs)的鱼种渔获量组成存在显著差异(P<0.05,R=0.528),近年间,自由集群作业方式渔获比重增大。2)各船队捕捞区域主要集中于太平洋西部海域,不同年代捕捞热点区域与物种组成存在差异,而同一年代内各物种渔获量比例较为相似,统计年间渔场中心呈从西部海域向东南方向移动的趋势。3)3种金枪鱼CPUE季间差异较小,鲣年间CPUE差异较大,呈连年增加的趋势。研究结果可为中西太平洋金枪鱼围网渔业的可持续发展提供科学参考。展开更多
为了分析围网渔业的兼捕渔获物组成分布并评估其对非目标物种的潜在影响,本研究基于中西太平洋渔业委员会(Western and Central Pacific Fisheries Commission,WCPFC)提供的2013—2022年金枪鱼渔业及兼捕数据,对兼捕渔获物的种类、数量...为了分析围网渔业的兼捕渔获物组成分布并评估其对非目标物种的潜在影响,本研究基于中西太平洋渔业委员会(Western and Central Pacific Fisheries Commission,WCPFC)提供的2013—2022年金枪鱼渔业及兼捕数据,对兼捕渔获物的种类、数量及空间分布特征进行了系统分析。并将兼捕率与三大目标鱼种[鲣鱼(Katsuwonus pelamis)、黄鳍金枪鱼(Thunnus albacores)、大眼金枪鱼(Thunnus obesus)]的渔获率进行相关性分析,以探讨不同非目标物种的兼捕模式及其与目标渔获物的关系。研究结果显示,围网渔业的主要兼捕渔获物共48种,总计439 623尾,包括鲸豚类、鲨鱼和海龟等。其中,镰状真鲨(Carcharhinus falciformis)兼捕最多,达418 387尾,占兼捕总量的95%。兼捕主要发生在10°S~10°N和140°E~150°W附近海域。此外,东经海域的兼捕率普遍高于西经海域,且鲸豚类的兼捕率在东西经海域的差异最为显著。相关性分析结果表明,鲸豚类和鲨鱼的兼捕率与目标鱼种的渔获率无显著相关性,而海龟的兼捕率与鲣鱼和大眼金枪鱼的渔获率呈正相关关系。研究表明,围网渔业在特定海域对部分非目标物种存在较高的兼捕风险,特别是镰状真鲨的兼捕占比极高,同时东经海域的兼捕率整体高于西经海域。该研究结果为制定减少兼捕的措施提供了科学依据,进而保护生态系统平衡发展。展开更多
为了解中西太平洋主要金枪鱼产量情况,通过收集中西太平洋渔业委员会(Western and central Pacific fisheries commission,WCPFC)提供的金枪鱼渔业数据,进行回顾性分析,厘清了中西太平洋主要金枪鱼产量时空变化情况。结果显示,中西太平...为了解中西太平洋主要金枪鱼产量情况,通过收集中西太平洋渔业委员会(Western and central Pacific fisheries commission,WCPFC)提供的金枪鱼渔业数据,进行回顾性分析,厘清了中西太平洋主要金枪鱼产量时空变化情况。结果显示,中西太平洋主要金枪鱼年产量变化可分为3个时期,其中渔业起步期的捕捞范围较小,以延绳钓为主,产量集中在近岸高产区域,远洋捕捞空间范围受限;渔业扩张期引入围网捕捞技术,促使捕捞范围向太平洋中部和更深、更远的海域扩展;渔业稳定期捕捞技术现代化,以围网捕捞为主,高产渔场分布清晰,捕捞范围趋于固定。研究还重点分析了主要中西太平洋金枪鱼生产国和地区(日本、韩国、中国台湾省、巴布亚新几内亚、美国和中国内地)的渔业产量、主要捕捞物种、作业时空分布及产量变化趋势,并且讨论了自然、经济与政策等多重因素可能对金枪鱼产量的影响。本研究可为金枪鱼资源的科学管理与保护提供依据,有助于促进海洋生物多样性保护和全球金枪鱼资源的可持续管理。展开更多
The use of high-power lights during night-time purse seining is common in Vietnam.Typically,metal halide(MH)lamps are used in the commercial fishery to attract fish,however these lights require more energy,have a shor...The use of high-power lights during night-time purse seining is common in Vietnam.Typically,metal halide(MH)lamps are used in the commercial fishery to attract fish,however these lights require more energy,have a shorter lifespan,and lower chromatic performance than light emitting diode(LED)lamps.This study examined catch efficiency and fuel consumption when using LED lamps in combination with reduced numbers of MH lamps(10.24 kW),compared to conventional lighting(28.6 kW),used during purse seining off the coast of Ninh Thuan province,Vietnam.The economic performance associated with using LED lamps in this fishery was also assessed.We found no significant differences in catch rates between the different light treatments,however fuel consumption was significantly reduced.Fuel consumption per nightly trip using LED with MH lamps was 70.8 l(11.1 l/h)compared to114 l(17.45 l/hr)using MH lamps alone,an estimated 37.9%reduction in fuel consumption.An investment in LED lamps by a fishing enterprise will require additional initial costs,however our analysis revealed the financial break-event point can be reached after approximately 101 nightly trips when the fuel price is at the 2015 level of USD$0.74 per l.Fishing enterprises can increase their profitability,and reduce CO2 emissions,by using LED lamps in the Vietnamese purse seine fishery.展开更多
文摘In this paper Cheng Yanqiu’s personality,manliness and his hobbies are discussed.From the narration of his farming life in the 1940s and his founding of schools his view on life is to be seen.In the latter part of the paper the artistic achievements of his masterpiece“The Lucky Purse”are explored.
基金financially supported by the National High Technology Research and Development Program of China (No. 2012AA092302)the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20103104120006)the Project of First-class Disciplines Shanghai Universities: Eco-Friendly Fishing Gear and Fishing Methods in the Field of Fisheries Science (B-5005-12-0001-4C)
文摘This study applies the mass-spring system to model the dynamic behavior of a submerged net panel similar to the shooting process in actual purse seine fishing operation. Modeling indicates that there is insufficient stretching with the net panel under the floatline in the prophase of the shooting process. Sinkers at different locations along the leadline descend successively after submergence, and the sinking speed decreases gradually with elapsed time until attainment of a stable state. Designs with different current speeds and sinker weights are executed to determine the dimensional shape and sinking characteristics of the net. The net rigged with greater sinker weight gains significantly greater sinking depth without water flow. Compared with the vertical spread of the net wall in static water, the middle part of the netting presents a larger displacement along the direction of current under flow condition. It follows that considerable deformation of the netting occurs with higher current speed as the sinkers affected by hydrodynamic force drift in the direction of current. The numerical model is verified by a comparison between simulated results and sea measurements. The calculated values generally coincide with the observed ones, with the former being slightly higher than the latter. This study provides an implicit algorithm which saves computational loads for enormous systems such as purse seines, and ensures the accuracy and stability of numerical solutions in a repetitious iteration process.
基金supported by the State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection (IPP),Chinese Academy of Agricultural Sciences,China (SKL2010OP15)the National Natural Science Foundation of China (31000856)
文摘Shepherd＇s purse seeds were collected from winter wheat fields and road sides in Hebei Province,China.Their sensitivities to tribenuron-methyl were evaluated in a whole plant dose response assay in the greenhouse.Results revealed that HB-1,HB-2,HB-3,HB-4,HB-6,HB-7,HB-17,HB-18,HB-19,HB-20,HB-21,and HB-22 populations were susceptible to tribenuron-methyl characterised by very low GR50 values of about 0.10 g a.i.ha-1.On the other hand,populations HB-15 and HB-16 had moderate resistance to tribenuron-methyl with resistance indices （RI） ranging from 10-100 folds,whilst populations HB-5,HB-8,HB-9,HB-10,HB-11,HB-12,HB-13,and HB-14 expressed high level of resistance to tribenuron-methyl with resistance indices over 100.The proportion of moderate resistance level was about 9.09%,and that of high resistance was about 36.36%.
基金Supported by the Shanghai Ocean University Graduate School (PhD Dissertation Grant)the Project of Shanghai Science and Technology Innovation(No.12231203900)+4 种基金the National Natural Science Foundation of China(No.NSFC41276156)the Industrialization Program of the National Development and Reform Commission(No.2159999)the Shanghai Leading Academic Discipline Projectthe National Distant-water Fisheries Engineering Research Center,the Scientific Observing and Experimental Station of Oceanic Fishery Resources,Ministry of Agriculture,China.Y.supported by the Shanghai Leading Teacher Program
文摘In the Indian Ocean, bigeye tuna supports one of the most important fisheries in the world. This fishery mainly consists of two components: longline and purse seine fisheries. Evidence of overfishing and stock depletion of bigeye tuna calls for an evaluation of alternative management strategies. Using an age-structured operating model, parameterize dwith the results derived in a recent stock assessment,we evaluated the effectiveness of applying constant fishing mortality (CF) and quasi-constant fishing mortality (QCF) strategies to reduce fishing effort of purse seining with fish aggregating devices (FADs) at different rates. Three different levels of productivity accounted for the uncertainty in our understanding of stock productivity. The study shows that the results of CF and QCF are similar. Average SSB and catchduring simulation years would be higher if fishing mortality of FAD-associated purse seiningwas reduced rapidly. The banning or rapid reduction of purse seining with FAD resulted in a mean catch, and catch in the last simulation year, higher than that of the base case in which no change was made to the purse seine fishery. This could be caused by growth overfishing by purse seine fisheries with FADs according to the per-recruit analysis. These differences would be more obvious when stock productivity was low. Transferring efforts of FAD-associated purse seining to longline fisheries is also not feasible.Our study suggests that changes are necessary to improve the performance of the current management strategy.
基金funded by the Hue University DHH 2019-02-109 grant for the project:“Study on the applied LED lamps in offshore seine fishery in Quang Trịprovince”from Hue University,Hue city,Vietnam.
文摘Fishing with artificial light has become one of the most advanced,efficient,and common methods for the night-time purse seining in Vietnam.This study evaluated the radiation spectrum,CIE chromaticity coordinates,correlated color temperature(CCT),catch rate,fuel consumption,and CO_(2)emissions when using Light emitting diode(LED)lamps(0.196 kW)in comparison with the use of metal halide(MH)lights(1 kW)in the offshore purse seine fishery in Quang Tri province,Vietnam.The fishing efficiency of the purse seine fishing boats using LED lamps has increased 1.58 times in catch rate than MH lights,although the energy consumption of LED lamp is 4 times smaller.Fuel consumption of boats per trip using LED lamps was one third of that using MH lights.The use of LED reduced the radiation spectrum,especially the intense UV radiation which negatively affects the health of fishermen.This study also showed the potential of CO_(2)emission reduction up to 1.09 tons of CO_(2)per trip per boat from the use of LED lamps in the offshore purse seine fishing boats.
文摘EVER since Yang Yue got married six years ago, she has kept her husband, Liang Xiaoming, on a short financial leash, giving him about 2,500 yuan （$393） a month for his own personal use.
文摘The Double Take column looks at a single topic from an African and Chinese perspective. This month we discuss whether husbands should surrender their salary within a family or not.
基金The National Key Research and Development Program of China under contract No.2023YFD2401303.
文摘Understanding the catch composition of multispecies fisheries is fundamental to effective spatial fishery management.In the Equatorial Western and Central Pacific Ocean(EWCPO),the main catches of the tuna purse-seine fishery include skipjack tuna(Katsuwonus pelamis),yellowfin tuna(Thunnus albacares),and bigeye tuna(Thunnus obesus).Studying the spatiotemporal distribution of the catch composition in the context of climate change contributes to the sustainable development of this fishery.Our study analyzed purse seine fishery data and environmental data from 1997 to 2019,using a random forest model to explore the changing mechanisms of catch composition under different El Niño-Southern Oscillation(ENSO)episodes with catch mean trophic level(CMTL)as the response variable.Emerging hot spot analysis was used to identify significant spatiotemporal hot(cold)spot areas.The results revealed two hot spot areas,namely the western hotspot area(WHA)and the eastern hotspot area(EHA),and two cold spot areas,namely the northern cold spot area(NCA)and the southern cold spot area(SCA).EHA spans the entire central Pacific east of 170°E among different ENSO episodes,expanding and contracting in tandem with the 28℃isotherm.WHA is mainly influenced by surface organic matter and the Western Boundary Currents and remains among different ENSO episodes.NCA is formed by the westerly anomalies and positive wind stress curl anomalies and exists only under La Niña episodes.SCA persists within the unproductive South Equatorial Current(SEC)and remains stable among different ENSO episodes.Our study contributes to revealing the spatiotemporal dynamics in tuna catch composition and their relationships with environmental factors and interspecies competition,providing valuable insights for ecosystem-based dynamic fishery management.
文摘为了解中西太平洋金枪鱼围网渔业的渔获组成及其时空变化规律,根据1984—2020年中国、美国、西班牙围网作业渔船在中西太平洋海域的生产统计资料,对金枪鱼渔获量、单位捕捞努力量渔获量(catch per unit effort,CPUE)以及鲣(Katsuwonus pelamis)、黄鳍金枪鱼(Thunnus albacares)和大眼金枪鱼(Thunnus obesus)3种金枪鱼渔获量比例等进行分析,重点研究了渔获率的年代间变化。结果表明:1)同一作业方式的不同船队鱼种渔获量比重相似;自由集群与人工集鱼装置(fish aggregation devices,FADs)的鱼种渔获量组成存在显著差异(P<0.05,R=0.528),近年间,自由集群作业方式渔获比重增大。2)各船队捕捞区域主要集中于太平洋西部海域,不同年代捕捞热点区域与物种组成存在差异,而同一年代内各物种渔获量比例较为相似,统计年间渔场中心呈从西部海域向东南方向移动的趋势。3)3种金枪鱼CPUE季间差异较小,鲣年间CPUE差异较大,呈连年增加的趋势。研究结果可为中西太平洋金枪鱼围网渔业的可持续发展提供科学参考。
文摘为了解中西太平洋主要金枪鱼产量情况,通过收集中西太平洋渔业委员会(Western and central Pacific fisheries commission,WCPFC)提供的金枪鱼渔业数据,进行回顾性分析,厘清了中西太平洋主要金枪鱼产量时空变化情况。结果显示,中西太平洋主要金枪鱼年产量变化可分为3个时期,其中渔业起步期的捕捞范围较小,以延绳钓为主,产量集中在近岸高产区域,远洋捕捞空间范围受限;渔业扩张期引入围网捕捞技术,促使捕捞范围向太平洋中部和更深、更远的海域扩展;渔业稳定期捕捞技术现代化,以围网捕捞为主,高产渔场分布清晰,捕捞范围趋于固定。研究还重点分析了主要中西太平洋金枪鱼生产国和地区(日本、韩国、中国台湾省、巴布亚新几内亚、美国和中国内地)的渔业产量、主要捕捞物种、作业时空分布及产量变化趋势,并且讨论了自然、经济与政策等多重因素可能对金枪鱼产量的影响。本研究可为金枪鱼资源的科学管理与保护提供依据,有助于促进海洋生物多样性保护和全球金枪鱼资源的可持续管理。
文摘The use of high-power lights during night-time purse seining is common in Vietnam.Typically,metal halide(MH)lamps are used in the commercial fishery to attract fish,however these lights require more energy,have a shorter lifespan,and lower chromatic performance than light emitting diode(LED)lamps.This study examined catch efficiency and fuel consumption when using LED lamps in combination with reduced numbers of MH lamps(10.24 kW),compared to conventional lighting(28.6 kW),used during purse seining off the coast of Ninh Thuan province,Vietnam.The economic performance associated with using LED lamps in this fishery was also assessed.We found no significant differences in catch rates between the different light treatments,however fuel consumption was significantly reduced.Fuel consumption per nightly trip using LED with MH lamps was 70.8 l(11.1 l/h)compared to114 l(17.45 l/hr)using MH lamps alone,an estimated 37.9%reduction in fuel consumption.An investment in LED lamps by a fishing enterprise will require additional initial costs,however our analysis revealed the financial break-event point can be reached after approximately 101 nightly trips when the fuel price is at the 2015 level of USD$0.74 per l.Fishing enterprises can increase their profitability,and reduce CO2 emissions,by using LED lamps in the Vietnamese purse seine fishery.
