中国和日本渔业产量的比较

分析比较了中日两国近年来渔业生产情况的变化。日本近年来水产品的年产量由１２００多万ｔ逐渐下降到８００多万ｔ，由全世界第一位的水产大国下降为第二位。中国由十多年前的６００多万ｔ年产量逐渐上升，１９９５年达２５００多万ｔ，跃居全世界第一位。两国近年来的海洋捕捞、淡水捕捞、海水养殖、淡水养殖的年产量都发生了变化。中国呈上升趋势，日本却出现了下降状态。并分析了中日两国渔业产量变化的主要因素。     

中国海洋渔业人力资源结构的灰色分析及其预测

用灰色关联和灰色预测的方法，对我国沿海省市海洋渔业人力资源的结构和现状进行了分析，并对2000～2005年的人力资源发展状况进行了预测。结果认为，对海洋渔业劳动力影响最大的因素是海洋捕捞专业的劳动力，其次是海洋兼业劳动力，再次是海洋养殖和后勤专业的劳动力，这一人力资源的组成结构对可持续渔业的发展要求不尽合理。通过分别建立灰色模型GM（1，1），预测到2000～2005年从事海洋渔业的劳动力人数将达到291.9～343.8万人，海洋捕捞的劳动力人数为128.5～149.2万人，海洋养殖的劳动力人数为54.3～77.9万人，海洋后勤的劳动力人数为29.1～35.4万人，海洋兼业的劳动力人数为81.3～87.9万人。     

浅谈南海渔业管理对策

南海渔业资源衰退的主要原因是捕捞过度和海洋生态环境破坏。由于海洋生态过程是动力学过程,很多生态因素的变化会相应引起生态过程的变化,同时生态动力学过程的因素又是多方面的,因此南海渔业资源的管理和生产方式应该从过去的开发型管理向着管理型管理方向转变。这种管理方式涉及面较广,必须实施从渔业资源管理、渔业水域管理、渔业水域周围环境管理到加强对渔船与船员管理、捕养并重、健全法制、强化治政队伍与执法力量配置以及开展国际渔业合作等管理措施。     

Assessing benthic ecological status in stressed Liaodong Bay (China) with AMBI and M-AMBI

Rapid economic development in recent decades has resulted in environmental degradation of Liaodong Bay, North China, where eutrophication is becoming more evident because of excess nutrients inputs. To assess the benthic ecological status in Liaodong Bay, AZTI’s Marine Biotic Index (AMBI) and multivariate-AMBI (M-AMBI) were applied using both benthic macroinvertebrate density and biomass data collected from Liaodong Bay in July 2007. This first application of AMBI and M-AMBI in Liaodong Bay showed that the nearshore areas of the bay, especially near river estuaries, were severely disturbed, with a clear gradient of disturbance decreasing seaward. Ecological status assessed from density and biomass data was quite similar. Significant relationships were also found between both indices and environmental variables in Liaodong Bay. Moreover, the spatial distributions of both AMBI and M-AMBI matched those of plotted eutrophication indices (EI) in the surface water layer, and significant linear correlations were found between both benthic indices and EI. In general, both AMBI and M-AMBI worked well on assessing the ecological status of Liaodong Bay under eutrophication stress due to excess nutrients inputs.     

Comparison of Two Methods to Assess the Size Structure of Phytoplankton Community Assemblages,in Liaodong Bay,China

Liaodong Bay is one of the largest semi-enclosed bays located in Bohai Sea, in northeast China. It is an important feeding and spawning place, even wintering and breeding migration base for many marine organisms. The size structure of phytoplankton communities is a key feature of marine ecosystems and can be used as an indicator for algae disaster, but the methods to evalute is still challenging. Here, we compared the size-fractionated chlorophyll-a method with a high-throughout sequencing method in an evaluation of the size structure of phytoplankton assemblages in Liaodong Bay, China, in 2014. The proportion of picophytoplankton was estimated at just 19% according to the results based on size-fractionated chlorophyll-a, which likely represents a severe underestimation. The sequencing method confirmed that many kinds of phytoplankton species appeared in more than one size-fractionated filter membrane, with some even dominating where the filter membrane pore size was greater than the individual phytoplankton size. According to the sequencing method, the phytoplankton assemblages in Liaodong Bay were dominated by picophytoplankton(average proportion = 44%), followed by the nanophytoplankton(average 32%), a composition that is more consistent with other studies. The sequencing method provides a more robust way to assess the size structure and taxonomic diversity of marine phytoplankton communities.     

A Holocene Yalu River-derived fine-grained deposit in the southeast coastal area of the Liaodong Peninsula

High-resolution seismic profiles and surface samples were studied in detail in order to determine the structures, provenance, and dynamic mechanisms of a fine-grained deposit in the southeast coastal area of the Liaodong Peninsula, China. Results indicate that there is a prominent fine-grained deposit distributed alongshore up to 14 m thick, which thins out to less than 2 m in both seaward and landward directions, forming an Ω-shaped pattern of cross-section. The deposit is 180–300 km away from the Yalu River mouth and extends along the southeast coast of the Liaodong Peninsula between the northeast of Dalian Bay and southwest of the Changshan Islands, in water depths of 20–40 m. The deposit, which is mainly derived from the Yalu River, represents a Holocene Highstand System Tract sequence formed since the highest sea level around 7.0 ka. The Yalu River-derived sediments were redeposited in the area off the southeast coast of the Liaodong Peninsula after resuspension and transportation by the Liaonan Coastal Current.     

南海区域渔船活动时空特征分析

近年来海洋资源的不断开发利用,使得海洋空间规划变得尤为重要,其中以渔业资源占主要比重。为了对渔业资源监测与规划提供辅助决策信息,本文通过对南海及周边国家2018年船舶自动识别系统（AIS）数据进行预处理,采用数理统计和GIS空间分析方法,实现了南海区域渔船活动强度时空特征分析。结果显示： ① 2018年南海及周边国家渔船以区域性分布为主,集中在中国和越南沿海岸100 km以内区域,在秋季11月捕捞活动频繁,全年渔船平均活动强度白天大于夜晚,16:00 PM 时达到最大渔船活动强度; ② 中国在广东省、广西省和海南省各主要港口渔船活动强度呈现聚集性点状分布,渔船活动强度多大于100,部分港口附近海域呈条带状分布,西沙群岛相较南海其他群岛渔船活动强度较大,除越南外其他周边国家靠近南海附近海域部分海湾和港口有聚集式分布,渔船活动强度都小于2; ③ 越南渔船区域性分布明显,在胡志明港口呈现稳定的块状聚集性分布,且一年四季活动强度变化趋势不大,近岸渔船活动强度保持在50~100,越南渔船在中国南海禁渔线内靠近海南省西南部有两处活动较强的块状分布区域,2018年全年在此区域活动频率占采样天数的87.71%,且平均每小时有7~10艘渔船在该海域活动,休渔期内平均每小时渔船数量大于5,给中国南海海域渔业资源造成巨大威胁。本文通过AIS数据研究分析渔船活动可为海洋空间规划与政府相关部门提供数据支撑。     

基于AIS的海上渔船捕捞活动聚集区提取方法研究

船舶自动识别系统(Automatic Identification System, AIS)不仅是海上交通监管的有效工具,也为研究海上交通运输及其相关产业活动特征提供了一种良好的数据源。基于海上渔船AIS数据,本研究利用高斯混合模型(Gaussian Mixed Model,GMM)识别渔船捕捞活动状态,提出一种将核密度估计(Kernel Density Estimation,KDE)与热点分析(Hot Spot Analysis, HSA)相融合用于渔船捕捞活动聚集区提取的方法。结果显示：与单一KDE或HSA方法相比,二者相融合的方法将KDE的距离衰减效应与HSA统计指数相结合,在渔船捕捞活动聚集区提取中的应用效果较好、效率较高;采用该融合方法,基于2018年9—12月AIS数据,实现对渤海海峡周边海域渔船捕捞活动聚集区的提取,发现不同月份,渔船捕捞活动聚集区的分布范围和空间形态特征具有一定差异性,烟威近岸海域和渤海海峡是主要的捕捞活动聚集区,其结果可为该海域捕捞活动管理和海洋生态保护提供技术方法和决策支持。     

2015—2020年辽东湾海冰冰情时空特征及其影响因素

受冬季强寒潮侵袭,辽东湾会出现大范围结冰现象。为了分析2015—2020年辽东湾海冰冰情的变化规律与影响因素,本文选取Sentinel-1A/B数据开展辽东湾海冰监测。首先,采用巴氏距离选择最优纹理特征组合,再利用最大似然方法实现海冰分类;然后,根据上述海冰分类结果,分析海冰冰情等级、海冰外缘线、海冰面积、海冰类型和海冰结冰概率等冰情特征的变化规律;最后,研究海水深度、海温、气温和风速与海冰冰情的关系。主要结论如下：① 采用不同纹理特征组合方法和本文方法对2020年2月1日Sentinel-1B影像进行实验,结果表明本文方法的总体分类精度和Kappa系数分别为93.16%和0.85,分类精度最高。② 11月末到12月海冰类型以初生冰为主,间有灰冰;1月到2月中上旬以灰冰为主,间有初生冰和白冰;2月下旬到3月上旬的海冰类型以灰冰和初生冰为主。辽东湾内部结冰概率存在差异,北部沿岸结冰概率高于南部,东部结冰概率高于西部。辽东湾海冰冰情受海水深度、海温和气温影响明显,受风速影响较小。     

The observed currents in summer in the Bohai Sea

A harmonic method was used to analyze the tidal currents observed in summer at 11 stations made from 1996 to 2001 in the Bohai Sea, China. Data was compared among different instruments and intervals. Elliptic elements were calculated based on harmonic constants, of which vertical distributions of the maximum speed and rotation direction were discussed for understanding the characteristics of diurnal and semi-diurnal tidal current components. The results indicate that the maximum speed of M2 tidal current component is much larger than that of K1; the rotation direction of M2 tidal current constituent is clockwise in the central part of the Bohai Sea and in the Laizhou Bay, but anticlockwise in the Liaodong Bay and Bohai Bay. For K1 tidal current constituent, it is clockwise in the central Bohai Sea but anti-clockwise in the Laizhou Bay and Liaodong Bay. The tidal currents in most stations in the Bohai Sea were regular semidiurnal except for those in the central Bohai Sea, being irregular semidiurnal.     

Natural mortality estimation and rational exploitation of purpleback flying squid Sthenoteuthis oualaniensis in the southern South China Sea

Based on the biological data of purpleback flying squid(Sthenoteuthis oualaniensis)collected by light falling-net in the southern South China Sea(SCS) during September to October 2012 and March to April 2013,growth and mortality of 'Medium' and 'Dwarf' forms of squid are derived using the Powell-Wetherall,ELEFAN methods and length-converted catch curves(FiSAT package).Given a lack of commercial exploitation,we assume total mortality to be due entirely to natural mortality.We estimate these squid have fast growth,with growth coefficients(k) ranging from 1.42 to 2.39,and high natural mortality(M),with estimates ranging from 1.61 to 2.92.To sustainably exploit these squid stocks,yield per recruitment based on growth and natural mortality was determined using the Beverton-Holt dynamic pool model.We demonstrate squid stocks could sustain high fishing mortality and low ages at first capture,with an optimal fishing mortality 3.0,with the optimal age at first capture increased to 0.4-0.6 years when fishing mortality approached optimal levels.On the basis of our analyses and estimates of stock biomass,we believe considerable potential exists to expand the squid fishery into the open SCS,relieving fishing pressure on coastal waters.     

深圳湾和岘港湾30年土地利用变化研究

本文以南海周边的岘港湾和深圳湾为研究对象,选取了1987年和2015年的遥感影像,基于土地利用转移矩阵、土地利用动态度模型和土地利用程度模型,对2个海湾近30年来的土地利用变化情况进行了对比研究,对所属海岸带的绿地、围填海及城市扩张等变化程度进行了整体分析,透过海湾不同的土地利用特征探究其发展情况。研究结果表明：（1）深圳湾原本的耕地全部被开发为城镇用地,约51%的养殖用地转变为城镇用地,而岘港湾约有86%耕地转化为城镇用地,养殖用地面积则增加了1.43 km²;（2）深圳湾填海造陆面积达32 km²,岘港湾填海造陆面积约5 km²,远小于深圳湾的造陆强度;（3）岘港湾城镇土地增加速度略高于深圳湾,其2015年土地利用综合指数为283.28,而深圳湾在1987年就达到274.12,且2015年该值高达320.52,岘港湾的土地利用综合指数远低于同期深圳湾的水平,岘港湾的土地利用呈现出明显的工业化中期的土地利用特征,而深圳湾则已进入工业化后期;（4）岘港湾裸地面积增加了3.5倍,而深圳湾没有增加,深圳湾的红树林面积增加了2.1倍,而岘港湾的红树林在1987年前已消失,深圳湾的开发方式更注重对自然土地类型及功能性绿地的保护。     

Relationship between trawl selectivity and fish body size in a simulated population

Trawl is a main fishing gear in Chinese fishery,capturing large fish and letting small ones at large.However,long-term use of trawl would result in changes of phenotypic traits of the fish stocks,such as smaller size-at-age and earlier age-at-maturation.In this study,we simulated a fish population with size characteristics of trawl fishing and the population produces one generation of offspring and lives for one year,used trawl to exploit the simulated fish population,and captured individuals by body size.We evaluated the impact of the changes on selectivity parameters,such as selective range and the length at 50% retention.Under fishing pressure,we specified the selectivity parameters,and determined that smaller selection rates and greater length at 50% retention were associated with an increased tendency towards miniaturization.     

Bacterial community succession in response to dissolved organic matter released from live jellyfish

Jellyfish blooms have increased worldwide,and the outbreaks of jellyfish population not only affect the food web structures via voracious predation but also play an important role in the dynamics of nutrients and oxygen in planktonic food webs.However,it remains unclear whether specific carbon compounds released through j ellyfish metabolic processes have the potential to shape bacterial community composition.Therefore,in this study,we aimed to investigate the compositional succession of the bacterioplankton community in response to the dissolved organic matter(DOM)released by the live Scyphomedusae Cyanea lamarcki'i and Chrysaora hysoscella collected from Helgoland Roads of the North Sea.The bacterial community was significantly stimulated by the DOM released form live jellyfish and different dominant phylotypes were observed for these two Scyphomedusae species.Furthermore,the bacterial community structures in the different DOM sources,jellyfish-incubated media,Kabeltonne seawater,and artificial seawater(DOM-free)were significantly different,as revealed by automated ribosomal intergenic spacer analy sis fingerprints.Catalyzed reporter depo sition fluorescence in situ hybridization(CARD-FISH)revealed a rapid species-specific shift in bacterial community composition.Gammaproteobacteria dominated the community instead of the Bacteroidetes community for C.lamarckii,whereas Gammaproteobacteria and Bacteroidetes dominated the community for C.hysoscella.The significant differences in the bacterial community composition and succession indicate that the components of the DOM released by jellyfish might differ with jellyfish species.     

东海中南部海域锈斑蟳渔业生物学和数量分布

研究了1998—1999年东海区虾蟹类调查所获的部分锈斑蟳样品与1998~2004年在东海拖虾作业与蟹笼作业等周年逐月渔获物中采集的锈斑蟳样品的生物学特性,结果表明:东海锈斑蟳渔获群体的甲长范围为26~105mm,甲宽范围为36~165 mm,体重范围为5~610 g,雄性个体平均要略大于雌性个体;周年雌蟹略多于雄蟹,性比为1∶0.94,繁殖期为7~12月,繁殖高峰期为8~10月,不同个体怀卵量在113 867~1 594 167粒之间;调查海区10月开始出现幼蟹,5月生长加速,最小抱卵个体的甲长为60 mm,甲宽为85 mm,体重为110 g。另根据1998~1999年调查资料分析得知:锈斑蟳主要分布在长江口渔场以南水深60 m以内海域,中心区分布在闽东渔场,渔期为11月~翌年2月,是舟山、长江口渔场三疣梭子蟹汛期结束后,蟹笼、流刺网作业的又一主捕对象。     

西北太平洋柔鱼中心渔场环境分析系统的设计与开发

针对海洋渔业领域中,运用SST(海洋表层温度)数据进行中心渔场预测分析的实际情况以及地理信息系统的设计,完成了西北太平洋柔鱼中心渔场环境分析系统的需求分析、总体设计,并采用ArcGIS软件为二次开发平台研发了原型系统。系统采用三层结构模型,运用关系型数据库存储空间数据,实现了空间数据和属性数据一体化的无缝管理;并且采用成熟的COM技术和先进的WebService技术用于系统的集成与发布,确保了系统的可靠性、规范性和可扩展性,为海洋渔业部门提供决策支持。     

Experimental clearance rates of Aurelia coerulea ephyrae and medusae,and the predation impact on zooplankton in Jiaozhou Bay

The population explosion of jellyfish Aurelia coerulea occurred in Jiaozhou Bay,China in 2009.The potential predation impact of A.coerulea on zooplankton was investigated.Population clearance potential and residence time(t_(1/2)) for copepods were calculated from laboratory clearance rates and measurements of jellyfish size and abundance from May to August 2009 in Jiaozhou Bay.Clearance rates varied widely with prey organisms,but they were not significantly different among various prey concentrations.Medusae captured rotifers,fish larvae and hydromedusae more efficiently than fish eggs,copepods and chaetognaths.Ephyrae captured rotifers and hydromedusae more efficiently than fish larvae and copepods.Clearance rate linearly increased with the cro s s sectional area of A.coerulea(size from 0.3 to7.1 cm).Water temperature also had a marked effect on clearance rate and this was related to the increased beat freque ncy as water temperature increased.In early May 2009,A.coerulea potentially cleared the volume of water in the Bay less than 0.001 times a day,but this value was estimated to be more than 0.3 times a day in July.The t_(1/2) for copepods was less than 6 d in June and July.Abundances of copepods,hydromedusae and chaetognaths were extremely low in 2009 compared to 2008 and 2010(jellyfish non-bloom years).Large predation pressure by the A.coerulea population occurred to control zooplankton communities in Jiaozhou Bay.A.coerulea,when present at a high population level,can be a keystone species in Jiaozhou Bay and control the trophic structure here.     

DNA barcoding of the family Sparidae along the coast of China and revelation of potential cryptic diversity in the Indo- West Pacific oceans based on COI and 16S rRNA genes

Journal of Oceanology and Limnology - Sparids are of considerable economic importance in marine fishery and aquaculture in China, and the species diversity of this group is considered relatively...     

Importance of kelp-derived organic carbon to the scallop <Emphasis Type="Italic">Chlamys farreri</Emphasis> in an integrated multi-trophic aquaculture system

Bivalves and seaweeds are important cleaners that are widely used in integrated multi-trophic aquaculture (IMTA) systems. A beneficial relationship between seaweed and bivalve in the seaweed-based IMTA system has been confirmed, but the trophic importance of seaweed-derived particulate organic materials to the co-cultured bivalve is still unclear. We evaluated the trophic importance of the kelp Saccharina japonica to the co-cultured scallop Chlamys farreri in a typical IMTA farm in Sungo Bay (Weihai, North China). The dynamics of detritus carbon in the water were monitored during the culturing period. The proportion of kelp-derived organic matter in the diet of the co-cultured scallop was assessed via the stable carbon isotope method. Results showed that the detritus carbon in the water ranged from 75.52 to 265.19 μg/L, which was 25.6% to 73.8% of total particulate organic carbon (TPOC) during the study period. The amount of detritus carbon and its proportion in the TPOC changed throughout the culture cycle of the kelp. Stable carbon isotope analysis showed that the cultured scallop obtained 14.1% to 42.8% of its tissue carbon from the kelp, and that the percentages were closely correlated with the proportion of detritus carbon in the water (F =0.993, P= 0.003). Evaluation showed that for 17 000 tons (wet weight) of annual scallop production, the kelp contributed about 139.3 tons of carbon (535.8 tons of dry mass). This confirms that cultured kelp plays a similar trophic role in IMTA systems as it does in a natural kelp bed. It is a major contributor to the detritus pool and supplies a vital food source to filter-feeding scallops in the IMTA system, especially during winter and early spring when phytoplankton are scarce.     

Hydrobiology of a flooding ecosystem,Lake Chenhu in Hanyang,Hubei, with preliminary estimation of its potential fishery production capacity

For the purpose of fishery development, a hydrobiological investigation of Lake Chenhu was carried out in 1983 with reference to the productivity of various food organisms as well as fish. Of the entire lake, the annual net primary production was determined to be 27,818×10⁶ kcal for phytoplankton, 2,898×10⁶ kcal for macrophytes and 64,840×10⁶ kcal for wet land vegetation. The annual secondary production chiefly from gastropods was 2,632×10⁶ kcal. On the basis of 1981–1982 fishery data, the production of the main stocked fishes in the lake was also roughly computed. Analysing all obtained production data, we find the energy conversion rate of food organisms to fish in the water at the present stage is fairly low. Even in 1982, the year of better fishery management, food energy converted to plankton feeders or herbivores was only 1.6–1.8%; energy converted to fish yield was even lower, only 0.2–0.8%. To get a potential fish output of the ecosystem, a tentative estimation of fishery capacity of Lake Chenhu was made by using the index of food quotients and relevant conversion factors. The theoretical fish production in the lake is estimated to be around 6,000 t and, through the improvement of fishery management, an annual fish yield of 2,000 t can be expected.