Non-destructive and more effective approaches are needed in the context of monitoring the biodiversity of fish. Accordingly, the emergence of environmental DNA (eDNA) technology provides a valuable and non-invasive means to evaluate fish community diversity in marine ecosystems. In this study, we used eDNA metabarcoding to investigate the species composition and diversity of fish communities in the Xiamen Sea to explore the feasibility of applying this technology toward the characterization of fish diversity in this region. A total of 98 fish species across 16 orders, 52 families, and 77 genera were identified. Most of these species have been previously reported in traditional fishery resource surveys conducted in the Xiamen Sea. Species with relatively high sequence abundance included Johnius belangerii (relative abundance 58.42

本文根据2018年10月(秋季)和2019年4月(春季)在福建厦门和漳州近海拖网定点调查资料,分析了该海域游泳动物的种类组成、数量分布、优势种及群落多样性特征.结果显示,调查海域共有游泳动物204种,隶属于23目82科141属,其中鱼类种类最多,有131种,甲壳类次之,有64种,头足类有9种;游泳动物优势种春季为哈氏仿对虾(Parapenaeopsis huardwickii)、二长棘鲷(Parargyrops edi-ta)、鹰爪虾(Trachypenaeus curvirostris);秋季为哈氏仿对虾、大头白姑鱼(Argyrosomus macrocepha-lus)、矛形梭子蟹(Portunus hiastatoide)和红星梭子蟹(Portunus sanguinolentus);春、秋季质量资源密度分别为239.1 kg·km-2和261.7 kg·km-2;春、秋季数量资源密度分别为24 943 ind·km-2和38 384 ind·km-2;游泳动物群落Shannon-Wiener多样性指数春季略高于秋季,平均值为2.342.

为探求闽东海区桁杆张网不同网目尺寸网囊对带鱼(Trichiurus lepturus)的选择性,于2019年秋季采用套网法对25、35、45、55 mm四种不同网目尺寸网囊进行对比试验,运用Logistic模型,结合极大似然法,拟合带鱼的选择性曲线并估算模型参数.结果表明:带鱼的50％选择肛长(L0.5)总体上随网囊网目尺寸的增大而逐渐增大,说明增大网目尺寸能够有效释放带鱼;L0.5与网目尺寸(m)的关系为L0.5=1.877m+45.323(R2=0.712);随着网目尺寸的增大,带鱼的重量逃逸率和尾数逃逸率总体也呈增大趋势,皆在60％以上.

本文根据2019年8月(夏季)和11月(秋季)、2020年1月(冬季)和2021年4月(春季)在厦门文昌鱼自然保护区进行的4个季度文昌鱼资源现状调查研究,并结合历史调查数据资料分析了厦门文昌鱼资源变动原因.结果 表明:调查期间厦门文昌鱼平均体长为29.71 mm,平均体质量为68.0 mg,主要以2龄(39.7％)和3龄(36.5％)为主,合占76.2％,4个季度文昌鱼体长和体质量均值均有显著性差异.保护区4个海区中,实验区鳄鱼屿海区文昌鱼的平均栖息密度最高,为50.0 ind/m2,但分布范围狭小;核心区黄厝、南线-十八线和小嶝岛-角屿岛海区平均栖息密度分别为4.1、1.5、0.4 ind/m2,与历史调查数据相比下降较为显著,尤其小嶝岛-角屿岛海区文昌鱼资源密度下降最为严重.栖息地环境变化是导致厦门文昌鱼保护区适宜生存场所缩小、资源衰退的最主要原因.

China's 13th Five-Year Plan elevated the national mandate for environmental sustainability. Chinese fisheries are characterized by full retention of high diversity catch harvested using unselective gears, creating ecological risks. Therefore, China launched pilot projects in management by Total Allowable Catch (TAC) in five coastal provinces in 2017 and 2018 to build experience with output controls. Fujian province launched an important pilot in its swimming crab fishery, the first to adopt a multispecies approach. To guide Fujian and other provinces in multispecies management, a workshop in April 2018 shared international experience. The workshop considered 13 case studies spanning a wide range of underlying scientific models and types of harvest controls. Multispecies harvest controls based on simple survey- or index-based models that aggregate trends for many species are typically operationally easier for managers and fishers. However, inadequate management can cause declines of individual species, sometimes leading to adoption of species-specific models and then species-specific harvest controls. This transition often incurs economic costs through scientific and management demands, and constraints on harvest of co-occurring species. The lessons revealed by the case studies suggest multispecies TACs might be effective in the Fujian swimming crab fishery given the modest number of species with similar and productive life history traits, and the market demand for all species. Continued experimentation with different management approaches through pilot projects can enable China to maintain progress toward sustainable fisheries goals under the 14th Five-Year Plan.

根据2021年3月、5月、7月和8月福建闽江口及附近海域4个航次的拖网调查资料,研究分析了该海域鱼类群落的种类组成、数量分布、优势种及多样性特征.结果显示,调查海域共捕获鱼类104种,隶属于13目46科71属,其中鲈形目种类最多,有50种,鲱形目次之,有16种;暖水性鱼类占70.19％,底层、近底层鱼类合占69.23％;鱼类优势种有凤鲚(Coilia mystus)、二长棘鲷(Parargyrops edita)、斑鱼祭(Konosirus punctatus)等14种,多数鱼种仅是1～2航次的优势种,季节性差异明显;鱼类资源平均质量密度和数量密度分别为667.10 kg·km-2和71.91×103 ind·km-2,夏季明显高于春季;鱼类群落Shannon-Wiener多样性指数海区均值为2.622,处于较好水平.

根据2019年1月、4月、7月和10月四个季度10个站位定置张网调查资料,对福建三沙湾游泳动物的种类组成及季节变化进行分析研究.结果表明:调查共获得游泳动物209种,隶属于3门4纲19目73科144属,其中鱼类154种,甲壳类48种,头足类7种.游泳动物种类数以秋季出现最多,四个季节共同出现的种类有42种.鲈形目种类最多,其次是十足目.鱼类适温性以暖水性种类居多,占71.43％,暖温性种类次之(27.92％);生态类型以底层、近底层鱼类居多,两者合占75.97％.鹰爪虾(Trachypenaeus curvirostris)、大黄鱼(Larimichthys crocea)、棘头梅童鱼(Collichthys lucidus)、红星梭子蟹(Portunus san-guinolentus)和日本(Charybdis japonica)等14个种类是三沙湾游泳动物的优势种类,季节性优势种居多.三沙湾定置张网调查渔业资源质量密度为111.09 kg/km2,尾数密度为13.72×103 ind./km2,均以夏季最高,春季最低.应该进一步加强对三沙湾渔业资源的合理利用和有效保护,同时重视对外来物种的监测.

Red swimming crab, Monomia haanii, is one of China's most valuable crab export products, but the fishery is managed with very limited scientific information. There is currently no analytical stock assessment for this little studied, but highly sought-after species. Here, a new equilibrium-based bioeconomic model was developed and applied to the M. haanii fishery in the southern Taiwan Strait, China to assess the performance of the current management approach in terms of revenue, yield, and egg production. Because the species is short-lived and grows rapidly, simulations were conducted to evaluate whether temporal allocation of fishing effort can improve performance along these dimensions by optimizing the tradeoffs between growth and mortality. Overall, we found that M. haanii is both highly productive and heavily exploited. Rapid harvest of sublegal individuals and females in the first half of the fishing season (August-December) after the national summer fishing moratorium, results in reduced yield, revenue, and egg production relative to management approaches that either spread fishing mortality throughout the year enabling more somatic growth, or target larger crabs. These outcomes were robust over a variety of model sensitivity scenarios, including changes in the timing of settlement, growth rate, and fishery selectivity. Evaluating such tradeoffs will be essential for sustainable management of Chinese swimming crabs in the face of heavy fishing pressure and environmental change.

本文基于线粒体细胞色素C氧化酶亚基I(COI)基因和16 S rRNA基因片段对采集于厦门海域的仔稚鱼样品进行种类鉴定,探究其在仔稚鱼种类鉴定中的适用性.研究共获得64条COI基因序列和74条16S rRNA基因序列,通过序列比对,COI基因将仔稚鱼样品鉴定为26个种类,其中19个种类鉴定到种、6个鉴定到属、1个种类仅鉴定到科;16S rRNA基因将仔稚鱼样品鉴定为29个种类,其中23个种类鉴定到种、6个鉴定到属.COI基因的平均种内遗传距离为0.0015,平均种间遗传距离为0.1976,16S rRNA基因的平均种内遗传距离为0.0003,平均种间遗传距离为0.0892,COI和16S rRNA基因的平均种间遗传距离都为平均种内遗传距离的10倍以上,两者都可以进行有效的仔稚鱼种类鉴定.在基于COI和16S rRNA基因构建的系统进化树上,所有物种都分别单独聚为一支,同一个种类的不同个体都能聚在同一个分支,这些物种均能得到有效区分.以上结果表明,COI和16S rRNA基因均可以实现仔稚鱼的种类鉴定,两种基因结合使用可以提高仔稚鱼种类鉴定的准确性.

基于2016年4月和10月闽南渔场渔业资源的专项调查数据,运用相对性重要指数、平均拥挤度指数、聚块指数、Cassie指标、Mrisita指数等方法分析闽南渔场游泳动物优势种组成及其种群聚集特性,比较不同的季节、类群和种类及其相互间的聚集状态,探究种群聚集驱动因子,旨在发现闽南渔场游泳动物优势种种群聚集的特征、内在规律和形成机制。结果表明,闽南渔场游泳动物优势种共17种,其中鱼类6种、虾类3种、蟹类4种、头足类4种;鱼类中六指马鲅（Polydactylus se-xfilis）聚集强度最强,头足类中火枪乌贼（Loligo beka）聚集强度最强;虾类和蟹类中春季以哈氏仿对虾（Parapenaeopsis hardwickii）和拥剑梭子蟹（Portunus gladiator）的聚集强度最强,而秋季以鹰爪虾（Trachypenaeus curvirostris）和日本蟳（Charybdis japonica）的聚集强度最强;鱼类、虾类、蟹类和头足类中春季分别以二长棘犁齿鲷（Evynnis cardinali）、鹰爪虾、三疣梭子蟹（P.trituberculatus）和火枪乌贼的平均拥挤度最高,而秋季分别以带鱼（Trichiurus lepturus）、鹰爪虾、拥剑梭子蟹和杜氏枪乌贼（Loligo duvaucelii）的平均拥挤度最高;闽南渔场游泳动物优势种的平均拥挤度呈现出秋季高于春季,虾类、蟹类种群聚集强度大于鱼类、头足类的特点。

福建省是我国海洋渔业大省,海水养殖产量位居全国第一,海洋捕捞产量位居全国第三,海洋渔业为保障优质动物蛋白供给、提高全民营养健康水平、促进渔业产业兴旺和渔民生活富裕等做出突出贡献,同时,在实现碳中和/减排二氧化碳、净化水质/缓解水域富营养化等生态服务功能方面也发挥着重要作用.该文在广泛调研福建省海洋渔业资源禀赋、发展现状、制度建设等方面的基础上,深入剖析福建省海水养殖、伏季休渔、限额捕捞、增殖渔业等面临的问题和挑战,综合分析了国内外渔业高效管理和实践的成功案例,从发展环境友好型的海水养殖业和发展资源养护型的捕捞业两个方面,提出了适宜福建省海洋渔业绿色发展的实施路径、保障措施和政策建议,以期为福建省海洋渔业绿色发展提供技术支撑.

2015年3月(春季)和10月(秋季)用110 kW、囊网网目30 mm桁杆单拖作业船于九龙江口海域10个调查站位,每个站位拖捕1网次,每次拖曳20 min,研究该海域渔业生物群落的种类组成、优势种、数量分布、多样性等特征,为九龙江口渔业资源可持续利用和管理、渔业资源承载力研究提供基础资料.调查结果表明,春、秋两季调查共捕获渔业生物种类114种,隶属18目48科81属,以热带和亚热带暖水性种为主,其区系属印度西太平洋区的中国 日本亚区;渔业生物种类更替率为68.4％,渔获物优势种(相对重要性指数＞1000)有脊尾白虾、凤鲚、日本蟳等8种,优势种类更替明显,经济种类占有较大比例,以生命周期短、中小型种类居多;春、秋两季渔获质量平均密度指数分别为167.43 kg/km2和163.36 kg/km2,渔获类群均以鱼类为主;Shannon-Wiener多样性指数平均为2.38,Margalef物种丰富度指数为4.64,Pielou均匀度指数为0.76,渔业生物群落丰度等具有较强的季节变化,多样性较历史数据有所下降.

利用2017年8月-2018年4月采集单船底层拖网调查的白姑鱼渔业生物学数据,研究了闽南-台湾浅滩渔场白姑鱼体长组成、体质量组成、体长与体质量关系、性比、性腺成熟度和摄食等级等渔业生物学特性.结果 表明,白姑鱼体长范围为45 ～202 mm,优势体长组为120 ～150mm,占总数48.4％;体质量范围为2.0～219.0 g,优势体质量组为40.0 ～70.0 g,占总数43.0％.各月份之间体长均值和分布均存在显著性差异(F=25.161,P＜0.05);体长与体质量关系为W=2.560×10-5L2.9717 (R2 =0.983 8);雌雄性比为2.16:1,性腺成熟度以Ⅱ期为主,占86.32％,未发现有Ⅴ期及以上样本;摄食等级以0～1级为主,占样本总数71.11％,各月份摄食等级也存在显著性差异(F=10.346,P＜0.05).本次调查白姑鱼达到可捕体长的仅占16.1％,说明拖网作业对幼鱼的损害比较严重.为持续利用白姑鱼资源,建议加强生殖群体和幼鱼群体的保护.

为探讨DNA条形码技术在石首鱼科鱼类物种鉴定中的有效性,本研究扩增测序7个物种的石首鱼科COⅠ基因序列,并从GenBank下载同源序列,最终获得石首鱼科14属23种65个个体的COⅠ基因进行序列分析和系统进化研究.结果 表明,石首鱼科COⅠ基因序列中A+T含量高于G+C含量,且第1个密码子位点G+C含量显著高于第2和第3密码子位点.石首鱼科种内遗传距离为0～0.014,平均种内遗传距离为0.004,种间遗传距离为0.050～0.368,平均种间遗传距离为0.202,是种内遗传距离的50.5倍.在系统进化树上,除仅有单一序列的物种外,其他种类的不同个体分别聚为独立的一支;黄鱼属、梅童鱼属有明显的单系性,而白姑鱼属、黄姑鱼属、叫姑鱼属没有呈现明显的单系性.以上结果表明,线粒体COⅠ基因可以实现石首鱼科鱼类的有效鉴定,并且可以用来进行属、种水平的系统进化分析.

根据2016年秋季北太平洋公海调查所采集的鲐鱼样本生物学数据,对其生物学特性进行了初步研究.结果表明,8～10月鲐鱼叉长范围为160～425mm,优势叉长组为170～230mm,占总数的48.65％,各月份之间叉长均值和分布均存在显著性差异(F=57.132,P＜0.05);叉长与体重关系为W=1.056×10-6L3.4101(R2=0.9868);雌雄性比为1.23:1,性腺成熟度以Ⅰ期为主,占63.40％,未发现有Ⅲ期及以上样本;摄食等级以2～4级为主,占样本总数的79.15％,各月份摄食等级也存在显著性差异(F=9.921,P＜0.05).

[Objective]Studied and analyzed the quantitative distribution and population structure of P.hardwickii.[Method]The shrimp survey of four seasons was conducted in the outer-sea of Northeast Fujian (26°- 28° N,120°-125°30′ E) in May, August, November of 2008 and February of 2009.[Result]The catch of P.hardwickii accounted for 4.8％ of the total biomass of shrimp, and the total frequency was 22.4％. The average density index of total catch was 3.47 kg·km-2. The average density index of appearance station ranged from 0.04 to 60.11 kg·km-2, with an average of 15.50 kg·km-2. The quantity in August and November 2008 was higher with the total catch accounted for 35.6％ and 40％ respectively. The average density index of the catch was lower in February 2009 and May 2008 with.4.78 kg·km-2 and 5.56 kg·km-2 respectively The frequency of the survey station within 60 m depth was 100％, and the catch accounted for 73.4％ of the total catch. The average density index of the catch was 16.44 kg·km-2 and increased to 60.11 kg·km-2, the frequency of 60 to 80 m depth of water was 31.2％, the catch accounted for 23.7％ of the total catch, the average density index was5.97 kg·km-2, and the depth of water more than 100 m had no distribution. The body length varied between 32 and 119 mm with the dominant between 80 to 100 mm which occupying 54.8％; the average body length and weight of the female were 86.2 mm and 7.2 g, and the male were 66.5 mm and 3.1 g respectively. The female and male ratio was1︰0.11, the feeding intensity was slightly larger, the empty stomach and satiety rate were all low, the average feeding level was 1.62.[Conclusion]The spatial and temporal variation of the quantity distribution of P.hardwickii was obvious. This mainly occurred in summer and autumn, and the quantity of spring was very low. The spatial distribution is mainly inhabited by the offshore waters within 60 m depth. The fishing season was from February to May and August to November. To make suitable temperature and migrate to the deep water area was at the end of autumn and start of winter. The female was obvious larger than the male, and the quantity was more than the male. The average feeding intensity was slightly larger, and the average feeding intensity of different seasons and sexes was not significantly different. In order to comprehensively analyze the population structure and sustainable utilization of P.hardwickii, we should further strengthen the dynamic monitoring and collection of biological data on the resources.

根据2016年4月(春季)和10月(秋季)东山湾拖网定点调查资料,研究分析了东山湾渔业生物群落结构及其生物量分布特征.结果表明,调查共获取渔业生物128种,其中鱼类88种、虾类9种、蟹类19种、口足类4种、头足类8种,主要以暖水性种类为主;春季渔获物优势种为斑鰶(Clupanodon Punctatus)、黄吻棱鳀(Thrissa vitirostris)和短吻鲳(Leiognathus brevirostris)等3种,秋季则为日本蟳(Charybdis japonica)、青鳞小沙丁鱼(Sardinella zunasi)、食蟹豆齿鳗(Pisodonophis cancrivorus)、矛形梭子蟹(Portunus hastatoides)、黄吻棱鳀和赤鼻棱鳀(Thrissa kammalensis)等6种,优势种季节更替明显;春、秋季渔业生物群落质量平均资源密度指数分别为214.91 kg·km-2和265.19 kg·km-2,数量平均密度指数分别为12.51×103尾·km-2和12.02×103尾·km-2,渔业资源有衰减趋势;Margalef种类丰富度指数平均值为5.112,Shannon-Wiener种类多样性指数平均值为2.179,Pielou种类均匀度指数平均为0.635,春季均明显低于秋季,生物多样性处于较低水平.

依据2016年秋季西北太平洋公海灯光敷网探捕调查采集的数据,对其渔获组成及主要种类生物学特性进行了初步研究.结果表明:调查期间平均日产13.65t,最高出现在10月,为19.14t,最低出现在8月,为10.58t;CPUE平均为1822.4kg/h,最高出现在10月,为2492.2 kg/h,最低出现在9月,为1412.8 kg/h.渔获种类隶属于8目12科16属16种,其中鱼类7目11科14属14种、头足类1目1科2属2种;渔获种类总质量组成中,日本鲭(Scomber japonicus)占绝对优势,产量所占比例高达72.0％,其次是远东拟沙丁鱼(Sardinops sagax)、秋刀鱼(Cololabis saira)和柔鱼(Ommastrephes bartrami),分别占比19.41％、7.94％和0.58％.群体组成中幼鱼数量比例较大,性腺成熟度均较低,对幼鱼的损害较为严重.

In the current study,we analyzed the aggregation pattern of Parapenaeus fissuroides Crosnier in sea area in the northeast of Fujian based on pattern intensity index of the negative binomial parameter,Morisita index,mean crowding,poly block index,and diffusion coefficient.We also discuss the factors that affect pattern intensity and ecological significance of the pattern intensity indices.The aim of the study was to explore new aspects in the protection of the fishery resources for P.fissuroides Crosnier.In spring,its population primarily consisted of twelve patches,which showed dispersed population distribution and the second smallest poly block index.The population in spring had the smallest mean crowding,the largest average distance between individuals,and the biggest diffusion coefficient compared to that in other seasons.In summer,the population mainly consisted of four patches with most concentrated population distribution.The biggest poly block index,biggest mean crowding,smallest average distance between individuals,and smallest diffusion coefficient were observed.In autumn,the population primarily consisted of five patches with moderately concentrated population distribution.The second largest poly block index and mean crowding as well as the second smallest average distance between the individual diffusion coefficient were explored.In winter,the population primarily consisted of fourteen patches with highly dispersed population distribution,the smallest poly block index,the second smallest mean crowding,and the second largest average distance between individuals and diffusion coefficient.The negative binomial parameter and Morisita index were employed to characterize the aggregation intensity.When the Morisita index is greater and the negative binomial parameter is smaller,the aggregation intensity is stronger,and vice versa.Mean crowding provided a more actual representation of the average individual crowding degree compared with the average density.Mean crowding reflected the average individual crowded degree.When mean crowding was large,the inter-specific competition was intense,and average distance between individuals was smallest.The poly block index revealed the constitution of the population patches.When the poly block index was big,the population primarily consisted of a few patches,and vice versa.The diffusion coefficient reflected the diffusion degree.The bigger the diffusion coefficient,the greater was the significant spread of the population.The food zooplankton was the major factor influencing the pattern intensity,and the inter-specific competition was the major factor mediating diffusion degree of the Parapenaeus fissuroides Crosnier in the sea area northeast of Fujian.In this study,the population distribution pattern intensity simplified the research of school behavior,which reflect the aggregation intensity,poly block,mean crowding,inter-specific competition degree,and diffusion degree to meet the school behavior inherent law.

The current study analyzed the aggregation of Solenocera crassicornis in the sea area northeast of Fujian based on the pattern intensity index of the negative binomial parameter,mean crowding,and poly block index and discussed the driving factors of population aggregation.Results revealed that the aggregation intensity and mean crowding were high and the population was mainly concentrated in small reunion plaques with a season-specific pattern.In spring,the population primarily consisted of a single patch with stronger aggregation intensity and the lowest mean crowding than that in the other seasons.In summer,the population primarily consisted of four patches with weaker aggregation intensity and higher mean crowding than those in the other seasons.In the fall,the population primarily consisted of seven patches with the weakest aggregation intensity and higher mean crowding than that in the other seasons.In winter,the population primarily consisted of a single large patch with the strongest aggregation intensity and the highest mean crowding.The population spread with increased individual growth rates.Zooplankton biomass (diet) and bottom water temperature were the major factors affecting aggregation intensity of S.Crassicornis.