南麂列岛岛礁区域鱼类种类组成和数量分布

采用底层拖网方法,以渔获率作为鱼类资源分布的数量指标,进行了南麂列岛岛礁区域2011年4月、8月、11月和2012年3月4个季节的鱼类种类组成、数量分布以及时空变化研究。结果表明:(1)调查海域鱼类有69种,鱼类种数夏季>秋季>冬季>春季;(2)六指马鲅、海鳗、棘头梅童鱼、龙头鱼、赤鼻棱鳀、白姑鱼、、中颌棱鳀、六丝钝尾虎鱼等15种鱼占鱼类总渔获量的89.13%,是调查海域底层拖网的主要捕捞鱼类;(3)不同季节的鱼类渔获量组成相差较大,优势种季节演替现象明显;(4)渔获率的季节变化明显,渔获率夏秋季明显高于冬春季,夏秋季渔获率较高的区域一般在调查海域西北方向的开阔海域。     

2007—2008年伏季休渔深圳市海域鱼类资源调查研究

为了解深圳海域鱼类资源的体长状况及种类变化所反映的伏季休渔效果,对2007-2008年休渔前、后四个时期所捕获的鱼类进行生物学称量、种类鉴定及其数据统计,结果表明:2007年共捕获鱼类90种,休渔前和休渔后均有66种;2008年共61种,休渔前后分别为30种、46种.另外,从休渔前后变化、年间变化等不同角度的数据比较分析,2007年和2008年休渔后比休渔前优质鱼类均有所增加,渔获个体稍有增大,但鱼类质量没有发生根本性变化;2008年与2007年相比,鱼类种类减少,个体小型化,沿海常见种出现频率降低,优质鱼类比例下降,伏季休渔成果难以长期巩固.     

厦门东海域鱼类的群落结构及种类多样性研究

2003年7月至2006年6月对厦门东部海域用定置网和流刺网渔获鱼类进行周年逐月采样分析.结果表明,该海域鱼类至少有287种,录属于21目87科164属,以鲈形目最多,有151种,占总种数的52.6%.渔获物组成以近岸小型鱼类为主,底层鱼类和中下层鱼类合计有235种,占81.88%;中上层鱼类仅52种,占18.12%.鱼类的亚热带动物区系特征明显,暖水性种类达221种,占77%,暖温性种类66种,占23%,未出现冷温性种类及冷水性种类.鱼类种类存在明显的季节更替现象,月更替率大多在30%以上,最高达72.1%.定置网渔获鱼类年平均数量为277尾·网-1,年平均产量为1.93kg·网-1,平均数量和平均产量均以夏季大于秋季大于春季大于冬季;月平均数量和月平均产量均以8月最高,分别为700尾·网-1和5.0kg·网-1,2月最低,分别仅为55尾·网-1和0.38kg·网-1.种类丰度及数量变化与海域水温变化总体呈正相关关系.Shannon-Wiener种类多样性指数的月变化在1.555-4.337之间,多数月份的指数值在3以上,多样性水平较高.渔获鱼类中经济种类占比例较大,但绝大多数个体都比较小,年平均尾重仅6.97g.根据营养动态法估算潜在资源量为1 133.30t年-1,目前厦门东海域鱼类总渔获量已超过最大可捕量一倍以上,应加强资源的管理和保护.     

厦门东海域定置网渔获鱼类种类组成及其季节变化

2003年7月～2004年6月对厦门东部海域的定置网渔获鱼类进行采样分析．结果表明厦门东海域至少有鱼类242种，隶属于19个目81科145属，主要是沿岸近底层和底栖的小型鱼类．以鲈形目种类最多，共计127种，占总数的52．5％、经济种类有116种．主要优势种有：青鳞小沙丁鱼、孔鳞小沙丁鱼、斑鲦、马拉邦虫鳗、裸鳍虫鳗、中华须鳗、前鳞鲻、眶棘双边鱼、多鳞鳝、皮氏叫姑鱼、短棘银鲈、列牙垒幸4、黄斑蓝子鱼、褐蓝子鱼、锯塘鳢、锻虎鱼类、褐菖鲇、绿鳍鱼、鳄鲡、卵鳎、中华单角鲍等．渔获种类在秋季及冬初最多，夏季较多，而冬末和春初最少．渔获种类的季节变化比较明显，与海洋表层水温变化有关，种类的月更替率比较高．     

东海区小型鱼类生态研究Ⅰ——小型鱼类的种类组成及季节变化

根据1997~2000年东海区底拖网渔业资源调查资料,分析和讨论了东海区小型鱼类的种类组成和季节变化。结果表明,东海区小型鱼类共有98种,优势种为发光鲷(Acropomajaponicum)、鳄齿鱼(Champsodon capensis)、鳀鱼(Engraulis japonicus)、七星底灯鱼(Benthosema pterotum)、细条天竺鲷(Apogon lineatus)、尖牙鲈(Synagrops japonicus)、黄鲫(Setipinna taty)、麦氏犀鳕(Bregmaceros macclellandi),各季节小型鱼类出现种类数及出现频率变化较小,渔获尾数和渔获质量变化显著。     

舟山渔场及邻近海域鱼类种类组成和数量分布

根据2006年8月、2007年1、5、11月在舟山渔场及邻近海域(29°30′—32°00′N,127°E以西)开展海洋生态系统综合调查所获得的游泳动物调查资料,用渔获率作为鱼类资源分布的数量指标,对舟山渔场及邻近海域的鱼类种类组成、数量分布、季节变化趋势作了定量分析。结果表明,舟山渔场及邻近海域鱼类种类约有139种,隶属14目、56科、105属,其中日本红娘鱼、绿鳍鱼、六丝矛尾虎鱼、细条天竺鱼、海鳗、黑、星康吉鳗、小黄鱼、前肛鳗、短吻舌鳎、棘头梅童鱼等25种鱼类占鱼类总渔获量的84.18%,是调查海域桁杆拖网的主要捕捞鱼类,而其它种类的渔获量较少。不同季节的经济鱼类渔获物组成相差较大,而优势种种类组成变化较少。渔获量高峰期主要出现在夏季,从不同区域的渔获率分布趋势来看,春、夏、秋季的鱼类渔获率都以江外渔场最高,其次是长江口渔场,舟山渔场居第三,而杭州湾河口区的鱼类渔获率明显偏低。冬季鱼类渔获率分布趋势与春夏秋季不同,以长江口渔场为最高,其次是舟山渔场,而江外渔场和杭州湾河口区渔获率明显偏低。与以往(20世纪60年代初)调查结果相比,舟山渔场及邻近海域鱼类种数组成、种群动态及群落结构都发生了很大的变化。     

南海北部陆架区底层渔业资源的空间分布特征

根据2006年10月至2007年9月南海北部大陆架海域4个航次底拖网调查资料,分析了该海域渔业资源的种类组成、种类丰富度和渔获率的空间分布。结果表明,渔获种类数以湛江断面最多(405种),汕头断面最少(337种)。种类数随水深变化呈非对称正态分布,以40—80m水深组种类数最多。物种丰富度指数D的空间分布与种类数基本一致。在总渔获物中,鱼类、头足类和甲壳类3大类群重量组成比例为80:12:8,在断面分布上,组成比例鱼类以珠江口断面最高,头足类以湛江断面最高,甲壳类以阳江断面最高。在水深分布上,鱼类占比随水深的增加而增加,头足类占比在40—100m水深较高,甲壳类在10—20m浅水区最高。鱼类最主要的优势种有6种,其中,深水金线鱼主要在90—120m水深占优势,黄鳍马面鲀在60—90m水深占优势,条尾绯鲤在60—120m水深占优势,单棘豹鲂鮄在120—200m水深占优势,六指马鲅在30—60m水深占优势,龙头鱼在10—30m水深占优势。鱼类渔获率断面分布以珠江口和粤西海域较高,汕头海域最低;水深分布渔获率随水深的增加而增加。头足类渔获率以粤西和珠江口海域较高,粤东海域较低;在100m水深范围内,渔获率随水深的增...     

胶州湾浅水区鱼类种类组成及其季节变化

根据2009年3月～2010年2月在胶州湾潮下带浅水区进行的逐月鱼类定置网调查,分析了胶州湾浅水区鱼类种类组成及其季节变化.结果表明:本调查共鉴定出鱼类44种,隶属于9目24科39属.渔获鱼类皆为硬骨鱼类,以鲈形目(Perciformes)的种类最多,有11科23属25种.在各科中,以虾虎鱼科(Gobiidae)鱼类种类最多,共9属10种.按适温类型分,暖温性鱼类共23种(占52.27％),暖水种14种(占31.82％),冷温种7种(占15.91％);按栖息水层组成分,底层鱼类36种(占81.82％),中上层鱼类8种(占18.18％);按产卵类别分,产浮性卵鱼类21种(占47.73％),黏着沉性卵鱼类11种(占25％),附着性卵鱼类9种(占20.45％),卵胎生鱼类3种(占6.82％).各生态类型鱼类种类组成季节变化明显,种类组成的平均季节更替率达63.3％.本调查在胶州湾浅水区发现40余种幼鱼,尤其仍存在鮻、许氏平鲉、钝吻黄盖鲽和短吻红舌鳎等经济种类,表明胶州湾仍是重要的鱼类产卵和育幼场,应加强对其生态环境和渔业资源的保护,以期保护渔业生物多样性和实现渔业资源的可持续利用.     

南澎列岛近海海域底拖网鱼类组成的季节性变化

1991年逐月对南澎列岛近海海域作底拖网调查,共捕获鱼类132种,其中软骨鱼类7种（4目6科6属）,硬骨鱼类125种（10目58科95属）,后 者以鲈形目居多（69种）。全年渔获优质种类为条尾鲱鲤、黑天竺鱼、二长棘鲷、大头狗母鱼、多齿蛇鲻、三线矶鲈、绿布氏筋鱼、多鳞Xi和乔氏台雅鱼等9种,其渔获尾数之和是渔获总数的71．1％。季节性优势种类除全年优势种类外,尚有粗纹Fu、半线天竺鲷、印白姑鱼、静Fu和翼红娘鱼等5种;各种类全的渔获尾数及出现月份数相关,各月份的渔获尾数和渔获种数不相关;渔获物中仅有少量的中上层鱼类（13种）。就适温性而言,该海区鱼类以亚热带性为主并兼有热带性特征,以Shannon、Brillouin、Simpson和McIn-tosh等多样性指标及相应的Hurlbert均匀度指标对逐月样本做估计,这8种指标之间高度显著相关;该海域鱼类的Shannon多样性指标及相应的均匀度指标皆以秋冬季为高,春夏季较低。     

杭州湾海域春、秋季鱼类种类组成和数量分布

采用底层拖网法,用渔获率作为鱼类资源数量分布的指标,进行了杭州湾调查海域2012年5月(春季)、10月(秋季)2个季节的鱼类种类组成、区系特点、数量分布等研究。结果表明:(1)杭州湾海域春、秋两季共获得并鉴定出的鱼类有31种,隶属于9目15科,其中以石首鱼科和■虎鱼科的种类为最多,各有5种,分别占总种数的16.7%;鳀科鱼类次之,有4种,占总种数的13.3%,优势种有睛尾蝌蚪■虎鱼、龙头鱼、刀鲚、棘头梅童鱼;(2)根据鱼类适温性可将该海域的鱼类分为暖水性、暖温性和冷温性3种适温类型,以暖温性种类为主,暖水性种类次之,而冷温性种类极少,仅有1种;(3)根据其生态习性,可分为河口性、沿岸性和近海性3种生态类群;(4)渔获数量分布规律是春季在调查海域的内侧或者说中西部较高,而湾口较低,秋季则正好相反。     

Effects of naphthalene and phenanthrene on visual and prey capture endpoints during early stages of the dourado Salminus brasiliensis

Naphthalene (NAP) and phenanthrene (PHE) effects on Salminus brasiliensis, a carnivorous freshwater fish, were investigated using behavioral tests. Larval stages of S. brasiliensis were exposed to water concentrations of 0, 0.04 mg/l, 0.20mg/l and 0.50mg/l for naphthalene and 0, 0.01 mg/l, 0.05 mg/l and 0.1mg/l for phenanthrene during two developmental phases. The prey fish Prochilodus lineatus were not exposed. Visual acuity was measured at the end of phase 2 in individual S. brasiliensis, which were also tested at the end of each phase for number of attacks on prey, number of prey captured, prey capture efficiency, and distance swam. Vision was impaired by PHE exposure, as acuity angles increased in exposed fish. At Stage I 2.3+/-1.2 prey were captured with 46% efficiency in controls compared to 0.4+/-0.3 prey captured with 13.4% efficiency in fish exposed to 0.05 mg PHEl(-1), the LOEL for both endpoints. At Stage II 4.0+/-1.1 preys were captured in controls compared to 2.5+/-0.9 preys captured in fish exposed to 0.01 mg PHEl(-1), the LOEL. Stage II control fish captured prey with 70% efficiency compared to 30% efficiency at Stage II fish exposed to 0.05 mg PHEl(-1), the LOEL. Distance swam was not affected by either NAP or PHE exposure. The exposure of larval stages of S. brasiliensis to realistic water concentrations of PHE impairs foraging skills and could affect recruitment of the species.     

Are vegetated areas of mangroves attractive to juvenile and small fish? The case of Dongzhaigang Bay,Hainan Island,China

Well-developed aerial roots of mangroves make it difficult to study how fish utilize the mangrove forest as a habitat. In the present study, we compared the differences in fish assemblages in three major types of habitats of mangrove estuary (vegetated area, treeless mudflat, and creek) of a mangrove bay in Hainan Island, China, at different seasons during two consecutive years. Three types of gears, centipede net, gill net and cast net, were used in the different habitats of mangrove estuary and sampling efficiencies among gears were evaluated. Centipede nets were used in all the three types of habitats and cast nets and gill nets in treeless mudflats and creeks. Fish assemblages were dependent on gears used. Centipede net could efficiently catch fish occurring both inside and outside of vegetated areas efficiently. A total of 115 fish species in 51 families were collected. In terms of numbers of species per family, Gobiidae was the most diverse (17 species), followed by Mugilidae (5 species). Almost all of the fish were juvenile or small fish and few predators were recorded, implying low predation pressure in the bay. ANOVA analysis showed that significant seasonal and spatial variation existed in species richness, abundance, and biomass, which were less in the vegetated areas than those of treeless mudflats and creeks. The attraction of vegetated areas to fish was less than that of creeks and mudflats. Many species were specific to a particular habitat type, 4 species occurring exclusively in the creeks, 45 species occurring exclusively in the treeless mudflats, and 5 species occurring exclusively in the vegetated areas. The results indicated that mangrove estuaries were potentially attractive habitats for juvenile and small fish, but this attraction was accomplished by a connection of vegetated areas, treeless mudflats and creeks, not only by vegetated areas.     

Histopathological biomarkers in estuarine fish species for the assessment of biological effects of contaminants

The increasing emphasis on the assessment and monitoring of estuarine ecosystems has highlighted the need to deploy appropriate biological indices for these locations. Fish diseases and histopathology, with a broad range of causes, are increasingly being used as indicators of environmental stress since they provide a definite biological end-point of historical exposure. This study reports on the histopathological alterations observed in selected organs and tissues of three species of estuarine fish (Platichthys flesus, Pomatoschistus minutus and Zoarces viviparus), captured from four British estuaries (the Tyne, Tees, Mersey and Alde), differently impacted by contaminants, including PAHs. A biannual sampling regime was used to identify the important seasonal variations that occur in terms of the observed biological effects. Inflammatory lesions and hepatocellular fibrillar inclusions attained their highest prevalence in P. flesus captured from the Tyne, Tees and Mersey. The presence of pre-neoplastic and neoplastic toxicopathic lesions was highest in P. flesus captured from these sites, when compared to fish from the Aide reference site. In particular, the prevalence of hepatic foci of cellular alteration (up to 43.3%) and hepatocellular adenoma (up to 10%) were highest in P. flesus captured from the Mersey estuary. Intersex (ovotestis) was only recorded in male P.flesus captured from the Mersey estuary (up to 8.3%) and from male Z. viviparous captured from the Tyne estuary (25%). Pathologies associated with the gill and the kidney were also most prevalent in fish captured from the Tyne, Tees and Mersey estuaries. This study has successfully applied histopathology to an estuarine monitoring program, both for the recording of toxicopathic lesions in the liver and other organs, and for the detection of the endpoint of endocrine disruption, intersex. As such, it provides a powerful integrative tool for the assessment of biological effects of contaminants in these environments.     

长江口张网鱼类群落结构特征及月相变化

为了解长江口鱼类群落结构的现状及变化特征,用张网作业对长江口2010年5月至2011年4月12个月鱼类群落进行了调查。结果1周年共记录56种鱼类,以鲈形目(27种)和鲱形目(10种)种类数目最多。鱼类区系为典型的亚热带动物区系,只出现暖水种(25种)及暖温种(31种)2种适温类型。鱼类种类数目以底栖鱼类(26种)和中上层鱼类占多数(21种),底层鱼类数目较少(9种)。丰度或生物量均由少数几种鱼类占优势。根据鱼类生态类群,海洋洄游性鱼类及河口性鱼类占据种类数目的主要地位,而生物量或丰度均由海洋洄游性鱼类占据主导。每网平均种类数目的最大值和最小值分别出现在7月(18.3种)和1月(7.2种),每网丰度最大值和最小值出现在11月(2 272尾/网)和1月(71尾/网),生物量的最大值出现在9月(11 892g/网),最小值出现在1月(351g/网),而主要种类丰度的时间分布差异也较大;基于丰度计算的Shannon-Wiener多样性指数及Simpson优势度集中指数在时间上也有较大差异,NMDS非度量多维尺度分析显示根据相似性鱼类群落在时间上可分为4组,相邻月一般相似性较近,但2010年12月和2011年1月相似性较小。此外,多元回归分析表明,在径流量、盐度及水温3个环境因素中,引起张网鱼类群落丰度时间变化的主要影响因素是水温。鉴于当前长江口张网捕捞努力量有增加趋势,为保护长江口鱼类群落,需要控制过高的捕捞努力量。     

大亚湾春秋季鱼类种类组成及年龄结构分析

2006年4月和9月对大亚湾海域通过拖网和流刺网捕获的鱼类进行初步调查.结果表明,渔获物中出现18目76科135属200种鱼类,其中软骨鱼纲4目5科5属6种,占调查鱼类总种数的3.0%;硬骨鱼纲14目71科130属194种,占调查鱼类总种数的97.0%.根据其适温类型可分为暖水性种、暖温性种和冷温性种,其中暖水性鱼类有183种,占总种数的91.5%;暖温性鱼类有16种,占总种数的8.0%;冷温性鱼类仅有1种,占总种数的0.5%.渔获物中底层和近底层鱼类占多数,其中,底层鱼类共有74种,占总种数的37.0%;近底层鱼类共有68种,占总种数的34.0%;中上层鱼类共有45种,占总种数的22.5%;岩礁鱼类有13种,占总种数的6.5%.大亚湾鱼类的年龄普遍偏低,以1 a龄鱼为主.与相邻海区鱼类区系特征比较,大亚湾海域具有我国热带和亚热带性海湾的鱼类区系特征.     

Acoustic monitoring using bamboo set net in the Southern Sea of Korea

High-temporal resolution profiles of acoustic backscatter were collected from a traditional bamboo set net along the coast of the Southern Sea, Korea, using sideward-looking multi-beam imaging sonar. These data were used to examine the impact of variations in tidal cycles and current speeds on the bamboo set net. The relatively high influx of fish during the nighttime compared to the low influx and high outflux of fish during the daytime suggests visual avoidance of the net by the fish during the daytime. The observed diel variation in the captured fish flux was significantly correlated with the current speed (day: r = 0.35, p = 0.002, night: r = 0.60, p < 0.001). The ratio of influx and outflux of fish, and current speed were correlated in a linear relationship (day: r = 0.45, p < 0.001; night: r = 0.56, p < 0.001). The fish activity of those inhabiting the bamboo set nets appears to be greatly influenced by day-night differences and current speed. The present study enhances understanding of fish behavior via utilization of a bamboo set net in the coastal zone.     

The importance of estuary head waters as nursery areas for young estuary- and marine-spawned fishes in temperate South Africa

The restriction of freshwater flow into estuaries, the presence of in-stream barriers and the occurrence of invasive fish species in these habitats are identified as major threats to these young estuary- and marine-spawned fish species. These aspects have been investigated using the distribution and abundance of young estuary- and marine-spawned fish species in the headwater environments of four permanently open estuaries of the Eastern Cape, South Africa. Fishes were collected twice per season over the 2009 and 2010 period, using mixed method sampling with seine net hauls and overnight fyke net deployments. Of the 74,751 fishes collected, 37,444 fishes, 18 families and 34 species were taken in fyke net catches, while 34,308 fishes, 21 families and 38 species were caught in seine nets. In the Great Fish, Kowie, Kariega and Sundays River systems, juveniles of estuarine residents dominated headwater catches, followed by juveniles of estuary-dependent marine species. The prevalence of larval and small juvenile stages of estuary- and marine-spawned fish species highlights the potential importance of these transitional areas for young fish.     

东海南部海域头足类群落结构特征及其与环境关系

根据2008年春(5月)、夏(8月)、秋(11月)、冬(2009年2月)四季东海区桁杆拖虾网调查期间所采集的头足类资料,分析了东海南部海域头足类种类组成及优势种,采用生态多样性指数分析了群落物种多样性,并运用典范对应分析法研究了头足类群落变化与主要环境因子的关系。结果表明:东海南部海域共捕获头足类22种,隶属于3目6科8属,优势种主要有神户乌贼(Sepia kobiensis)、双喙耳乌贼(Sepiola birostrata)、短蛸(Octopus ocellutus)和杜氏枪乌贼(Loligo duvaucelii)等;种类丰富度指数D变化范围为0—1.30,多样性指数H′变化范围为0—1.69,均匀度指数J变化范围为0.02—1.00,t检验表明,各群落多样性指数四季之间的差异均不显著(P0.05);根据典范对应分析认为,底层水温为影响调查海域头足类种类组成的主要环境因子。     

2010-2011年长江河口及邻近水域春夏季仔稚鱼群落结构及其多样性的研究

根据2010—2011年春夏季对长江河口及邻近水域进行了仔稚鱼生态调查,应用单元和多元统计方法分析了春夏季长江河口及邻近水域仔稚鱼群落结构。4个航次调查共获得27个种类的仔稚鱼,隶属5目14科。优势种类主要包括鳀Engraulis japonicus、凤鲚Coilia mystus、康氏小公鱼Stolephorus commersonii、鮻Liza haematocheila、黄姑鱼Nibea albiflora、黄鳍刺虎鱼Acanthogobius flavimanus和寡鳞飘鱼Pseudolaubuca engraulis等。Shannon-Weaver指数(H′)在调查周期内的波动幅度较大,且2011年明显低于2010年。仔稚鱼群落结构和多样性指数春季年间较夏季年间差异性显著。调查区夏季群落结构年间相似性不高,春季群落结构格局年际变化则较明显。聚类分析表明,春夏季长江河口近岸水域仔稚鱼群落可划分为2个站位组,分别对应于长江河口淡水水域和长江口咸水水域。淡水水域组群落和咸水水域组群落总丰度与盐度相关性较高。表明盐度可能是造成长江河口仔稚鱼群落结构时空差异性的主要原因。