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1.
根据2018年4月(春季)和10月(秋季)在舟山群岛东侧海域(29°10′25.54"~30°45′00"N,122°53′3.88"~124°48′28.31"E)开展的渔业资源底拖网调查所获得的蟹类数据,研究了该海域蟹类资源的种类组成、优势种、生物多样性等群落结构特征,同时分析了蟹类数量分布及其群落结构与温、盐等环境因子之间的关系。结果表明,调查海域春、秋季蟹类种类共有40种,隶属于12科,23属;其中,春季优势种为双斑鲟(Charybdis bimaculata),秋季优势种为双斑鲟和三疣梭子蟹(Portunus trituberculatus),均为广温、广盐性种类;秋季丰富度指数(D)及Shannon-Wiener多样性指数(H')高于春季,而Pielou均匀度指数(J')则相差不大;独立样本T检验方法显示,春、秋两季渔获量之间存在显著性差异(p<0.01);根据聚类分析与非度量多维标度排序分析,春、秋季蟹类均可划分为4个组群,SIMPER分析结果显示,秋季群落相似性大于春季;典范对应分析结果表明,底层水温和表层盐度是影响调查海域蟹类群落结构及数量分布的主要环境因子。  相似文献   

2.
This study reports the seasonal variability in aspects of the physiology of the shore crab Carcinus maenas from three estuaries in South-west England, each with varying anthropogenic inputs: Avon Estuary (‘relatively low’ impact), Yealm Estuary (‘intermediate’ impact) and Plym Estuary (‘relatively high’ impact). Crabs collected over 12 months from the Avon had a significantly ‘lower’ physiological condition in winter and spring compared to summer and autumn; in particular, haemocyte phagocytic capability (a general indicator of immune function) was significantly higher in winter and spring compared to summer and autumn, and total haemolymph antioxidant status (an indicator of oxidative stress) was significantly lower in winter compared to the remainder of the year. Potentially, shore crabs may be more susceptible to the effects of contaminant exposure, such as increased immunotoxicity (thus, reduction of immune function) and/or oxyradicals (or reactive oxygen species) exposure) especially in seasons of increased susceptibility i.e. summer/autumn (lower phagocytic capability) and winter (lowest antioxidant function). As the Avon was taken to represent the ‘reference’ site, this pattern is considered to reflect the ‘normal’ seasonal variability in shore crab physiology. Shore crab physiological condition from the ‘relatively high’ impact estuary (Plym) revealed increased cellular viability and antioxidant status in autumn and winter compared with that of the ‘standard’ pattern (Avon) However, crabs from the intermediate impact estuary (Yealm) only demonstrated significant physiological differences in summer as shown by a lower cellular viability. All crabs had been exposed to PAHs (confirmed by the presence of PAH metabolites in their urine) which may account for the observed differences in shore crab physiology. In conclusion, to aid understanding of the potential contaminant impacts on biota it is imperative that the ’normal’ seasonal variability of physiological condition be established. Biological effects-based monitoring studies should therefore be employed seasonally to potentially highlight ‘windows of sensitivity’ to contaminant impact.  相似文献   

3.
厦门港湾蟹类的分布   总被引:2,自引:1,他引:2  
蔡尔西 《台湾海峡》1990,9(2):166-171
本文根据我所1980年8月至1981年10月厦门港湾海洋环境综合调查,选取其季度月(11,2,5,8月)资料,研究该港湾蟹类的种类组成、数量分布与季节变化。  相似文献   

4.
We investigated sources of inter-annual variability in larval supply to crab and sea urchin populations at Bodega Head and Point Reyes in northern California. During the spring and summer upwelling seasons of the years 1992 through 1997 we monitored the weekly settlement rates of nine species of crabs and two species of sea urchins. As observed in previous studies, daily values of alongshore windstress, temperature and salinity provided evidence for the poleward flow of relatively warm, low salinity water from south of Point Reyes, an apparent retention zone, during upwelling relaxation events. In years dominated by these events (1992, 1993, 1995 and 1996) we observed that alongshore windstress, temperature and salinity were coherent and temperature was significantly correlated with cancrid crab settlement. During these years the magnitude of cancrid crab settlement and the fraction of cancrid crabs relative to other crab species settling were high. Over four years of concurrent sampling there was consistently greater cancrid crab settlement at the Point Reyes site, within the retention zone, than at Bodega Head. Settlement of non-cancrid crabs (porcellanids, grapsids, pagurids and majids) was not as closely linked to intra-annual patterns of upwelling and relaxation, possibly due to the shorter seasonal availability of larvae allowing for the influence of fewer relaxation events. Settlement of this group among years was positively correlated with environmental indicators of strong seasonal upwelling; high salinity, Bakun upwelling index and low temperature. Sea urchin settlement events were observed in June and July of 1992, 1994 and 1997 during warming periods when salinity and temperature were increasing and alongshore windstress was low. Across the six years of the study, we found that cancrid crab larvae had a more even seasonal availability than larvae of non-cancrid species, which settled in greatest numbers during the early portion of the upwelling season. Sea urchins settled in greatest numbers during the later part of the upwelling season. Together these patterns demonstrate the taxon-specific way that inter-annual variability in larval supply is forced by the coincidence of larval availability with favorable physical transport mechanisms.  相似文献   

5.
莱州湾鱼卵、仔稚鱼群落结构及多样性的季节变化   总被引:1,自引:1,他引:0  
为了解鱼卵、仔稚鱼的种群动态以及生物多样性的变化规律,2014-2015年利用大型浮游生物网对莱州湾海域20个站位进行表层水平拖网调查.4个航次共采获鱼卵135275粒,仔稚鱼2456尾,隶属于9目16科20属.鱼卵、仔稚鱼主要种类变化依次从春季的鳀(Engraulis japonicus)和鰉(Liza haemat...  相似文献   

6.
山东近海底层鱼类资源空间异质性   总被引:1,自引:0,他引:1  
本文根据2016−2017年山东近海渔业资源底拖网季度调查数据,应用多项空间自相关指标和变异函数,分析了山东近海底层鱼类资源的空间自相关性与空间异质性。结果表明,山东近海底层鱼类资源呈现出显著的空间聚集格局,存在着空间自相关性,其中在春季、夏季和冬季的空间自相关性较强,在秋季的空间自相关性较弱。从空间分布上来看,底层鱼类相对资源量指数高值区在春季、夏季位于山东半岛南部海域,在秋季、冬季高值区的范围大幅减小,而低值区四季均集中在莱州湾附近。变异函数的参数表明,秋季具有较强的块金效应,随机部分的空间异质性占总空间异质性的76.0%,春季、夏季和冬季随机部分的空间异质性仅占总空间异质性的26.2%、27.7%和23.6%。山东近海底层鱼类的空间自相关性和空间异质性呈现一定的季节变化,其与水温等环境因子的变化有较大关系。  相似文献   

7.
本文根据2016?2017年在长山列岛邻近海域开展的渔业资源和环境季度调查数据,利用两阶段广义可加模型分析了该海域褐牙鲆资源丰度的时空分布及其与相关因子之间的关系.结果表明,长山列岛邻近海域褐牙鲆资源丰度具有明显的季节变化,春、秋季资源丰度高于冬、夏季;褐牙鲆春、秋季主要分布在120.5°~122.5°E水域,夏、冬季...  相似文献   

8.
山东半岛南部近岸海域渔业资源群落结构的季节变化   总被引:1,自引:0,他引:1  
根据2006年夏、冬季和2007年春、秋季在山东半岛南部近岸海域进行的渔业资源底拖网调查资料,初步分析了该海域渔业资源群落结构特征。结果表明,该海域4个航次的调查共捕获渔业资源种类72种。2006年夏、冬,2007年春、秋4个航次的单位网次渔获量分别为18.1、6.9、1.3、10.3 kg/h。生物量的季节变化,依次呈夏季>冬季>秋季>春季。优势种类主要为赤鼻棱鳀(Thryssakammalensis)、长蛇鲻(Sauridaelongate)、方氏云鳚(Enedrias fangi)及口虾蛄(Oratosquillaorato-ria)、剑尖枪乌贼(Loligoedulis)、鹰爪虾(Rachypenaeus curvirostris)等。根据4个航次的调查数据,分别计算了渔业生物群落的种类丰度指数R、Shannon-Wiener多样性指数H′、Pielou均匀度指数J′。通过聚类分析、单因子相似性分析(ANOSI M)、相似性百分比分析(SI MPER),以及对该海域游泳动物资源结构现状与历史调查数据对比分析表明,该海域渔业资源群落结构存在衰退现象。本研究为山东半岛南部海域渔业生物多样性保护和资源管理提供了参考依据。  相似文献   

9.
浙南近岸海流季节变化特征   总被引:7,自引:1,他引:6  
为了揭示浙南海流特征及其季节和垂向变化规律,于2006—2007年在浙南岸外一固定点(平均水深约32m)利用ADP潜标进行了春、夏、秋、冬季4次多个潮周期分层海流流速流向观测。结果表明:(1)测点最大流速为148.9cm/s,相应流向为75°,出现在春季表层大潮落潮阶段;垂向平均最大流速为106.2cm/s,平均流向为81°,出现在夏季大潮落潮落急阶段。(2)剖面各层流速垂向差异明显,表层流速(28m层以上)受海况影响明显,秋季平均流速最大(65.4cm/s),冬季最小(42.8cm/s),20~28m层冬季最强,春季最弱,20m层以下夏季最强,秋季最弱(仅小潮);垂线平均流速夏季最强(46.5cm/s),春季最小(33.7cm/s)。(3)夏季海流基本上为(偏)北向流;秋、冬则基本上为(偏)南向流;春季具往复流特点,但以北向流为主。(4)垂向上夏季和春季流向较一致,冬季和秋季流向分异明显(20m和10m层)。(5)垂线平均余流为12.8~29.8cm/s,夏季最强春季最弱;夏季和春季各层余流均为东北向,冬季为西南向,而秋季11m层(包括11m层)以下为E-NEE向,11m层以上为西南向。结论:测点海流受到潮汐、季风和台湾暖流的共同制约。季风的影响夏、冬两季大于春、秋两季;季风的影响自表层向底层减弱(主要限于表层以下10m)。  相似文献   

10.
分别研究了2006年7月(夏季)和2007年1月(冬季)、5月(春季)、10月(秋季)黄海西北部海域浮游细菌生物量的分布特征,探讨了它们与温度、盐度和Chl a含量之间的关系.结果表明,研究海区平均细菌生物量春、夏、秋和冬季分别为:41.083,8.34,16.68和6.20 mg/m3.4个季节表层细菌生物量分布均呈现出从辽东半岛近岸区域向外海逐渐降低的趋势.春、秋季除浮游植物Chl a外各生态因子与细菌生物量之间均无显著性相关关系.夏、冬季与温度、盐度和Chl a含量的相关性均不显著.  相似文献   

11.
On the basis of seasonal investigations at 23°30'~33°00'N,118°30'~128°00'E of the East China Sea during 1997~2000,dynamics on the density and diversity of Ostracoda was discussed.Results showed that totally 26 species were identified.The Ostracoda diversity was opposite to the change of its density in most seasons which reflected an uneven assignment of Ostracoda density among its different species.The Ostracoda density was 0.70 ind./m3 in spring,1.72 ind./m3 in summer,2.57 ind./m3 in autumn and 0.90 ind./m3 in winter.Euconchoecia chierchiae in spring and winter,Euconchoecia maimai in summer and Cypridina dentata in autumn were main dominant species in each season.The Ostracoda density did not show an obvious linear relationship with the hydrologic factors in summer and autumn,but was related to the surface salinity in spring and the surface temperature in winter.Its high density areas mainly distributed in the north offshore in all the seasons while in the south offshore in winter and in spring,and the south nearshore in summer and autumn,implied the zooplankton was a typical warm water animal,whose high density distribution in autumn were located in a similar position to Todarodes pacificus,Navodon Septentrionalis,Scomber japonicus and other fishes in the sea,so as to be an important indicator for fishing ground.The main species dominating in Ostracoda now are different from the species twenty years ago probably attributes to global warming.  相似文献   

12.
2004年10月至2005年8月,对不同季节千岛湖蚤状潘的垂直分布情况以及昼夜迁移进行了研究。结果表明,蚤状潘在千岛湖分布广泛,春季和夏季蚤状潘主要分布在15-25m水层,而在秋冬季分布相对均匀,从表层到60m水深都有分布;比较了蚤状漫在不同季节的迁移现象,春季和秋季蚤状潘为夜间迁移模式,而在夏季和冬季虽然都存在迁移现象,但不同于常见的三种迁移模式。  相似文献   

13.
千岛湖蚤状溞垂直分布格局及其季节与昼夜变化   总被引:3,自引:0,他引:3  
2004年10月至2005年8月,对不同季节千岛湖蚤状溞的垂直分布情况以及昼夜迁移进行了研究。结果表明,蚤状溞在千岛湖分布广泛,春季和夏季蚤状溞主要分布在15-25m水层,而在秋冬季分布相对均匀,从表层到60m水深都有分布;比较了蚤状溞在不同季节的迁移现象,春季和秋季蚤状溞为夜间迁移模式,而在夏季和冬季虽然都存在迁移现象,但不同于常见的三种迁移模式。  相似文献   

14.
福建宁德晴川湾海域水母群落特征及其潜在生态风险分析   总被引:1,自引:1,他引:0  
根据2018年1月(冬季)、4月(春季)、7月(夏季)和11月(秋季)在宁德晴川湾海域浮游动物调查的4个航次数据,分析该海域水母群落结构和季节变化特征,讨论了水母对宁德晴川湾核电站安全生产潜在的风险。结果表明:宁德晴川湾海域水母类种类组成、丰度分布和优势种演替均存在季节变化,春、夏、秋、冬该海域水母种数分别为7种、16种、9种和3种,丰度均值分别为(45.48±8.24)个/m3、(50.26±12.13)个/m3、(3.68±1.91)个/m3和(0.18±0.07)个/m3,首要优势种分别为印度感棒水母(Laodicea indica)、球型侧腕水母(Pleurobrachia globosa)、双生水母(Diphyes chamissonis)和耳状囊水母(Euphysa aurata),优势种类组成季节演替明显。春季和夏季水母的丰度与浮游动物的总丰度呈极显著相关,在夏季其数量与浮游动物中的桡足类数量呈显著相关(p<0.05,R=0.363),秋季和冬季水母群落的丰度主要受盐度的影响。秋...  相似文献   

15.
锯缘青蟹秋苗土池越冬的试验研究   总被引:4,自引:0,他引:4  
王桂忠  林琼武 《台湾海峡》1998,17(4):468-472
本文报道1993和1994年秋季作者培育的部分锯缘青蟹仔蟹苗土池越冬试验。结果表明人工培育的青蟹苗在闽南地区的自然条件下,可以在室外土池完全越科,成活率可达60-80%,水温是影响青蟹生命活动的主要因素;由于越冬期间青蟹营养积累不足,导致难以顺利地完成越冬后的第一次生长蜕壳,造成大量死亡,这是影响青蟹越冬存活率的主要因素之一;越科后期病死青蟹肝胰组织进行涂片处理,发现6只受检蟹中2只肝胰组织中有日  相似文献   

16.
2006年1月~10月福建闽东大嵛山附近海域游泳动物调查研究结果表明,该海域的游泳动物有97种,其中鱼类51种(软骨鱼1种,硬骨鱼类50种),隶属于9目24科42属;甲壳类42种,隶属于2目15科20属;头足类4种,隶属于3目3科3属.暖水性种类为33种,占鱼类总种数的64.7%;暖温性鱼类18种,占鱼类总种数的35.3%,未出现冷温性和冷水性鱼类.种类数的季节变化依次呈夏季〉冬季〉秋季〉春季.生物量的季节变化,依次呈夏季〉秋季〉春季〉冬季;而生物量尾数的季节变化,依次呈夏季〉春季〉秋季〉冬季.平均单位网次渔获生物量和密度分别为9.53kg/h和1 319 ind/h.生物量优势种和密度优势种分别为大黄鱼和中华管鞭虾.扫海面积法估算年平均现存资源量为57 370 ind/km^2和404.51kg/km^2.同时,本文对该海域游泳生物的资源结构现状与历史调查数据作了对比分析,并讨论了多样性结构与生物量的季节性变化规律.结果表明,该海域渔业资源有严重衰退的现象,多样性结构与生物量的季节性变化并不具有必然的一致性.  相似文献   

17.
于2009年7月20日至8月16日(夏季),2010年1月6日至30日(冬季),2010年10月26日至11月24日(秋季)和2011年4月30日至2011年5月24日(春季)在南海北部调查了微型异养鞭毛虫的生态分布特点。结果表明:春、夏、秋、冬的微型异养鞭毛虫丰度分别为0.05×103~1.93×103,0.03×103~2.65×103,0.09×103~2.05×103和0.04×103~1.84×103 cells/mL,生物量(以碳计)分别为0.56~19.50,0.04~24.11,0.96~14.80和0.29~22.26 μg/L。4个季节的微型异养鞭毛虫丰度均以2~5 μm粒级的为主,其所占比例超过65%,10~20 μm粒级所占比例通常低于10%。在水平分布上,微型异养鞭毛虫的丰度随离岸距离的增加逐渐降低;在垂直分布上,微型异养鞭毛虫的丰度随深度的增加逐渐降低,但夏季微型异养鞭毛虫丰度的高值多出现在次表层叶绿素a极大值层(DCM层)。微型异养鞭毛虫的丰度分布受到多重因素的交互影响,并且其所受调控模式在不同季节存在差异:春季和秋季微型异养鞭毛虫主要受下行调控;夏季微型异养鞭毛虫主要受上行调控;冬季上行和下行调控对微型异养鞭毛虫的影响相近。  相似文献   

18.
On the basis of the four-season investigation in 23°30′~33°N and 118°30′~128°E of the East China Sea from 1997 to 2000, the seasonal distribution of Calanus sinicus was studied with aggregation intensity, regression contribution and other statistical methods. It was inferred that C. sinicus’s predominance presented from winter to summer, especially in spring and summer, because its dominance amounted to 0.62 and 0.29 respectively. The percent of its abundance in copepod abundance was 76.71% in summer, greater than 66.60% in spring, greater than 19.02% in winter, greater than 4.02% in autumn. The occurrence frequency in winter and spring was 83.08% and 93.89%, higher than that in summer and autumn, 76.71% and 73.87%. Compared with other dominant species of copepods, C. sinicus’s contribution to the copepod abundance was obviously greater than that of the other species in winter, summer and spring, but smaller in autumn. C. sinicus tended to have an aggregated distribution. The clumping index peaked in summer (50.19), followed in spring (19.60), declined in autumn (13.18) and was the lowest in winter (3.04). The abundance changed in different seasons and areas, relating to temperature but not salinity in spring and autumn, to salinity but not temperature in summer; to neither temperature nor salinity in winter. In spring and summer, its high abundance area was often located in the mixed water mass formed by the Taiwan Warm Current, the Huanghai Sea Cold Water Mass, the coastal water masses and the Changjiang Dilute Water. In spring and autumn, its abundance was affected by the warm current, as well as the runoff from continental rivers affected it in summer. It can be inferred that C. sinicus was adapted to wide salinity and temperature, as a euryhalinous and eurythermous species in the East China Sea.  相似文献   

19.
The demand for mud crab Scylla serrata (Forsskål 1775) in the global market has increased, hence there is growing momentum to farm the species in Africa. Aquaculture production in Kenya and elsewhere in East Africa currently relies on juvenile seeds sourced from the wild. Wild-seed collection calls for management of the juvenile crab industry founded on knowledge of the species’ ecology, so as to achieve a sustainable seed supply and recruitment to the capture fishery. This study investigated the tidal, diurnal and seasonal occurrence of juvenile crabs in three habitats (intertidal-flat boundary zones, inside the mangroves, and in channels) in small creeks (Mida, Kilifi and Mtwapa) and Gazi Bay, on the coast of Kenya. Sampling was done with scoop nets and seining at receding tides and via burrow searches at low spring tides (day and night). Juveniles in the mangrove/intertidal-flat boundary zone were found sheltered under mangrove leaves or debris, or in shallow burrows during low spring tides, whereas at receding tides they could be seen moving out with the tide or searching for sheltering substrate or burrows. Catch per unit effort at high-abundance sites varied between 59 and 68 crabs fisher?1 day?1. More juvenile crabs, sized 10–80 mm internal carapace width (ICW), occurred at night during the receding tide. Net-seining was effective in the collection of juvenile mud crabs <30 mm ICW, whereas burrow sampling was effective for gathering larger crabs. However, collection of juveniles by seining reduced the quality of the crabs caught due to frequent loss of chelipeds, as compared with retrieving individual crabs by searching burrows. Some juveniles collected in the intertidal-flat boundary-zone habitat were either in the process of moulting or had just moulted, indicating the significance of this habitat for mud crabs at this physically delicate life stage.  相似文献   

20.
山东近岸黄海海域初级生产力的时空分布变化研究   总被引:2,自引:0,他引:2  
于2006年8月(夏季)、2006年12月(冬季)、2007年4月(春季)、2007年10月(秋季)对山东黄海近岸初级生产力的分布进行了4个航次的调查,并对其时空分布特征进行了分析.结果显示:(1) 调查海域春、夏、秋、冬4个航次的初级生产力平均值分别为808.798,372.23,324.717和246.146 mg·m-2·d-1,春季的初级生产力最高,冬季的最低.(2) 春、夏、秋季初级生产力的变化在水平方向上总体呈现出近岸高于远岸的分布特征,而冬季的变化趋势正好相反;在垂直分布上,4个航次初级生产力均以相对海平面光强30%~10%的水层为最高,其中夏季初级生产力分层现象明显,春、秋、冬季各水层间的差异不显著.(3) 环境因子的变化对初级生产力的作用不同,利用同化指数法求得的初级生产力比14C同位素示踪法测得的数值高出1~70倍.  相似文献   

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