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1.
Zooplankton of the lake Jaisamand was represented by 50 taxa out of which 22 were Rotifera, 18 Cladocera, 5 Protozoa, 3 Copepoda and 2 Ostracoda. The total zooplankton exhibited a bimodal pattern with the first peak occurring in December and the second of a little less magnitude in June. The perennial zooplankters were Keratella valga, Brachionus falcatus from Rotifera, Ceriodaphnia spec. from Cladocera and Mesocyclops and Heterocyclops spp. from Copepoda. Considering surface zooplankton as a whole, Rotifera dominated the planktonic biomass followed by Copepoda, Cladocera, Ostracoda, Protozoa and Insecta. The species composition of the mid-stratum zooplankton was not much different from that of the surface. Interestingly, there was a presence of Cladocera in the anoxic bottom waters. The low and occasional presence of Calanoid copepods, the abundance of Cyclopoids and Cladocerans point to the eutrophication in the lake.  相似文献   

2.
抚仙湖浮游甲壳动物群落结构与空间分布   总被引：4，自引：3，他引：1  
云南抚仙湖是我国典型的高原深水湖泊,为揭示湖中浮游甲壳动物对生态系统变化的响应,研究了其群落结构与空间分布特征.2005年6-7月在抚仙湖共采集浮游甲壳动物8种,平均密度为27.6ind./L,优势类群为桡足类.桡足类优势种为舌状叶镖水蚤(Phyllodiaptomus tunguidus Shen et Tai),枝角类优势种为角突网纹涵(Ceriodaphnia cornuta Sars)和象鼻溞(Bosmina sp.).浮游甲壳动物主要分布在0-30m水层,密度随水深增加而下降;0-10m水层,枝角类和无节幼体占优势,大于10m水层,桡足类占优势.浮游甲壳动物密度南区大于北区(P<0.01),而沿岸区与湖心区之间、沉水植物区与非沉水植物区之间无显著性差异(P>0.05).相关分析表明:浮游甲壳动物密度的垂直分布与藻类密度和水体理化凼子相关关系显著,而水平分布与藻类密度和水体理化因子相关关系不显著.与20世纪80年代相比,抚仙湖浮游甲壳动物优势种发生了演替,西南荡镖水蚤(Neutrodiaptomus mariadviagae mariadviagae (Brohm))消失,被舌状叶镖水蚤代替,可能与太湖新银鱼(Neosalanx taihuensi Chen)引入有关;浮游甲壳动物密度表现出增加趋势,但仍处于较低水平,与水体营养水平的提高及太湖新银鱼的捕食压力有关.  相似文献   

3.
安徽女山湖自然保护区浮游生物群落生态   总被引：2，自引：0，他引：2  
鲍方印  肖明松  王松  崔峰 《湖泊科学》2010,22(5):729-734
2007年4月-2009年5月对安徽女山湖自然保护区浮游生物群落生态进行调查研究,共检出浮游植物8门45属113种;浮游动物包括原生动物、轮虫、枝角类、桡足类,共检出33属78种.分析表明女山湖不同季节浮游生物种类组成的变化趋势不同,但整体看来,浮游植物组成以蓝藻为主,浮游动物以轮虫为主;浮游生物量在不同季节波动较大,表现为夏季春季秋季冬季,而不同年份同一季节的生物量变化不大.浮游生物的多样性指数在不同季节的变化较大,而丰富度指数D在不同季节变化不大,大多数在1.3-3.9之间,均匀度指数J′在0.5-0.8之间.平均溶氧量PG达2.62mg/L.综合判定,女山湖属于中富营养型,浮游动物群落结构和组成相对稳定,具有较大的开发利用潜力.  相似文献   

4.
The objective of the study was to determine which factors regulate zooplankton organisms along Lake Nasser. Temperature, pH, DO, conductivity, turbidity, nutrients, and zooplankton abundance were measured. Twenty-three species of zooplankton were recorded in Lake Nasser included in Copepoda, Cladocera and Rotifera. Copepoda represented the main bulk of the community. The lowest standing stock of zooplankton was noticed during spring due to the highest fish predation during this season associated with the lowest turbidity. Big difference in temperature in Lake Nasser along the year round is considered as a controlling factor related to range of tolerance of species. The oscillation of the lake water level and the different factors affect the standing stock of zooplankton in the lake. Thus, continuous monitoring of Lake Nasser biota should be undertaken to follow the changes in the ecosystem.  相似文献   

5.
高山湖泊对于全球气候变化及人类影响是一个极为敏感的参照系统.九寨沟国家级自然保护区长海作为一个独特的高山湖泊,研究其浮游植物群落结构及其与环境的关系,评估其水质现状及影响因素,有着重要的意义.本文于2014年7月对长海浮游植物群落结构进行了研究.全湖共布设12个采样点,并在中心采样点进行了垂直分层采样.本次调查共发现浮游植物6门38属63种,平均丰度为6.98×10~5cells/L,平均生物量为0.31 mg/L.浮游植物的水平分布差异不大;在垂直分布上,浮游植物的丰度从表层0.5 m至水下50 m呈现先增加后减少的趋势,在20 m水深处达到最大.长海浮游植物的优势种是长海小环藻(Cyclotella changhai)和飞燕角甲藻(Ceratium hirundinella),长海小环藻数量较多,飞燕角甲藻生物量较大.长海浮游植物多样性指数较低,综合各类水质评价方法,可以得出九寨沟长海处于贫-中营养状态.  相似文献   

6.
The feeding activity of adult roach (Rutilus rutilus), perch (Perca fluviatilis) and ruffe (Gymnocephalus cernuus) was studied over a one year cycle to show trophic relations between fish and the prey communities in eutrophic Lake Aydat.Daily consumption rates were referred to the stock of the different age classes of fish. Seven food compartments (phytoplankton, macrophytes, Cladocera, Copepoda, macroinvertebrates, fish and sediment) were used by the fish. The main prey compartment ofR. rutilus were macroinvertebrates (39.7%), sediment (29.0%), macrophytes (15.4%) and phytoplankton (14.9%). Little zooplankton was consumed (2.4%).P. fluviatilis fed mainly on macroinvertebrates and fish fry (both 41.8%) and some zooplankton (15.0%). ForG. cernuus, macroinvertebrates dominated in the diet (97.4%). During spring, Bacillariophyceae and macroinvertebrates represented the principal preys. During summer, insect larvae, phytoplankton and macrophytes were the principal components of the diet. At the end of summer, macrofauna was scare and fish tended to move to the pelagic zone feeding on plankton. In autumn, the prey spectrum was large. During winter, sediment was the most important item consumed, together with some macroinvertebrates. The impact of this fish community through consumption is highest on macroinvertebrates (40.7%), flora (27.7%) and sediment (28.4%). The predation of these three fish on zooplankton was low (1% per day of the zooplankton biomass) and restricted to periods when the other items were scarce. Interspecific competition is not excluded for macroinvertebrates.  相似文献   

7.
太湖新银鱼、鲚鱼的食性比较及相互影响分析   总被引：9，自引：2，他引：7  
在太湖,通过对263个太湖新银鱼和鲚鱼胃含物样本的食物组成分析和比较,研究了两种鱼类间的食物关系;并结合太湖历年鱼类渔获量资料,对渔获量变化间可能存在的相互影响进行了偏相关分析.结果表明:太湖新银鱼在4月份的食物中以桡足类为主,占个数的70.11%±10.57%,其次是枝角类,为29.84%±10.62%,轮虫的数量极少,仅占0.05%±0.11%;在4月份1 鲚鱼的食物中以枝角类为主、占79.35%±11.42%,桡足类占19.97%±10.78%,而轮虫和虾的数量很少,分别占0.49%±0.45%和0.20%±0.44%.而在9-10月份0 鲚鱼的食物中,枝角类占89.77%±13.69%,桡足类占7.84%±11.53%,轮虫占2.39%±4.95%;用Pianka提出的公式,计算两种鱼类在4月份5个采样点的饵料重叠系数平均为0.4739±0.2810,没有达到Keast提出的Ojk＞0.7的严重重叠水平;计算5个采样点的相同食物组成比平均为46.42%±20.32%,和饵料重叠系数接近.而偏相关分析表明:两种鱼类数量变化间的相关关系是负向的,且随着鱼类密度的增加,负相关关系的显著水平有不断提高的趋势.如1973-1984年期间的负相关关系远没有达到显著水平(r=-0.2531 p=0.584),而1985-2004年期间的负相关关系接近显著水平(r=-0.4395 P=0.101).分析认为:太湖新银鱼和鲚鱼的食物虽有重叠,但通常情况下食物竞争并不激烈;种群数量变化间的相互影响是负向的,没有达到显著水平.可能仅在两种鱼类密度很高时,激烈地食物竞争才会发生、并主要表现为对哲水蚤和剑水蚤的竞争;且数量间负向的相互影响有加强趋势.  相似文献   

8.
Limnological characteristics of Lake Burdur in Lake District in south‐western Turkey are presented. It is a deep, tectonic (estimated max. depth 100 m), athalassic, highly alkaline, and saline lake. A set of physical and chemical variables was monitored, phyto‐ and zooplankton was sampled from surface layer of the lake during 1997. Physico‐chemical variables indicated that the lake is hyposaline and composed of some hydrochemically different water layers formed by groundwater sources located on the bottom of the lake. The phytoplankton composition of Lake Burdur consisted of Cyanophyta, Chlorophyta, Bacillariophyta, Dinophyta, and Chrysophyta. The abundance and number of species of Chlorophyta and Cyanophyta were higher than the other taxa. The zooplankton composition of the Lake consisted of Rhizopoda, Rotifera, and Crustacea. Number of species of Rotifera was higher than the other taxa. The diversities of the phyto‐ and zooplankton were calculated according to the Shannon‐Weaver diversity index. The diversity of each group was found to be low in the lake.  相似文献   

9.
Microcosm tests were conducted to investigate the effects of the estrogenic substances nonylphenol (NP) and 17α‐ethinylestradiol (EE) on aquatic ecosystems. Maximum concentrations of 9 to 120 μg L—1 NP resp. 49 to 724 ng L—1 EE were induced by controlled release. The controlled release method allows the establishment of a continuous concentration course. The microcosms proved to run robustly with abiotic conditions close to natural. They developed biocenosis with similar characteristics as in natural ecosystems and, considering their given level of complexity, they can be used to describe possible risks for the environment. Both tested chemicals unveiled the potential to affect the plankton communities in the tested concentration range. NP exposure caused a reduction of Cladocera and Copepoda abundances and disturbed the phytoplankton structure. A NOECcommunity of 30 μg L—1 was calculated. In the first EE study, a flood in the lake where the microcosm water was collected caused additional stress and thereby a high variability, both between the microcosms and in each microcosm over time. Probably therefore the only effect found was a reduction of Copepoda abundance. In a second EE study Cladocera and Copepoda abundances were reduced, from which the phytoplankton benefited. Although a final interpretation is difficult for results of microcosm tests, there are indications that the found effects of EE and perhaps also NP may be caused at least partially by endocrine disruptive activity.  相似文献   

10.
滇池沉水植物的分布格局及其水环境影响因子识别   总被引：2，自引：2，他引：0  
研究滇池沉水植物的分布及其与水环境因子的关系,对于滇池沉水植物的恢复具有重要的指导意义.2016年4-11月对滇池24个典型点位沉水植物群落特征进行调查,共发现16个调查区存在9种沉水植物,以篦齿眼子菜(Potamogeton pectinatus)、微齿眼子菜(P.maackianus)、穗花狐尾藻(Myriophyllum spicatum)、轮叶黑藻(Hydrilla verticillata)、马来眼子菜(P.wrightii)等为主,沉水植物主要分布在近岸3 m以内水域,盖度在10%左右.主成分分析结果表明,总氮、总磷、悬浮物、化学需氧量和叶绿素a浓度是影响沉水植物种类和生物量的主要因素,透明度是影响沉水植物盖度的主要因素;典范对应分析结果显示,滇池沉水植物的分布主要受水体中营养盐含量和化学需氧量的影响,穗花狐尾藻和轮叶黑藻对有机物和藻类的耐受能力较强,马来眼子菜和篦齿眼子菜适于生长在高营养盐的环境.滇池沉水植物恢复初级阶段的关键是降低水体中化学需氧量、抑制藻类的生长,其次是控制水体营养盐浓度.按照"一区一策"的原则,草海东风坝内和外海南部适于进行沉水植物恢复,外海北部实行控藻治理,外海东部需改善水体有机物浓度和营养盐条件,外海西部以沉水植物自然保育为主.  相似文献   

11.
太湖五里湖生态重建示范工程—大型围隔试验   总被引：35，自引：5，他引：30  
五里湖是太湖北部富营养化程度最为严重的一湖湾．从2004年1月起,为了改善水质,重建五里湖生态环境,在五里湖南岸建立了一个面积为10×104m2示范工程试验区,采用多技术措施集成应用,开展湖泊生态重建技术研究．经过近2年的生态重建研究与实践,在示范工程试验区内建立了挺水植物、浮叶植物和沉水植物群丛23个,水生植物种类从生态重建前的零上升至15科、22属、32种,水生植物的多样性指数(Shannon-Wieher index)达到2．33,覆盖度达到40％- 55％．水质监测结果表明,示范工程区内水体的TN、TP、NH4-N、NO3-N、NO2-N及PO4-P的平均值分别比示范工程区外下降了20．7％、23．8％、35．2％、21．1％、45．6％和54．0％,TN、TP分别下降至2．50mg／L、0．080mg/L以下,水质得到明显改善,达到或低于“浅水湖泊稳态转换理论”指出的向“稳定清水态”转换的临界值,水体透明度(SD)平均值也有较大幅度提高,平均从0．39m提高至0．70m;初步实现湖泊水体从藻类占优势浊水态向大型水生植物占优势的清水态转变．因此重建与恢复湖泊生态系统要从沿岸带着手,首先重建湖滨带结构与功能,通过湖滨带水生生物一系列反馈机制, 逐步改善湖泊水质,最终实现沉水植被恢复;湖泊敞水区应主要采用生物操纵技术措施来实现湖泊生态恢复．  相似文献   

12.
The community structure of zooplankton was studied in relation to physico-chemical characteristics of the river Chambal polluted by industrial effluents and domestic sewage near Nagda. Thirtytwo species of zooplankton of five main groups, viz. Protozoa, Rotifera, Cladocera, Copepoda and Ostracoda were observed at pre-pollution sampling stations. The abundance, distribution, total population, group percentage and species diversity were studied and correlated with pollution-indicating parameters. Species diversity values indicated a decrease from the sampling station near a pre-effluent point to an effluent discharge channel and an increase at a post-effluent discharge point revealing a slight recovery zone. Keratella tropica and Kellicottia sp. were identified as pollution tolerant taxa.  相似文献   

13.
Long-term dynamics of water level in Lake Nero (1930–2011) has been analyzed. Pronounced trends, determined by the climate and anthropogenic components have been identified. Up to the 1970s, at a drop in lake water level, the ecosystem still showed the main features of a shallow water body overgrown with macrophytes. Water level rise caused a more intense development of phytoplankton, an increase in biogenic element concentrations, a decrease in water transparency and the contribution of cyanobacteria of S1 codon; pondweed disappeared almost completely. Step-by-step regression analysis of phytoplankton development indices and hydrological characteristics showed that water transparency in Lake Nero depends by 80% directly on water exchange and inversely on the concentration of chlorophyll a in seston. The main hypothesis of the study was confirmed: the key trigger in phytoplankton–macrophytes competition is water level rise.  相似文献   

14.
Monthly collections of phytoplankton were supported by physical–chemical data and measures of chlorophyll a concentrations in the search for particular environmental factors that could explain the constant presence of desmids in a Mexican tropical lake, a characteristic not common among the phytoplanktic communities of Mexican lakes. Samplings were taken from the water column in the deepest part of the lake (40 m) and intensified in the metalimnetic zone, whose establishment was monitored by observations of temperature and oxygen profiles. The general behavior of Lake Zirahuén was typical of warm monomictic tropical lakes at high elevation: a short mixing phase during the hemispheric winter. The depth of ZMIX and Zeu revealed a well-illuminated epilimnion, suggesting that phytoplankton communities are not likely to be light-limited. The oligotrophic nature of the lake is indicated by discrete concentrations of inorganic nutrients, PTOT in the interval of 0.01–0.03 mg l−1 and chlorophyll a between 0.23 and 3.98 μg l−1. These characteristics together with a low concentration of calcium, define a lacustrine environment different from other Mexican lakes, and one that could be suitable for desmids communities.  相似文献   

15.
湖泊水深是影响沉水植物生长、繁殖与分布的重要环境因子,水深增加改变了水下光照、风浪和底泥特性等,因而可能导致沉水植物的生理生化指标发生相应变化.本研究通过对云南洱海沉水植物苦草(Vallisneria natans)随水深分布的情况进行调查,并分析了定植于不同水深的苦草叶片碳(C)、氮(N)和磷(P)含量及其比率,以阐明水深变化对苦草叶片生态化学计量学的影响.结果表明洱海苦草定植的水深范围为0.5~5.6 m,在1.5~2.4 m处达到最大频度,在2.5~3.4 m处达到最大相对生物量,这表明苦草在洱海中的最适生长深度在1.5~3.4 m范围内;苦草叶片C、N和P含量平均值分别为356.10、26.13和3.54 mg/g,C:N、C:P和N:P的平均值分别为14.38、113.46和7.85;苦草叶片C含量、C:N和C:P均随水深增加而降低,N和P含量则随水深增加而升高,N:P在0.5~1.4 m较高,其余水深梯度之间则没有显著差异.总体上,苦草叶片C、N、P含量及其化学计量特征显著地受到了湖泊水深的影响.另外,本研究还发现水深的增加使得苦草叶片N、P含量发生聚敛,这导致其N、P之间的耦合性变弱.  相似文献   

16.
In the Galenbeck lake, a shallow lake covering 700 ha and having a nutrient load of 0.23 g/m2a P as well as 4.3 g/m2a N, in 1965 a stock of carp of 500 animals/ha was established and additionally fed with grain. This stock of carp resulted in a considerable whirling-up and redeposition of the soft lime sediments, the rich submersed vegetation disappeared and the phytoplankton reached maxima of 885,420 cells/ml, whereas the zooplanktion reached only 4530 ind./l. The chlorophyll contents increased to 464 mg/m3, the depth of visibility decreased to 10 cm. The total planktonic primary production is estimated at 500 g/m2a C at least. These changes are regarded as eutrophication, its cause being attributed mainly to the internal fertilization by an intensified recirculation of nutrients from the sediment, but also by the fertilization which is connected with feeding. When the fish rearing had ceased and the stock of carp had been fished off, in 1970 a reacreation of the lake began, and in 1974 the lake reached again its original state as a clear-water lake with an abundant contents of macrophytes, supported also by the P-retention in an upstream storage reservoir for spray-irrigation water.  相似文献   

17.
淀山湖水生维管束植物群落研究   总被引：16，自引：1，他引：15  
由文辉 《湖泊科学》1994,6(4):317-324
论述了淀山湖水生维管束植物的种类组成、分布、群落类型、群落的数量特征及演替。结果是:（1）湖中分布有26种水生维管束植物,隶属16科,21属;其优势种为苦草、菹草、马来眼子菜、芦苇等。（2）湖中水生植被呈不规则环带状分布,并可划分为挺水、浮叶、沉水三个植物带,12个主要水生维管束植物群落。（3）水生维管束植物的重要值以苦草最大,茨藻属植物最小。（4）淀山湖水生维管束植物群落有由沉水型向浮叶型、挺水型或漂浮型过渡的趋势。  相似文献   

18.
鄱阳湖碟形湖生物群落分布特征很大程度上受区域与主湖区水文连通性影响。由于水位波动,东部湖湾水文连通性受鄱阳湖主湖体水位影响较为敏感。本文以东部湖湾为例,分析主湖区水位变异程度及其影响,并从连通天数和发生时间等方面定量表征东部湖湾与主湖区的水文连通性,进而讨论水文连通性变化及其对湿地植物生境和候鸟栖息地的潜在影响。结果表明,当水位在13～16 m时,东部湖湾与主湖区存在着良好的水文连通关系,湿地植物适宜生境面积最大。2003年以后,鄱阳湖主湖区水位普遍降低,低枯水位持续时间延长,IHA/RVA法分析表明主湖区水位发生了中等程度改变,整体改变度为40.2%,东部湖湾与主湖区的连通关系发生明显改变,年连通天数减少了46.2 d,变化幅度为15.9%,而非连通期发生时间提前约1个月且年内时间跨度更长。水文连通性减弱造成3 10月东部湖湾平均水位下降了0.6 m,其中9 10月减少了约1 m,使薹草（Carexsp．）和苦草（Vallisneria natans）适宜水深对应的水面面积在多数月份呈增加趋势,特别是9 10月（幅度超过40%）,但枯水提前导致沉水植物面积减少,湿生植物生物量增加。水...  相似文献   

19.
A comparative limnological study was carried out to present a snapshot of crustacean zooplankton communities and their relations to environmental factors to test whether there is a consistent relationship between crustacean biomass and trophic indicators among lake groups with similar trophic conditions. The study lakes showed a wide range of trophic status, with total phosphorus (TP) ranging from 0.008 to 1.448 mg L−1, and chlorophyll a from 0.7 to 146.1 μg L−1, respectively. About 38 species of Crustacea were found, of which Cladocera were represented by 25 taxa (20 genera), and Copepoda by 13 taxa (11 genera). The most common and dominant species were Bosmina coregoni, Moina micrura, Diaphanosoma brachyurum, Cyclops vicinus, Thermocyclops taihokuensis, Mesocyclops notius and Sinocalanus dorrii. Daphnia was rare in abundance. Canonical correspondence analysis showed that except for four species (D. hyalina, S. dorrii, C. vicinus and M. micrura), almost all the dominant species had the same preference for environmental factors. Temperature, predatory cyclopoids and planktivorous fishes seem to be the key factors determining species distribution. TP was a relatively better trophic indicator than chlorophyll a to predict crustacean biomass. Within the three groups of lakes, however, there was no consistent relationship between crustacean biomass and trophic indicators. The possible reason might be that top-down and bottom-up control on crustaceans vary with lake trophic state. The lack of significant negative correlation between crustacean biomass and chlorophyll a suggests that there was little control of phytoplankton biomass by macrozooplankton in these shallow subtropical lakes.  相似文献   

20.
浮游动物牧食、水温及营养可利用性均可影响优势浮游植物功能群的转变,但这些驱动因素的交互作用尚不清楚。为了解云南高原湖泊——洱海浮游植物优势功能群的分布特征及其主要驱动因素,于2018年1月2020年12月进行月度采样,结合聚类分析、方差分析和冗余分析等,分析驱动浮游植物优势功能群转变的主要因素。结果表明,共鉴定浮游植物7门96属,划分为27个浮游植物功能群,其中优势功能群有15个。聚类分析结果表明,根据浮游植物功能群密度数据可将优势功能群转变过程分为3个由不同类型藻类主导的时期（S期、M期和P期）,其中S期（为期18个月）以功能群S1和H1（代表藻为假鱼腥藻、浮丝藻和长孢藻等丝状蓝藻）为主,M期（为期10个月）以功能群M（微囊藻群体）为主,P期（为期8个月）以功能群P和M（脆杆藻和单个微囊藻等）为主。RDA分析及变差分解分析结果表明,卡尔森营养状态指数（TSI）（主要是总磷）是影响以丝状藻类为主的浮游植物功能群的主要驱动因素,TSI和水温是影响以微囊藻为主的浮游植物功能群的重要驱动因素。因此,在富营养化初期湖泊中,降低湖泊营养负荷是首要任务。同时可以考虑增加浮游动物丰度的策略,以增强浮...  相似文献   

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