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1.
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
2.
武汉后湖浮游植物现存量与生产量季节变动的初步研究 总被引：3，自引：1，他引：2
根据1990年5月—1991年4月武汉后湖浮游植物种类组成、现存量和生产量的周年资料分析,绿藻、硅藻、蓝藻为优势类群;现存量和生产量高低次序依次为:秋、冬、夏、春。并以浮游植物群落生态作为主要依据对后湖的营养状态进行了综合评价。 相似文献
3.
山西宁武亚高山湖群浮游植物群落结构特征 总被引：6，自引：2，他引：4
通过对山西宁武亚高山湖群浮游植物群落结构的调查研究,共鉴定出浮游植物291个种、变种及变型,隶属于8门,45科,108属.各采样站点间种数相差较大,以马营海种类最多,干海最少.硅藻门、绿藻门和蓝藻门明显占优势,优势科、优势属和优势种也都较为明显.优势种有蓝藻门的细小隐球藻(Aphanocapsa elachista)、铜绿微囊藻(Microcystis aeruginisa)和小席藻(Phormidium tenue),硅藻门的库津小环藻(Cyclotella kuetzingii)、肘状脆杆藻(Fragilaria ulna)、尖针杆藻(Synedra acus),绿藻门的狭形纤维藻(Ankistrodesmus angustus)和小球藻(Chlorella vulgaris).浮游植物平均密度为3.49 × 106cells/L.水面下0.5m处比水表层的细胞密度高.综合4种生物多样性指数,宁武亚高山湖群水质总体为轻污染. 相似文献
4.
《Limnologica》2021
Ecological restoration of eutrophic lakes using aquatic macrophytes is an important and practical technology. Here, we investigated the response of phytoplankton and zooplankton to a large-scale 2015-built aquatic macrophyte enclosure (AME, 200,000 m2) screened of by a PVC net in Baima Lake, a eutrophic lake, from spring to autumn of 2019. AME significantly improved water quality by increasing water transparency, and reducing total nitrogen, total phosphorus, and chlorophyll-a content during the growing season. AME significantly decreased phytoplankton abundance and biomass and marginally increased zooplankton abundance and biomass. Phytoplankton and zooplankton communities were closely related to environmental factors, such as water temperature, conductivity, total phosphorus, chemical oxygen demand, and chlorophyll-a inside and outside the AME. The zooplankton:phytoplankton biomass ratio inside was slightly higher than outside the AME. Zooplankton and phytoplankton biomass were significantly positively correlated inside and outside the AME, as were chlorophyll-a and total phosphorus. We found phosphorus to be a key factor limiting primary productivity in Baima Lake, and that bottom-up effects were the main driver to control phytoplankton in the AME. Using aquatic macrophytes to reduce nutrient loads is an effective way to manage eutrophication in Baima Lake. 相似文献
5.
6.
Major biological parameters of four permanent (Lake Colac, Modewarre, Bolac and Tooliorook), shallow and slightly saline lakes in the volcanic plains of western Victoria, Australia recorded bi-monthly between November 1999–September 2001 are described. Chlorophyll a concentration ranged from 3–29 μg l−1 with peaks in autumn. Phytoplankton taxa recorded were diverse, with Chlorophyta and Bacillariophyta being common. Cyanobacterial blooms were recorded mostly in summer. Zooplankton abundance in the lakes ranged from 12–368 individuals per litre. Rotifera dominated Lake Bolac, Copepoda dominated Lake Modewarre and they co-dominated Lake Colac and Tooliorook. Zooplankton interactions with phytoplankton suggest that simple predator-prey relationships cannot fully explain the trends exhibited and that a more complex model was acting to regulate algal biomass. A decline in the abundance of zooplankton in summer in Lake Modewarre was attributed to predation by high number of exotic larval carp at that time of the year. A total of 25 benthic macroinvertebrate taxa were recorded from Lake Colac, 30 from Modewarre, 22 from Bolac and 35 from Tooliorook. Twenty-one of the 45 taxa identified occurred in at least three lakes. Nine of the 12 taxa that occurred in only one lake were from Lake Tooliorook. Simpson's diversity index was low in Lake Bolac when compared to other three lakes. Lake Modewarre had more benthic individuals (3246 Ind m−2) than other three lakes (range 624–1397 Ind m−2). The combined contribution of Ostracoda, Amphipoda and Gastropoda dominated the benthos in all the lakes throughout the study period. Macroinvertebrate taxa richness was higher in the present study lakes than recorded from the lakes in the region. Frequency of sampling and number of sampling sites seemed more important in determining species richness than the size and shallowness of the lakes. 相似文献
7.
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
8.
Lake Hayq, a highland lake in Ethiopia, was stocked with Tilapia fish (Oreochromis niloticus) in late 1970s, offering an opportunity to study the effect of fish predation in a natural lake. Since 1930s, some limnological surveys have been done sporadically documenting a change in zooplankton composition including the disappearance of cladocerans, hypothesizing the stocked planktivorous fish could be a cause. Nevertheless, no detailed research was conducted to identify potential effects of fish stocking predominantly due to its remote location. The article presents data about zooplankton composition, abundance and biomass done between October 2007 and January 2009 on short-time intervals including the underlying limnological variables. The zooplankton community was depauperate comprising two copepods, three cladocerans, and six rotifers taxa, as typical for tropical lakes. Total mean standing biomass of all crustacean zooplankton was 237 mg dry mass m−3, which gave Lake Hayq an intermediate position when compared with other tropical lakes. Of copepods, Thermocyclops ethiopiensis was almost an exclusive species, and its temporal variation was influenced by food supply and water temperature. We refute the hypothesis that Tilapia was the cause for the seasonal disappearance of cladocerans, and attribute it to the adverse effect of episodic mixing. Nevertheless, the planktivorous fish probably plays a key role in structuring the cladocerans in particular the large-sized Daphnia magna. In January 2008, we observed a massive planktivorous fish mortality that triggered high algal biomass, which was later grazed by large-sized D. magna demonstrating the trophic cascade hypothesis in a natural ecosystem. 相似文献
9.
Plankton community as an indicator of water quality in tropical shrimp culture ponds 总被引：5，自引：0，他引：5
Casé M Leça EE Leitão SN Sant Anna EE Schwamborn R de Moraes Junior AT 《Marine pollution bulletin》2008,56(7):1343-1352
The plankton was examined as an indicator of water quality in 14 shrimp Litopenaeus vannamei farms in Brazil in 2003. The ponds were categorized by high stocking density (>30 PL m−2) of phytoplankton, consisting of 51 species with concentrations ranging from 365,218 ± 416,615 cells mL−1 to 1,961,675 ± 3,160,172 cells mL−1. Diatoms contributed to almost 70% of the species number and high densities resulted from Cyanophyta blooms, mainly Pseudanabaena cf limnetica. Forty zooplankton taxa were registered and were essentially composed of typical marine euryhaline species and suspension-feeders. Copepoda dominated (45%) the make-up, followed by Protozoa (18%), Rotifera (12%), and Mollusca (12%) larvae. Zooplankton varied from 972 ± 209 ind m−3 to 4235 ± 2877 ind m−3. Enhanced nutrient input affected plankton density and composition. Diatom and Copepoda dominance was replaced by cyanobacteria, protozoan, and rotifers as nutrient concentrations increased with the cultured period, indicating that plankton structure is affected by eutrophic conditions. 相似文献
10.
山西晋阳湖浮游藻类分布的时空格局及水质分析 总被引：6，自引：2，他引：4
对山西晋阳湖的浮游藻类进行了研究,共发现156种及11变种,隶属于5门,25科,67属.其中以绿藻门种类最多,达29属57种4变种;硅藻门次之,17属34种6变种;蓝藻门和裸藻门分别为15属32种1变种和5属31种,黄藻门最少,只有1属2种.秋季浮游藻类种类最多,冬季最少.浮游藻类细胞密度变化范围为2.84×10~6-2.30×10~9 cells/L,平均细胞密度为4.86×10~8 cells/L.每个季节水体的浮游植物细胞密度均已达到富营养化水平.多样性指数、均匀度指数均较低,而优势度很高,说明水体处于富营养状态,污染严重. 相似文献
11.
Griselda Chaparro María Cristina Marinone Ruben J. Lombardo María Romina Schiaffino Alice de Souza Guimarães Inés O’Farrell 《Limnologica》2011,41(4):371-381
We examined the zooplankton abundance and composition of Laguna Grande, a floodplain wetland of the Lower Paraná Basin (Argentina), during an extraordinary drought–flood cycle that affected both the environment and the biological conditions of the lake. Low waters were characterised by remarkably high conductivities and pH values, and high phytoplankton and bacterioplankton abundances with cyanobacterial blooms, while high waters showed opposite features. In relation to zooplankton, the mean abundances of all the taxonomic groups (rotifers, cladocerans, copepods, ciliates, and heterotrophic nanoflagellates) were slightly higher at low waters. Major changes were observed in the specific composition of metazooplankton: the euryhaline species assemblage that dominated in the dry warm period was replaced by several oligohaline littoral and planktonic species characteristic of the Paraná River Basin, when the water level rose. Mean species richness values at high waters doubled those of low waters and were directly correlated to water depth. Most of the rotifers of the genus Brachionus and the cladoceran Moina micrura switched from parthenogenetic to sexual reproduction during low waters, as a response to a harsh environment and crowding. We suggest that the main changes in the environmental conditions in this eutrophic floodplain lake are driven by the hydrology, which regulates the zooplankton succession. The herein described shifts in the zooplankton structure and dynamics of Laguna Grande over an extraordinary drought–flood cycle contribute to the understanding of the processes that might occur under the scenarios predicted by climate change models. 相似文献
12.
以洞庭湖流域的典型城市湖泊常德柳叶湖表层沉积物中浮游动物休眠卵为研究对象,采用DNA条形码技术进行种类鉴定,从191个休眠卵中成功获得101条有效序列,鉴定成功率约为53%.根据NCBI数据库比对成功鉴定休眠卵9科12属11种,另有6个样品鉴定到属或科;3个类群的种间遗传距离平均为种内遗传距离的68倍,表明可以利用线粒体细胞色素c氧化酶第一亚基编码基因(COⅠ)对休眠卵进行有效物种鉴定.通过Neighbor-Joining树进行系统发育分析,发现所鉴定的物种与其参比序列聚类为一支,所有物种分别聚为独立的一个支系,不同物种可有效区分.研究结果均表明,COⅠ基因作为DNA条形码可以实现沉积物中浮游动物休眠卵的物种鉴定. 相似文献
13.
太湖梅梁湾与五里湖浮游植物群落的比较 总被引：19，自引：4，他引：15
富营养化和风浪是影响大型浅水湖泊浮游植物群落的重要因素,本文于2003年10月至2004年9月对太湖梅梁湾和五里湖理化环境因子(水温、透明度值、悬浮质浓度和氮、磷营养盐浓度)和浮游植物群落进行了逐月监测,通过对两个湖区理化因子和浮游植物群落结构在周年内季节变化的比较研究,探讨富营养化程度以及风浪对浮游植物群落结构的影响,结果为:(1)梅梁湾由于受风浪影响悬浮物含量较高,五里湖则富营养化水平更高.(2)周年内五里湖浮游植物平均生物量(6.85 mg/L)高于梅梁湾的平均生物量(4.99 mg/L),两个湖区都呈现夏秋高峰、冬季低谷的变化特征.梅梁湾浮游植物群落季节演替的模式基本为:冬季硅藻(小环藻属Cyclotella spp.)和隐藻(隐藻属Cryptomonas spp.)-春季绿藻(细丝藻属Planctonema sp.)-夏季绿藻(绿球藻目Chlorococcales种类)和蓝藻(微囊藻属Microcystis spp.和浮游蓝丝藻属Planktothrix spp.)-初秋蓝藻(微囊藻属)和硅藻(浮游直链硅藻Aulacoseira spp.)-秋季隐藻(隐藻属).五里湖的季节演替模式没有梅梁湾明显,全年隐藻(隐藻属)都占优势,在此基础上,秋冬季硅藻(小环藻属和浮游直链硅藻属)占优势,裸藻(裸藻属Euglena spp.)在冬春季占优势,绿藻(绿球藻目种类和团藻目衣藻属Chlamydomonas spp.)在整个春季和初夏的优势地位在夏季被蓝藻(微囊藻属和浮游蓝丝藻属)所取代.群落构成的差异是浮游植物对两个湖区不同风浪条件和富营养化水平的响应结果.(3)通过与PEG(Plankton Ecology Group)模式的比较,梅梁湾和五里湖浮游植物群落的季节演替主要受水温、光照、营养盐(氮、磷)浓度和浮游动物牧食等因子的影响,因此,大型富营养化浅水湖泊浮游植物群落演替规律需要进一步的研究. 相似文献
14.
江汉平原湖群藻相特征及其环境状况评价 总被引：1，自引：1，他引：0
于2011年4月—2012年5月丰、平、枯3个水期对江汉平原水面面积为10 km2以上的22个湖泊进行了水质和藻类同步监测.结果显示:江汉平原主要湖泊中鉴定出藻类7门100属191种(亚种、变种),其中蓝藻门17属29种,绿藻门45属99种,硅藻门26属40种,隐藻门2属5种,裸藻门4属9种,甲藻门3属5种,金藻门3属4种;全年平均藻细胞丰度为0.93×106~84.18×106cells/L,细胞丰度以蓝藻门最高(50.65%),其次是绿藻门(29.56%),再次是硅藻门(12.30%)、隐藻门(6.19%)、裸藻门(0.56%)、甲藻门(0.39%)和金藻门(0.35%);丰水期生物量显著高于平水期和枯水期,Shannon-Wiener多样性指数年均值在1.44~2.10之间,丰水期的多样性指数略高于其他水期;藻类种类组成及优势种有明显的季节变化和空间差异.依据藻相特征的PCA分析将22个湖泊分为4个类群,不同类群具有显著不同的环境状况,氮磷营养负荷、水质状况和开发利用程度的不同是导致湖泊分化的内在原因;研究结果显示,江汉平原湖群总体上属于轻度污染状况,水体主要是中营养状态,丰水期与枯水期的湖泊生态环境状况具有显著差异;以藻相特征判断22个湖泊存在明显的时空异质性,部分湖泊因过度开发利用存在严重的富营养化风险;基于湖泊生态状况的显著时空异质性,对江汉平原湖群的管理应"因湖而异"制订科学合理的方法. 相似文献
15.
城市湖泊富营养化问题日趋严峻,以往对水华的研究多集中于大型自然淡水湖库,而对小型城市浅水湖泊的水华动态相对较少.以宁波月湖为研究对象,探讨水华暴发期间浮游植物变化特征及与影响因子之间的关系,以期判别影响城市湖泊水华的主控因子.月湖水华期间营养盐水平处于中富营养至极端富营养之间,此次共检出浮游植物8门61属,藻种组成以绿藻门（51.79%）和硅藻门（21.43%）为主,各点位浮游植物生长主要受水温、光照驱动,经历了隐藻门→硅藻门→绿藻门→蓝藻门的演替.水华种为雷氏衣藻（Chlamydomonas reinhardtii）,总藻密度最高达到1.55×108 cells/L,水华暴发后各点位衣藻属比例升高（最高达到81.10%）,群落结构呈现单一化特征.通过Pearson相关性分析和RDA分析发现衣藻属生长与水温、pH、总磷浓度均呈显著正相关,春季气温回升、天气持续晴好,城市浅水湖泊高营养盐负荷、水体流动性差等特点为带鞭毛的衣藻属提供了适宜的生存条件,在环境条件均适宜的情况下拥有最大生长潜力的衣藻属在营养盐、光照等竞争中生长速率明显优于其他藻种,从而发生绿藻水华. 相似文献
16.
Gunnar Persson 《Limnologica》2008,38(1):1-13
Taxonomic composition and variation in density of zooplankton were studied since 1989 to investigate possible long-term effects of anthropogenic acidification and liming in Sweden (the Integrated Studies of the Effects of Liming in Acidified Water (ISELAW) programme). In the programme, 15 long-term (18-31 years) limed lakes were studied in parallel with 8 untreated circumneutral lakes (representing target conditions) and 7 acid lakes. Five-year means from these lakes were used to evaluate differences between the three lake groups. Water chemistry (including trace metals), phytoplankton, invertebrate predators and fish were also monitored. Older records from 8 of the limed lakes obtained during the acid period preceding the initial liming were compared with records from the limed period. The number of taxa more than doubled in 6 lakes after liming. Total present-day zooplankton biovolume showed insignificant differences between the neutral and limed groups, i.e., conformed with the target conditions. Trace metals, including inorganic aluminium, appeared in low concentrations in limed and neutral lakes whereas zooplankton in one acid lake was Al-intoxicated. Daphnid populations in 4 other lakes may suffer from effects of high Cd or Cu concentrations. “Bottom-up” regulation of the zooplankton biovolumes was indicated by positive regressions between total phosphorus-phytoplankton and phytoplankton-zooplankton. Corresponding tests showed no “top-down” regulation of zooplankton by fish and of phytoplankton by zooplankton. Biomasses of planktivorous fish were higher in the neutral reference lakes than in both the acid and the limed lake groups, but neither zooplankton density and biovolume nor mean body size were lower in the neutral references. A higher production and turnover of zooplankton in neutral reference lakes may explain similar densities and structure of zooplankton in spite of a heavier predation pressure. 相似文献
17.
Patterns of zooplankton–phytoplankton interactions in subtropical lakes of the Southern Hemisphere may deviate from those established for north-temperate lakes. We tested the responses of phytoplankton growth to different community structures of zooplankton and nutrient enrichment in a subtropical Australian reservoir for the prediction of potential outcomes of lake biomanipulation. Two zooplankton communities were created in lake enclosures over 4 weeks: a rotifer-dominated community developed in the presence of planktivorous fish (Hypseleotris spp.) and a Ceriodaphnia-dominated community developed in the absence of fish. Biomass gradients of both communities were established in 20 L containers and several separate containers received no additions (controls) or were enriched with nitrogen and/or phosphorus. The growth rate of total phytoplankton significantly increased in response to nutrient enrichment, indicating nutrient limitation. Most phytoplankton taxa were not markedly affected by grazing of either zooplankton community. However, both communities had significant stimulatory effects on the growth of inedible chlorophytes. The ability of zooplankton grazing to negatively affect phytoplankton growth during the summer was counteracted regardless of zooplankton community structure, possibly by nutrients regenerated by zooplankton. We hypothesise that in the subtropical system studied, changes in food web nutrient recycling may be more important for the outcome of biomanipulation than grazing impacts. 相似文献
18.
为探究呼伦湖浮游植物群落的季节变化特征及其与环境因子的关系,本研究分别于2019年3、5—10月对呼伦湖浮游植物的种类、细胞密度和生物量及湖水水质进行调查.结果显示,共鉴定出120种浮游植物,隶属于7门72属.从浮游植物群落季节组成差异上来看,春季绿藻门种类数最多,其次是硅藻门、蓝藻门;夏秋季绿藻门种类数最多,蓝藻门次之;冬季硅藻门种类数最多,绿藻门次之.呼伦湖浮游植物优势种主要为硅藻门的梅尼小环藻（Cyclotella meneghiniana）、蓝藻门的卷曲长孢藻（Anabaena circinalis）和细小平裂藻（Merismopedia minima）,种类数在春季最多,秋冬季最少.浮游植物细胞密度在春季（123.52×104 cells/L）和冬季（16.41×104 cells/L）较夏季（280.80×104 cells/L）和秋季（380.63×104 cells/L）低,春冬季绿藻门细胞密度最高,夏秋季蓝藻门细胞密度最高.就浮游植物生物量而言,夏季（0.38 mg/L）最大,其次是秋季（0.26 mg/L）和春季（0.24 mg/L）,冬季（0.13 mg/L）最小.香农-威纳（Shannon-Wiener）多样性指数、均匀度指数和综合营养状态指数均表明呼伦湖水体处于中营养状态.冗余分析（RDA）表明：水温、叶绿素a、pH和营养盐浓度是影响呼伦湖浮游植物群落分布的主要环境因子. 相似文献
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水体氮、磷营养盐水平对蓝藻优势形成的影响 总被引：1，自引：1，他引：0
以江苏省南京市富营养化程度不同的清溪、护城河、玄武湖、月牙湖、琵琶湖和前湖为研究对象,调查各水体浮游植物的群落特征和优势种,并结合藻类生长潜力试验,探究不同氮、磷营养水平的自然水体对铜绿微囊藻（Microcystis aeruginosa）和斜生栅藻（Scenedesmus obliquus）生长与竞争的影响.野外调查发现不同营养水平水体浮游植物优势种不同,按水体富营养化程度从高到底依次以绿藻、蓝藻、硅藻和隐藻分别占优势.单一藻种培养时,铜绿微囊藻在清溪、护城河和玄武湖水体中生长均较好,而斜生栅藻仅在高氮、磷浓度的清溪和护城河水体中有较大生长量,说明斜生栅藻对氮、磷的需求高于铜绿微囊藻;两种藻共培养时,清溪水体中斜生栅藻占优势,护城河和玄武湖水体中铜绿微囊藻占优势,但其他水体中两种藻均不能生长,说明氮、磷浓度过高或过低都不利于蓝藻形成优势.对低营养水平的玄武湖、琵琶湖、月牙湖和前湖水体进行氮、磷加富后,两种藻均能较好地生长,且各组没有显著差异,说明藻类在这些水体中生长受到氮、磷的限制,氮、磷浓度升高会增加水华发生的风险.本研究将野外调查和藻类生长潜力实验相结合,深入探究了蓝藻优势形成与水体氮、磷营养水平的关系,揭示了蓝藻水华是湖泊富营养化发展到特定阶段的产物,水体氮、磷浓度过高或过低均不易产生蓝藻优势. 相似文献