抚仙湖浮游甲壳动物群落结构与空间分布

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.     

On the Limnology of Deep and Saline Lake Burdur in Turkey

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.     

The Structure of the Zooplankton Community and the Dynamics of its Biomass in the Lake Jaisamand (Rajasthan: India)

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.     

疏浚后杭州西湖的桡足类

本文调查了疏浚后杭州西湖(小型、浅水、富营养化湖泊)四个采样站(Ⅰ-Ⅳ)桡足类的密度、生物量和多样性指数,并对桡足类生物量与水质理化因子之间进行了相关分析．共发现桡足类9种,其中哲水蚤3种,剑水蚤6种．疏浚后,桡足类群落密度随着引水水流路程的加大而逐渐增大,多样性指数逐渐下降．桡足类群落丰度夏秋季明显大于冬春季．汤匙华哲水蚤(Sinocalanus dorrii)成体在营养水平较低的Ⅰ站(TLI=55．3)具有较大的密度和生物量,其分市沿着引流方向逐渐下降,而哲水蚤的桡足幼体则沿引流方向逐渐增加;粗壮温剑水蚤(Thermocyclops dybowskii)成体在营养水平较高的Ⅱ-Ⅳ站(TLI=62．7-63．5)具有较大的密度和生物量;疏浚使底柄种类猛水蚤(Harpacticoida)消失了.疏浚对哲水蚤密度分布分异的影响较大,对剑水蚤密度分布分异的影响较小．桡足类群落Ⅱ-Ⅲ站桡足类生物量随水体叶绿素a、高锰酸盐指数和总磷含量的升高而显著增加,随水体透明度的增大而显著下降．     

安徽女山湖自然保护区浮游生物群落生态

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.     

Physico‐Chemical and Bacterial Characteristics of Water Quality in Three Villages West of Lake Nasser,Egypt

The present study aims to investigate physico‐chemical and bacterial characteristics of Nasser Lake water and houses drinking water, as well as fish cultures and its wastewater, in three villages west of Lake Nasser, Egypt. Fifteen representative water samples (Nasser Lake, different drinking water, fish cultures, and wastewater sources) were collected from three villages (Garf Hussein, Bashaier, and Kalabsha) in the west of Lake Nasser. Physico‐chemical, total viable counts, and bacterial qualification of water were achieved. The obtained results indicated that the produced water, supposed to be for domestic use in the three villages, contained all the tested organisms. The investigated water samples of the lake and drinking water in the selected three villages are supposed to be chemically safe according to World Health Organization and to Egyptian standards for drinking water. Water pollution index (WPI) was used in this study and the result concluded that for irrigation canals from the lake to the agriculture site, fish cultures (both concrete and earth pond systems), and drainage canal of fish ponds need to be treated before it is discharged to the lake. It is better to reuse it after treatment for agricultural purposes or recycled it to the fish cultures.     

内蒙古锡林郭勒盟盐湖浮游生物的群落特征

通过2003年9月-2004年1月的渔获物调查,并结合1984-2002年的鱼类产量统计资料,分析了近二十年来太湖鱼类产量和组成的变化规律以及环境间的相互作用关系.结果表明,太湖鱼类的种类在不断减少,如本次调查和2002年3月-2003年12月的调查只采集到48种鱼类,和历史资源料比较有55种鱼类难以采到;鱼类产量组成表现为仅鲚鱼的产量和组成比例总体呈较快的上升趋势,从1984年的5153.7t、占总产量的36.2%上升到2002年的19571t、64.1%,鲤、鲫鱼基本维持不变,但近四年略有上升,其余鱼类均呈下降趋势.用Wilhm改进式计算的鱼类产量组成的均匀度指数H总体呈逐年下降趋势,近二十年来平均以每年-0.0465的速率下降;分析认为,人类活动以及由此引起的太湖生态环境变化,包括江湖阻隔、过渡捕捞、富营养化及太湖特有的鱼类生态学特点决定了鱼类组成的这一变化趋势:江湖阻隔、过度捕捞是引起太湖鱼类种类减少和鱼类组成发生巨大变化的主要原因;太湖近二十年来富营养化程度不断加重,由此使初级生产力水平持续增长,浮游生物饵料丰富,使鲚鱼等浮游生物食性鱼类产量逐年提高;舶鱼数量的减少又使鲚鱼失去抑制.随着鲚鱼等浮游动物食性鱼类产量的升高,太湖浮游动物的生物量呈下降趋势,这可能是太湖浮游植物数量倍增的生物学因素之一.目前太湖鱼类产量组成的变化正向着抑制浮游动物和有利浮游植物生长的方向发展.     

Rapid shoreline flooding enhances water turbidity by sediment resuspension: An example in a large Tibetan lake

Rapid water level rise due to climate change has the potential to remobilize loose sediments along shorelines and increase the turbidity of nearshore waters, thereby impacting water quality and aquatic ecosystem health. Siling Lake is one of the largest and most rapidly expanding lakes on the Tibetan Plateau. Between 2000 and 2017, this lake experienced an increase in water level of about 8 m and a doubling in water turbidity. Here, using this lake as a study site, we used a wave model and high-resolution remote sensing of turbidity (Landsat-8) to assess the potential connection between water-level rise, enhanced wind-driven sediment resuspension and water turbidity. Our analysis revealed that strong bottom shear stresses triggered by wind-generated waves over newly flooded areas were related to an increase in water turbidity. The spatial variability of Siling Lake turbidity showed a strong dependence on local wind characteristics and fetch. Two factors combined to drive the increase in turbidity: (1) high wave energy leading to high bottom shear stresses, and (2) flooding of unvegetated shallow areas. Using a new relationship between wave energy and turbidity developed here, we expect the increase in turbidity of Siling Lake to taper off in the near future due to the steep landscape surrounding the lake that will prevent further flooding. Our results imply that rising water levels along the coast are not only expected to influence terrestrial ecosystems but could also change water quality. The methodology presented herein could be applied to other shorelines affected by a rapid increase in water level. © 2020 John Wiley & Sons, Ltd.     

Groundwater–surface water interaction in Lake Nasser,Southern Egypt

A cross‐sectional model, based on the two dimensional groundwater flow equation of Edelman, was applied at seven transects distributed over four geological cross sections to estimate groundwater heads and recharge from/or groundwater discharge to Lake Nasser. The lake with a length of 500 km and an average width of 12 km was created over the period 1964–1970, the time for constructing the Aswan High Dam (AHD). The model, constrained by regional‐scale groundwater flow and groundwater head data in the vicinity of the lake, was successfully calibrated to timeseries of piezometeric heads collected at the cross sections in the period 1965–2004. Inverse modeling yielded high values for the horizontal hydraulic conductivity in the range of 6.0 to 31.1 m day^?1 and storage coefficient between 0.01 and 0.40. The results showed the existence of a strong vertical anisotropy of the aquifer. The calibrated horizontal permeability is systematically higher than the vertical permeability (≈1000:1). The calibrated model was used to explore the recharge from/or groundwater discharge to Lake Nasser at the seven transects for a 40‐year period, i.e. from 1965 to 2004. The analysis for the last 20‐year period, 1985–2004, revealed that recharge from Lake Nasser reduced by 37% compared to the estimates for the first 20‐year period, 1965–1984. In the period 1965–2004, seepage of Lake Nasser to the surrounding was estimated at 1.15 × 10⁹ m³ year^?1. This led to a significant rise of the groundwater table. Variance‐based sensitivity and uncertainty analysis on the Edelman results were conducted applying quasi‐Monte Carlo sequences (Latin Hypercube sampling). The maximum standard deviation of the total uncertainty on the groundwater table was 0.88 m at Toshka (west of the lake). The distance from the lake, followed by the storage coefficient and hydraulic conductivity, were identified as the most sensitive parameters. Copyright © 2012 John Wiley & Sons, Ltd.     

Heavy mineral composition and texture of the recently formed fluvial delta sediment of Lake Nasser/Nubia,Egypt and Sudan

Surficial sediment samples collected from the recently formed fluvial delta in Lake Nasser/Nubia (Egypt and Sudan) in conjunction with data on bottom current and depth soundings are examined to interpret hydraulic-sorting processes and transport/depositional patterns.The～500 km long northeastwardtrending lake,lies within Egypt and Sudan,is created as a result of the construction of the Aswan High Dam in 1964.The original grain-size distribution and heavy mineral compositions of these samples hel...     

太湖春季浮游动物磷释放的初步研究

浮游动物是湖泊生态系统的主要组成之一,于2004年3月至5月间调查了太湖梅梁湾、五里湖浮游动物数量,并在实验室条件下分别测定了浮游动物正磷酸盐(PO4-P)的释放率．结果表明,研究期间梅梁湾的枝角类密度都高于五里湖,五里湖的轮虫数量高于梅梁湾,两水域桡足类密度上的差异不明显;梅梁湾和五里湖浮游动物PO4-p释放率的范围分别为0．20-O．43 mg／(g(DW)·h)和0．19-0．54 mg／(g(DW)·h)．因此浮游动物营养盐释放对湖泊生态系统营养盐循环具有一定的作用．     

Zooplankton Community Structure of Çavuşcu and Eber Lakes in Central Anatolia Struktur von Zooplankton-Gemeinschaften im Çavuşcu Lake und im Eber Lake in Zentralanatolien

This research has been undertaken to determine the zooplanktonic fauna (Rotatoria, Crustacea) and their seasonal distribution in two lakes with different characters. Çavu?cu lake has a surface area of 1000 ha with a maximum depth of 4 m and is classified as an oligo-mesotrophic lake. Eber lake has a surface area of 5200…17000 ha with a maximum depth of 2.5 m and is classified as an eutrophic lake. Zooplankton samples have been collected seasonally between the period of 1990 to 1993 from three stations with a zooplankton net of 44 μm mesh size. From Çavu?cu lake totally 50 Rotifera, 2 Copepoda, and 7 Cladocera species; 49 phytoplankton genera and 5 macrophytes have been identified while, 37 Rotifera, 3 Copepoda, 5 Cladocera; 45 phytoplankton genera and 6 macrophytes have been identified from Eber lake. 13 new rotifer records for the Turkey were found, which were Brachionus diversicornis, Macrochaetus collinsi, Lecane stichaeta, Cephalodella sterea, Cephalodella auriculata, Trichocerca iernis, Encentrum saundersiae. Pompholyx complanata, Floscularia ringens, Conochilus natans, Filinia pejleri, Rotaria rotatoria, and Philodina megalotrocha.     

Importance of aquatic macrophyte for invertebrate diversity in large subtropical reservoir

The abundance and preferences of individual invertebrate populations (including zooplankton) closely associated with the substrates provided by aquatic plant structures and open-water areas of Lake Nasser were quantified in this study in order to gain understanding of the importance of submerged macrophyte for invertebrate diversity, and their relation to water properties. The following water parameters were measured: temperature, pH, dissolved oxygen (DO), total dissolved salts, electrical conductivity, turbidity, total suspended solids, carbonate, bicarbonate, nitrate, nitrite, phosphate, sulphate, silica, potassium, total hardness, calcium and magnesium.Five macrophyte species were recorded: Myriopyllum spicatum, Najas horrida, Potamogeton schweinfurthii, Potamogeton pectinatus and Vallisneria spiralis. In total 67 invertebrate species were recorded, comprising 39 Rotifera, 12 Cladocera, 4 Copepoda, 4 Insecta, 2 Protozoa, 2 Ostracoda and one species of Turbellaria, Tardigrada, Annelida and Nematoda. Thirty-seven species were exclusively epiphytic, 11 species were collectively planktonic and 19 species were found in both habitats. The greatest abundance of epiphytic invertebrates occurred in association with N. horrida-P. schweinfurthii community.The results indicated that total suspended solids (TSS), TH and NO₂ are the most influential water variables on the distribution of the aquatic macrophyte samples and their invertebrate communities. Also, the study indicates that water variables have a higher impact on the aquatic macrophytes than on the associated invertebrate populations. P, NO₃, K, Na, Mg, Cl and DO were the most influential water variables that dictate the distribution of invertebrate groups recorded in the open-water zone. Water temperature, electric conductivity, pH, NO₂, SO₄⁻⁻, SiO₃⁻, CO₃⁻⁻ and turbidity have a lesser influence of the distribution of the invertebrates recorded in this zone.     

Ecological engineering in a eutrophic lake: A case study of large aquatic macrophyte enclosures in Baima Lake,China

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.     

Zooplankton community structure and ecology of the tropical-highland Lake Hayq, Ethiopia

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.     

Variability of a cyprinid lake ecosystem with special emphasis on the native fish fauna under intensive fisheries management including common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix)

The lake investigated (Lake Heiliger See near the town of Angermünde, North-East Germany) is small (10.2 ha) but deep (z_max = 12 m, ? = 6.5 m). During summer the thermocline is at a depth of 4-5 m, and the hypolimnion is filled with H₂S already by mid-June, making 60-75% of the bottom area inaccessible to fish. The native fish fauna is dominated by planktivorous roach (Rutilus rutilus). A test stocking of silver carp (Hypophthalmichthys molitrix) together with an unplanned and erroneous stocking of common carp (Cyprinus carpio), coupled with an incorrectly calculated strong stocking of eel (Anguilla anguilla), which assumed that the total lake area yielded fish food organisms, brought about a strong depression of the food biomass available to native fish. Both silver carp and common carp showed a pattern of behaviour which only partly agreed with results obtained in experimental ponds prior to lake stocking. At least for 10 years there was a very low zooplankton biomass (mostly below 1 mg/l fresh weight) caused by silver carp and a strongly reduced benthos biomass (frequently below 1 g/m² fresh weight) caused by common carp and eel on H₂S-free bottom areas. Despite this extreme situation, which lasted for 20 years and is rarely found in lakes elsewhere, it was not possible to demonstrate negative effects on the native fish fauna comprising 16 species. Also the dominance pattern seems uninfluenced in the long run. A strong decline of the catchable roach stock was observed for some years, but the stock reappeared soon in comparable quantity. During the time of roach stock depression the individual growth of roach (and common carp) was particularly low. Nevertheless, roach succeeded in reproduction during this time in spite of the reduced zooplankton and detritus concentrations. Fry numbers per year ranged from 500-15 000 individuals/ha. The pike perch (Stizostedion lucioperca) was perhaps the most endangered species of all those living at small population numbers in the lake, since its fry is confined to the limnion where competition from silver carp and adult roach and perhaps predation by roach is highest. However the pike perch stock remained unchanged at the low level of 1950, the time prior of carp and eel stocking. All other rare species of Lake Heiliger See spawn in the littoral zone where fry survival conditions were less impacted. In summary, we present more evidence that the fish fauna of cyprinid lakes is more robust than in salmonid lakes. The regulation capacity of fish communities of eutrophic lakes seems to be able to offset even severe direct and indirect influences of fisheries management.     

内蒙古乌梁素海浮游动物与底栖动物调查

乌梁素海是全球荒漠半荒漠地区极为少见的大型草原湖泊,是我国北方侯鸟重要的迁徙和繁殖地,2002年被国际湿地公约组织正式列入国际重要湿地名录.为了对乌梁素海的浮游动物及底柄动物进一步深入的研究,从2004年4月至2005年1月共进行了4次监测.浮游动物共检出34属62种,比20年前减少3种.其中原生动物11属16种;轮虫17属33种;枝角类4属4种;桡足类5属9种.大型浮游动物(包括枝角类、桡足类及轮虫)全年平均丰度为687ind.、L,平均生物量为3.4985mg、L;原生动物平均丰度为2.508×104 ind/L.平均生物量为0.1254mg/L.底栖动物共检出4科11种,比20年前减少39种.底栖动物两次调查的平均丰度为3031.4ind/m2.平均生物量为71.67g/m2.调查结果显示,随着季节的变化,浮游动物丰度及生物量变化幅度很大,夏季最高,春季次之,秋冬两季极低.利用浮游动物和底栖动物生物量作为水体状况评价指标对乌梁素海营养状况进行初步评价,得出乌梁素海水体处于富营养化状态.     

Limnology of four saline lakes in western Victoria, Australia: II. Biological parameters

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.     

Horizontal and seasonal patterns of tropical zooplankton from the eutrophic Prado Reservoir (Colombia)

Zooplankton community analyses can reveal valuable information about the trophic status and secondary production in reservoirs. The zooplankton seasonal distribution and important physical and chemical parameters in Prado Reservoir (Tolima, Central Colombia) were studied in monthly surveys throughout a hydrological cycle (February 2000-January 2001) in order to establish seasonal patterns and the biotic and abiotic relationships for the reservoir. Surface zooplankton collections at 1 m depth were taken at six sampling stations with regard to reservoir morphometry, location of main tributaries and mixing areas of the incoming tributaries. Cladocerans numerically dominated (48.1%) the community throughout the study period followed by Copepoda (32.7%), Rotifera (19.1%), and Diptera larvae (0.01%). Among the cladocerans, there was a greater abundance of Bosmina longirostris (69.8%) than other crustaceans. Among the Rotifera, Brachionus falcatus was the most abundant with 23% and Keratella tropica was least abundant with 8%. The only cyclopoid species found was Thermocyclops decipiens. The phantom midge Chaoborus sp. was also part of the zooplankton community. Based on numbers, cladocerans represented a significant component of the zooplankton in both dry and rainy seasons. Four species (Brachionus spp., K. tropica, Diaphanosoma brachyurum, Ceriodaphnia cornuta, Moina sp., and T. decipiens) had never previously been found in the reservoir, but were recorded for other standing Colombian water bodies. The replacement of B. longirostris instead of Daphnia sp. as dominant species was observed. The results of the comparison of the different studies confirmed that the trophic state of this artificial lake may be classified as eutrophic, and in general, physical, and chemical homogeneity were observed both spatially and temporally.