Regional coherence of climatic and lake thermal variables of four lake districts in the Upper Great Lakes Region of North America

1. Within a region with common climatic conditions, lake thermal variables should exhibit coherent variability patterns to the extent to which they are not influenced by lake specific features such as morphometry and water clarity. We tested the degree of temporal coherence in interannual variability for climatic variables (air temperature and solar radiation) among four lake districts in the Upper Great Lakes Region. We also tested the degree of coherence of lake thermal variables (near‐surface temperature, eplimnetic temperature, hypolimnetic temperature and thermocline depth) for lakes within these districts. 2. Our four lake districts included the Experimental Lakes Area in north‐western Ontario, the Dorset Research Centre area north of Toronto, Ontario, the Northern Highland Lake District in northern Wisconsin, and the Yahara Lakes near Madison in southern Wisconsin. Seventeen lakes were analyzed for lake thermal variables dependent on stratification. Another five lakes were added for the analysis of near‐surface temperature. 3. The analysis tested whether for monthly and summer means, the climate (air temperature and solar radiation) across the four lake districts was coherent interannually and whether variables which measure the thermal structure of the lakes were coherent interannually among lakes within each lake district and across the four lake districts. 4. Temporal coherence was estimated by the correlation between lake districts for meteorological variables and between lake pairs for lake thermal variables. Mean coherence and the percentage of correlations exceeding the 5% significance level were derived both within and between lake districts for lake thermal variables. 5. Across the four lake districts, summer mean air temperature was highly coherent while summer solar radiation was less coherent. Approximately 60–80% of the interannual variation in mean summer air temperature at a site occurred across the entire region. Less than 45% of the variation in solar radiation occurred across sites. 6. Epilimnetic temperature and the near‐surface temperature were highly coherent both within and between lake districts. The coherence of thermocline depth within and between lake districts was weaker. Hypolimnetic temperature was not coherent between lake districts for most lake pairs. It was coherent among lakes within some lake districts. 7. The influences of local weather and differences among lakes in water clarity are discussed in the context of differences in levels of coherence among lake thermal variables and among lake pairs for a given variable.     

A photographic method for detailing the morphology of the floor of a dynamic crater lake: the El Chichón case (Chiapas,Mexico)

The active volcano El Chichón (Chiapas, Mexico) hosts a shallow acidic crater lake. During the period 2001–2007, 26 photographs of the crater lake were taken from the same spot at the eastern crater rim, ~160 m above the crater floor. The size of the lake was extremely variable. Using a GPS track from around the lake shore as a reference, 26 digitized lake outlines were corrected simultaneously for the perspective angle. The corrected lake outlines were superposed, leading to a “morphological map” of a large section of the lake bottom. This map provides insight into the erosive–sedimentary regime of the lake floor. The inner section of the lake is more stable due to the precipitation of sealing clays. This is probably one of the reasons why the El Chichón crater lake has never disappeared during the past 28 years. The sealing clays at the lake bottom can be considered the superficial analog of impermeable clay caps at the depths of hydrothermal systems. The photographic procedure presented here may be useful for other limnological and (volcanic) lake studies aimed at describing lake morphology, and for eventually deducing the surface area and volume of the lake.     

湖泊最低生态水位计算方法

研究湖泊最低生态水位的计算方法 ,对解决我国湖泊生态退化问题具有重要现实意义。针对我国湖泊生态资料缺乏的情况 ,提出 3种确定湖泊最低生态水位的方法。认为湖泊天然生态系统已经适应了天然多年最低水位 ,据此提出利用湖泊多年天然水位资料确定湖泊最低生态水位的方法——天然水位资料法 .认为要使湖泊生态系统不出现严重退化 ,必须使湖泊水文和地形子系统不严重退化 ,据此提出湖泊形态分析法 .从生物对生存空间的最小需求角度 ,以鱼类为指示生物 ,提出生物最小空间需求法。采用上述 3种方法计算了南四湖最低生态水位。计算结果表明 ,南四湖上级湖最低生态水位的范围为 32 .75～ 33.2 5 m,平均值为 33m;下级湖最低生态水位范围 31.2 5～ 31.75 m,平均值为 31.38m。上下两湖最小生态水位相应湖面面积之和为 5 93～86 0 km2 ,平均水位相应面积之和 70 8km2 ,占 195 3～ 1979年多年平均湖面面积 12 2 5 km2 的 5 8%。从保护南四湖自然保护区的角度看 ,确定的最低生态水位合理     

Habitat-specific adaptation of immune responses of stickleback (Gasterosteus aculeatus) lake and river ecotypes

Freshwater populations of three-spined sticklebacks (Gasterosteus aculeatus) in northern Germany are found as distinct lake and river ecotypes. Adaptation to habitat-specific parasites might influence immune capabilities of stickleback ecotypes. Here, naive laboratory-bred sticklebacks from lake and river populations were exposed reciprocally to parasite environments in a lake and a river habitat. Sticklebacks exposed to lake conditions were infected with higher numbers of parasite species when compared with the river. River sticklebacks in the lake had higher parasite loads than lake sticklebacks in the same habitat. Respiratory burst, granulocyte counts and lymphocyte proliferation of head kidney leucocytes were increased in river sticklebacks exposed to lake when compared with river conditions. Although river sticklebacks exposed to lake conditions showed elevated activation of their immune system, parasites could not be diminished as effectively as by lake sticklebacks in their native habitat. River sticklebacks seem to have reduced their immune-competence potential due to lower parasite diversity in rivers.     

青藏高原淡水湖普莫雍错和盐水湖阿翁错湖底沉积物中细菌群落的垂直分布

【目的】湖泊沉积物中存储着大量独特的微生物,这些微生物在湖泊生态系统生物地球化学循环中扮演着非常重要的角色。然而,很少有研究报道微生物群落在湖泊沉积物中的垂直分布。本文比较研究青藏高原淡水湖普莫雍错和盐水湖阿翁错沉积物在不同深度下细菌的丰度和群落结构。【方法】利用定量PCR(q PCR)和变性梯度凝胶电泳(DGGE)技术分别测定细菌群落的丰度与群落结构。【结果】定量PCR结果显示,湖泊沉积物中细菌丰度均随深度增加而降低,盐水湖阿翁错和淡水湖普莫雍错的细菌丰度分别从1011数量级降到108数量级,从1012数量级降到1010数量级。在相对应的沉积物层,淡水湖沉积物的细菌丰度比盐水湖高1-2个数量级。变性梯度凝胶电泳(DGGE)指纹图谱的分析表明,淡水湖沉积物细菌群落的DGGE条带数(丰富度)显著高于盐水湖(P=0.014);淡水与盐水湖泊沉积物细菌群落结构明显不同,同时在同一湖泊沉积物中上层(0-6 cm)和下层(7-20 cm)细菌群落结构也呈明显分异。系统发育分析表明,盐水湖阿翁错沉积物特有菌门为Gamma-变形菌、拟杆菌门、蓝细菌和栖热菌门,而淡水湖普莫雍错沉积物中特有菌门为Delta-和Beta-变形菌、酸杆菌和绿弯菌门。【结论】青藏高原淡水与盐水湖泊沉积物细菌丰度与群落结构具有明显的差异;同时,细菌群落结构在沉积物的不同深度也表现出差异。这些结果可为进一步阐明青藏高原湖泊生态系统中微生物对气候环境变化的响应提供科学依据。     

A geomorphic template for the analysis of lake districts applied to the Northern Highland Lake District, Wisconsin, U.S.A.

1. We tested the degree to which a lake's landscape position constrains the expression of limnological features and imposes a characteristic spatial pattern in a glacial lake district, the Northern Highland Lake District in north‐central Wisconsin. 2. We defined lake order as a metric to analyze the effect of landscape position on limnological features. Lake order, analogous to stream order, is based solely on geographical information and is simple to measure. 3. We examined the strength of the relationship between lake order and a set of 25 variables, which included measures of lake morphometry, water optical properties, major ions, nutrients, biology, and human settlement patterns. 4. Lake order explained a significant fraction of the variance of 21 of the 25 variables tested with ANOVA. The fraction of variance explained varied from 12% (maximum depth) to 56% (calcium concentration). The variables most strongly related to lake order were: measures of lake size and shape, concentrations of major ions (except sulfate) and silica, biological variables (chlorophyll concentration, crayfish abundance, and fish species richness), and human‐use variables (density of cottages and resorts). Lake depth, water optical properties, and nutrient concentrations (other than silica) were poorly associated with lake order. 5. Potential explanations for a relationship with lake order differed among variables. In some cases, we could hypothesize a direct link. For example, major ion concentration is a function of groundwater input, which is directly related to lake order. We see these as a direct influence of the geomorphic template left by the retreat of the glacier that led to the formation of this lake district. 6. In other cases, a set of indirect links was hypothesized. For example, the effect of lake order on lake size, water chemistry, and lake connectivity may ultimately explain the relation between lake order and fish species richness. We interpret these relationships as the result of constraints imposed by the geomorphic template on lake development over the last 12 000 years. 7. By identifying relationships between lake characteristics and a measure of landscape position, and by identifying geomorphologic constraints on lake features and lake evolution, our analysis explains an important aspect of the spatial organization of a lake district.     

Movement of plankton through lake-stream systems

1. River plankton are often assumed to come from upstream lakes, but the factors controlling the movement of plankton between lakes and rivers into outflow streams are unclear. We tested the possibility that the physical structure of the littoral zone near the lake outlet (depth, presence of macrophytes) and diurnal differences in plankton composition at the lake surface influence the movement of plankton from the lake into the stream and determine their persistence downstream. 2. Zooplankton and phytoplankton biomass, community composition and mean body size were compared between two deep lakes without macrophytes at the lake edge and two shallow lakes with macrophytes at the lake edge. Samples were collected day and night on three dates, in the lake centre, in the littoral zone adjacent to the lake outlet, at the outlet and at two sites downstream in Algonquin Park, Ontario, Canada. 3. The morphology of lake edges clearly affects the movement of lake zooplankton into outlet streams. Outlets draining deeper littoral zones had higher zooplankton biomass than shallow littoral outlets (P < 0.0001), but these differences disappeared within 50 m downstream of the lake. There was no difference in mean zooplankton body size among lake outlets or between littoral and outlet samples. However, shallow littoral zones were dominated by cyclopoid copepods and deeper littoral zones were dominated by Bosmina longirostris. In contrast, phytoplankton biomass entering the outlet was similar to that found within the lake and did not vary with lake outlet morphology. These effects were consistent across several sampling weeks and were not affected by surface zooplankton biomass changes associated with diurnal vertical migration in the lake centre. 4. A comparison with published river zooplankton data suggests that zooplankton are rapidly eliminated from shallow outlet streams (≤1 m deep) but persist in most deeper outlet rivers (≥2 m deep). Because the depth of an outlet river determines downstream zooplankton community development, the contribution of lakes to river plankton communities may be influenced by the location of each lake within the drainage basin. These findings suggest that lake and outflow physical structure influences connection strength between spatially successive habitats.     

Vertical distribution of primary production and phytoplankton in two small lakes with different humus concentration in southern Finland

Vertical distribution of primary production and phytoplankton was studied in a polyhumic brownwater lake and in an oligo-mesohumic lake. During summer both lakes were thermally, chemically and biologically stratified. In the brownwater lake primary production was restricted to the uppermost layer of 1–1.5 m of epilimnion. In the oligo-mesohumic lake noticeable primary production was detected down to depths of 2–3 m. The ice-free period primary production was about 20% higher in the oligo-mesohumic lake, though occasionally the surface production was 2–3 times higher in the brownwater lake. Epilimnetic total phosphorus and total nitrogen concentrations were higher in the brownwater lake, while nitrate-nitrite, ammonium and phosphate concentrations were very low in both lakes.
Phytoplankton was confined to the uppermost productive layer in the brownwater lake. In the oligo-mesohumic lake phytoplankton was distributed more evenly, though the mean maximum biomass was at the depth of 3–4 m. Below the oxic water layer biomass decreased abruptly in both lakes. In the oligo-mesohumic lake chlorophyll concentration was extremely high (max. 320 mg chl a m⁻³) in the anoxic hypolimnion, due to green sulphus bacteria.
Flagellated chlorophytes and thrysophytes dominated in the brownwater lake; in spring Chlamydomonas species, followed by Mallomonas caudata . In the oligo-mesohumic lake small coccal green algae, such as Oocystis, Scenedesmus and Westella -like species, dominated in mid-summer, and chrysophytes and cryptomonads in autumn.     

基于管理目标的湖泊生态系统动力学

基于生态系统管理的目标,在对相关研究分析的基础上,依据生态系统生态学、淡水生态学的理论,提出了湖泊生态系统动力学研究的2个理论基础：生态系统管理和生态系统特征.在此基础上,分析得到湖泊生态系统动力学的研究方法体系,主要包括研究内容与技术路线、关键问题识别和动力学模拟、湖泊生态系统的适应性管理决策等部分.其中,湖泊生态系统结构和过程、湖泊中食物网营养动力学研究、生源要素循环、湖泊中关键过程的生态作用以及湖泊生态系统动力学模拟是研究的核心问题.此后,以P为主要的生源要素,将生态系统分为3个子过程：入流、出流和内部反馈,并以此建立了湖泊生态系统动力学的模型框架,以辅助于湖泊的生态系统管理.     

Geochemical and physical characteristics of river and lake [2pt] sediments at Naivasha,Kenya

Prior studies on Lake Naivasha relevant to understanding sediment dynamics include a bathymetric map, a paleolimnological study of fossil invertebrate assemblages in lake sediment, an overview of lake level fluctuations throughout the 20th century, and identification of a dynamic assemblage of macrophyte zones that has responded both to these changes in lake level and to more recent, alien species. Sediment samples collected from the rivers systems and the lake were examined physically and chemically. River sediment characteristics reflect geology and geomorphological processes in the catchment, whereas lake sediment stratigraphy has responded to past lake level changes. Such changes have caused significant changes in aquatic vegetation assemblages. Present day sediment dynamics in the lake are governed by the presence of river point sources in the north and wave-induced re-suspension, such that sediments introduced by rivers are transported in easterly and southerly directions, and are eventually deposited in the eastern, central and southern parts of the lake. Sedimentary deposition is also occurring in northern areas that once were protected by papyrus swamp vegetation but now only have a narrow fringe, highlighting the important role of swamp vegetation in filtering out suspended particulates and thereby controlling water quality in the lake. Geochemical analyses of river and lake sediments indicate that they represent fairly undisturbed background conditions. Higher-than-expected concentrations of cadmium, iron, nickel and zinc found in both river and lake sediment are likely to derive from volcanic rocks and/or lateritic soils found in the lake catchment.     

The syn-volcanic Naajaat lake, Paleocene of West Greenland

The Naajaat lake in the Nuussuaq Basin on Disko and Nuussuaq formed in a geological setting between cratonic crystalline Precambrian rocks overlain by Cretaceous sediments and an actively forming Paleocene volcanic province. The lacustrine deposits, shales as well as hyaloclastite breccias, accumulated in low-lying areas inundated by fresh water and sealed off from marine transgressions by a broad subaerial volcanic terrain. Foreset-bedded hyaloclastite breccias demonstrate water depths of up to 450 m, and the area of the lake was 2500 km² at its maximum extent. The lake probably existed for less than 0.5 million years. The lake received clay and silt from two provenance areas. Quartz contents of more than 25% in the majority of the sediment samples indicate that large amounts of material were continuously supplied to the lake from the crystalline terrain, whereas the volcanic terrain supplied smectite and mixed-layer minerals to the lake. High kaolinite contents stem from the crystalline or both provenance areas. The shales are characterized by high TOC (up to 11%), lack of pyrite, presence of terrestrial spores and pollen and lack of marine dinoflagellates. The lacustrine sediments rest on an erosional unconformity and its correlative conformity. The unconformity developed during the latest Cretaceous and Early Paleocene. Five stages are recognized in the geological development of the lake. Stages 1–4 are characterized by accumulation of hyaloclastite breccias, rise in lake level, and eventual transgression of subaerial terrains. The rises in lake level were caused by stemming of fluvial run-off behind the aggrading volcanic pile. Stage 5 corresponds to cessation of volcanic activity, a stable lake level, and progradation of clastic sediments, resulting in infilling of the lake. During the lacustrine transgression only sediment in suspension was transported into the central parts of the lake.     

河湖生态系统生态用水优化研究——以滇池流域为例

生态需水是河流与湖泊生态系统健康的重要基础。湖泊流域的河流与湖泊生态系统之间存在密切的水量联系,目前对流域内生态用水的研究多为单一生态系统生态需水简单相加,忽略了河流和湖泊之间复杂的水量联系。基于河湖复合生态系统之间的水量联系构建了河湖生态系统生态用水优化模型,并以滇池为例分析了河湖生态系统生态用水规律。结果表明：湖泊流域中单一河流或湖泊生态需水计算结果不能满足复合生态系统的生态用水要求,需要综合考虑河流和湖泊之间的水量联系;在当前水质状况下,牛栏江每年的调水量不能满足滇池流域的生态用水要求;滇池流域水体污染对流域内生态用水影响较大,随着水体污染程度的下降,流域生态用水量和调水量呈指数下降,河流生态用水呈线性下降。     

Biomass and Production of Lake Charr During the Acidification and PH Recovery of A Small Ontario Lake

The biomass and production of lake charr, Salvelinus namaycush, was studied in Lake 223, a lake that was intentionally acidified to pH 5.0 and then allowed to gradually recover, and in Lake 224, a natural lake of neutral pH. During the first 6 years pH decreased, biomass of Lake 223 lake charr increased, primarily due to high recruitment during the initial years of acidification. Biomass then decreased the final year of acidification. Biomass of Lake 223 lake charr remained low during the subsequent 10 years of pH recovery and 5 additional years after lake pH had returned to neutral pH. Production of lake charr decreased during acidification and increased during pH recovery. Production was still at least an order of magnitude lower at the end of this study than 22 years earlier before lake pH was lowered. The continued low production was caused primarily by low abundance during the years of pH recovery and following years. Production per individual fish in Lake 223 decreased during acidification and quickly increased during pH recovery to values similar to that prior to acidification. Production, biomass, and production per individual varied little between years for lake charr in Lake 224.     

An indicator framework for assessing the technology aspect of Integrated Lake Basin Management for Lake Malawi Basin

Lake Malawi is one of the African Great Lakes and is well known for its fish biodiversity which is the greatest in the world for freshwaters. The lake basin is a valuable resource to the riparian countries. Activities associated with the derivation of the values offered by the lake basin, however, result in the generation of wastes and pollutants that also impact on the lake basin. Such anthropogenic activities within the lake basin place considerable strain on the lake system and may lead to the degradation of the lake basin. Proper application of technology can effectively supplement command-and-control measures and economic instruments for better lake basin management. Currently, no comprehensive framework exists to assess the management of the lake basin. Such a framework is necessary to guide managers and policy-makers in the formulation of management plans and strategies for the sustainable management and utilization of the lake basin. We propose an indicator framework for assessing the technology aspect of Integrated Lake Basin Management (ILBM) in the context of the Lake Malawi Basin. We further demonstrate applicability of the proposed framework through a study conducted in the Malawian side of the basin. We applied a five point Likert-type scale in our indicator assessment. Overall, our results show that the technology aspect of the management of the lake basin is weak to moderate. This threatens the sustainability of the lake especially in the areas of solid waste management, sanitation services, pollution control and protection of wetlands and lagoons which performed from very low to moderate. The major challenges are weak institutional capacity, weak regulation enforcement, and insufficient resources.     

Cost of predation avoidance in young-of-year lake trout (Salvelinus namaycush): growth differential in sub-optimal habitats

Selection of habitat to avoid predation may affect the diet of young-of-year (YOY) lake trout (Salvelinus namaycush). YOY lake trout may use inshore habitat to avoid predation; this habitat may be sub-optimal for growth. To test this, YOY lake trout were penned in nearshore and offshore pelagic areas of two arctic lakes. Toolik Lake had a lake trout population, the other lake, S6, did not. YOY lake trout in Toolik Lake lost weight, but those offshore lost less weight. The YOY lake trout in Lake S6 gained weight and those offshore gained more weight. The primary diet item of the YOY lake trout in both lakes during this experiment was the zooplankter Diaptomis probilofensis; it was also one of the most abundant species. However, its density inshore in Lake S6 was similar to inshore and offshore densities in Toolik Lake. The increased availability of alternative zooplankton prey in Lake S6 may account for the growth differential of YOY lake trout in Lake S6 relative to Toolik Lake. Bioenergetic modeling of YOY lake trout suggests that growth similar to that in the offshore of Lake S6 would be necessary for successful recruitment. If the reduced zooplankton availability in Toolik Lake leads to the reduced growth of YOY in the inshore and offshore pelagic areas, then these fish will be more susceptable to winter predation/starvation. For YOY lake trout to survive in Toolik Lake they most likely shift to feeding on benthic prey before the end of their first summer. Dept. of Chemical Engineering     

城市湖泊景观水体形态定量研究

湖泊水体形态是景观空间的重要组成部分,以往对于湖泊景观水体形态的研究多囿于定性描述,本文引入了定量方法对城市湖泊景观的水体形态展开研究,采用基本几何、分形几何与欧式几何形态指标对水体形态进行描述,以28个公众认可度高的城市湖泊为案例,通过定量评价得到水体形态指标数值或区间,并基于线性回归分析,探讨了各个指标之间的影响及关联,解析归纳了湖泊景观水体的“形态”特征。     

The distributions and effects of nutrients in the sediments of a shallow eutrophic Chinese lake

The temporal and spatial distribution of total nitrogen and total phosphate in the sediments of a shallow eutrophic Chinese lake (Lake Chao), and their relationships with the physical and chemical features of sediments, and their effects on the lake water quality and trophic state, are presented in this paper. The following results were obtained: (1) higher concentration of Tot-N and Tot-P in the sediments occurred in the summer and the autumn seasons; (2) higher annual average Tot-N and Tot-P concentrations were observed in the sediments near the various river mouths and in the western part of the lake; (3) Tot-N and Tot-P concentration in the lake sediments generally increased with increase in lake sediment Eh, pH, and Al₂O₃, and declined with decrease in lake sediment size diameters and SiO₂; and, (4) correlations were observed in both the temporal and spatial distributions between the trophic state, Tot-N and Tot-P concentration in the lake water, and the Tot-N and Tot-P concentration found in the lake sediments.     

Late Quaternary palaeohydrology of Lake Huinaymarca (Bolivia)

In lake Titicaca, the distribution of the modern ostracod fauna appears to be controlled by a combination of two factors: a) the equilibrium between carbonates and organic matter, b) the ionic composition of the lake water and its tributaries. Therefore, the Limnocythere-Pampacythere group generally predominates on an alkaline-carbonate lake floor. In parts of the lake receiving an NaCl input from tributaries, Cyprideis and Cyprinotus occur. These are generally absent elsewhere. The Candonopsis group is found in the deepest part of the lake.Analysis of ostracod assemblages recovered from a number of cores permitted the reconstruction of the hydrological evolution of lake Huinaymarca for the last 10000 years. This included: low water levels, variations of oxygenation related to the position of the thermocline, and interconnections between different basins of the lake.     

1995-2015年武汉城市湖泊景观生态安全格局演化

以1995、2005、2015年3期遥感影像为数据源,通过景观指数和GIS空间分析方法研究武汉中心城区湖泊系统景观格局的演化特征,进而构建湖泊景观生态安全评价模型,以揭示武汉中心城区湖泊系统景观生态安全格局演变规律,并探讨其驱动因素。研究结果表明：（1）近20年来武汉中心城区湖泊系统总面积呈现不断下降趋势,1995-2005年以年均2.4%的速率缩减了28.95 km²,2005-2015年以年均1.8%的速率缩减了17.47 km²。（2）研究期湖泊系统的斑块密度、分维数呈现不断降低趋势,这表明武汉中心城区湖泊破碎化程度在不断降低,湖泊形状趋于简化;而连接度呈现不断增加趋势,湖泊分布集聚趋势不断加强,空间结构趋于紧凑集中。（3）武汉城市湖泊系统总体景观生态安全呈现不断恶化趋势,而次级湖泊水系景观生态安全呈现不同的演化特征。城市建成区的迅速扩展、湖泊由农业生产对象转化为可利用发展用地、房地产事业成为支柱产业是湖泊系统遭填占最主要的动力,直接危害了其景观生态安全,而市民环境意识提高引发湖泊保护倡议和实践,对湖泊景观生态安全产生着积极影响。对湖泊景观生态安全格局演变特征及驱动因素的研究,可以为武汉制定行之有效的生态管理政策和环境治理措施提供重要支撑。     

Assessing Seasonal and Inter-Annual Variations of Lake Surface Areas in Mongolia during 2000-2011 Using Minimum Composite MODIS NDVI

A minimum composite method was applied to produce a 15-day interval normalized difference vegetation index (NDVI) dataset from Moderate Resolution Imaging Spectroradiometer (MODIS) daily 250 m reflectance in the red and near-infrared bands. This dataset was applied to determine lake surface areas in Mongolia. A total of 73 lakes greater than 6.25 km²in area were selected, and 28 of these lakes were used to evaluate detection errors. The minimum composite NDVI showed a better detection performance on lake water pixels than did the official MODIS 16-day 250 m NDVI based on a maximum composite method. The overall lake area detection performance based on the 15-day minimum composite NDVI showed -2.5% error relative to the Landsat-derived lake area for the 28 evaluated lakes. The errors increased with increases in the perimeter-to-area ratio but decreased with lake size over 10 km². The lake area decreased by -9.3% at an annual rate of -53.7 km² yr^-1 during 2000 to 2011 for the 73 lakes. However, considerable spatial variations, such as slight-to-moderate lake area reductions in semi-arid regions and rapid lake area reductions in arid regions, were also detected. This study demonstrated applicability of MODIS 250 m reflectance data for biweekly monitoring of lake area change and diagnosed considerable lake area reduction and its spatial variability in arid and semi-arid regions of Mongolia. Future studies are required for explaining reasons of lake area changes and their spatial variability.