广东省大中型供水水库营养现状及浮游生物的响应

于2000年调查了广东省18座大中型供水水库的水质现状并探讨了浮游生物对营养水平的响应。总氮、总磷、透明度和叶绿素a分别为0．15～7.15mg／L、0．003～0．387mg／L、0．4～6．3m和0．6～32．3ug／L。总氮、总磷、透明度均与叶绿素a呈较高的相关性。根据这4个因子的综合加权营养状态指数为23．7～55．1,季节差异不大,大多数水库处于中营养状态。金藻在中-富及富营养型水库中没有分布,而蓝藻、绿藻、硅藻和甲藻在调查水库中均有比较广的营养生态位,但它们的密度及相对优势度在各营养型水库中有一定的差异。高营养水平水库有较高的细胞密度和叶绿素a含量。营养水平较低的水库浮游植物以硅藻-甲藻、硅藻-绿藻或金藻-硅藻为主;营养水平较高的水库以蓝藻-硅藻或蓝藻-绿藻为主,并有较高的裸藻密度。浮游动物基本上以桡足类为优势种群,但在中-富营养和富营养型水库中,哲水蚤种类比低营养型水库中少。枝角类优势种类在各营养型水库差别不大。轮虫对水体营养水平的响应相对比较显著。低营养水平水库的轮虫以广营养型、中营养型或寡中营养型种类为主,种类数目比较少;富营养和中-富营养型水库的轮虫以喜在中营养到富营养条件下生长的种类为主,且轮虫种类数目比较多。     

南水北调中线水源区浮游植物时空分布及其营养状态

2004年3月-2006年5月,在南水北调中线水源区选择4个监测点进行了7次采样,获取了表层浮游植物和水质理化指标数据,采用污水生物系统法、营养状态指数法和单因子评价法综合评价了水源区的营养状态.结果表明:中线水源区浮游植物群落具有明显的时空变异性;浮游植物共有8门67属161种(含变种),硅藻占39%,污染指示种21属24种(含变种),β-中营养型占污染指示种的38%;在检出的浮游植物中未发现水体重污染指示种;水源区叶绿素a质量浓度为0.00425 mg·m-3,营养状态指数为0.0001;除总氮外,其他理化检测指标均符合Ⅰ类水质标准;综合评价水源区处于中营养状态.本研究可为中线水源区长期生态研究数据信息库的建立及库区环境保护政策的制定提供科学依据.     

滴水湖叶绿素a时空分布及其与水质因子的关系

根据2011年9月-2012年8月监测数据,分析上海市人工湖泊——滴水湖叶绿素a的时空分布及其与主要环境因子的相互关系.结果表明:滴水湖叶绿素a含量随时间的变化幅度较大,表现为3、7月出现高峰而其他月份较低;叶绿素a含量在空间分布上具有一定的分异性,湖心普遍偏高,其他各点相对较低;对滴水湖叶绿素a采用主成分多元线性回归分析(APCS-MLR),得到描述水质因子的潜变量F1、F2与其相关性较大,建立了潜变量与叶绿素a含量的相关性模型;滴水湖叶绿素a含量与溶解氧(DO)、水温、总溶解磷(TDP)、活性磷(AP)有着密切的相关性;磷为滴水湖水体初级生产力的限制因子;因此,磷是有效控制滴水湖水体富营养化的关键因子.     

基于宏基因组的保安湖浮游动物多样性研究

研究于2019年春、夏、秋、冬四季对保安湖进行了水样采集, 基于宏基因组测序, 在优化物种鉴定和丰度计算方法的基础上, 考察了保安湖浮游动物的多样性、群落结构及其影响因素。共鉴定到浮游动物OTU 374种, 其中原生动物282个; 枝角类45个; 桡足类26个; 轮虫21个。从季节来看, 夏、秋季保安湖的浮游动物多样性高; 从湖区来看, 肖四海和主湖区浮游动物多样性高。季节因素对保安湖浮游动物群落结构的影响高于湖区影响。保安湖营养状态为中营养型, 水体温度、叶绿素a是影响保安湖浮游动物群落结构的主要环境因子, 不同类群与环境因子相关性不同, 总体可分为5类。其中原生动物优势类群为混合营养的纤毛虫和丝足虫, 同硝氮、化学需氧量、温度有明显的相关性, 而枝角类和桡足类同环境因子的关系较为相似, 与溶氧、叶绿素a、正磷酸盐存在明显相关。研究利用宏基因组方法对保安湖浮游动物多样性开展了研究, 为从浮游动物这一角度来理解保安湖这一江湖阻隔型湖泊的生物多样性的变化提供了支撑。     

东海赤潮高发区春季叶绿素a和初级生产力的分布特征

2002年4-5月对东海海域进行了综合调查,分析了海区叶绿素a和初级生产力的分布特性．结果表明,大面站表层平均叶绿素a浓度为1．086mg·m-3．分级叶绿素a结果显示．春季东海浮游植物以微型和微微型(<20μm)占优势,其对海区叶绿素a的贡献为64％,超微型浮游植物(<5μm)占浮游植物生物量的27％．营养盐分布和浮游动物的摄食压力影响了叶绿素a及其粒级结构的分布．平均初级生产力为10．091mg·m-3·h-1。赤潮跟踪的R-03、RL-01、RG-01站的平均初级生产力为399．984mg·m-3·h-1．光和营养盐成为叶绿素和初级生产力平面分布的主要限制因子．表层叶绿素a和初级生产力均在调查海区的123·E纵断面冲淡区产生高值区．DC-11站浮游植物生物量异常高,表层叶绿素a达到9．082mg·m-3,初级生产力为128．79mg·m-3·h-1．但并未出现水色异常．     

钱塘江干流杭州段水体叶绿素a浓度及与环境因子的关系

2006年1月至2007年12月,对钱塘江干流杭州段水体的叶绿素a 时空分布及其与环境因子的关系进行研究.结果表明钱塘江干流杭州段的叶绿素a 浓度时间差异显著,空间差异不显著.叶绿素a 浓度呈现夏秋季节高、冬春季节低的规律.叶绿素a 浓度与温度呈显著正相关,叶绿素a 与透明度在不同范围内表现出不同的相关关系,叶绿素a 与TN 、TP 之间的相关关系在不同江段有所差异.钱塘江干流杭州段总氮和总磷浓度均很高,足够满足藻类生长需要;氮磷比较低,基本在8 ～30 之间,说明氮磷含量可能不是钱塘江藻类生长的限制因子.     

中国典型湖泊富营养化现状与区域性差异分析

为全面科学地综合评估全国富营养化现状, 以全国五大湖区22个典型湖泊为研究对象, 科学评估了其富营养化状态, 分析了全国湖泊富营养化状态的区域性差异, 并探讨了富营养化状态与总磷的定量关系。结果表明, 2010—2011年, 59.1%的调研湖泊处于不同程度的富营养化状态, 其中云贵湖区的富营养化程度最为严重, 蒙新湖区的富营养化呈两极分化状态, 东北山地-平原湖区与东部湖区的湖泊基本均处于中营养-轻度富营养之间, 青藏高原湖区的富营养化程度最低。通过分析日照数、无霜期、气温、水深、海拔、降雨与湖泊营养状态的关系, 揭示了湖泊所处的地理位置是影响湖泊富营养化的基本因素, 具有区域性的分布规律。综合分析结果表明, 全国范围内湖泊中叶绿素a与总磷浓度存在显著相关性, 其中东部平原湖区、东北平原-山地湖区、青藏高原湖区和云贵高原湖区的叶绿素a与总磷浓度符合三次曲线方程, 蒙新湖区的叶绿素a与总磷浓度符合S型曲线方程; 东部平原湖区、东北平原-山地湖区、青藏高原湖区叶绿素浓度随着总磷浓度的增加, 首先出现1个极小值点, 然后出现1个极大值点, 其中3个湖区极小值点对应的总磷浓度分别为: 0.054、0.089和0.072 mg/L, 可为我国对应湖区的湖泊富营养化控制指标提供借鉴。     

东湖浮游生物群落DNA指纹结构及其与环境理化因子的关系

对武汉东湖5个不同湖区的浮游生物群落DNA进行了RAPD指纹分析,并探讨了DNA指纹结构与环境理化因子的关系．结果表明：所筛选的9条随机引物共扩增210条大小为150～2000bp的谱带,多态率为93．3％．各站点平均有42条谱带,其中Ⅳ站最多（53条）,Ⅴ站最少（35条）．Ⅰ站的PO4^3--P、TP含量最高,Ⅴ站的NH4^＋-N、TN、NO2^--N含量最高,Ⅳ站各理化因子含量均低于其他站点,站点间COD、碱度、硬度、钙含量差异不大．相似性聚类分析表明,基于RAPD标记的浮游生物群落指纹将5个站点划分为两类：Ⅰ、Ⅱ、Ⅲ站聚为一枝,Ⅳ、Ⅴ站聚为另一枝．这与湖区主要理化因子的聚类结果一致．说明东湖不同湖区浮游生物群落DNA指纹与其环境理化因子密切相关．     

巢湖西半湖富营养化时空变化趋势与成因分析

收集整理了巢湖西半湖6个国控监测点1983~2008年（26年）主要富营养化指标TP、TN、CODmn、Chla的监测数据,计算了6个监测点和西半湖总体26年的综合营养状态指数（∑TLI图示）时空变化情况。并用Spearm an秩相关系数分析检验了西半湖总体和6个监测点26年∑TLI年变化趋势。结果表明：按总平均∑TLI排列,6个监测点富营养化由重到轻依次为：南淝河入湖区（66.64）〉塘西（64.93）〉十五里河入湖区（63.35）〉派河入湖区（61.38）〉新河入湖区（59.51）〉西半湖湖心（59.18）;在显著水平0.05和0.01各点∑TLI均有上升趋势,其中十五里河入湖区（R=0.715）、新河入湖区（R=0.824）和西半湖湖心（R=0.811）以及西半湖总体（R=0.512）∑TLI有显著上升趋势,而南淝河入湖区（R=0.192）、塘西（R=0.045）和派河入湖区（R=0.325）上升趋势均不显著。最后在上述研究的基础上,对巢湖西半湖富营养化时空变化的成因进行了简要分析。     

肇庆星湖水质现状与变化趋势

在2002年对星湖四个子湖进行采样调查,运用相关加权综合营养状态指数来评价水质营养状态,结果富营养化程度由高到低依次为波海湖、中心湖、青莲湖、仙女湖。与1996～1997年的调查结果比较,波海湖仍处于富营养化状态,中心湖富营养化程度加剧,其富营养化程度超过了青莲湖和仙女湖,由中营养型过渡到了中富营养型。营养盐与叶绿素a的相关分析表明,硝态氮与叶绿素有正相关关系,与磷盐没有明显相关性,说明了硝态氮是星湖初级生产力的主要限制因子之一,而磷的含量充足,对初级生产力没有明显的限制作用。与1996～1997年比较,星湖总氮负荷增加46.5%,总磷负荷下降40.8%,而叶绿素a由6.0mg·m-3升高到16.9mg·m-3,说明星湖的富营养化仍在进一步加剧。     

Predictors of Seasonal Oxygen Levels in Small Florida Lakes: The Importance of Color

This study examines the relationship of profundal oxygen concentrations in 55 shallow Florida lakes to humic color, trophic state, and lake size during different seasons. The data set represented a broad range of color and trophic state. The percent saturation of dissolved oxygen remained relatively constant during the fall (mean 78.4%), winter (mean 81.3%), and spring (mean 82.5%), but declined markedly during summer (mean 65.2%). Chlorophyll a concentrations were highest during the winter (mean 2.52 mg m^–3) and lowest during the fall (mean 1.17 mg m^–3), while color peaked during the fall (mean 30.1 mg Pt l^–1) and was lowest during the summer (mean 12.7 mg Pt l^–1). The relative importance of lake size, chlorophyll a, and color in explaining variation in percent oxygen saturation was examined using multiple regression. Percent oxygen saturation was negatively correlated with color during the winter, spring, and summer, and positively correlated with lake size in the winter and spring. However, percent oxygen saturation showed no relationship with chlorophyll a during any season. These results suggest that colored Florida lakes are naturally oxygen depleted and that profundal oxygen values have little relationship to lake trophic state. This revised version was published online in July 2006 with corrections to the Cover Date.     

Combining multivariate statistical techniques and random forests model to assess and diagnose the trophic status of Poyang Lake in China

Floodplain lakes are valuable to humans because of their various functions. An emerging public concern on lake eutrophication has heightened the need to assess and predict the trophic status in floodplain lakes, particularly for those with high spatial heterogeneity. In this study, combined multivariate statistical techniques and random forests model were used to characterize the water quality and trophic status of Poyang Lake. By classifying and characterizing seasonal water samples comprising 11 water quality parameters collected from 13 sampling sites in Poyang Lake between 2008 and 2014, the dataset was divided into the central and northern lake groups, which corresponded to lentic and lotic regions in Poyang Lake, respectively. The spatial water quality variations and underlying patterns were investigated by performing discriminant analysis and principal component analysis (PCA). Lastly, random forests (RF) were used to predict the chlorophyll a (Chl-a) variations of the central and northern lakes. The PCA results indicated that the water quality of the central and northern areas of the lake was controlled by different environmental variables and underlying pollutant sources. The RF model outperformed the artificial neural network and linear regression and was robust with strong predictive capabilities. It was determined that the most important predictors of the Chl-a variations in the northern lake were water temperature (T) and water level, whereas transparency, T, and water level were the most efficient predictors in the central lake. The RF model can also be applied to trophic prediction in other large lakes with considerable spatial variations. This study will have implications on water quality management and eutrophication prevention in floodplain lakes with high spatial heterogeneity.     

惠州西湖富营养化现状评价及治理探讨

惠州西湖属于城市型浅水湖泊,本文通过历史和现状数据整理和分析,采用Carlson的营养状况指数(TSI)进行评判,表明惠州西湖处于富营养阶段。通过近几年的疏浚湖底沉积物、截流城市污水和换水等工程措施,惠州西湖水体总氮和总磷有所下降。日前两湖水生生态系统处于逆向演替的藻形湖泊时期,其水生植物受到严重破坏,湖水的透明度等指标没有得到改善。研究结果表明,今后惠州西湖应走生态修复途径,生态系统的恢复与重建和非点源污染控制是关键。     

Deepwater sediments and trophic conditions in Florida lakes

Sediment cores were taken from near maximum depth in 15 Florida lakes representing a wide range of trophic conditions. Chemical analyses of surface sediments showed Al, Fe, and Ca to be the most abundant elements in all samples, and the ratio of Al to Ca to be smaller for eutrophic lakes. Sediment organic matter increased with trophic state, as did the degree to which it was enriched in nitrogen. Corresponding sediment C/N ratios decreased with increasing lake trophic state and showed significant negative correlation with chlorophylla, total N, and total P in the water column. Concentrations of sedimentary chlorophyll derivatives showed some relation to trophic state but differences in basin morphometry hinder its use as an inter-lake index of chlorophyll production.     

Tests of autotrophic picoplankton as early indicators of nutrient enrichment in an ultra-oligotrophic lake

1. The potential of picocyanobacteria as early indicators of changes in nutrient loading and trophic status was examined in an ultra-oligotrophic lake.
2. The study consisted of in situ, short-term, nutrient-addition bioassays and surveys of picocyanobacterial variables and other indices of trophic state at six sites selected to include a range of localized nutrient loadings to the lake from its catchment. The bioassays and surveys were conducted six times throughout 1 year.
3. Experimental additions of small amounts of ammonium-N and phosphate-P did not stimulate picocyanobacterial growth, and phosphate additions often reduced picocyanobacterial growth rates.
4. A correlation analysis using pooled data from all sites and sampling dates showed that the abundance of aggregated picocyanobacteria was strongly correlated with nutrient concentration and ratios. Other variables, including the concentration of single-cell picocyanobacteria, chlorophyll a and primary production, were poorly correlated with nutrients.
5. The results show that picocyanobacteria in oligotrophic lakes are sensitive to extremely small changes in nutrient availability and that they can respond in complex ways. The mechanisms by which they respond to such changes require further study before they can be used as bio-indicators of nutrient enrichment.     

Classification, assessment and trophic reconstruction of Danish lakes using chironomids

1. Surface-sediment assemblages of subfossil chironomid head capsules from fifty-four primarily shallow and nutrient-rich Danish lakes were analysed using multivariate numerical techniques. The species data, comprising forty-one chironomid taxa, were compared to environmental monitoring data in order to establish a relationship between chironomid faunal composition and lake trophic state.
2. The subfossil assemblages were compared to the chironomid bathymetric distributions along transects from four lakes. Correspondence analysis and similarity coefficients showed that the subfossil assemblages, sampled in the lake centre, reflect the chironomid communities in the littoral at a depth of 2–7 m.
3. Two-way indicator species analysis (TWINSPAN) was used to classify the Danish lakes into five groups defined by trophic state, lake depth and pH. Eighteen chironomid taxa showed significant differences in abundance among the five groups. Canonical correspondence analysis (CCA) showed the chlorophyll a concentration ([Chl a ]) and Secchi depth to be the variables best correlated to the faunal data, and fourteen taxa were significantly correlated to [Chl a ].
4. The strong correlation between chironomid data and the ln-transformed ([Chl a ]) was used to create a weighted averaging (WA) model to infer lake trophic state. Several models were tested by cross validation (leave-one-out jack-knifing), and a simple WA model using inverse de-shrinking had a RMSEP_jack of 0.65 (ln units) and a r ²_jack of 0.67.
5. The results can be used in the assessment and reconstruction of lake trophic state for long-term monitoring and palaeoecological investigations of shallow, temperate lakes in the mesotrophic to hypertrophic nutrient range.     

Temporal and spatial variations of aquatic environmental characteristics and sediment bacterial community in five regions of Lake Taihu

Sediment bacterial community and their relation with environmental factors were investigated in the five different trophic status lake regions sediment, Meiliang Bay, Wuli Lake, Gonghu Bay, Western Lake Taihu and Xukou Bay in a large, shallow, eutrophic freshwater lake (Lake Taihu, China). Water and surface sediment samples were collected at 35 sampling sites in January 2014 (winter) and July 2015 (summer). The physicochemical characterization showed that there were obvious changes in the trophic status and eutrophic index of five lake regions, which was mainly due to the difference of organic matter source. Based on the analysis of aquatic environmental characteristics, the organic nitrogen or nitrate nitrogen was the main storing form in the overlying water of five lake regions. In addition, nitrate nitrogen in pore water was lower than in overlying water, while ammonia nitrogen in pore water was higher than in overlying water. According to the DGGE profiles, temporal and spatial variations of bacterial community were apparent. Bacterial diversity was higher in summer than in winter and increased with the decrease in the lake region trophic status. The dendrogram of the bacterial community similarities revealed that samples were almost all grouped into two defined clusters (summer and winter), which indicated that season rather than region was the dominant factor. Canonical correspondence analysis demonstrated that ammonia nitrogen and nitrate–nitrite nitrogen in the sediment and pore water, organic matter and temperature significantly influenced the sediment bacterial community in the five lake regions.     

安康水库表层浮游藻类群落结构及其与环境因子的关系

为了解安康水库表层水质与浮游藻类群落现状以及浮游藻类群落结构与环境因子之间的关系,于2012年1—12月对水库表层水进行每月一次的采样,分别对浮游藻类分布状况和理化因子进行分析.利用Shannon指数(H)和Pielou均匀度指数(J)分析浮游藻类群落特征,根据理化指标和综合营养状态指数(TSI)评价水体营养状态.共检测到浮游藻类7门110属,丰度为0.11×10⁴～2.08×10⁴ cells·L^-1.藻类组成、污染指示种分布情况、多样性分析和TSI显示安康水库表层属于中污染水质,处于中营养状态.此外,高密度投饵水产养殖及生活污水直接排放入库对水质产生负面影响,支流岚河的水质状况也较差.典范对应分析(CCA)结果显示,测定的8个环境因子中,不同季节影响浮游藻类群落组成及分布的环境因子不同,且氮是影响浮游藻类组成的主要营养盐因子.理化指标分析显示,安康水库表层水大体满足Ⅱ类水标准,水质良好.但部分采样点的总氮出现差于Ⅱ类水标准的现象,表明安康水库水质有变差的趋势.     

Phytoplankton distribution along trophic gradients within and among reservoirs in Catalonia (Spain)

1. Longitudinal gradients in the epilimnetic waters of stratified reservoirs provide a useful database to study changing environmental conditions. The spatial distribution, assemblage structure and specific adaptations of phytoplankton assemblages can be analysed along these gradients over short time scales. 2. Four reservoirs with a similar typology, located along an altitudinal gradient in the same eco‐region, were sampled along their longitudinal axes. In total, 19 sampling stations provided a trophic spectrum, ranging from oligo‐mesotrophy to hypertrophy, which was quantified by calculating the trophic state index of each sampling station in the four reservoirs. 3. Several patterns in phytoplankton assemblage structure were detected. Total chlorophyll‐a (Chl‐a), biovolume, abundance and the relative biomass contribution of the main algal groups (chlorophytes, cyanobacteria, cryptophytes and diatoms) were highly correlated with their location along the trophic gradient. 4. We also adopted the functional classification of Reynolds et al. (2002) : this effectively summarized differences among phytoplankton assemblages under varying resource‐limiting combinations, especially nutrients and underwater light climate. 5. In terms of relationships with the trophic gradient, diatoms and cyanobacteria exhibited significant opposing trends in both their relative chlorophyll contribution to total Chl‐a and biovolume. Chlorophytes were more abundant at an intermediate position along the trophic spectrum. 6. The identified patterns are consistent with models of self‐organization of phytoplankton assemblages. In particular, light availability was a strong determinant of size and shape diversity, especially in hypertrophic conditions, where ‘R‐strategist’, needle shaped species, dominated the system. In contrast, under decreased availability of nutrients and higher light extinction coefficients (K_d), the system was co‐dominated by C‐ and S‐strategist species, having shapes with a higher surface/volume ratio.     

Eastern spread of the invasive <Emphasis Type="Italic">Artemia franciscana</Emphasis> in the Mediterranean Basin,with the first record from the Balkan Peninsula

Long-term (1987–2015) monitoring data from Lake Lugano (Switzerland/Italy) were used to examine the effects of winter weather, solar radiation and mixing regime on the recovery of the trophic state of a lake undergoing nutrient management. Main hypotheses were that (H1) trends in trophic state were influenced not only by nutrient management, but also by winter weather and solar radiation, and (H2) the effects of management were more pronounced in the holomictic South basin than in the meromictic North basin of the lake. External loadings of phosphorus were strongly reduced during the study period, but key indicators of trophic state, including phosphorous concentration, primary production, chlorophyll a and deep-water oxygenation, showed inconsistent responses. Supporting H1, winter weather (parameterized using an index of the East Atlantic pattern) influenced temporal variation in phosphorus concentration and primary production in the North basin. Supporting H2, the effects of management on trophic state were clearer in the South basin, where most trophic-state indicators declined. Meromixis affected the restoration of the North basin lake by transmitting effects of climatic variation on trophic state. The added variability obscured the effects of restoration and caused sudden deteriorations in water quality, indicating that the restoration of meromictic lakes presents unique challenges.