Abstract:A physic-ecological engineering (PEEN) for aqua-eco-remediation was performed in a local area (enclosed water with surface area of 1.33 ha) with depth round 10 m and variation of water level of 7 m in Lake/Reservoir Hongfeng. Results showed that the construction, abundance and biomass of the phytoplankton may be regulated by PEEN, when the ratio of the sum area of floating islands with plant to the total enclosed area is above 1/5-1/3(as the threshold). The dominant phytoplankton population shifted from Cyanophyta (Microcystis), Pyrrophyta (Ceratium hirundinella) and Cyanophyta (Dactylococcopsis acicularis) in surrounding algae-type water to Bacillariophyta (Melosira) after the construction of engineering. Species of Cyanophyta in plant-type water were less than that of surroundings at 17.6%-29.4% (especially the species with microcystin, such as Microcystis, Anabaena, Oscillatoria, Aphanizomenon, were detected in surroundings algae-type water did not been detected in plant-type water); while the species of Bacillariophyta increased to 120.0% in comparison with that in the surroundings. The abundance and biomass of Cyanophyta in the plant-type area of the PEEN decreased by 55.5% and 57.9% in comparison with those in surroundings, respectively. Meanwhile, the abundance and biomass of Bacillariophyta in the plant-type area of the PEEN increased by 56.4% and 60.3% in comparison with those in surroundings, respectively. The total phytoplankton abundance and biomass decreased by 53.6% and 39.1%, respectively in comparison with those of the surroundings. All these facts benefited the increase of transparency in plant-type water, where the water quality improved obviously and the secchi depth is stably observed at 120-220 cm and higher than that in surrounding algae-type water in dozen centimeters. The engineering area appears as the "green island" in the algae bloom occupied surroundings frequently. The eutrophication in local area of Lake Hongfeng with surface area of 57.2 km² at normal water level is controlled without algae bloom. The PEEN including floating eco-islands, which can be used for culturing various water surface plant, including aquatic plant, wetland plant, terrestrial plant (Vetiver Grass, salix integra linn., etc), for relieving high wind-driven wave, suppressing blue algae, improving water quality and transparency and other techniques is important for guaranteeing the remediation of submerged vegetation in shallow lakes and preventing algae bloom under severe environmental pressure at present.

Abstract:Cyanobacteria after outbreak and being randomly distributed produced microcystins, polycyclic aromatic hydrocarbons, harmful gases and other toxic substances. In this paper, the process of cyanobacteria decaying was simulated in laboratory, and the changes of organic elements, chloroform extracts A, saturated hydrocarbons and aromatic hydrocarbon during decaying of cyanobacteria had been surveyed. On this basis, we discussed the countermeasure of aromatic hydrocarbons and other toxic substances produced from the accumulation cyanobacteria. Results showed that after 1-month aerobic and 1-month anaerobic decaying, the contents of total aromatics and polycyclic aromatic hydrocarbons in cyanobacteria were decreased to the lowest. Besides, the anaerobic treatment increased the content of total aromatics slightly. The longer the action time of aerobic, the higher content of saturated hydrocarbons, and to the highest in cyanobacteria after 3-month aerobic decaying. N-alkanes will occur relatively strong C-C bond cleavage process, mainly generated small molecules gaseous hydrocarbons. Therefore, we argued that the cyanobacteria, which after 1-month aerobic and 1-month anaerobic decaying, was more suitable for organic fertilizer resource utilization in a pool, then the gas collected for combustion; the cyanobacteria after 3-month aerobic decaying was more suitable for bio-energy. Accordingly, we proposed that monitoring the humification process and to control the formation of harmful ingredients relying on the fluorescence intensity of phycobiliprotein and chlorophyll.

Abstract:Understanding the temporal-spatial distribution characteristics of Huangtai algae bloom can provide support decisionmaking for prevention and control of Huangtai algae bloom in Lake Ulansuhai, China. Cloud-free images shot by MODIS sensor from May to September and from 2000 to 2010 were utilized to extract algae bloom area and spatial distribution by means of Normalized Difference Vegetation Index. According to the analysis, conclusions are as below:(1) as for area variation, Lake Ulansuhai had a severe situation of Huangtai algae bloom in 2000, 2001, 2005, 2006, 2008 and 2010, more than the average of the whole period (24 km²). In regard to monthly variation, Huangtai algal areas in May, June, July remained low around 20 km². Yet Lake Ulansuhai have larger Huangtai algal areas in August and September, around 28 km² and 40 km², respectively. (2) As for occurrence frequency, the highest frequency of Huangtai algae bloom occurred in 2001 (0.58), followed by 2005, 2006 and 2010 fluctuating around 0.25 (higher than the average of 11 a, 0.19); occurrence frequency in other years kept a low level around 0.10. In the aspect of monthly variation, occurrence frequency in May, June, July kept a low level around 0.10. The times of Huangtai algal bloom experienced a more rapid increase and a larger scale of outbreak frequency in August and September, 0.27 and 0.52, respectively, higher than the average of 5 months (0.19). (3) Huangtai algae blooms mostly lied in the region called Xidatan, the north coast and middle of the region called Dongdatan, and along the west coast of south Lake Ulansuhai, where local agricultural irrigation drainage water flows into the lake and thus the most striking algal blooms emerge there. (4) Daily average temperature, precipitation and nutrient concentrations (total nitrogen and total phosphorus) in two months ago have a significant correlation relationship with Huangtai algae's occurrence. Additionally, synchronous wind speed has a significant correlation relationship with Huangtai algae's occurrence. The spatial distribution of nutrient (TN, TP) is well consistent with the distribution of Huangtai algae's occurrence. Human activities, especially artificial supplement for water in Lake Ulansuhai, have great impact on the variation of Huangtai algae occurrences.

Abstract:In this experiment, cysteine was used as an Oxidation Reduction Potential (ORP) adjustment to explore the responses of Microcystis aeruginosa (FACHB 469) under different ORPs'stimulation. A recovery experiment was also designed with M. aeruginosa separated from the former experiment and cultured in fresh medium. Results showed a negative effect of low ORP stimulation on the growth of M. aeruginosa. Within the range of -50 to -100 mV, inhibition effect was intensified with the ORP's decline. The uptake rate of phosphorus decreased under low ORP's stress but had no relationship with stress strength. A proper low ORP' s stimulation (e. g. -50 and -75 mV) could intensify the SOD enzyme activity of M. aeruginosa, while over low (e. g. -90 and -100 mV) had negative effects. M. aeruginosa could recover its growing ability after removing the lower ORP's stimulation. The uptake rate of phosphorus and the SOD enzyme activity returned to normal as well. Moreover, the enhancement of growth ability was observed by a low ORP's stimulation (e. g. -50 and -75 mV). Thus, the low ORP's stimulation had negative effect on the growth of M. aeruginosa, however the process can be reversible.

Abstract:Based on municipal pollutant sources data of Jiangsu coastal area in 2008, the main pollutant source composition and pollution characteristics of Guanhe River, the total amount of pollutants into the river was calculated and corrected. Results showed that the total input amount of chemical oxygen demand, ammonia nitrogen, total nitrogen and total phosphorus to Guanhe River was 36944.2, 4366.5, 6507.4 and 444.6 t/a, respectively, all of which were mostly originated from agricultural pollution. According to the pollution characteristics of Guanhe River, various pollution sources were clarified. Therefore we put forward countermeasures to control the pollution, which provide a foundation for effectively protecting the Guanhe River water quality and supporting the development of the region.

Abstract:To explore the influence of different extractant (1 mol/L KCl, 2 mol/L KCl, 4 mol/L KCl and 0.01 mol/L CaCl₂) and ratio of water to sediment (5:1, 10:1, 50:1 and 100:1) on the determination of extractable nitrogen in sediments from an urban polluted river, surface sediments of Jiuxiang River in Xianlin university town of Nanjing was used in the experiment. Result showed that KCl extract nitrogen more effectively than CaCl₂. The amount of NH₄⁺-N extracted by KCl and CaCl₂ ranged from 312.17 mg/kg to 479.23 mg/kg and 177.52 mg/kg to 339.31 mg/kg, respectively, while NO₃^--N extracted by them ranged from 4.49 mg/kg to 21.56 mg/kg and 4.25 mg/kg to 8.53 mg/kg, respectively. The amount of extractable nitrogen increased with water-sediment ratios. In the experiment group of 1 mol/L KCl, the extract amount of NH₄⁺-N and NO₃^--N increased by 41.97% and 187.08%when the ratio of water to sediment ranged from 5:1 to 100:1, respectively. The amount of NH₄⁺-N extracted increased with higher extractant concentrations, while NO₃^--N decreased with lower ones. The experiment suggested that 1 mol/L KCl as extractant and the water-sediment ratio of 100:1 make a better combination when using for extracting NH₄⁺-N and NO₃^--N from the urban river sediment.

Abstract:Anthropogenic influence on lake environmental change is one of the focus of global change research. It is necessary to identify anthropogenic sources of nitrogen in rivers and lakes. Stable nitrogen isotope ratios (δ¹⁵N) have been widely used in tracer studies of anthropogenic nitrogen sources in aquatic environments. Lake Taihu is a large, eutrophic, shallow freshwater lake in China, and is located in the Yangtze delta with high population density and economic development. It serves as an ideal site for examining human impacts on aquatic environment in China. Results of δ¹⁵N values measured in inorganic nitrogen fractions (INF) showed that a small river basin and its estuary in Yixing city were characterized by agricultural origin, while INF in Xukou Bay and East Taihu Bay by aquiculture, and INF in Meiliang Bay by discharge of human sewage. δ¹⁵N values in the macrophyte-dominated zones were much lower than those in the phytoplankton-dominated zones of the studied water body of southern estuary-East Taihu Bay-Meiliang Bay, indicating the progressive intensification of human pressure on the lake from south to north. However, elevated δ¹⁵N values in lake water which were consistent with high primary production in summer (June) suggested the consequence of biological processes. Using these values for tracing anthropogenic sources of nitrogen during algae blooms might be misleaded.

Abstract:Based on the in situ data collected in August 2010, hyperspectral data models estimating summer chlorophyll-a concentration in Lake Qiandao are presented. A large quantity of hyperspectral reflectance data and water quality data of the typical area of the lake were obtained. Hyperspectral data were measured using ASD FieldSpec3, and were calculated for water-leaving radiance and reflectance of water. Different methods including band ratio model, the first derivative model, three-band-model and BP neural network model were used to estimate chlorophyll-a concentration. Results showed that single band reflectance model gave the worst estimation on chlorophyll-a concentration. Band ratio model with the ratio of reflectance 596 nm/489 nm and the first derivative model of reflectance near 545 nm gave better results with high determination coefficients of 0.782 and 0.590, respectively. By comparison, the three-band-model had higher estimation precision (coefficient of 0.838) than the band ratio model and the first derivative model. BP neural network model performed best with a high determination coefficient of 0.942. The root mean square error between measured and estimated chlorophyll-a concentrations using the four models was 0.89, 1.98, 0.71 and 0.63 μg/L, respectively. Therefore, three-band-model and BP neural network model was recommended to estimate chlorophyll-a concentration with remote sensing data for large area of Lake Qiandao in the summer.

Abstract:It's important to study the response of wetland plants to submergence and its recovery growth status for lacustrine wetland restoration. In this study, we revealed the varieties of relative chlorophyll content (rChlc), malondi-aldehyde content (MDA) and chlorophyll fluorescence characteristics of Phragmites communis in submergence every 5 d during one month in two types of sediment (one from Lake Chaohu (LS), and the other from farmland (AS)), and its recovery status in 10 d, 20 d and 30 d after submergence. Results showed that, compared to AS, P. communis growing in LS had higher rChlc and chlorophyll fluorescence characteristics during the rejuvenate period. rChlc decreased after submergence and obviously after 20 d, and further decreased by 40.82% and 39.49% in 30 d in LS and AS, respectively. However, MDA increased, and it was higher in AS than in LS. Chlorophyll fluorescence parameters Fv/Fm and Y both decreased, with significant correlation with rChlc varieties as a whole. The rapid light curves (RLCs) of P. communis growing in LS decreased slowly in 25 d, comparing to an obvious decrease in 15 d in AS. After submergence, rChlc and chlorophyll fluorescence characteristics of P. communis in two sediments all increased, with a greater range of the plant in AS than that in LS; however, they were both higher in LS than those in AS, and MDA had a same decreasing trend. It took longer time for P. communis to recover to the normal growth status with the extension of submergence, the leaves withered after 30 d submergence and sprouted new leaves and plant. At the same time, the recovery time was shorter of the plant grown in LS than that in AS. Consequently, submergence inhibits the growth of P. communis, and the inhibited effect is greater with the extension of submergence. It takes a short time for plant to recover to the normal growth status when in short submergence, and it needs to sprout new leaves and plants to adapt when in long submergence. Simultaneously, it's meaningful for P. communis to increase its submergence tolerance and recover growth after submergence when growing in sediment with relative better nutritional status.

Abstract:Using multi temporal satellite images of remote sensing, wetland information was extracted by decision tree classification method combined with field surveying and four Lake Dongting's wetland type distribution maps were drawn out. This paper mainly analyzes the dynamic characteristics of wetland vegetation, driving factors and their influence on the wetland ecosystem in this region. Results show that vegetation community distribution and proportion changed obviously. In the past 17 a, forest area increased by 367.88 km² at a rate of 1127.51%. The forest area extended to main part of beaches and became the main vegetation type of Lake Dongting. Reed area decreased by 44.09 km², while sedge land area increased by 2.99 km², with change rate of -5.80% and 0.40%, respectively. This change resulted from both natural environment evolution and human activities. The destruction of natural wetland vegetation, especially planted reed and poplar, destroyed the structure and function of Lake Dongting wetland ecosystem. In order to protect the Lake Dongting wetland effectively, we must rationally exploit bottomland resource, protect natural wetland vegetation and make good management on shoal forestation.

Abstract:This paper is about the structure of phytoplankton communities in the autumn of 2010 in Anxing Wetland, Heilongjiang Province, China. The abundance of phytoplankton communities, cell density and dominant species were analyzed. In total, 146 taxa were identified from nine sampling sites. The 146 taxa included 6 divisions, 8 classes, 12 orders, 25 families, 45 genera, 128 species, 17 varieties and 1 form. Chlorophyta were dominant and accounted for 39.7% of the total phytoplankton, while Euglenophyta and Bacillariophyta accounted for 30.8% and 21.9%, respectively. The abundance of phytoplankton was 181.4×10⁶ cells/L. Dominance analysis showed that there were more than three dominant species at each sampling site, including Trachelomonas granulosa Playf., Cyclotella meneghiniana Kütz. and Trachelomonas granulosa var. crenulatocollis(Szab.) Hub. -Pest.. Cluster and non-metric Multi Dimensional Scaling analysis showed that nine sampling sites were divided into five groups and the composition of phytoplankton communities were significant different spatially when the similarity of the phytoplankton community reached to 60%. That was related to different ecological characteristics of each site. Canonical Correspondence Analysis showed that dominant specie change was mainly influenced by temperature and pH. In addition, a large number of β-mesosaprobic zone indicators and lower diversity index were monitored in Anxing Wetland, suggesting that the water quality from the wetlands might have been polluted.

Abstract:Rotifers were sampled monthly from February to November in 2009 in Lake Erhai, Yunnan Province, China, in order to study their diversity and seasonal dynamics. Lake Erhai has a rotifer composition with tropical-subtropical characteristics:68 species belonging to 25 genera of 17 families were identified, the majority of which were eurythermal or mesophilic. The genera of Trichocerca, Lecane and Brachionus were more abundant than others, accounting for 37% of the total community. Lecane arcuata and Trichocera inermis are new records in China. Biomass of the rotifer communities in Lake Erhai exhibited a bimodal seasonal cycle. An increase occurred during spring from low winter levels to an annual maximum in the mid fishing moratorium and a second increase in the early fishing season. In the mid fishing moratorium, the rotifer biomass was dominated by Asplanchna priodonta; while in the early fishing season, it was dominated by the small-sized Keratella cochlearis and Polyarthra vulgaris, then by A. priodonta again. The seasonal fishing moratorium affected not only the predation pressure on rotifers, but also competitive pressure on rotifer through influencing the community structure of Cladocera. Through the influence of predation and competition, rotifers were dominated by large omnivorous A. priodonta, which showed a bimodal seasonal distribution pattern.

Abstract:Macrozoobenthos community structure in the lower reaches of Ganjiang River was investigated in June (wet season) and November (dry season) 2009 and April (normal-water period) 2010. A total of 25 species from 15 families were recorded. Results showed that temporal and spatial variations of the macrozoobenthos community structure were obvious in the lower reaches of Ganjiang River. The mean maximal density (145.9 ± 81.8 ind./m²) occurred in June while the minimum (89.6 ± 15.9 ind./m²) appeared in April. On the contrary, the mean maximal biomass (90.1 ± 25.4 g/m²) occurred in April while the minimum (62.9 ± 20.9 g/m²) appeared in June. Their mean densities in the main stream were always higher than those in branches. However, the mean biomass in main stream was lower than that in branches in November. Temporal and spatial variations of three indices (including Shannon-Wiener index, Margalef index and Pielou evenness index) were apparent. Maximal values of all the indices occurred in November while the minimum appeared in June. The Shannon-Wiener index and Margalef index in the main stream were lower than those in branches in June and April; however, the Pielou evenness index in branches was constantly higher than that in the main stream, which showed that the community structure of macrozoobenthos in branches was more diversiform, uniform, and stable than that in the main stream. According to Shannon-Wiener index and Margalef index, the lower reaches of Ganjiang River was polluted to a certain extent and the main stream was more serious.

Abstract:Water chemical composition of a lake and its inflow rivers is an important lake characteristic, which can reflect the climatic and environmental background of the basin where the lake is located and the river flows through. Water samples were collected and their major ions were measured from the major lakes (i. e., Yamzhog Yumco, Bajiu Co, Chen Co, Kongmu Co and Pumoyong Co), inflow rivers, and wells in the Yamzhog Yumco Basin. Possible controlling factors on the major ion compositions from different waterbody were analyzed. Results revealed that the major ion compositions (e. g. hydrochemical types) of the water in the basin were significantly different as follows. The major ion compositions of lake water in Yamzhog Yumco, Bajiu Co, Chen Co, Pumoyong Co and Kongmu Co were SO₄^2--HCO₃^--Mg²⁺-Na⁺, SO₄^2--Mg²⁺-Na⁺, SO₄^2--Na⁺-Mg²⁺-Ca²⁺, HCO₃^--SO₄^2--Mg²⁺-Ca²⁺, and HCO₃^--SO₄^2--Ca²⁺, respectively. For the inflow river water, the major anions were HCO₃^- and SO₄^2- and the preponderant cation was Ca²⁺. Comparing with the water chemical compositions of inflow rivers, the contents of Mg²⁺, Na⁺ and SO₄^2- in Yamzhog Yumco and Chen Co were much higher with a relative low contents of Ca²⁺ and HCO₃^-. On the contrary, there was little difference for the Kongmu Co and its inflow rivers. In addition, the major ion compositions of well waters were characterized by HCO₃^--Ca²⁺. Further analysis indicated that the water chemical compositions were mainly controlled by rock weathering in the whole basin, and also by evaporation and crystallization for Yamzhog Yumco, Bajiu Co and Chen Co. For the inflow river waters in the basin, the main controlling factors of chemical compositions were carbonate weathering and evaporite weathering, while the effect of the silicate weathering on the river water chemistry was minor. Thereinto, the dominant controlling processes were carbonate weathering for inflow river waters flowing into Yamzhog Yumco, and the evaporite weathering for the inflow river waters flowing into Chen Co and Kongmu Co. As for the different water chemical characteristics between the inflow river water and lake water of Yamzhog Yumco and Chen Co, the possible reason should own to the strong evaporation of two lakes which may intensify calcium phosphate precipitation. The small lake area of Kongmu Co and the vast amounts of inflowing river water can explain the little difference of water chemical compositions between the lake and its inflow rivers. The study also showed that the controlling processes of water chemical compositions among inflow rivers were different because the different rock-stratigraphic area they flowed was dominated by physical weathering/erosion. With global warming, the style and intensity of rock weathering would be changed. So it is indispensable to further investigate the speed of rock weathering in the basin and its possible response to climate change.

Abstract:Ecological compensation is an important means to coordinate the contradiction between environmental protection and regional development fairness. Eastern Lake Taihu is an important source of drinking water for Suzhou, Jiaxing and Shanghai cities. This paper analyzes the connection between water quality protection behavior and loss of development right value in Suzhou city. Based on geographic factor correction, the paper applies regional comparison method to evaluate the loss of development right in drinking water source protection region in eastern Lake Taihu, as the standard of eco-compensation. It shows that the loss of development right in eastern Lake Taihu in 2009 is 4.239 billion yuan, while the loss of local fiscal revenue, farmers' income and urban residents' income accounting for 75.88%, 13.58% and 10.53%, respectively. In order to narrow the income gap between urban and rural residents, farmers should be given priority on the implementation of eco-compensation. The external benefit from water protection behavior has beyond the value of water supply, so overall the eco-compensation police in a greater region is needed.

Abstract:Three sediment cores were extracted from Maigang Reservoir, located in the southwest of Guizhou Province, China. Ferrimagnetic minerals are the main magnetic minerals of the sediments. There are also other magnetic minerals, for instance, antiferromagnetic component. Super-paramagnetic grains were widely observed in the sediments. There is no significant relationship between mineral magnetic parameters, _χlf, _χfd, SOFT and textural parameters. Mineral magnetic parameters, _χARM, SIRM, F₃₀₀ is correlated with textural parameters but with low correlation coefficients; Given the significant correlations between _χARM/_χlf, _χARM/SIRM and textural parameters, _χARM/_χlf, and _χARM/SIRM can be used as a proxy of particle size. Results presented here do indicate that mineral magnetic parameters can be used as a particle size proxy. These data and other studies on different environments demonstrate that the relationship between mineral magnetic parameters and textual properties can vary from different sedimentary environments even in the same overall sedimentary system, and in some circumstances, mineral magnetic parameters are not suitable to be particle size proxy. To employ magnetic characteristics as a particle size proxy, the mechanism behind the relationship between magnetic parameters and particle size should be explored fully for each sedimentary environment.

Abstract:The oxygen isotopic composition of ostracod shells has been used as a useful indicator in plaeolimnological research. But studies on the oxygen isotopic fractionation of ostracod shells and its environmental significance were still not enough. In this study, surface sediments and co-existing water were systematically collected at different sites in Lake Qinghai. The oxygen isotopic composition of lake water and ostracod shells of Limnocythere inopinata Bird selected from the surface sediments were measured to test the oxygen isotopic fractionation of ostracod shells and evaluate its environmental significance in Lake Qinghai. Our results show that the oxygen isotopic composition of L. inopinata is mainly controlled by the water isotope and the oxygen isotopic fractionation between ostracod shells and water is not only affected by temperature but also maybe by water salinity. The oxygen isotopic fractionation factor of ostracod shells reduces with increasing water salinity, eliminating the effect of temperatures. However, the oxygen isotopic compositions of both ostracod shells and water become enriched with increasing salinity in Lake Qinghai. The oxygen isotopic composition of L. inopinata may be used to indicate the variability of salinity in Lake Qinghai, and further works need to be done in future.

Abstract:Evolution of Jilantai Salt Lake in the last 13.8 ka was reconstructed based on the analysis of evaporate minerals, carbonate minerals and detrital minerals from the core JLT-2010. The lake water was fresh or slightly salty between 13.8 and 11.7 cal ka BP. The lake began to shrink between 11.7 and 10.2 cal ka BP, and then it entered into the lagoon stage. Sulfate deposition occurred in Jilantai Salt Lake between 10.2 and 5.5 cal ka BP, meanwhile, from 9.0 to 8.2 cal ka BP there existed a significant desalination process. The lake reached full chloride deposition stage between 3.7 and 2.0 cal ka BP, and a short and obvious desalt period occurred between 2.0 and 1.7 cal ka BP. Overall, evaporate minerals appeared just at the beginning of the Holocene when temperature increased relative to the late glacial. As the regional arid climate continually affecting the area, Jilantai Salt Lake gradually shrank and salinized.

Abstract:Since 1980s, with the increasing impacts of human activities on the river basin landscape, it is significant to investigate the impact of landscape changes on the rainfall-runoff regime. This paper simulated the floods occurred in the Zijingguan and Fuping catchments of the Haihe Basin using an empirical method. The flood data were segmented by time for creating the P+P_a~R_s curve to analyse the influence of the altered catchment landscapes on surface flow regime. Based on the unit hydrograph method, the relationship between the runoff R and peak discharge Q_m was established. The results show that by comparison of the trendlines in different time periods, with the same runoff volume, the peak discharge after 1980s is less than that before 1980s. It indicates that the water regulation function of Haihe Basin was enhanced. Based on the relationship between the changes of runoff and peak discharge induced by the altered basin landscapes, it is found that there is a positive correlation between them.

Abstract:During our recent ecological survey in Lake Poyang in August 2011, a new type of bloom-forming cyanobacterial species-Merismopedia convoluta Breb. Kützing was identified. The present study described its morphological features and distribution in the lake.

Abstract:About fifty common species of Microcystis have been reported worldwide by far, but only twelve species were recently reported in China. Based on field material collected from Lake Taihu, the Microcystis panniformis belonging to Microcystis (Cyanophyta) was reported for the first time in China in this paper. The morphological characteristics of M. panniformis were described in detail. Comparisons among Microcystis and its related genera Pannus were also conducted.