Abstract:This paper reviewed on the studies on the effects oh microcystins on human health. So far, there have been severalimportant historical events related with this. First, scientists revealed for the first time that microcystins could potently inhibit proteinphosphatase 1 and 2A in 1990, which was the most important molecular basis for the toxicity of microcystins. Second, humanintoxications by MCs (-LR, -YR and -AR) caused deaths of 52 patients at Caruaru dialysis centers in Brazil in 1996. Third, highincidence of primary liver cancer in southeast of China was related with MC contamination of drinking waters. Fourth, World HealthOrganization provided a provisional guideline value of 1 μg/L for drinking water in 1998. Recently, microcystins were identified forthe first time in the serum of a chronically exposed human population (fishermen at Lake Chaohu, South China) together withindication of hepatocellular damage. Conclusively, there have been substantial evidences to indicate the harmful influences ofmicrocystins on human health, and therefore the toxic effects of microcystins on human being can not be ignored especially innowadays with ever-increasing eutrophication and frequent occurrence of toxic cyanobacterial blooms.

Abstract:The progress of reservoir nutrient retention was reviewed. Challenges had been risen about whether the huge reservoirsaltered river-borne nutrient transport significantly since controversial results for nutrient retention of reservoirs were found. Mostdocuments supported the conclusion that the reservoirs changed the riverine biogeochemistry process, which resulted in a serial ofimpacts on downstream and estuary. In this paper, we classified nutrient retention by “sediment filter” and “biological andbiochemical filter”, and listed some estimating methods of nutrient retention and efficiencies.

Abstract:The contents and distribution characteristics of soluble organic nitrogen (SON) extracted with 1mol/L KCl from thesediments of six typical lakes including Lake Poyang, Lake Dongting in Hunan and Jiangxi Provinces were studied. The resultsindicated that the SON contents varied greatly from 17.18mg/kg to 292.31mg/kg (mean content,134.45mg/kg), comprising 51.86% oftotal soluble nitrogen (TSN) and 7.14% of total nitrogen (TN) in six lakes. The SON contents were significantly correlated with theircontents of TN and TSN, and SON were higher in the heavily polluted sediments than the light polluted ones. Their distributions ofSON were closely related to their lake pollution levels. The contents of free amino acid in the sediments were also studied, and theyvaried from 4.69 to 42.04mg/kg, comprising 18.80% of SON, and 1.24% of TN, and were significantly correlated with their SONcontents. The mean content of FAA was 23.27mg/kg, higher than those in soils in the same region. It indicated that there was morebioavailable SON from lake sediment than those from soil. The contents of SON in the sediments were also correlated with inorganicnitrogen, OM and CEC and so on. As one of the most important nitrogen compositions in lake sediments, SON should be paid moreattention to the nitrogen cycling and entrophication control in lakes.

Abstract:Twenty-nine shrimp samples from 15 sites in Lake Taihu and Lake Dongting were collected and measured, and 8 kinds oforganochlorine pesticides (OCPs) in wild shrimps muscle tissue were analyzed with Gas Chromatography/Mass Spectrometry.Hexachlorobenzene(HCB), Chlordane, ∑DDTs(p,p′-DDT、 o,p′-DDT、 p,p′-DDE、 o,p′-DDE、 p,p′-DDD、 o,p′-DDD), Aldrin, Dieldrin,Endrin, Heptachlor and Mirex were quantified. The results showed HCB and p,p′-DDE were detected widely in all shrimp samples.HCB residues in shrimp muscle ranged from nd to 13.2μg/kg and p,p′-DDE ranged from 0.790 to 5.82μg/kg. Much higherconcentration of OCPs was found in shrimp’s muscle of Lake Taihu than that of Lake Dongting. In addition, the levels of OCPs inshrimps muscle in dry seasons was little higher than in rainy season for two lakes.

Abstract:The contents of 15 priority polycyclic aromatic hydrocarbons (PAHs) in water, suspended particulate matter (SPM) andsediment from six sampling sites in Lake Small Baiyangdian nearby Duancun Village were measured by GC-MS. The PAHsdistribution, composition, source and ecological risk were analyzed. The following results were obtained: (1) the total contents of 15priority PAHs (PAH15) varied from 40.1 to 74.0ng/L with the average of 51.0ng/L in water, from 2438.0 to 5927.0ng/g with theaverage of 4528ng/g in SPM, and from 466.9 to 1366.4ng/g with the average of 755.6ng/g in sediments. Compared with other areasin or out of China, the PAHs contamination was not serious. (2) The percentages of 2- and 3-rings PAHs accounted for more than80% of PAH15 in water, SPM and sediment, respectively. From water, SPM, to sediments, the percentages of 2-rings PAHs weredeclined sequentially; while these of 3- and 4-rings as well as 5- and 6-rings PAHs were increased gradually. (3) The major sources ofPAHs in sediments were the combustions of biomass fuels (straw, firewood) and coal; while the combustions of liquid fossil fuelsincluding gasoline, diesel and crude oil was the secondary sources. (4) Owing to the contents of Fluorene (FLO) and Phenanthrene(PHE) varying between the ERL(effects range low) and ERM (effects range median), their probabilities of ecological risks wasestimated between 10%-50%. The probabilities of ecological risks for the rest species of 15 priority PAHs were below 10%, sincetheir contents were lower than the ERL.

Abstract:16 polycyclic aromatic hydrocarbons (PAHs) of sediments were measured in Wangkuai Reservoir, Hebei Province. Theresults showed that the sediments of Wangkuai Reservoir appear to be moderate pollution by PAHs. PAH pollutions became moreserious from reservoir upstream to front of the dam. The total PAHs concentrations decrease with the depth of sediment. Nap, Phe,Fla, BbF, Chr, and Pyr were dominant in sediments. The total PAHs concentration was directly proportional to the content of TOCwith a correlation coefficient of 0.8154 in surface sediments and 0.9534 in profile sediments. Combustion of fossil fuels and biomasswas the main source of PAHs in sediments of Wangkuai Reservoir. The result of ecological risk assessment indicated that highpotential ecological risks of PAHs were not found in sediments of Wangkuai Reservoir, but Flo compound was present in excess ofthe lower ERL and may exist biological effects.

Abstract:Aquatic and land plants as well as surface sediments from Nam Co in Tibetan Plateau were collected and n-alkanes analysishad been conducted to identify the sources and spatial distribution of these molecular. The results indicated that n-alkanes rangingfrom 21 to 25 were identified to be derived from submerged plants, while n-alkanes ranging from 27 to 33 with n-C₂₉ or n-C₃₁peakwere derived from land plants except Androsace tapete and Sabina pingii. These two species contain n-alkanes with n-C₃₃ peak whichwere seldom reported before. Combined with information on plant sources and principal component analyses, three distinct groups ofn-alkanes with different spatial distribution in surface sediments were defined. Short-chain n-alkanes derived from photosyntheticbacteria and algae were relatively uniform in whole lake. But concentration of long chain n-alkanes gradually reduce from lake shoreto center coincided with transport distance increasing, indicating the main controlling mechanism of spatial distributions in surfacesediments was connected with biodegradation.

Abstract:The phosphorus stored in the sediments can be released into the overlying water, acting as internal source for lakes. pH isone of the important factors influencing phosphorus release. In this paper, phosphorus fractions and the effect of pH on P release (48h)were investigated for the sediment from Meiliang Bay, Lake Taihu. The pH of the system was controlled with different buffersolutions. The release characteristics of phosphorus were influenced markedly by the pH condition. Specifically, acidity (pH=2.0) andalkalinity (pH=9.5, 11.8) conditions were more beneficial for phosphorus release than the neutral pH(pH=7.2) condition. The amountof phosphorus released from the sediments under alkalinity conditions (pH=9.5, 11.8) was about 4 folds than that in the acidity(pH=2.0, 4.6) and neutral condition when the release of phosphorus tended to be stable(14h). There had been distinct difference forthe phosphorus speciation in the sediments of different simulation system. With the analysis to the phosphorus speciation ofsediments after release experiment, it can be concluded that acidic condition can enhance Ca-bound phosphorus release, whereasalkaline condition can promote the release of Fe-bound phosphorus significantly. Fe-bound phosphorus is the key form of phosphorusrelease in Meiliang Bay of Lake Taihu. pH value is an important mechanism of influencing phosphorus content and eutrophication.

Abstract:Microcystis waterbloom always occurs in colonial forms in natural waters. However, most laboratory studies on removal ofMicrocystis cells by various approaches were performed by using single-cell Microcystis strains. This study aimed to removeMicrocystis aeruginosa, as the dominant species in Chinese waters, by Chitosan and Polymeric Aluminum Chloride (PAC) modifiedclays(Kaolin). Using colonial Microcystis aeruginosa strain HAB 657, the relationships between the quantity of the chitosan modifiedclays(y) and OD 680 (x) and between the quantity of the chitosan modified clays(y) and the concentration of chlorophyll-a(Chl.a)(x) wasexpressed as y=0.0349x-0.0019 and y=0.0524x-0.009, respectively. While relationships between the quantity of the PAC modifiedclays(y) and the OD 680 (x), and between the quantity of the PAC modified clays(y) and the Chl.a(x) content were expressed asy=0.0351x+0.0065 and y=0.0676x-0.0059 respectively. It showed that the optimal pH ranged from 5 to 8 for chitosan modified claysto remove Microcystis cells, and PAC modified clays with 5-9 optimal pH. Analysis of Electron Transport Rate (ETR) showed thatsedimented Microcystis cells became yellowish and decayed in a week after treatment by PAC modified clay, and were dead in onemonth after the treatment of chitosan modified clays.

Abstract:The substrate of the riparian wetland of Maliao River, Lake Fuxian catchment, was selected to investigate the removal andtransfer process of phosphorus. The experiments of adsorption dynamics was examined under the low concentration scenario(P≤3.0mg/L), and the experiment of adsorption isotherms also was examined under high and low concentration scenario. The results ofdynamic adsorption showed that phosphorus release existed in the substrate when the initial concentrations of phosphorus were 0.02and 0.03mg/L. The phosphorus had been adsorbed by substrate when the initial concentration had been increased to 0.5mg/L. Finallythe adsorption curves tended to be stable after 24 hours. Regression analysis based on Freundlich model and Langmuir model on theadsorption isotherms of substrates was carried on by monadic linear regression method. Based on Freundlich model analysis, theadsorption experiment of phosphorus on substrate was examined between overlying water and substrate under the high initialconcentration as well as 24 hours oscillation. The results showed that most of the phosphorus adsorbed originally in the substrate wasreleased within 24 hours under high concentration condition.

Abstract:The litter and the residue of the aquatic plants play an important role in the nutrient cycle and energy flow. Under naturalconditions, the sediment was collected in situ at different stages of Eichhornia crassipes, and its changes of the litter and residue werestudied. The weight of sediment had an obviously increasing trend from waterhycinth death to its disappearance from water surface.When the litter and residue disappeared completely from water surface, the weight of sediment and the downward fluxes reached themaximum value 579.59g/m², 7.54g/(m²·d) respectively. Both of them had a significantly positive correlation with the watertemperature. When the litter and residue disappeared completely from water surface, the organic carbon, total nitrogen and totalphosphorus were low in the growth but high in the floating, and reached the maximum values 40.29%, 3.66%, 0.90% respectively,then they gradually decreased, and tended to be stable.

Abstract:Recent reports suggested that when certain contaminants may present in aquatic ecosystem at levels, it would disruptendocrine functions of a variety of aquatic invertebrates. For this hypothesis, we sought to determine whether the estrogeniccompound Fenvalerate and androgenic compound TBTC can individually inhibit the development and reproductive output of thefreshwater rotifer Brachionus calyciflorus. The present study focused on the life history characteristics of B. calyciflorus undereffects of different concentrations of Fenvalerate and TBTC. The result showed that Fenvalerate and TBTC had significant effectson the durations of different development stages of B. calyciflorus and the characterristics of its population growth. Treatmentwith Fenvalerate at the concentrations of 200 and 1000μg/L significantly lengthened the duration of reproductive period.However, the duration of pre-reproductive, post-reproductive periods and the lifespan were shortened. In treatment with 1 and5μg/L TBTC, the number of eggs and population growth rate were also increased compared to the control, however, thepre-productive period was significantly lengthened, and the reproductive, post-reproductive periods and the lifespan weresignificantly shortened compared to the control. The total number of eggs and population growth rate were both decreasedsignificantly when the rotifer was exposed to 0.001 and 1-5μg/L of the above contaminants, and the number of eggs wascurve-related with the concentrations of Fenvalerate and TBTC (Fenvalerate: Y=-0.6745X²+6.6884X+5.855(R²=0.7027); TBTC:Y=0.2054X²-2.3178X+16.666(R²=0.6535)). Consequently, Fenvalerate and TBTC showed differently effects on the durations ofdifferent development stages of B. calyciflorus and the characterristics of its population growth.

Abstract:For exploring the seasonal succession of planktonic diatom in shallow eutrophic lakes, two small shallow lakes—LakeQianhu and Lake Yueya in Nanjing were chosen and monitored monthly in 2006. We discussed the relationship between the diatomdensity, diatom assemblages and environmental factors by the analyses of CCA. The results showed the obvious seasonal successionsof diatom assemblages in the two lakes. Cyclostephanos was the dominant species in winter, representing the cool eutrophic diatomassemblage; while the assemblage changed into Cyclotella atoms and C. meneghiniana dominant in summer and autumn whichrepresented warm and eutrophic assemblage. CCA analysis using the monthly data indicated that temperature did not only control thebiomass of diatom, but also affected the seasonal succession of diatom assemblages. The increasing diatom biomass in spring had alittle contribution to primary production. When the level of eutrophication was higher, the temperature plays more important role ininfluencing the planktonic diatom.

Abstract:A laboratory experiment was conducted to evaluate the effect of different natural food on the growth and reproduction ofDaphnia carinata. The natural food came from the three lakes: Lake Huashen, Lake Xuanwu and Lake Nanhu with differentconcentrations of nitrogen and phosphorus. D. carinata had the lowest growth rate and all died before starting reproduction with thefood from Lake Huashen. Both nutrient concentrations and phytoplankton biomass in Lake Xuanwu were lower than that in LakeNanhu. However, the growth rate, the average body length and the reproductive capacity of D. Carinatacultured with the food from LakeXuanwu were higher than that in Lake Nanhu. The experiment showed that the nutrition level of nitrogen and phosphorus and the foodconcentration had an evident influence on the growth and reproduction of D. Carinata. When the nutrition level of nitrogen andphosphorus and the food concentration in the lakes were too high or low, the growth and reproduction of D. Carinatawould be restrained.

Abstract:During the investigation from August 2007 to April 2008, a total of 17 species of macrozoobenthos were recorded at 6sampling stations in Sandaohe Reservoir, Hubei Province, including 11 Chironomidae and 6 Tubificidae Oligochaetes. Procladius sp.was the dominant specie in spring while Microchironomus sp., Rheotanytarsus sp. and Procladius sp. were the dominant in summer.In autumn and winter Limnodrilus hoffmeisteri was the dominant. The species number, the density and biomass changed obviouslywith seasons. The seasonal density and biomass variation order were spring>winter>autumn>summer; and species number ranked assummer>winter>autumn>spring. The density and biomass of macrozoobenthos were 366.42±102.93ind./m²and 0.5649±0.1779g/m²respectively, which could be classified the reservoir as oligotropic level. The density and biomass increased from the front of dam tothe bay, and the Shannon-Wiener index, Margalef index and Pielou index were all at the highest in summer and the lowest in autumn.The density of Oligochaetes did not exceed 1000ind./m²in our surveys, which showed the water may be slightly polluted.

Abstract:An annual investigation of Mollusca was carried out in Lake Taihu between November 2006 and October 2007. Altogether12 species were recorded, belonging to 12 genera of 9 families in 232 samples. The occurrence frequency of benthic Mollusca was90.0% in 30 sampling sites. The annual average density and biomass of Mollusca in its distribution area were 266ind./m², 102.2g/m²,respectively. Corbicula fluminea and Bellamya aeruginosa were the dominant species of Mollusca in Lake Taihu. The occurrence frequencyof C. fluminea was 90.0%, and the annual average density and biomass were 174ind./m², 58.3g/m², respectively, which mainlydistributed in the southwest part of Lake Taihu(393-896ind./m²) and Gonghu Bay (393-552ind./m²); the occurrence frequency of B.aeruginosa was 56.7%, and the annual average density and biomass were 58ind./m²,61.6g/m², respectively, which mainly distributedin the east part of Lake Taihu. Principal Components Analysis showed that habitat types and characteristics of sediment were the keyfactors determined the spatial distribution pattern of C. fluminea, while that of the gastropods was mainly influenced by the distribution ofmacrophytes, which coincided with the “mutualistic theory”. Analyzing the variation of Mollusca community structure between 1987and 2006, the results showed that the mainly distributed area of C. fluminea has changed from Meiliang Bay and Zhushan Bay to thecentral and southwest part of Lake Taihu, and the size of C. fluminea showed a tendency of decrease (P<0.001), while the averageweight of B. aeruginosa did not changed remarkably (P=0.051).

Abstract:Flooding is a natural calamity that can caused great loss. Flooding hazard mapping is an effective tool for managingflooding to reduce the destructivity. In this paper, we suggested a new method to map the flooding hazard for alluvial plain withmulti-temporal remote sensing images and lake level records. 9 images gained at different date for Poyang Lake Region were used topickup the inundation extent with different lake level, and the annual and monthly exceedance probability of lake level for Poyangwas estimated by sorting all lake level records. The boundary of inundation extent from remote sensing images was regarded asisolines valued as exceedance probability for the lake level happened on the image taken time. With the interpolation processprovided by ArcGIS software, the flooding hazard were mapped for Poyang Lake Region.

Abstract:It is an important part of harmonizing the spatial relationship between development and ecological protection anddevelopment leading and space control to adjust the spatial arrangement of industry and town according to the distribution ofecological protection space. Taking Jiangsu Province as a case, matrix-analysis and spatial analysis method was applied to exploringthe spatial coupling characteristic of ecological function protection area and construction land and status of the ecological functionarea occupied by space development based on extracting the information of ecological functional protection zones and constructionland distribution, later the adjusting route of space order was recommended. Conclusions were as follows: Firstly, the spatial couplingrelationship between ecological function protection area and construction land was harmonious in most part of Jiangsu Province, butSuzhou and Wuxi cities were out of line, the construction land’s expanding should be decreased in the future. Secondly, constructionland occupies a large part of important everglade, riverhead protection area, and landscape area, spatial development should keepaway from them. Thirdly, the ecological function area covered by the rural resident area is larger than other kind construction land, sothe pressure on the region’s ecosystem can be alleviated by the way of changing the spatial distribution of rural resident area in thefurther.

Abstract:Pollen analysis and charcoal indices of a 153-cm-long lake sediment core from Lake Taibai (TN1 core) in Hubei Provincedisclosed seven stages of the vegetational changes in Lake Taibai drainage area over the past 1500 years. During 520-1310AD, thevegetational changes were mainly controlled by the climatic changes and the influence of human activities on vegetation wasrelatively weak. Stage of 1310-1710AD, the influencing intensity of human activities on vegetation gradually increased, and thestage was a transitional period of main factors from natural control to human activities drive. Since 1710AD, the vegetational changeswere controlled by human activities and the climatic signal from the vegetational changes was relatively weak. According to thepollen assemblage, the climatic changes with three warm periods of 520-720AD, 1050-1310AD and since 1950AD and two coldperiods of 720-1050AD and 1310-1710AD could be speculated.

Abstract:The sediment of Lake Chenghu, located in the southeastern area of Suzhou, is mainly composed of ‘hard clay’ (a kind ofsediment consisting of silt and clay), and has been featured with lake depressions and a paleo-channel in the central area. Thepaleo-channel, along the direction of NNW-SSE, is accord with the Dongjiang River recorded in historical documents, and itssediments may become good archives of environmental evolution of the hard clay plain from river to lake. The grain-sizecharacteristics of core SC7 of Lake Chenghu, AMS 14 C and their magnetic susceptibility were analyzed in this paper, then thesedimentary characteristics and paleoenvironmental significance were discussed. The results indicate that the sediments of LakeChenghu mainly consisted of fine-medium silt and clay, and the percentage of fine-medium silt was about 53%-65.8%, clay about19.7%-40.1%. The grain-size parameters of the sediments above 336cm was different from hard clay, and magnetic susceptibilitywas significantly higher. Grain-size parameters and magnetic susceptibility of the sediments show that the sedimentary environmentof Lake Chenghu had experienced four main phases from river to lake after the formation of hard-clay plain, and also provided newevidence for the causes of river-flooding lakes in Taihu Plain. It also suggested that the formation of surface sediments had beenseriously affected by human activities.