Abstract:In memorial of Dr. Prof. Kerry Kelts, a distinguished lascustrine sedimentologist

Abstract:The Napahai Lake, situated in the hinterland of the Hengduan Mountains, is a basin by the erosion of carbonate rocks.The lake levels have experienced great fluctuation between low-stand and high-stand stages.The lake level changes di rectly inf luences the amount and distribution of aquatic plant communities that used different sources of carbon for photosy nthesis, thereby imprinting the organic sediments with a characteristic ¹³C composition.Ano ther reason influencing the ¹³C composition for bulk organic sediment, in this case, is the change of reduction-o xidation condition in the alternative stages.In addition with the strong dissolution of carbonate strata in humid-cool conditions, the lake level fluctuations and climatic changes could be reconstructed using HI, TOC and δ¹³C.The results show that increase in total organic carbon and hydrogen index correlates in general, with decrease in δ¹³C values, which could be at tributed to the flourishing of emerging and floating aquatic plants as well as a relative reduction envi ronment in a low lake level associated with a warm-dry or temperate-dry climate.The decreases of TOC and HI often correlate well with δ¹³C value increasing in a high lake level stage accompanied with a cool-humid climate, which might be att ributed to low productivity of aquatic plants, oxidation that triggers decomposition oforganic matters and strong dissolution of carbonate st rata in humid-cool conditions. The palaeo-environmental reconstruction shows that major environmental changes took place at 32kaBP and 15kaBP respectively.The lake levels exhibited frequent fluctuations between ca.57-43kaBP, and then the lake level slightly rose from ca.43kaBP to ca.37kaBP.After then, the lake level dropped dramatically when the climate became warm and dry.From ca.32kaBP, the lake level had a distinct rise due to cool-humid climate and kept high until the end of the Last Glacial Maximum.A warm-dry climate returned to the areas again and the lake level remained lowering during the Holocene.Af ter the lake level rose in a minor amplitude from ca.3 -2kaBP., modern climate dominates the Napahai lake.

Abstract:Core samples were collected from the Honghu Lake and in paddy soil profiles around the lake.Using SEM and polarizing microscope, the microfabrics property, grain size and organic matter content of three types of lacust rine clays were examined.The microfabrics of green clay formed during 0.9-2.5kaBP are illustrating gelat inous texture, fine particles, small voids, subangular to angular surface texture of the particles, which also has a relatively hig her content oforg anic matter (average 3.14%).The green clay was formed by the interaction of the colloids of suspended clay sediment with that oforganic matter.The Hong hu lake had a open, stable environment enriched in plankton diatoms, with less sediment from the river during this period.The black clay that was formed during 0.45-1kaBP was gelatinous texture, larger circular voids, with plant remain frame.Its void size dist ribution display sbimodes.The origin is ascribed to the accumulation of great amount of aquatic vascular plant.During the period, the lake was shallower than the present with a lot of vescular plants.The gray clay formed since 0.45kaBP was agglutinational texture, larger sizes of voids and grain particles, orientation of flaky hydromica, subrounded to subangular surface texture of the particles, indicating certain inf luence by the sediment from river discharge.

Abstract:The difficulties involved in manually calibrating the Xinanjiang watershed model have in the past been partly attributable to the lack of robust optimization tools. In fact manual calibration process can be a rather frustrating and time-consuming exercise for an inexperienced person. Therefore,in recent years researchers are exploring ways to incorporate "expert knowledge" of conceptual watershed models into the automatic calibration procedures. This paper presents a brief introduction to the Xinanjiang model and a researdiw Tork on application of SCE-UA method for calibrating Xinanjiang watershed model using hydrological data of three catchments of different size and dimatic mnditioiis. Results show that the overall performance of SCE-UA method for calibrating the Xinanjiang model is very good. On the basis of the results derived from the calibration and verification stages it seems that SCE-UA is capable of finding a global optimum and (onceptually realistic parameter set for the Xinanjiang model.

Abstract:The Yilihe watershed is the main water catching area of the Taihu Lake. The conditions of water quality and nutrition of water bodies of the watershed closely relates to that of the Taihu Lake. Based on the large-scale synchronous environmental monitoring of December 14-15 of 2000 and April 18-19 of 2001 we give systematically assessment of the conditions of water quailty and nutrition to water bodies of the plain river network area. The results indicate that, water bodies have bad quality and high nutiite either in normal period or in drought period but, in drought period,water quality became worse and water bodies have even higher nutrite contents.

Abstract:This paper deals with the results with regard to protozoan community diversity of Stechlin Lake in Berlin Germany, conducted during November 1994 and January, 1995. About 128 species of protozoa have been first recorded following the examination of colonization on polyurethane foam unit (PFU) artificial substrates and various types of natural substrates in this lake. The differences in species richness individual abundance and rates of PFU protozoan colonization at three sampling sites with the different habitat conditions are described. Based on analysis and comparison, PFU can collect more protozoan species than natural substrates do. The results of this research provide further evidence that the PFU method offers the advantages of sampling protozoa compared with other routine collecting methods.

Abstract:Plant material decomposition experiment was carried out in room condition from 1998 to 1999 (lasted for 12 months) The plant material and top-layer sediment was collected from East Taihu Lake Jiangsu Province, China. Three ecotypes of aquatic plant were used:emerged plant (Zizania latifolia), floating-leafed plant (Nimphoides peltatum), and submerged plant (Vallisneria spiralis, Potamogeton maackianus) It resulted that, floatnig-leafed plant had the highest decomposition rate and annual reduction ratio. Submerged plant had high decomposition rate in the early stage and the lowest annual reduction ratio. The decomposition process of emerged plant was very lengthy. By the end of the experiment,more than 70% of the bio-mateiialwas reduced by decomposition for emerged and floating-leafed plan, but less then 50% for submerged plant. Phosphorus release was prior to TOC in the decomposition process. It means that most of the phosphorus in the plant material can be released to the water when aquatic plants die down in the winter Nitrogen was released from the plant material parallely to TOC reduction,and nitrogen content ratio in the plant material nearly kept constant in the decomposition process for emerged and floating-leafed plant.

Abstract:Pen culture in lakes has been developed greatly especially in the past ten year's and has become a main part of the inland freshwater fisheries in China. East Taihu Lake is a typical one involving the development of fish pen farming in the past 20 years. Here the impacts of pen farming on lake ecological environment are analyzed and discussed from aspects of local and whole lakes.The resultshows that the ecological environment to has deteriorated a certain degree and has affected the functioning of water supply flood storage,flood discharge etc. As a feedback, the deterioration of lake environment has also strongly affected the pen farming and other fishery activities and caused the decrease of economic benefits. So it is very important to find a scientific strategy to keep a sustainable development of pen-culture of fishes. In this paper a conceptual model of capacity of pen culture of fishes in shallow lakes is promoted and discussed based on a case study on East Taihu Lake. Finally,the regulation and planning of fishery, especially the pen-culture in East Taihu Lake are presented which would be helpful to the management of the lake.

Abstract:The variance of water quality was studied by adding different concent ration of nitrogen and phosphorus into the tested enclosure.The results show that:(1)There existed strong relationship between the hetero trophic bacteria abundance and the concentration of ni trogen and phosphorus, especially the phosphorus.(2)The nitrogen and phosphorus concentration and ratio of N to P significantly affected the algae abundance and biomass.The suitable N:P value for algae grow th was 10:1.(3)There existed signif icant relationship between the ni trogen and phosphorus removing capacity and the algae biomass and the N:P value.When the N:P value was 10:1, the algae grew well and the biomasses were increased most quickly.In this case, the nitrogen and phosphorus removing capacity was the highest.

Abstract:The hatching time of Artemia parthenogenetica of Aibi Lake at different temperatures is tested.According to the relationship between developmental rate and temperature, the mathematical model is established as following:V(T)=(k·T+c)·(1-exp(-(T-T_H)/r_H)), where V is developmental rate, T is temperature and other parameters are calculated based on the test data.From these, we compute the minimum and the average threshold of development (T_min-0, T_aver-0), the minimum and the average cumulative temperature (Q_min, Q_aver)are:T_min-0=5.56℃, T_aver-0=5.96℃, Q_min=342.47℃·h, Q_aver=413.63℃·h.Additionally, the different abilities at suiting temperature of cysts are discussed accomplishing with the fittesttemperature and high lethal-temperature.Finally, the signif icance of these factors in breeding aquatics was expatiated on.

Abstract:The investigate results of the phosphate-banning in detergents in Taihu region show that 98% of the shops in the whole Taihu catchment sale phosphate-free detergents and 99% of the people use phosphate-free detergents at the end of 1999. So the measure of banning phosphate in detergents is very effective and about 1353. 81t/a of phosphorus 14.07% of the total phosphorus loading of Taihu Lake is cut off. These are advantages of controlling eutrophication in Taihu Lake. Otherwise these are still some problems taken into account such as the quality and cost of phosphate-free detergents.

Abstract:In this paper, on determination the proportion and contribution rate of the phosphorus indetergents to the phosphorus loading in the water body, the mathematical model of Thomamn is employed to predict the response effect arising from restricting or banning phosphorus in detergents.The prediction results show that phosphorus content of the water will reduced to 0.18mg/L from the present 0.24mg/L and the phospho rus loading will decrease by 25%;if the scat tered culture of poultry and livestock in the valley pollut ion source by 60%, the water can achieve phosphorus quality standard of Class Ⅱ (0.1mg/L)of surface water.

Abstract:Ost racodes, the microscopic bivalved crustaceans, survive in a wide diversity of lakes and ostracod fossil valves are often found well preserved in the lake sedimentsequences.The characteristics of ostracod palaeoecology and particularly geochemical characteristics of fossil ostracod shells buried in the lake sedimentsequences are increasingly studied and used to indicate the past environmental changes on the globe.The isotopic composition and temperature of the lake water in which the shells formed determine the oxygen iso topic composition of shells.Changes in δ¹⁸O_ostracod in a sedimentsequence may reflect the past variations of δ¹⁸O_water relating to climate-induced changes in precipi tation-to-evaporation balance.In general, low δ¹⁸ Oost racod may reflect warm or moist climate, while high δ¹⁸O_ostracod may represent cold or dry climate.The δ¹³C_ostracod may reflect the iso topic ratios of total dissolved inorg anic carbon (TDIC)and the changes of factors controlling δ¹³CTDIC value, especially palaeoproductivity of a lake.The uptake of Mg and Sr into ost racod shells may be a function of salini ty and temperature of host water, which can be used to reconst ruct palaeosalini ty and palaeotemperature of a lake.The following aspects are required in order to conduct quantitative research:(1)firm understanding of the life history and ecological procedure of the ostracod species concerned, (2)analyzing field regular collect ions of ostracod shells and lake waters, to learn the controls of the water chemistry and temperature on the composition of stable isotopes and trace elements of ost racod shells, (3)detailed know ledge of the limnology of the lake investigated, including the relationship between M/Ca and salinity, the iso topic composition and the spatial and seasonal variations in these properties, and (4)culture experiments for each species used, to establish the effects of phy siology on the trace elements uptake and determine the isotopic behavior of indivdual ostracod species with host water.

Abstract:Maintypes and characteristics of algal to xins of blooms and red tides are presented in this paper.Some important methods for assaying algal toxins are summarized.Emphases are given on the methods of ext raction and analysis of microcy stin (MCYST, MC)and Paralytic shellfish poisoning (PSP).