418 results on '"eutrophic lake"'
Search Results
202. Bacteria, carbon cycling, and biogeochemical processes
- Author
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Brock, Thomas D., Billings, W. D., editor, Golley, F., editor, Lange, O. L., editor, Olson, J. S., editor, Remmert, H., editor, and Brock, Thomas D.
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- 1985
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203. Physical Limnology
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Brock, Thomas D., Billings, W. D., editor, Golley, F., editor, Lange, O. L., editor, Olson, J. S., editor, Remmert, H., editor, and Brock, Thomas D.
- Published
- 1985
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204. Long-term Change in Lake Mendota
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Brock, Thomas D., Billings, W. D., editor, Golley, F., editor, Lange, O. L., editor, Olson, J. S., editor, Remmert, H., editor, and Brock, Thomas D.
- Published
- 1985
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205. Introduction
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Brock, Thomas D., Billings, W. D., editor, Golley, F., editor, Lange, O. L., editor, Olson, J. S., editor, Remmert, H., editor, and Brock, Thomas D.
- Published
- 1985
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206. Zooplankton
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Brock, Thomas D., Billings, W. D., editor, Golley, F., editor, Lange, O. L., editor, Olson, J. S., editor, Remmert, H., editor, and Brock, Thomas D.
- Published
- 1985
- Full Text
- View/download PDF
207. Phytoplankton
- Author
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Brock, Thomas D., Billings, W. D., editor, Golley, F., editor, Lange, O. L., editor, Olson, J. S., editor, Remmert, H., editor, and Brock, Thomas D.
- Published
- 1985
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208. Phytoplankton photosynthesis and primary production
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Brock, Thomas D., Billings, W. D., editor, Golley, F., editor, Lange, O. L., editor, Olson, J. S., editor, Remmert, H., editor, and Brock, Thomas D.
- Published
- 1985
- Full Text
- View/download PDF
209. Energy flow in the Lake Mendota ecosystem
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Brock, Thomas D., Billings, W. D., editor, Golley, F., editor, Lange, O. L., editor, Olson, J. S., editor, Remmert, H., editor, and Brock, Thomas D.
- Published
- 1985
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210. Zooplankton and its Grazing as Indicators of Trophic Status in Dutch Lakes
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Gulati, R. D., Best, E. P. H., editor, and Haeck, J., editor
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- 1983
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211. The Fractional Composition of Phosphorus in Lake Sediments of Different Characteristics
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Pettersson, Kurt and Sly, Peter G., editor
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- 1986
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212. Oligochaeta Community Structure and Function in Agricultural Landscapes
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Kasprzak, Krzysztof, Brinkhurst, Ralph O., editor, and Cook, David G., editor
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- 1980
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213. Bimodality in stable isotope composition facilitates the tracing of carbon transfer from macrophytes to higher trophic levels
- Author
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Raquel Mendonça, Sarian Kosten, Gissell Lacerot, Néstor Mazzeo, Fábio Roland, Jean P. Ometto, Eduardo Alonso Paz, Claudia Petean Bove, Norma Catarina Bueno, José Henrique C. Gomes, and Marten Scheffer
- Subjects
aquatic cam plant ,Aquatic Ecology and Water Quality Management ,WIMEK ,δ13C ,concentrating mechanisms ,eutrophic lake ,Ecology ,shallow lakes ,Aquatische Ecologie en Waterkwaliteitsbeheer ,Aquatic Science ,Food web ,Macrophyte ,Isotopic signature ,Total inorganic carbon ,submerged macrophytes ,food webs ,fresh-water macrophytes ,photosynthetic characteristics ,Phytoplankton ,Environmental science ,microbial loop ,Microbial loop ,inorganic carbon ,Trophic level - Abstract
Even though the suitability of macrophytes to act as a carbon source to food webs has been questioned by some studies, some others indicate that macrophyte-derived carbon may play an important role in the trophic transfer of organic matter in the food web of shallow lakes. To evaluate the importance of macrophytes to food webs, we collected primary producers-macrophytes and periphyton-and consumers from 19 South American shallow lakes and analyzed their carbon stable isotopes composition (d13C). Despite the diversity of inorganic carbon sources available in our study lakes, the macrophytes' d13C signatures showed a clear bimodal distribution: 13C-depleted and 13C-enriched, averaging at -27. 2 and -13. 5‰, respectively. We argue that the use of either CO2 or HCO3 - by the macrophytes largely caused the bimodal pattern in d13C signals. The contribution of carbon from macrophytes to the lake's food webs was not straightforward in most of the lakes because the macrophytes' isotopic composition was quite similar to the isotopic composition of periphyton, phytoplankton, and terrestrial carbon. However, in some lakes where the macrophytes had a distinct isotopic signature, our data suggest that macrophytes can represent an important carbon source to shallow lake food webs. © 2012 Springer Science+Business Media Dordrecht
- Published
- 2012
214. Restoration of Shallow Lakes in Subtropical and Tropical China: Response of Nutrients and Water Clarity to Biomanipulation by Fish Removal and Submerged Plant Transplantation
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Haiyi Zeng, Hu Yaohui, Hu He, Yali Tang, Kuanyi Li, Erik Jeppesen, Jinlei Yu, Xuefeng Zhao, Zhengwen Liu, Baohua Guan, Ping Zhong, and Feizhou Chen
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0106 biological sciences ,Chlorophyll a ,lcsh:Hydraulic engineering ,Chinese shallow lakes ,Geography, Planning and Development ,biomanipulation ,010501 environmental sciences ,Aquatic Science ,EUTROPHIC LAKE ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Nutrient ,lcsh:Water supply for domestic and industrial purposes ,RESUSPENSION ,PIKE ESOX-LUCIUS ,nutrients ,lcsh:TC1-978 ,Phytoplankton ,parasitic diseases ,medicine ,14. Life underwater ,ENCLOSURE EXPERIMENT ,MACROPHYTES ,0105 earth and related environmental sciences ,Water Science and Technology ,Total suspended solids ,subtropical ,tropical ,TSS ,transparency ,Hydrology ,lcsh:TD201-500 ,Biomanipulation ,010604 marine biology & hydrobiology ,SPECIES RICHNESS ,15. Life on land ,Seasonality ,medicine.disease ,6. Clean water ,Macrophyte ,Transplantation ,CLIMATE ,SIZE ,chemistry ,Environmental science ,DANISH LAKES ,COMMUNITY STRUCTURE - Abstract
Fish removal has been used to restore temperate lakes, and positive effects on ecological state and water clarity have frequently been recorded in many lakes. Recently, a supplementary measure, transplantation of submerged macrophytes after fish removal, has been applied to restore warm Chinese shallow lakes in order to compensate for the expected lack of increasing grazing control of phytoplankton after the biomanipulation. These measures have successfully shifted turbid warm lakes to a clear water state, but little is known about the responses to restoration of key physico-chemical variables. We analyzed the seasonal variation in nutrient concentrations in two subtropical and one tropical biomanipulated shallow Chinese lakes subjected to restoration. In all three lakes, a marked decline occurred in the concentrations of lake total nitrogen (TN), total phosphorus (TP), total suspended solids (TSS), and chlorophyll a (Chl a), while the transparency (SD: WD ratio, Secchi depth to water depth ratio) increased. A clear water state was established, lasting so far for 7 to 23 months, and TN, TP, Chl a, and TSS levels in the three restored lakes decreased to, on average, 49%, 58%, 41%, and 18% of the level prior to restoration and/or the level in a reference lake, respectively, while the annual mean SD: WD ratio exhibited a 1.5-4 fold increase. In conclusion, lake restoration by transplantation of submerged macrophytes after fish removal had major positive effects on the physico-chemical variables in our study lakes. However, continuous control of omnivorous and herbivorous fish biomass is recommended as the fish typically present in warm, shallow lakes to some extent feed on submerged macrophytes, when available.
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- 2016
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215. Major changes in CO2 efflux when shallow lakes shift from a turbid to a clear water state
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Torben L. Lauridsen, Martin Søndergaard, Thomas Davidson, Rikke Bjerring, Søren Ejling Larsen, Liselotte S. Johansson, Erik Jeppesen, Anders Lade Nielsen, Mariana Meerhoff, and Dennis Trolle
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0106 biological sciences ,Chlorophyll a ,010504 meteorology & atmospheric sciences ,Air-water CO2 flux ,Aquatic Science ,INLAND WATERS ,EUTROPHIC LAKE ,01 natural sciences ,Dreissena ,chemistry.chemical_compound ,CARBON-DIOXIDE ,ELODEA-NUTTALLII ,FISH ,Abundance (ecology) ,Recovery ,parasitic diseases ,Phytoplankton ,ZEBRA MUSSELS ,SURFACE WATERS ,0105 earth and related environmental sciences ,ALGAL PRODUCTION ,Biomanipulation ,biology ,Ecology ,010604 marine biology & hydrobiology ,fungi ,SUBMERGED MACROPHYTES ,Zebra mussel ,Eutrophication ,biology.organism_classification ,Macrophyte ,Macrophytes ,Lake metabolism ,chemistry ,Environmental science ,DANISH LAKES - Abstract
Lakes can be sources or sinks of carbon, depending on local conditions. Recent studies have shown that the CO2 efflux increases when lakes recover from eutrophication, mainly as a result of a reduction in phytoplankton biomass, leading to less uptake of CO2 by producers. We hypothesised that lake restoration by removal of coarse fish (biomanipulation) or invasion of mussels would have a similar effect. We studied 14–22 year time series of five temperate Danish lakes and found profound effects on the calculated CO2 efflux of major shifts in ecosystem structure. In two lakes, where limited colonisation of submerged macrophytes occurred after biomanipulation or invasion of zebra mussels (Dreissena polymorpha), the efflux increased significantly with decreasing phytoplankton chlorophyll a. In three lakes with major interannual variation in macrophyte abundance, the efflux declined with increasing macrophyte abundance in two of the lakes, while no relation to macrophytes or chlorophyll a was found in the third lake, likely due to high groundwater input to this lake. We conclude that clearing water through invasive mussels or lake restoration by biomanipulation may increase the CO2 efflux from lakes. However, if submerged macrophytes establish and form dense beds, the CO2 efflux may decline again.
- Published
- 2016
216. Carbon burial by shallow lakes on the Yangtze floodplain and its relevance to regional carbon sequestration
- Author
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Xiangdong Yang, Xuhui Dong, N. John Anderson, Xu Chen, and Ji Shen
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floodplain ,Floodplain ,Drainage basin ,Carbon sequestration ,EUTROPHIC LAKE ,CHINA ,Sink (geography) ,Environmental Chemistry ,mineralization ,Organic matter ,MACROPHYTES ,General Environmental Science ,SOIL ORGANIC-CARBON ,Hydrology ,Total organic carbon ,chemistry.chemical_classification ,Global and Planetary Change ,geography ,Yangtze River ,geography.geographical_feature_category ,Ecology ,TERRESTRIAL ECOSYSTEMS ,CLIMATE ,PHOSPHORUS ,eutrophication ,lake sediment ,chemistry ,BALANCE ,shallow lake ,Environmental science ,Spatial variability ,Eutrophication ,SEDIMENTS ,MIDDLE - Abstract
Floodplain lakes may play an important role in the cycling of organic matter at the landscape scale. For those lakes on the middle and lower reaches of the Yangtze (MLY) floodplain which are subjected to intense anthropogenic disturbance, carbon burial rates should, theoretically, be substantial due to the high nutrient input, increased primary production and high sediment accumulation rates. There are more than 600 lakes >1 km2 on the Yangtze floodplain including 18 lakes >100 km2 and most are shallow and eutrophic. 210Pb-dated cores were combined with total organic carbon (TOC) analyses to determine annual C accumulation rates (C AR; g C m−2 yr−1) and the total C stock (since ~1850). The sediment TOC content is relatively low with an average
- Published
- 2012
217. Characterization of Chromophoric Dissolved Organic Matter in the Littoral Zones of Eutrophic Lakes Taihu and Hongze during the Algal Bloom Season
- Author
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Cheng Liu, Muhua Feng, Kaining Chen, Gu Xiaozhi, Ma Shuzhan, Bingfa Chen, and Wei Huang
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Biogeochemical cycle ,excitation emission matrix spectroscopy ,lcsh:Hydraulic engineering ,010504 meteorology & atmospheric sciences ,Geography, Planning and Development ,010501 environmental sciences ,Aquatic Science ,01 natural sciences ,Biochemistry ,Algal bloom ,lcsh:Water supply for domestic and industrial purposes ,lcsh:TC1-978 ,Dissolved organic carbon ,Littoral zone ,0105 earth and related environmental sciences ,Water Science and Technology ,lcsh:TD201-500 ,eutrophic lake ,chromophoric dissolved organic matter ,Humus ,Colored dissolved organic matter ,Productivity (ecology) ,Environmental chemistry ,littoral zone ,Environmental science ,Eutrophication - Abstract
Chromophoric dissolved organic matter (CDOM) is a key component with a critical role in the littoral zones of eutrophic shallow lakes, yet the characteristics of CDOM in these zones remain seldom systematically reported. In this study, the differences in sources, biogeochemical characteristics, and fates of CDOM between the littoral zones of eutrophic lakes Taihu (LLT, frequently occurring algal blooms and longer lake residence time) and Hongze (LLH, no obvious algal blooms and shorter residence time) were compared during the algal bloom season using ultraviolet-visible spectra and excitation and emission matrix spectroscopy combined with parallel factor analysis. Three humic-like fluorescent dissolved organic matter (FDOM) components (C1, C3, and C4) and one protein-like component (C2) were identified. Results showed that FDOM components were dominated by protein-like fluorescent substances in LLT, and humic-like materials in LLH, respectively. The CDOM in LLT had a lower relative aromaticity and molecular weight, humification degree and a higher autotrophic productivity because of algal blooms. Furthermore, CDOM depletion rates in LLT were higher than those in LLH due to a longer lake residence time in LLT. In addition, CDOM shifted from high molecular weight to low molecular weight as the humification degree decreased during the CDOM depletion process. This comparative study showed that algal blooms and lake residence time were the significant factors for distinguishing characteristics of CDOM between littoral zones of shallow lakes on a similar trophic level. This study provides field-based knowledge for remote sensing CDOM measurement and serves as a reference for lakeshore aquatic environmental management.
- Published
- 2018
218. Controls of H 2 S, Fe 2 + , and Mn 2 + on Microbial NO 3 - -Reducing Processes in Sediments of an Eutrophic Lake.
- Author
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Cojean ANY, Lehmann MF, Robertson EK, Thamdrup B, and Zopfi J
- Abstract
Understanding the biogeochemical controls on the partitioning between nitrogen (N) removal through denitrification and anaerobic ammonium oxidation (anammox), and N recycling via dissimilatory nitrate (NO
3 - ) reduction to ammonium (DNRA) is crucial for constraining lacustrine N budgets. Besides organic carbon, inorganic compounds may serve as electron donors for NO3 - reduction, yet the significance of lithotrophic NO3 - reduction in the environment is still poorly understood. Conducting incubation experiments with additions of15 N-labeled compounds and reduced inorganic substrates (H2 S, Fe2+ , Mn2+ ), we assessed the role of alternative electron donors in regulating the partitioning between the different NO3 - -reducing processes in ferruginous surface sediments of Lake Lugano, Switzerland. In sediment slurry incubations without added inorganic substrates, denitrification and DNRA were the dominant NO3 - -reducing pathways, with DNRA contributing between 31 and 46% to the total NO3 - reduction. The contribution of anammox was less than 1%. Denitrification rates were stimulated by low to moderate additions of ferrous iron (Fe2+ ≤ 258 μM) but almost completely suppressed at higher levels (≥1300 μM). Conversely, DNRA was stimulated only at higher Fe2+ concentrations. Dissolved sulfide (H2 S, i.e., sum of H2 S, HS- and S2- ) concentrations up to ∼80 μM, strongly stimulated denitrification, but did not affect DNRA significantly. At higher H2 S levels (≥125 μM), both processes were inhibited. We were unable to find clear evidence for Mn2+ -supported lithotrophic NO3 - reduction. However, at high concentrations (∼500 μM), Mn2+ additions inhibited NO3 - reduction, while it did not affect the balance between the two NO3 - reduction pathways. Our results provide experimental evidence for chemolithotrophic denitrification or DNRA with Fe2+ and H2 S in the Lake Lugano sediments, and demonstrate that all tested potential electron donors, despite the beneficial effect at low concentrations of some of them, can inhibit NO3 - reduction at high concentration levels. Our findings thus imply that the concentration of inorganic electron donors in lake sediments can act as an important regulator of both benthic denitrification and DNRA rates, and suggest that they can exert an important control on the relative partitioning between microbial N removal and N retention in lakes., (Copyright © 2020 Cojean, Lehmann, Robertson, Thamdrup and Zopfi.)- Published
- 2020
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219. Profile of micronucleus frequencies and DNA damage in different species of fish in a eutrophic tropical lake
- Author
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José G. Dórea, Antonio C. Barbosa, Cesar Koppe Grisolia, Izabel Cristina Rodrigues da Silva, Carla Letícia Gediel Rivero, and Fernando L. R. M. Starling
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lcsh:QH426-470 ,Zoology ,medicine.disease_cause ,Cyprinus ,Hoplias malabaricus ,Geophagus ,comet assay ,Cichla temensis ,Toxicologia genética ,Genetics ,medicine ,micronucleus ,Lago Paranoá (DF) ,Toxicidade ,Molecular Biology ,biology ,eutrophic lake ,Ecology ,genotoxicity ,fish biomonitoring ,biology.organism_classification ,lcsh:Genetics ,Oreochromis ,Mutagenesis ,Hoplias ,cytotoxicity ,Steindachnerina ,Genotoxicity ,Research Article ,Peixe - alimento - Abstract
Lake Paranoá is a tropical reservoir for the City of Brasilia, which became eutrophic due to inadequate sewage treatment associated with intensive population growth. At present, two wastewater treatment plants are capable of processing up to 95% of the domestic sewage, thereby successfully reducing eutrophization. We evaluated both genotoxic and cytotoxic parameters in several fish species ( Geophagus brasiliensis , Cichla temensis , Hoplias malabaricus , Astyanax bimaculatus lacustres , Oreochromis niloticus , Cyprinus carpio and Steindachnerina insculpita ) by using the micronucleus (MN) test, the comet assay and nuclear abnormality assessment in peripheral erythrocytes. The highest frequencies of MN were found in Cichla temensis and Hoplias malabaricus , which were statistically significant when compared to the other species. However, Steindachnerina insculpita (a detritivorous and lake-floor feeder species) showed the highest index of DNA damage in the comet assay, followed by C. temensis (piscivorous). Nuclear abnormalities, such as binucleated, blebbed, lobed and notched cells, were used as evidence of cytotoxicity. Oreochromis niloticus followed by Hoplias malaricus , ominivorous/detritivotous and piscivorous species, respectively, presented the highest frequency of nuclear abnormalities, especially notched cells, while the herbivorous Astyanax bimaculatus lacustres showed the lowest frequency compared to the other species studied. Thus, for biomonitoring aquatic genotoxins under field conditions, the food web should also be considered.
- Published
- 2009
220. Iron Isotopic Composition of Suspended Particulate Matter in Hongfeng Lake.
- Author
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Zheng, Xiaodi, Teng, Yanguo, and Song, Liuting
- Subjects
PARTICULATE matter ,IRON in water ,IRON isotopes ,WATER quality ,LAKES - Abstract
The geochemical study of iron isotopes is of great significance to comprehensively understand the surface material circulation process and its environmental effects in surface and subsurface environments. Eutrophic lakes are an important part of the surface and subsurface environment; however, knowledge of the geochemical behaviour and fractionation mechanism of iron isotopes in the biogeochemical cycling of eutrophic lakes is still scarce. In this study, a eutrophic lake with seasonal anaerobic characteristics (Hongfeng Lake) was selected as the study object to systematically analyse the iron isotope composition of suspended particles in lake water and the main tributaries in different seasons. The results show that the value of δ
56 Fe in Hongfeng Lake is between −0.85‰ and +0.14‰, and the value of δ56 Fe has a high linear correlation with Fe/Al, indicating that the continental source material carried by the main inflow tributaries of the lake has an important influence on the source of iron in the lake. And Hongfeng Lake is moderately eutrophic lakes. Algal bloom and the content of chlorophyll a (Chl-a) are high, combined with the high correlation between Chl-a and the value of δ56 Fe, which indicates that the growth of algae has an important influence on the change in the iron isotope composition of suspended particulate matter (SPM) in lake water and that the adsorption and growth absorption of Fe by algae are the main reason for the change in the value of δ56 Fe; therefore, Fe isotope can be used to trace the lake's biological action. For the lake and its inflow tributaries, δ56 Fe values are higher in summer than in winter. The variation in the δ56 Fe value of SPM with lake depth is more distinct in summer than in winter. In addition, there is a distinct thermocline in summer, which leads to hydrochemical stratification. Moreover, according to a linear correlation analysis, the content of dissolved organic matter (DOC) in Hongfeng Lake's upper and lower water bodies, respectively, has a high correlation with the value of δ56 Fe. Specifically, the correlation is positive in the upper water but negative in the lower water, which indicates that the difference in algae metabolism patterns between the upper and lower water bodies of Hongfeng Lake plays an important role in the iron isotope composition of SPM. The composition of the iron isotope in SPM is altered by organic adsorption and growth absorption of algae in the upper water. With an increase in depth, degradation becomes the main process. In addition, the value of δ56 Fe is low and that of Fe/Al is high in the water bottom, which indicates that a "ferrous-wheel" cycle forms at the bottom of the water. [ABSTRACT FROM AUTHOR]- Published
- 2019
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221. In situ, high-resolution evidence for iron-coupled mobilization of phosphorus in sediments
- Author
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Dan Wang, Chaosheng Zhang, Shiming Ding, Yan Wang, Yangyang Li, and Mengdan Gong
- Subjects
In situ ,010504 meteorology & atmospheric sciences ,thin-films technique ,Oxide ,chemistry.chemical_element ,depth attenuation ,010501 environmental sciences ,01 natural sciences ,Article ,chemistry.chemical_compound ,Phase (matter) ,Dissolution ,0105 earth and related environmental sciences ,dissolved reactive phosphorus ,Multidisciplinary ,Ecology ,eutrophic lake ,Phosphorus ,lake-sediments ,shallow lakes ,diffusive gradients ,labile phosphorus ,phosphate release ,Sediment ,Diffusive gradients in thin films ,green rust ,chemistry ,Environmental chemistry ,Eutrophication - Abstract
Reductive dissolution of phosphorus-bearing iron (Fe) (oxyhydr)oxides has been regarded as a primary mechanism responsible for the mobilization of phosphorus (P) in sediments for over 70 years. However, to date there is little in situ evidence to support this hypothesis. In this study, a total of 16 sites in the large eutrophic Lake Taihu were selected for investigation. Newly-developed diffusive gradients in thin films (ZrO-Chelex DGT) probes were deployed to simultaneously measure labile Fe and P mainly released from sediment solids at millimeter spatial resolution. Significantly positive correlations were observed between DGT-labile Fe and P at 14 sites, implying a release of P following reductive dissolution of Fe (oxyhydr)oxides. A coincident resupply of Fe(II) and P was observed from sediment solids to buffer their releases from DGT perturbance, further verifying the mechanism of Fe-coupled mobilization of P. The ratio of DGT-labile Fe/P was found to be positively correlated with the ratio of easily reducible (oxyhydr)oxide Fe to its associated P, indicating that this solid phase should retain P prior to its release. The results provide direct evidence for the coupling between Fe and P in sediments and further identify the easily reducible Fe (oxyhydr)oxide species involved in the coupling process.
- Published
- 2015
222. Vertical distribution of bacterial community structure in the sediments of two eutrophic lakes revealed by denaturing gradient gel electrophoresis (DGGE) and multivariate analysis techniques
- Author
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Zeng, Jin, Yang, Liuyan, Li, Jiayun, Liang, Yi, Xiao, Lin, Jiang, Lijuan, and Zhao, Dayong
- Published
- 2009
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223. Organic matter mineralisation in the hypolimnion of an eutrophic Maar lake
- Author
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Fahrner, Sven, Radke, Michael, Karger, Dorothée, and Blodau, Christian
- Published
- 2008
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224. Colloid formation in groundwater by subsurface aeration: characterisation of the geo-colloids and their counterparts
- Author
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Anke Wolthoorn, Erwin J. M. Temminghoff, and Willem H. van Riemsdijk
- Subjects
endocrine system ,Bodemscheikunde en Chemische Bodemkwaliteit ,Goethite ,Scanning electron microscope ,Mineralogy ,Sub-department of Soil Quality ,complex mixtures ,Colloid ,chemistry.chemical_compound ,Adsorption ,Geochemistry and Petrology ,fe(ii) oxidation ,Dissolved organic carbon ,goethite ,Environmental Chemistry ,lepidocrocite surface ,iron removal ,phosphate ,WIMEK ,eutrophic lake ,media ,scanning force ,digestive, oral, and skin physiology ,Phosphate ,Pollution ,Sectie Bodemkwaliteit ,body regions ,chemistry ,Chemical engineering ,adsorption ,visual_art ,transport ,visual_art.visual_art_medium ,Aeration ,Soil Chemistry and Chemical Soil Quality ,Groundwater - Abstract
Subsurface aeration is used to oxidise Fe in situ in groundwater to make the water potable. In a groundwater system with pH > 7, subsurface aeration results in a non-mobile Fe precipitate and mobile Fe colloids. Since originally the goal of subsurface aeration is to remove Fe in situ, the formation of non-mobile Fe precipitate is the desired result. In addition to this intended effect, subsurface aeration may also strongly enhance the microbiological removal of NH4 in the purification station. A hypothesis is that mobile Fe colloids may be the link between subsurface aeration and the positive effect on the microbiological removal of NH4. The objective of this study is to characterise the mobile Fe colloids and to derive a synthetic substitute for the naturally formed Fe colloids in order to be able to apply the Fe colloids as a management tool to enhance the removal of NH4 in the process of producing drinking water from groundwater. At a purification station in The Netherlands natural Fe colloids from an aerated well were sampled. Furthermore, eight synthetic Fe colloids were prepared by oxidising synthetic solutions differing in elemental composition. The colloids were analysed using chemical analysis and electron microscopy (SEM and SEM-EDAX). The Fe colloids sampled in the field contained Fe, Ca, Na, PO4 and Mn. Also in the synthetic Fe colloids PO4, Ca, Na and Mn were the most important elements next to Fe. Phosphate and dissolved organic C strongly influenced the morphology of the synthetic Fe colloids. When both the elemental composition and the morphology of the Fe colloids are taken into account, the synthetic Fe colloids formed in the synthetic solution containing Fe, Mn, PO4, SiO4 and dissolved organic matter best match the Fe colloids from the field. (C) 2004 Elsevier Ltd. All rights reserved.
- Published
- 2004
225. Methane flux and vertical-horizontal distributions of methane in Lake Fukami-ike
- Author
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FUNAHASHI, Junko, NISHIO, Naoko, and YAGI, Akihiko
- Subjects
organic acid ,eutrophic lake ,methane flux ,dissolved methane - Abstract
Lake Fukami-ike is a small eutrophic lake in central Japan and the lake water stratfies from April to October. The methane flux and vertical-horizontal distributions of dissolved methane were studied starting in March 1999. The vertical distribution of dissolved methane indicates the methane is produced in the hypolimnion, and the competition with sulfatereducing bacteria is clearly seen as hydrogen sulfide concentration increase. High dissolved methane concentrations were often found in the epimnion and hypolimnion in this lake. The high methane concentrations in the bottom layer were released from the bottom sediments (max. about 26.7 CH4 μl g-1), with a corresponding decrease in the acetic acid concentrations. The phenomenon in which there was a high methane concentration and methane flux was often seen in the surface layer. The horizontal dissolced methane distribution in the surface in the surface of lake water was not found to be affected by run off from the lake shore., Article, 信州大学山地水環境教育研究センター研究報告 2: 75-78(2004)
- Published
- 2004
226. The effect of environmental parameters and cyanobacterial blooms on phytoplankton dynamics of a Portuguese temperate Lake
- Author
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de Figueiredo, Daniela R., Reboleira, Ana S. S. P., Antunes, Sara C., Abrantes, Nelson, Azeiteiro, Ulisses, Gonçalves, Fernando, and Pereira, Mário J.
- Published
- 2006
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227. Population dynamics and growth of perch in a small, humic lake over a 20-year period - importance of abiotic and biotic factors
- Author
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Rask, M., Sairanen, S., Vesala, S., Arvola, L., Satu Estlander, Olin, M., Lammi Biological Station, Biological stations, and Environmental Sciences
- Subjects
CLIMATE-CHANGE ,ROACH RUTILUS-RUTILUS ,education ,EURASIAN PERCH ,1181 Ecology, evolutionary biology ,SMALL FINNISH LAKES ,RELATIVE ABUNDANCES ,INTERSPECIFIC COMPETITION ,YELLOW PERCH ,FLUVIATILIS L ,EUTROPHIC LAKE ,SOUTHERN FINLAND ,1172 Environmental sciences - Published
- 2014
228. Growth and production of free-living heterotrophic nanoflagellates in a eutrophic lake – Lake Donghu, Wuhan, China
- Author
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Zhao, Yufeng, Yu, Yuhe, Feng, Weisong, and Shen, Yunfen
- Published
- 2003
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229. Sources of suspended organic matter and selective feeding by zooplankton in an estuarine mangrove ecosystem as traced by stable isotopes
- Author
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N. Sreenivas, PC Mohan, Steven Bouillon, and Frank Dehairs
- Subjects
zooplankton ,food-webs ,Algae ,suspended organic matter ,amino-acids ,stable isotopes ,Seasonal variations ,Aquatic Science ,Excoecaria agallocha ,Zooplankton ,nitrogen ,Water column ,Phytoplankton ,Organic matter ,Mangrove swamps ,Ecology, Evolution, Behavior and Systematics ,Isotope analysis ,chemistry.chemical_classification ,geography ,geography.geographical_feature_category ,Detritus ,Ecology ,eutrophic lake ,mangroves ,coastal lagoon kenya ,Estuary ,Plankton ,penaeid prawns ,Carbon ,selective feeding ,fresh-water ,Oceanography ,chemistry ,carbon isotopes ,marine plankton ,phytoplankton ,Environmental science ,Avicennia ,relative importance - Abstract
Between January 1995 and August 1996, suspended matter and zooplankton were sampled at different locations in a mangrove ecosystem located in the Gautami Godavari estuary and adjacent Kakinada Bay (Andhra Pradesh, India). Suspended matter was sampled at 13 different stations, and was found to have a highly variable carbon stable isotope composition, with delta C-13 values ranging overall between -30.94 and -19.18 parts per thousand, and a highly variable elemental (C:N) composition. Our data suggest that the phytoplankton component has a seasonally and spatially variable delta C-13 signature, which is surpressed by the terrestrial signal but may at times fall in the same range as the delta C-13 of the allochtonous matter. It is argued that the phytoplankton delta C-13 decreases after the onset of the monsoon rains, most Likely due to the C-13-depletion of the DIC pool caused by the microbial respiration of the allochtonous organic matter. At each of the 4 sites selected for concurrent zooplankton sampling, the zooplankton showed a much wider range of delta C-13 than did the suspended matter, with overall delta C-13 values between -30.14 and -16.45 parts per thousand. In addition, spatial differences in average delta C-13 were much more pronounced for zooplankton than for total suspended matter. These data indicate that zooplankton feed on a component of the suspended matter pool, which has more pronounced seasonal and spatial delta C-13 variations than the total suspended matter. Thus, despite the large amounts of terrestrial and mangrove detritus present in the water column, the locally produced phytoplankton appears to be a more important carbon source for the zooplankton. ispartof: Marine ecology-progress series vol:208 pages:79-92 status: published
- Published
- 2000
230. Annual budget of chemical elements in a eutrophic lake, Aydat lake (Puy-de-Dôme), France
- Author
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Michard, Gil, Sarazin, Gérard, Jézéquel, Didier, Albéric, Patrick, and Ogier, Sylvie
- Published
- 2001
- Full Text
- View/download PDF
231. Vertical variations in kinetics of alkaline phosphatase and P species in sediments of a shallow Chinese eutrophic lake (Lake Donghu)
- Author
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Yiyong, Zhou, Jianqiu, Li, and Min, Zhang
- Published
- 2001
- Full Text
- View/download PDF
232. Effects of solar radiation, humic substances and nutrients on phytoplankton biomass and distribution in Lake Solumsjö, Sweden
- Author
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Danilov, Roman A. and Ekelund, Nils G. A.
- Published
- 2001
- Full Text
- View/download PDF
233. Aluminum distribution heterogeneity and relationship with nitrogen, phosphorus and humic acid content in the eutrophic lake sediment.
- Author
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Lin Q, Peng X, Liu B, Min F, Zhang Y, Zhou Q, Ma J, and Wu Z
- Subjects
- China, Ecosystem, Humic Substances analysis, Nitrogen analysis, Phosphorus analysis, Aluminum analysis, Eutrophication, Geologic Sediments chemistry, Lakes chemistry, Water Pollutants, Chemical analysis
- Abstract
Increasing amount of aluminum (Al) gets into aquatic ecosystem through anthropogenic activity, but the knowledge about Al migration and relationships with sediments possessing different physico-chemical properties in eutrophic lakes is limited. Here, the Al migration rule and relationships with sediment nutritions in the Hangzhou West Lake, China was investigated, where a certain amount of residual Al-salts can enter because of the pre-treatment of the Qiantang River diversion project every day. Results revealed the obvious spatial distribution heterogeneity of Al in sediment vertical direction and horizontal direction following water flow. The Al content in sediment ranged 0.463-1.154 g kg
-1 in Maojiabu Lake, and ranged 9.862-40.442 g kg-1 in Xiaonanhu Lake. Higher Al content distributed in upper layer sediment in lake with more disturbance. Total nitrogen (TN) contents were higher 0.917-3.387 mg g-1 and 0.627-0.786 mg g-1 in upper layer sediment than that in lower layer in Maojiabu Lake and Xiaonanhu Lake, respectively. Total phosphorus (TP) content ranged 0.779-2.580 mg g-1 , in which IP and Fe/Al-P contributed 24.9-80.8% and 17.0-51.6%, respectively. Correlations between Al content with nutrition, humic acid (HA) etc. of sediment regionally varied in Maojiabu and Xiaonanhu Lake. Spatial distribution of Al-salt in eutrophic lakes closely related with the physico-chemical characteristics of nutrients, humus, human disturbance and water division parameters. Results provides new insight into Al-salts migration and references for Al-risk evaluating in eutrophic lakes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
234. Anaerobic ammonium oxidation coupled to ferric iron reduction in the sediment of a eutrophic lake.
- Author
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Yao Z, Wang F, Wang C, Xu H, and Jiang H
- Subjects
- Denitrification, Geologic Sediments, Lakes, Nitrogen Cycle, Oxidation-Reduction, Ammonium Compounds chemistry, Iron chemistry, Nitrogen chemistry, Shewanella chemistry
- Abstract
Anaerobic ammonium oxidation coupled to ferric iron reduction (Feammox) has been assumed to play an important role in nitrogen removal from ecosystems. This study assessed the potential role of Feammox in nitrogen transformation in eutrophic lake sediment using an isotope tracing technique in sediment slurry incubation experiments. Feammox was discovered in eutrophic lake sediment. A significant correlation was found between Feammox rates and iron-reducing rates. Furthermore, the positive correlations between the abundance of iron-reducing bacteria (FeRB), such as Geobacteraceae spp. and Shewanella spp., and Feammox rates indicate that Feammox was mediated by FeRB. The potential rate of Feammox in the isotopic tracer incubation treatment was 0.23-0.43 mg N kg
-1 day-1 . The estimated nitrogen loss caused by Feammox accounts for 5.0-9.2% of the human-induced N input annually into the eutrophic lake. Feammox alone or coupled with anaerobic ammonium oxidation (anammox) and/or denitrification may have an essential role in the nitrogen cycle within eutrophic lake sediment.- Published
- 2019
- Full Text
- View/download PDF
235. Long-term variation of phytoplankton biomass and physiology in Taihu lake as observed via MODIS satellite.
- Author
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Huang C, Zhang Y, Huang T, Yang H, Li Y, Zhang Z, He M, Hu Z, Song T, and Zhu AX
- Subjects
- Biomass, China, Eutrophication, Lakes, Phytoplankton
- Abstract
Estimation of phytoplankton biomass (noted as phytoplankton carbon, C
phyto ) and evaluation of phytoplankton physiology is central to the estimation of primary productivity and the carbon cycle. This issue has been widely considered in oceans but not in inland water. Here, we develop experiential and semi-analytical models, which validated by independent in situ measurement data, respectively, to derive Cphyto and phytoplankton absorption coefficient at 675 nm (aph (675)) from MODIS. The effects of nutrients and temperature on the seasonal variation of phytoplankton physiology were assessed through a novel proxy of Cphyto to aph (675) ratio (Cphyto /aph (675)) over the Lake Taihu, the third largest lake in China. Significant seasonal climatological cycles of Cphyto , aph (675) and Cphyto /aph (675) were observed in Lake Taihu, especially in Meiliang Bay and Zhushan Bay, where algal blooms occur frequently. The highest Cphyto and aph (675) values were observed in summer due to the growth of phytoplankton biomass and chlorophyll-a concentration. Lower values were observed in winter and spring, which are characterized by relatively high total nitrogen levels and low irradiance, owing to the low temperature astricts the algae growth. However, the Cphyto /aph (675) shows an opposite trend compared to Cphyto and aph (675), which have high values in winter and low values in summer. The analysis of Cphyto , aph (675) and Cphyto /aph (675) with total phosphorus (TP) levels and temperature indicates that TP are the main positive driver of the increase in Cphyto and aph (675) and negatively regulate Cphyto /aph (675). Warming promotes an increase in Cphyto and aph (675) and restricts Cphyto /aph (675) in summer. Biomass and nutrient levels are the primary drivers of the decrease of Cphyto /aph (675) in such a typical eutrophic lake. The results present some new findings compared to previous oceanic studies and expand our knowledge in the study of phytoplankton biomass and physiology in eutrophic lakes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
236. The feasibility of using bentonite, illite, and zeolite as capping materials to stabilize nutrients and interrupt their release from contaminated lake sediments.
- Author
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Gu BW, Hong SH, Lee CG, and Park SJ
- Subjects
- Water Pollutants, Chemical analysis, Bentonite chemistry, Geologic Sediments chemistry, Lakes chemistry, Minerals chemistry, Water Pollutants, Chemical chemistry, Zeolites chemistry
- Abstract
The aim of this study was to assess the feasibility of using bentonite, illite, and zeolite as capping materials to interrupt the release of and sequestrate carbon, nitrogen, and phosphorus from contaminated sediments. Their efficiency was assessed in batch isotherm, column incubation experiments, and nitrogen and phosphorus extraction from the capping materials and sediments. All capping materials contributed to the reduction of dissolved oxygen depletion and chemical oxygen demand in overlying water. Zeolite showed a high adsorption capacity for NH
4 -N; the zeolite cap produced the lowest NH4 -N flux constituting the highest percentage of total nitrogen in the overlying water. Significant changes in water conditions, such as an increased pH (>8) and lowered oxidation reduction potential (<-80 mV) were observed when a bentonite cap was used. Illite showed high capping efficiency (>130%) for both PO4 -P and total phosphorus, and phosphorus was adsorbed mainly as the high residual-P fraction (≈90%) in its strongest adsorbed form. The results of this study indicate that illite has potential for use as an agent to deactivate phosphorus in lake eutrophication control techniques., (Copyright © 2018 Elsevier Ltd. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
237. Three decades of changes in water environment of a large freshwater Lake and its relationship with socio-economic indicators.
- Author
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Li C, Feng W, Song F, He Z, Wu F, Zhu Y, Giesy JP, and Bai Y
- Subjects
- Biological Oxygen Demand Analysis, Nitrogen analysis, Phosphorus analysis, Environmental Monitoring, Gross Domestic Product trends, Lakes chemistry, Water chemistry
- Abstract
Tai Lake (Ch: Taihu) has attracted international attention forcyanobacteria blooms. However, the drivers of cultural eutrophication, especially long-term socio-economic indicators have been little researched. The results of research demonstrate how socio-economic development affected quality of water and how it has been improved by anthropogenic activities. This study described variability in indicators of water quality in Tai Lakeand investigated thedrivers. Significant relationships existed between concentrations of annual mean total nitrogen (TN), total phosphorous (TP), chemical oxygen demand (COD) and biological oxygen demand (BOD), and population, per capital gross domestic production (GDP) and sewage discharge (p < 0.05). However, mechanisms causing change varied among TN, TP, COD and BOD. Before 2000, the main contributors to increases in concentrations of TN were human population, GDP and volumes of domestic sewage discharges. After 2000, discharges of industrial sewage become the primary contributor. After 1998, the regressions of annual mean TN, TP and COD on per capital GDP, population and domestic sewage discharge were reversed compared to the former period. Since 1999, an apparent inverted U-shaped relationship between environmental pollution and economic development has developed, which indicated that actions taken by governments have markedly improved quality of water in Tai Lake. The statistical relationship between BOD and per capital GDP didn't conform to the Kuznet curve. The U-shaped Kuznet curve may offer hope for the future that with significant environmental investments a high GDP can be reached and maintained without degradation of the environment, especially through appropriate management of industrial sewage discharge., (Copyright © 2018. Published by Elsevier B.V.)
- Published
- 2019
- Full Text
- View/download PDF
238. Phosphorus mobilization in lake sediments: Experimental evidence of strong control by iron and negligible influences of manganese redox reactions.
- Author
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Chen M, Ding S, Wu Y, Fan X, Jin Z, Tsang DCW, Wang Y, and Zhang C
- Subjects
- Computer Simulation, Geologic Sediments chemistry, Iron chemistry, Manganese chemistry, Oxidation-Reduction, Oxides chemistry, Phosphorus chemistry, Water chemistry, Water Pollutants, Chemical chemistry, Environmental Monitoring methods, Harmful Algal Bloom physiology, Iron analysis, Lakes chemistry, Manganese analysis, Phosphorus analysis, Water Pollutants, Chemical analysis
- Abstract
Iron (Fe) and manganese (Mn) reactions have been regarded as the primary factors responsible for the mobilization of phosphorus (P) in lake sediments, although their individual roles are hard to distinguish. In this study, in situ mobilization of P, Fe and Mn in sediments was assessed by high resolution spatio-temporal sampling of their labile forms using diffusive gradient in thin films (DGT) and suction device (Rhizon) techniques. It was found that the monthly concentration distributions showed greater agreement and better correlation coefficients between labile P and labile Fe, than those between labile P and labile Mn, implying that Fe plays a key role in controlling P release in sediments. Furthermore, better correlations were observed between hourly changes in concentrations of soluble reactive phosphorus (SRP) and soluble Fe(II), than those between SRP and soluble Mn. Changes were observed under simulated anaerobic incubation conditions, suggesting that P release was caused by the reductive dissolution of Fe oxides. This was supported by the lack of influences on P release from reductive dissolution of Mn oxides in the sediment-water interface and top sediment layers under the anaerobic incubations. In simulated algal bloom experiments, positive correlations and consistent changes were observed between SRP and soluble Fe(II) concentrations, but not between SRP and soluble Mn concentrations. This further demonstrated the Fe-dependent and Mn-independent release of P in sediments. Therefore, Fe redox reactions have a high impact on P mobilization in sediments, while Mn redox reactions appear to have negligible influences., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
239. Combined Effects of Experimental Warming and Eutrophication on Phytoplankton Dynamics and Nitrogen Uptake.
- Author
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Yu, Chen, Li, Chao, Wang, Tao, Zhang, Min, and Xu, Jun
- Subjects
LAKES ,GLOBAL warming ,GREEN algae ,BIOMASS ,CRYPTOMONADS ,EUTROPHICATION - Abstract
Shallow lakes are highly vulnerable to damages caused by human activities and warming trends. To assess whether and how community structures of phytoplankton and nitrogen uptake respond to the combined effects of elevated temperature and eutrophication, we performed a mesocosm experiment in field by combining a 4.5 °C increase in temperature and the addition of phosphorus. Our results demonstrated that the combination of rising temperatures and phosphorus loading stimulated the maximum biomass built up by the phytoplankton community, and changed the phytoplankton community by significantly increasing the number of Chlorophyta and Cyanophyta, and decreasing that of Cryptophyta. We also examined the effects of climate warming and eutrophication on phytoplankton nitrogen uptake and dynamics using
15 N tracer techniques. The addition of phosphorus slightly increased the phytoplankton nitrate uptake velocity and relative preference index, but decreased the nitrate uptake turnover time. Warming relatively increased the ammonium uptake velocity and the relative preference index, but decreased the ammonium turnover time. In kinetic studies, NH4 + exhibited a higher maximum uptake rate (Vmax ) and a lower half-saturation constant (Ks ) than NO3 − substrates due to temperature elevation and the addition of phosphorus. Hence, warming and eutrophication increased the capacity of phytoplankton for NH4 + uptake and their affinity at low substrate concentrations. Thus, the combined effects of climate warming and phosphorus nutrient availability may increase the prevalence of Chlorophyta and Cyanophyta, and change the nitrogen cycling of aquatic ecosystems. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
240. Characterization of Chromophoric Dissolved Organic Matter in the Littoral Zones of Eutrophic Lakes Taihu and Hongze during the Algal Bloom Season.
- Author
-
Chen, Bingfa, Huang, Wei, Ma, Shuzhan, Feng, Muhua, Liu, Cheng, Gu, Xiaozhi, and Chen, Kaining
- Subjects
CARBON compounds ,LITTORAL zone ,ALGAL blooms ,HUMIFICATION ,MOLECULAR weights - Abstract
Chromophoric dissolved organic matter (CDOM) is a key component with a critical role in the littoral zones of eutrophic shallow lakes; yet the characteristics of CDOM in these zones remain seldom systematically reported. In this study, the differences in sources, biogeochemical characteristics, and fates of CDOM between the littoral zones of eutrophic lakes Taihu (LLT; frequently occurring algal blooms and longer lake residence time) and Hongze (LLH; no obvious algal blooms and shorter residence time) were compared during the algal bloom season using ultraviolet-visible spectra and excitation and emission matrix spectroscopy combined with parallel factor analysis. Three humic-like fluorescent dissolved organic matter (FDOM) components (C1, C3, and C4) and one protein-like component (C2) were identified. Results showed that FDOM components were dominated by protein-like fluorescent substances in LLT, and humic-like materials in LLH, respectively. The CDOM in LLT had a lower relative aromaticity and molecular weight, humification degree and a higher autotrophic productivity because of algal blooms. Furthermore, CDOM depletion rates in LLT were higher than those in LLH due to a longer lake residence time in LLT. In addition, CDOM shifted from high molecular weight to low molecular weight as the humification degree decreased during the CDOM depletion process. This comparative study showed that algal blooms and lake residence time were the significant factors for distinguishing characteristics of CDOM between littoral zones of shallow lakes on a similar trophic level. This study provides field-based knowledge for remote sensing CDOM measurement and serves as a reference for lakeshore aquatic environmental management. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
241. Spatial statistics of hydrography and water chemistry in a eutrophic boreal lake based on sounding and water samples.
- Author
-
Leppäranta, Matti, Lewis, John E., Heini, Anniina, and Arvola, Lauri
- Subjects
WATER chemistry ,HYDROGRAPHY ,WATER sampling ,CHLOROPHYLL ,ICE sheets - Abstract
Spatial variability, an essential characteristic of lake ecosystems, has often been neglected in field research and monitoring. In this study, we apply spatial statistical methods for the key physics and chemistry variables and chlorophyll a over eight sampling dates in two consecutive years in a large (area 103 km
2 ) eutrophic boreal lake in southern Finland. In the four summer sampling dates, the water body was vertically and horizontally heterogenic except with color and DOC, in the two winter ice-covered dates DO was vertically stratified, while in the two autumn dates, no significant spatial differences in any of the measured variables were found. Chlorophyll a concentration was one order of magnitude lower under the ice cover than in open water. The Moran statistic for spatial correlation was significant for chlorophyll a and NO2 +NO3 -N in all summer situations and for dissolved oxygen and pH in three cases. In summer, the mass centers of the chemicals were within 1.5 km from the geometric center of the lake, and the 2nd moment radius ranged in 3.7-4.1 km respective to 3.9 km for the homogeneous situation. The lateral length scales of the studied variables were 1.5-2.5 km, about 1 km longer in the surface layer. The detected spatial “noise” strongly suggests that besides vertical variation also the horizontal variation in eutrophic lakes, in particular, should be considered when the ecosystems are monitored. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
242. Biomechanical response of a submerged, rosette-forming macrophyte to wave action in a eutrophic lake on the Yungui Plateau, China.
- Author
-
Zhu G, Di G, Zhang M, Cao T, Ni L, Fang R, and Yu G
- Subjects
- Biomechanical Phenomena, China, Ecosystem, Eutrophication, Hydrocharitaceae anatomy & histology, Plant Leaves physiology, Plant Roots physiology, Hydrocharitaceae physiology, Lakes
- Abstract
Few studies have focused on the biomechanical responses of submerged, rosette-forming macrophytes to wave action, water depth, or their co-occurrence in naturally eutrophic systems. The plant architecture, root anchorage strength-related traits, leaf morphology, and biomechanics of Vallisneria natans inhabiting a range of water depths were examined along three transects (T1, T2, and T3) in a eutrophic lake, Lake Erhai, in Yunnan Province, China. These transects were exposed to weak wave action and hyper-eutrophication (T1), moderate wave action and eutrophication (T2), or strong wave action and eutrophication (T3). The results showed that V. natans was mainly distributed at intermediate depths, with the widest colonization depth in T1. The values of plant architecture, root anchorage strength-related traits, leaf morphology, and biomechanics were generally highest in T3 and smallest in T2. Along the depth gradient, these values were generally highest at 3.5, 2.5, and 2.5 m for the plants growing in T1, T2, and T3, respectively. These findings suggest that V. natans adopts a "tolerance" strategy to cope with the effects of strong wave action in eutrophic habitats and an "avoidance" strategy when exposed to moderate wave action in eutrophic areas. Since the absence of an avoidance strategy increases the resistance to low-light stress at the expense of increased drag forces, there is a limit to the wave action that V. natans can withstand. This study indicates that biomechanics could be important when determining the distribution pattern of V. natans in Lake Erhai.
- Published
- 2018
- Full Text
- View/download PDF
243. Abundance and diversity of iron reducing bacteria communities in the sediments of a heavily polluted freshwater lake.
- Author
-
Fan YY, Li BB, Yang ZC, Cheng YY, Liu DF, and Yu HQ
- Subjects
- Bacteria genetics, Bacteria isolation & purification, Biodiversity, China, Cloning, Molecular, Eutrophication, Geologic Sediments chemistry, High-Throughput Nucleotide Sequencing, Oxidation-Reduction, Phylogeny, Water Microbiology, Water Pollution, Geobacter genetics, Geobacter isolation & purification, Geologic Sediments microbiology, Iron metabolism, Lakes microbiology, Shewanella genetics, Shewanella isolation & purification
- Abstract
Iron reduction mediated by Fe(III)-reducing bacteria (FeRB) occurs in aqueous environments and plays an essential role in removing contaminates in polluted freshwater lakes. Two model FeRB species, Shewanella and Geobacter, have been intensively studied because of their functions in bioremediation, iron reduction, and bioelectricity production. However, the abundance and community diversity of Shewanella and Geobacter in eutrophic freshwater lakes remain largely unknown. In this work, the distribution, abundance and biodiversity of Shewanella, Geobacter and other FeRB in the sediments of a heavily polluted lake, Chaohu Lake, China, across four successive seasons were investigated. Shewanella, Geobacter, and other FeRB were found to be widely distributed in the sediment of this heavily eutrophic lake. Geobacter was abundant with at least one order of magnitude more than Shewanella in cold seasons. Three Shewanella-related operational taxonomic units were detected and sixty one Geobacter-related operational taxonomic units were grouped into three phylogenetic clades. Thiobacillus, Desulfuromonas and Geobacter were identified as the main members of FeRB in the lake sediments. Interestingly, nutrients like carbon, nitrogen, and phosphorus were found to be the key factors governing the abundance and diversity of FeRB. Total FeRB, as well as Geobacter and Shewanella, were more abundant in the heavily eutrophic zone than those in the lightly eutrophic zone. The abundance and diversity of FeRB in the sediments of freshwater lakes were highly related with the degree of eutrophication, which imply that FeRB might have a great potential in alleviating the eutrophication and contamination in aqueous environments.
- Published
- 2018
- Full Text
- View/download PDF
244. [CH 4 Emissions Characteristics and Its Influencing Factors in an Eutrophic Lake].
- Author
-
Shang DY, Xiao QT, Hu ZH, Xie YH, Huang WJ, and Zhang M
- Subjects
- China, Seasons, Temperature, Water Quality, Eutrophication, Lakes, Methane analysis
- Abstract
In order to identify methane (CH
4 ) diffusion emissions characteristics and their impact factors in an eutrophic lake, CH4 flux across the lake-air interface was observed in Meiliang Bay and the central zone of Lake Taihu over one year. The relationships between CH4 flux and environmental factors and water quality indices were analyzed. The results indicated that the annual mean CH4 diffusion flux in the eutrophic zone was significantly higher than that in the central zone, which were 0.140 mmol·(m2 ·d)-1 and 0.024 mmol·(m2 ·d)-1 , respectively. Additionally, the highest CH4 flux appeared in the eutrophic littoral zone. The CH4 flux varied seasonally, which was consistent with water temperature that peaked in summer. Furthermore, the difference in CH4 flux between seasons was an order of magnitude. The temporal variation in CH4 flux was mostly driven by wind speed and water temperature. The spatial correlation between CH4 flux and dissolved organic carbon concentration was highly significant ( R2 =0.62, P <0.01). Observing temporal and spatial patterns of CH4 flux was necessary to accurately estimate whole-lake CH4 emissions due to large variability across time and space.- Published
- 2018
- Full Text
- View/download PDF
245. Nutritional value of freshwater mesozooplankton assemblages from Hanna Dam Lake, Iran, during a one-year study
- Author
-
Farhadian, O., Kolivand, S., Mahmoudi Khoshdarehgy, M., Ebrahimi Dorch, E., and Mahboobii Soofiani, N.
- Subjects
Chemistry ,Ecology ,Nutritional value ,Iran ,Seasonal variability ,Eutrophic Lake ,Biology ,Zooplankton - Abstract
Nutritional value of freshwater mesozooplankton, fatty acid (FA) and amino acid (AA) compositions were determined in the middle of each season for a one-year period from May 2009 to February 2010 in Hanna Dam Lake, Isfahan, Iran. FA and AA composition significantly (P
- Published
- 2013
246. Target strength and vertical distribution of smelt (Osmerus eperlanus) in the IJsselmeer based on stationary 200 kHz echosounder recordings
- Author
-
Sascha M. M. Fässler, Ada Marieke Keller, Sven Gastauer, and Bram Couperus
- Subjects
consequences ,Population ,population ,Aquatic Science ,Visserij ,l ,Water column ,Hydroacoustics ,Osmerus eperlanus ,patterns ,Target strength ,education ,fish ,education.field_of_study ,Perch ,biology ,eutrophic lake ,shallow ,biology.organism_classification ,Wageningen Marine Research ,quantification ,Light intensity ,Oceanography ,Vis ,kinneret ,methane bubbles ,Environmental science ,Smelt - Abstract
a b s t r a c t Ventral target strength (TS) of smelt (Osmerus eperlanus) was measured using a bottom deployed Simrad EK60 200 kHz echosounder in the shallow lake Ijsselmeer (The Netherlands). Ventral TS values recorded (TS = 20 log10(L)–74.39) were lower but comparable to previous studies looking at the dorsal TS in other areas. Biological samples were collected simultaneously close to the bottom and close to the surface. The combination of acoustic measurements and catch information revealed a diurnal migration of smelt. Smelt was observed to be more dispersed during the night than during daytime, but showing no clear avoidance pattern for any environmental variable recorded by CTD measurements. Smelt was found in the upper water column during times of highest light intensity. Such behaviour is likely to occur due to a combination of turbid water conditions and predator avoidance, mainly of piscivorous fish species such as pike–perch (Stizostedion luciperca) and perch (Perca fluviatilis)
- Published
- 2013
247. What is the influence on water quality in temperate eutrophic lakes of a reduction of planktivorous and benhivorous fish? : A systematic review protocol
- Author
-
Per Larsson, Lennart Persson, Claes Bernes, Christian Skov, Stephen R. Carpenter, Anna Gårdmark, Ellen van Donk, and Aquatic Ecology (AqE)
- Subjects
fish removal ,Biomanipulation ,Ecology ,eutrophic lake ,Management, Monitoring, Policy and Law ,Plankton ,Biological Sciences ,Pollution ,Zooplankton ,Algal bloom ,water quality ,Macrophyte ,Fishery ,international ,Environmental science ,Biologiska vetenskaper ,Water quality ,Eutrophication ,Planktivore - Abstract
Background: In lakes that have become eutrophic due to sewage discharges or nutrient runoff from land, problems such as algal blooms and oxygen deficiency often persist even when nutrient supplies have been reduced. One reason is that phosphorus stored in the sediments can exchange with the water. There are indications that the high abundance of phytoplankton, turbid water and lack of submerged vegetation seen in many eutrophic lakes may represent a semi-stable state. For that reason, a shift back to more natural clear-water conditions could be difficult to achieve. In some cases, though, temporary mitigation of eutrophication-related problems has been accomplished through biomanipulation: stocks of zooplanktivorous fish have been reduced by intensive fishing, leading to increased populations of phytoplankton-feeding zooplankton. Moreover, reduction of benthivorous fish may result in lower phosphorus fluxes from the sediments. An alternative to reducing the dominance of planktivores and benthivores by fishing is to stock lakes with piscivorous fish. These two approaches have often been used in combination. The implementation of the EU Water Framework Directive has recently led to more stringent demands for measures against eutrophication, and a systematic review could clarify whether biomanipulation is efficient as a measure of that kind. Methods: The review will examine primary field studies of how large-scale biomanipulation has affected water quality and community structure in eutrophic lakes or reservoirs in temperate regions. Such studies can be based on comparison between conditions before and after manipulation, on comparison between treated and non-treated water bodies, or both. Relevant outcomes include Secchi depth, concentrations of oxygen, nutrients, suspended solids and chlorophyll, abundance and composition of phytoplankton, zooplankton and fish, and coverage of submerged macrophytes. A Systematic review to this article was published on 22 May 2015: ernes, C., Carpenter, S.R., Gårdmark, A. et al. What is the influence of a reduction of planktivorous and benthivorous fish on water quality in temperate eutrophic lakes? A systematic review. Environ Evid 4, 7 (2015). DOI: 10.1186/s13750-015-0032-9 Mistra
- Published
- 2013
248. Nitrate reductase activity of phytoplankton populations in eutrophic Lake Aydat and meso-oligotrophic Lake Pavin: a comparison
- Author
-
Mallet, C., Charpin, M. F., and Devaux, J.
- Published
- 1998
- Full Text
- View/download PDF
249. An example of relationships between macrophytes, macroinvertebrates and their food resources in a shallow euthrophic lake
- Author
-
Dvořák, Jan
- Published
- 1996
- Full Text
- View/download PDF
250. Taxonomic composition of rotifers in Lake Peipsi
- Author
-
Virro, Taavi
- Published
- 1996
- Full Text
- View/download PDF
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