To see the other types of publications on this topic, follow the link: Lake sediments.
Journal articles on the topic 'Lake sediments'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Lake sediments.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Pujate, Agnese, Karina Stankevica, Laimdota Kalnina, Maris Klavins, Aija Cerina, Anda Drucka, and Kristaps Kiziks. "Records of the anthropogenic influence on different origin lake sediments of Latvia." Baltica 28, no. 2 (December 11, 2015): 135–50. http://dx.doi.org/10.5200/baltica.2015.28.12.
Full textAbstract:
Sediments in lakes have formed under the conditions of sensitive ecosystem functions as archives of micro- and macrocomponents. Besides others, lake sediments preserve palaeobotanical and chemical evidence reflecting environmental changes. During the last centuries, sediment composition has been influenced also by inconsistent urban and industrial developments. This paper represents the results of chemical and palaeobotanical signatures in the sediments from four lakes of different origin: Lake Lilaste, Lake Velnezers, Lake Engure, and Lake Vevers. The data were compared with the results from sediment composition analysis obtained by Loss on Ignition and chemical methods taking into account changes in plant macroremains. The studies of lake sediments revealed that human impact is recognisable in the upper sediment layer of all investigated sites, but at different depth from sediment surface. The most recognisable traces of anthropogenic influence can be attributed to the sharp increase of the amount of lead (Pb) and number of plant macroremains in analysed lake sediments.
2
Wu, Chao, Xiaodong Wu, Xuguang Ge, Lian Feng, Ya Tan, Jiuyun Yang, Weixiang Ren, and Min Zou. "Characteristics of Dissolved Organic Matter in Sediments of Typical Lakes in Southeastern Hubei Province, China." International Journal of Environmental Research and Public Health 19, no. 12 (June 16, 2022): 7402. http://dx.doi.org/10.3390/ijerph19127402.
Full textAbstract:
This study aimed to reveal the distribution characteristics and sources of dissolved organic matter (DOM) in sediments of typical lakes in the southeastern of the Hubei province and provide a reference for pollution control of eutrophic lakes. The sediments of four typical lakes (Liangzi, Baoan, Daye, and Qingshan) in the southeastern of the Hubei Province were investigated in May 2019. Ultraviolet-visible (UV-Vis) absorption spectroscopy and excitation-emission matrixes characteristics of DOM were obtained by UV-Vis spectrophotometry and three-dimensional fluorescence spectroscopy. Moreover, the DOM fluorescence components were resolved by parallel factor analysis (PARAFAC). The results showed that: (1) The absorption coefficient a350 in surface sediments followed the order: Baoan Lake (16.99 ± 3.82 m−1) > Qingshan Lake (15.37 ± 3.8 m−1) > Liangzi Lake (12.54 ± 5.58 m−1) > Daye Lake (12.43 ± 1.43 m−1). Specifically, with increasing depth in the sediment cores, a350 increased and then gradually decreased in Daye Lake and Baoan Lake, but fluctuated in Liangzi Lake and Qingshan Lake with a roughly decreasing trend. (2) Two humic-like components (C1, C2) and one protein-like component (C3) were identified via PARAFAC. This analysis also showed that the surface sediment fluorescent dissolved organic matter (FDOM) was dominated by protein-like, while the sediment core FDOM was dominated by humic-like in Liangzi Lake. The proportion of humic-like in FDOM was higher than protein-like in surface sediments and sediment cores of Baoan, Daye, and Qingshan Lakes. (3) The DOM of surface sediments in the Liangzi Lake comprised mostly autochthonous components, mainly produced by the vital activities of aquatic organisms. The DOM of surface sediments in Baoan Lake and Qingshan Lake showed weak humic and moderate autochthonous characteristics. The humification of DOM in sediment cores of Liangzi, Baoan, and Qingshan Lakes gradually decreased from depth to the surface. The DOM in surface sediments of Daye Lake had strong humic and moderate autochthonous characteristics. (4) In general, the DOM of lake sediments in southeastern Hubei Province has dual-contribution characteristics representing terrigenous and endogenous sources. In the restoration and treatment of lake ecology, both internal and terrestrial pollution should be considered. At the same time, it is noteworthy that cyanobacteria depletion and aquatic residues caused potential internal pollution.
3
Wu, Xue, Yancai Wang, Lixin Jiao, Jia He, Hongbin Zhou, and Zhengzheng Hao. "Influencing Factors of Phosphorus Mobility and Retention in the Sediment of Three Typical Plateau Lakes." Toxics 13, no. 2 (February 3, 2025): 120. https://doi.org/10.3390/toxics13020120.
Full textAbstract:
The mechanisms driving changes in the stability of phosphorus (P) in sediments under lake ecosystem degradation remain poorly understood. This study investigated the P-binding forms in sediments from three plateau lakes with different trophic states in Yunnan Province, China, aiming to elucidate the responses of sediment P compositions to human activities, lake trophic status, and dissolved organic matter (DOM) characteristics. The results showed that human activity directly contributed to sediment P retention. The trophic type of lake exerted a discernible effect on P mobility in the sediments, as eutrophic algae-type lakes had a higher content of sediment mobile-P. Moreover, the sediment DOM promoted the adsorption of BD-P and NH4Cl-P. Generally, exogenous pollution caused by human activity leads to lake eutrophication and a decline in lake ecosystem stability. This variation was largely influenced by water depth. A decrease in lake ecosystem stability leads to increased P mobility in sediments, which increases the risk of endogenous pollution. The DOM plays an important role in the mobility of sediment P. These insights offer a novel perspective for understanding how lake ecosystem characteristics are related to endogenous P loads in lakes.
4
Ziganshin, Irek, Dmitriy Ivanov, and Lilia Mukhametzyanova. "Estimation of organic carbon stocks in bottom sediments of Middle Kaban lake (Kazan, Republic of Tatarstan)." E3S Web of Conferences 555 (2024): 01017. http://dx.doi.org/10.1051/e3sconf/202455501017.
Full textAbstract:
The lakes has an enormous sediment carbon storage potential. This study aims to estimate sediment organic carbon stock in the of Middle Kaban lake, Republic of Tatarstan. The study revealed that the in the surface layer of lake sediments carbon stocks amount to 1134 tons. Total organic carbon stocks in the bottom sediments of Middle Kaban lake amount to 5986 tons. In CO2 equivalent, 21949 tons of greenhouse gases are accumulated in the lake bottom sediments.
5
Luo, Wenguang, Yan Pan, Yangzhen Fan, Jing Lu, and Senlin Zhu. "Distribution Patterns of Sediment Organic Carbon Stocks in Shallow Lakes and the Significance for Sustainable Lake Management: Chaohu Lake in Eastern China as a Case Study." Land 13, no. 4 (April 12, 2024): 507. http://dx.doi.org/10.3390/land13040507.
Full textAbstract:
Shallow lake sediments have huge potential for carbon storage, but they are vulnerable to various environmental changes and are highly susceptible to becoming a source of carbon emissions. Understanding the amount of sediment carbon storage can provide information about the potential of shallow lakes in mitigating climate change. In this study, sediment sampling was conducted at 12 study sites in Chaohu Lake, China, and sediment water content, grain size, bulk density, and sediments organic carbon (SOC) content were examined in five layers along the vertical direction, respectively, and the distribution and storage of SOC were estimated. The results showed that the surface sediments in the west lake area of Chaohu Lake would release 66,300 tons of SOC to the overlying water body in the future. The sediments in the middle lake area and the east lake area will absorb another 15,900 t and 17,300 t of TOC from the water body in the future, respectively. Overall, the lake-wide sediments will release 33,100 t of SOC into the water body in the future. In addition, the results of the study also indicate that human activities are another major influence on the change in organic carbon stocks in lake sediments, and therefore, proactive measures for the restoration and protection of lake sediments are essential because increasing the SOC stocks in the sediments and maintaining the lakes in a sustainable manner can contribute to the crucial role they play in mitigating climate change.
6
Syrykh, Liudmila S. "SEDIMENTATION AS A CLASSIFICATION CRITERION FOR LAKES ON THE EAST EUROPEAN PLAIN." Географический вестник = Geographical bulletin, no. 3 (2023): 19–26. http://dx.doi.org/10.17072/2079-7877-2023-3-19-26.
Full textAbstract:
The article studies lake sedimentation on the East European Plain and adjacent areas. Lake sediment formation is researched in detail in paleolimnology. The main aim of the present study is to describe the features of lake sedimentogenesis on the East European Plain and to identify classes of lakes in accordance with the types of sedimentogenesis. PaleoLake Database, created for the analysis, contains paleolimnological information about the bottom sediments of lakes of the East European Plain and nearby territories. We analyzed 216 lakes located in different climatic and geological zones, for which the most complete information had been collected: lithostratigraphy, age and thickness of bottom sediments, lake coordinates, water depth etc. Claster analysis of the collected data identified three main types of lake sedimentation for the East European Plain. (1) Sedimentation of large deep-water lakes (minerogenic sedimentogenesis of the Pleistocene). The bottom sediments are represented by minerogenic sediments, mainly clays and silts. (2) Sedimentation of isolated lake basins (mineragenic-organogenic sedimentogenesis of the Pleistocene and Holocene). The main feature of the lithostratigraphy is the presence of three main sediment sequences: minerogenic sediments formed in a large reservoir, transitional deposits formed during the isolation, organic deposits of a shallow basin. (3) Sedimentation of lakes located outside maritime transgressions and regressions (organogenic sedimentogenesis of the Holocene). The bottom sediments of such lakes are mainly represented by gyttja.
7
Nik Daud, Nik Norsyahariati, Nur Safrah Anuar, Zainuddin Yusoff, and Amimul Ahsan. "Assessment of Lake Sediments Properties and Contaminations Level." Advanced Materials Research 610-613 (December 2012): 2100–2103. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.2100.
Full textAbstract:
Sediments are principal carriers of the trace elements in the hydrosphere. Properties of the sediment (such as grain size, specific surface area and pore volume) decide the concentration level of the pollutant contain in water. The properties of sediment differed in each lake according to the normal geological phenomenon and source of discharge wastewater. The purpose of this study is to investigate the properties and contamination level of the sediment collected from lakes in Universiti Putra Malaysia (UPM). Sediment samples are taken from three different lakes; Lake IT, Lake ENG and Lake PK. These locations are selected due to the type of wastewater has been discharged into the lakes which are from colleges and academic buildings. The sediments were tested in terms of physical, chemical properties and contaminant concentration (Pb, P and Cu). Using the contaminant concentration results; the sediment concentration level of the pollutant of each lakes were referred to the Consensus- Based Sediment Quality Guidelines (CBSQG-2003). The dominant grain sizes of the sediments were found in the range of silt/clay; with the size fraction in the range 12.74% to 12.83%. The specific surface areas of sediments were in the range of 16.3 to 22.5 m2/g with a pore size distribution in the range of 20 to 29 mm3/g. The chemical properties show that the pH values are in normal range; pH 7, TOC values in the range of 10.84 to 12.39% and salinity values in the range of 0.05 to 0.06 dS/m. The contaminant concentrations show that the main heavy metal presents in Lake IT, Lake ENG and Lake PK as Lead (Pb) with 0.033 mg/l, 0.036 mg/L and 0.038 mg/L, respectively. According to the CBSQG-2003, due to the concentration of Lead presents in lakes sediment in UPM area, the sediments were categorised as non-polluted.
8
Gyulai, István, János Korponai, Sheila Mumbi A. Wamugi, Jázmin Jakab, Umar Abba Kawu, Andor G. Soltész, Tamás Karches, and Uyanga Tumurtogoo. "Cladocera and Geochemical Variables from Core Sediments Show Different Conditions of Hungarian Lakes." Water 16, no. 9 (May 5, 2024): 1310. http://dx.doi.org/10.3390/w16091310.
Full textAbstract:
Studies on the sediments of lakes with varying trophic status are of particular importance when considering changes in the natural environment. In this study, our objective was to examine subfossil remains of Cladocera species and the relationship between the sedimental Cladocera assemblages and geochemical variables during 11 years of sediment records from northern Hungarian lakes. To achieve this, we compared sedimental cladoceran communities and the geochemistry of the sediment layers among lakes. Among the studied lakes, one was an intermittent lake (KMT: the Kis-Morotva Lake) which dried out in 2012 but was subsequently naturally refilled in 2013 by groundwater affected by the high-water level of the River Tisza. The other type consisted of permanent lakes (SZA: the Szabolcs oxbow lake, TI: the Timár Morotva Lake) that never dried out. The results of the beta diversity analysis show that the deposition of Cladocera communities was similar among the sediment layers of lakes, while the abundance differences contributed significantly to replacement. Subsequently, core sediment samples of the three lakes were compared based on the remains of Cladocera communities and geochemical variables using Adonis (PERMANOVA). The core sediment samples indicate variations in Cladocera communities alongside disparities in geochemical variables across the same lakes. In conclusion, the significance of sediment cores containing the remains of the Cladocera community has grown significantly in the reconstruction of historical ecological and climatic changes.
9
Orlov, A. V., M. S. Potakhin, and D. A. Subetto. "Correlation of small isolated reservoirs in the Zaonezhsky Peninsula area with the Onega Ice Lake level changes." Limnology and Freshwater Biology, no. 4 (2024): 761–66. http://dx.doi.org/10.31951/2658-3518-2024-a-4-761.
Full textAbstract:
The article discusses data on the lithological composition of bottom sediments from two small lakes – Lake Lavkozero and Lake Gangozero, located on the Zaonezhsky Peninsula, within the area of the Onega Ice Lake. In the recovered sediment sequences from studied lakes, two sediment units from top to down have been recognized: Holocene gyttja from small isolated lakes and Late Pleistocene sediments from the Onega Ice Lake, which are represented by varved clays and silts. Based on lithological data, a “pink horizon” of varved clays was identified. It is similar to one which found in the sediment section of the Unitskaya Bay in Lake Onega. The absolute hypsometric position of this “pink horizon” was determined based on the elevation levels of the lakes under study.
10
Woszczyk, Michał, Wojciech Tylmann, Jan Jędrasik, Tomasz Szarafin, Alfred Stach, Joanna Skrzypczak, and Monika Lutyńska. "Recent sedimentation dynamics in a shallow coastal lake (Lake Sarbsko, northern Poland): driving factors, processes and effects." Marine and Freshwater Research 65, no. 12 (2014): 1102. http://dx.doi.org/10.1071/mf13336.
Full textAbstract:
Despite the fact that sediment dynamics in shallow coastal lakes strongly influences lake water quality and is crucial for preserving good quality paleo-records from coastal zones, the depositional processes in coastal lakes have not been thoroughly recognised so far. The present study aims at investigating the relationship between lake water circulation and the distribution of surface sediments, identifying the postdepositional physical mechanisms affecting lake deposits, and estimating the intensity of sediment mixing in a coastal lake on the Baltic coast. Our approach includes analyses of sediment grain size and chemical composition, hydrodynamic modelling and measurements of 210Pb activity in sediment short-cores from various sections of the lake. We showed that the distribution of lithofacies in the lake is explained by hydrodynamic conditions. Enhanced water dynamics reduces spatial extent of organic-rich lacustrine deposits and results in the exposure of relic marine-lagoonal sediments. A major part of the lake sediments is prone to vertical mixing by wind waves to a depth of ≥ 40 cm. Hydrodynamic modelling and 210Pb displayed overall agreement in predicting the depth of sediment mixing. At the same time the limitations of 210Pb as a geochronologic marker in shallow coastal lakes are revealed. It appears that even exponential depth-wise 210Pb distributions may be produced by storm redeposition.
11
Tretjakova, Rasma, and Andris Karpovičs. "MINERAL COMPOSITION OF SOME LATGALE LAKE SEDIMENTS." ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 20, 2019): 304. http://dx.doi.org/10.17770/etr2019vol1.4146.
Full textAbstract:
Our research is focused on sedimentological conditions and postdepositional changes of recent fine grained lake sediments. We used bulk sediment mineralogical composition and grain size distribution as indicators to identify sediment source areas and possible changes during Holocene. We analysed fine grained (clayey) sediments from three Latgale lakes - Zeili, Pauguļi and Plusons, situated in Latgale upland. Lake sediments cover Late Pleistocene glacial deposits – loam and sandy loam. Bulk mineral composition of 6 sediment samples was determined by X-ray diffraction (XRD). Sediments contained typical minerals found in surrounding glacial sediments: rock-forming minerals as quartz, plagioclase, albite, enstatite, dolomite, calcite, and clay minerals - illite, kaolinite. To identify postdepositional changes in lake sediments of Holocene age clay minerals in clay fraction (<2 mkm) should be analysed. Particularly illite, smectite mixed layered minerals - illite/smectite (I/Sm) and chlorite. Additionally, grain size distribution of studied lake sediments was analysed. Accordingly, our studied sediments are clays, silty clays and clayey silts with bimodal particle distribution, except two samples from Zeiļi and Plusons with unimodal distribution.
12
Nzekwe, Obinna P., Pierre Francus, Guillaume St-Onge, Patrick Lajeunesse, David Fortin, Antoine Gagnon-Poiré, Édouard G. H. Philippe, and Alexandre Normandeau. "Recent sedimentation in three adjacent fjord-lakes on the Québec North Shore (eastern Canada): facies analysis, laminae preservation, and potential for varve formation." Canadian Journal of Earth Sciences 55, no. 2 (February 2018): 138–53. http://dx.doi.org/10.1139/cjes-2017-0070.
Full textAbstract:
This paper analyzes short gravity cores sampled along transects in three adjacent deep fjord-lakes (lakes Pentecôte, Walker, and Pasteur) on the Québec North Shore, eastern Canada, to evaluate the distribution of laminated sediments and potential for varve formation. Facies analysis based on lithological description, digital photos, CT-scan images, and bathymetric data allowed for the identification of four main sediment facies, namely laminated sediments, partially laminated sediments, bioturbated sediments, and massive sediments. Direct evidence that Lake Walker undergoes thermal stratification was monitored from 2014 to 2016. Mean sedimentation rates and sedimentation fluxes of postglacial sediments in the distal basin of the three studied lakes are ≤0.12 cm a−1 and 0.03–0.16 g cm−2 a−1, respectively, based on 210Pb, 137Cs, and AMS radiocarbon dating. On the basis of thin section image analysis and 210Pb (CIC) chronology model, Lake Pentecôte contains mainly massive, partially laminated sediments, while Lake Pasteur contains partially laminated sediments and non-annual varve-like sediments. However, Lake Walker contains laminated sediments that are likely varves. The increased potential for laminae preservation observed in Lake Walker compared to lakes Pentecôte and Pasteur is associated with more favourable morphological characteristics including higher relative depth, mean depth, maximum depth, and topographic exposure.
13
Tylmann, Wojciech, Paulina Głowacka, and Agnieszka Szczerba. "Tracking climate signals in varved lake sediments: research strategy and key sites for comprehensive process studies in the Masurian Lakeland." Limnological Review 17, no. 3 (September 1, 2017): 159–66. http://dx.doi.org/10.1515/limre-2017-0015.
Full textAbstract:
AbstractLake sediments are excellent archives of environmental and climate change. Especially important are varved sediments which can provide high-resolution (annual) records of those changes. Process studies including limnological measurements, particle flux monitoring and analyses of sediment structures give an opportunity to explain relationships between meteorological conditions, in-lake processes and varve formation. In our study, three lakes were selected in the Masurian Lakeland: Lake Żabińskie, Łazduny and Rzęśniki. These relatively small and deep lakes contain well preserved biogenic varves. The lakes are influenced by the same meteorological conditions but differ in terms of their catchment size, land use, hydrology, lake basin morphology and trophic status. To explore the relationships between different parameters and preservation/transformation of climate signals in the sediments we started systematic limnological measurements in the water column of these lakes, water sampling for hydrochemical analyses, monitoring of modern sedimentation using sediment traps and analysis of topmost varves from short sediment cores. With this comprehensive and high-resolution monitoring program scheduled for at least four years we are going to verify the potential of varves to track short-term meteorological phenomena in lake sediments.
14
Zhao, Chun, Fuyuan Ran, Sihong Liu, Liujiang Wang, and Chunzhen Fan. "Distribution Characteristics and Driving Mechanisms of Organic Matter in Sediment of Lakes in China: A Review." Water 17, no. 9 (April 26, 2025): 1294. https://doi.org/10.3390/w17091294.
Full textAbstract:
Sediment is a core part of lake ecosystems, and its organic matter (OM) content is a key indicator of lake ecological health and regional carbon cycling. OM provides nutrients for phytoplankton and algae in water, thereby influencing the degree of lake eutrophication. However, excessively high OM content may trigger water eutrophication, alter sediment’s physical and chemical properties, and ultimately threaten the stability and health of ecosystems. This study innovatively selected Poyang Lake, Taihu Lake, Qinghai Lake, and Hulun Lake from China’s four major geographical regions to systematically investigate sediments’ OM content, sources, and distribution characteristics at different times. The results showed that the organic matter content of sediments in lakes from different regions varied significantly and was influenced by multiple factors, such as watershed characteristics, eutrophication levels, human activities, and climate change. Poyang Lake and Taihu Lake, characterized by high levels of agricultural activities and urbanization within their basins, exhibit significant fluctuations in organic matter content, with total organic carbon (TOC) levels ranging from 0.35% to 2.9% and 0.7% to 2.4%, respectively. In contrast, Qinghai Lake and Hulun Lake, influenced by natural conditions and ecological policies, show relatively stable TOC levels, ranging from 1.3% to 2.75% and 1.25% to 3.58%, respectively. By analyzing sediments’ OM content and combining methods such as organic carbon, nitrogen isotopes, and organic C/N ratios, it is possible to effectively assess the ecological health of lakes, provide critical data support for pollution control, and play a significant role in carbon cycle management.
15
Young, Thomas C., Joseph V. DePinto, James R. Rhea, and Richard D. Scheffe. "Calcite Dose Selection, Treatment Efficiency, and Residual Calcite Fate after Whole-Lake Neutralization." Canadian Journal of Fisheries and Aquatic Sciences 46, no. 2 (February 1, 1989): 315–22. http://dx.doi.org/10.1139/f89-042.
Full textAbstract:
A modeling approach guided whole-lake neutralization treatments of two acidic Adirondack lakes and aided examination of treatment efficiency as measured by initial water column dissolution and calcite delivery to sediments, prediction of posttreatment water chemistry, and assessment of the fate of calcite deposited on sediments. The lake model incorporated both dissolution and sedimentation of calcite in a vertically segmented lake assumed to behave as a closed system. Observed short-term calcite dissolution exceeded predictions (75 versus 45%) because (1) dispersion and thermocline presence slowed calcite particle settling; and, (2) CO2 influx altered the chemical environment of the particles. Prior to calcite treatment, the two lakes had sediments with similar base neutralizing capacities (BNC). Quantitatively, minor sediment neutralization resulted from the treatment; however, sediment pH gradients changed from positive to negative downward, and Caτ in surficial sediments increased as sediment BNC decreased. During the subsequent 16 mo of reacidification, sediment chemical characteristics partially returned to pretreatment conditions by contributing alkalinity to the overlying water.
16
Vyse, Stuart A., Ulrike Herzschuh, Gregor Pfalz, Lyudmila A. Pestryakova, Bernhard Diekmann, Norbert Nowaczyk, and Boris K. Biskaborn. "Sediment and carbon accumulation in a glacial lake in Chukotka (Arctic Siberia) during the Late Pleistocene and Holocene: combining hydroacoustic profiling and down-core analyses." Biogeosciences 18, no. 16 (August 24, 2021): 4791–816. http://dx.doi.org/10.5194/bg-18-4791-2021.
Full textAbstract:
Abstract. Lakes act as important sinks for inorganic and organic sediment components. However, investigations of sedimentary carbon budgets within glacial lakes are currently absent from Arctic Siberia. The aim of this paper is to provide the first reconstruction of accumulation rates, sediment and carbon budgets from a lacustrine sediment core from Lake Rauchuagytgyn, Chukotka (Arctic Siberia). We combined multiple sediment biogeochemical and sedimentological parameters from a radiocarbon-dated 6.5 m sediment core with lake basin hydroacoustic data to derive sediment stratigraphy, sediment volumes and infill budgets. Our results distinguished three principal sediment and carbon accumulation regimes that could be identified across all measured environmental proxies including early Marine Isotope Stage 2 (MIS2) (ca. 29–23.4 ka cal BP), mid-MIS2–early MIS1 (ca. 23.4–11.69 ka cal BP) and the Holocene (ca. 11.69–present). Estimated organic carbon accumulation rates (OCARs) were higher within Holocene sediments (average 3.53 g OC m−2 a−1) than Pleistocene sediments (average 1.08 g OC m−2 a−1) and are similar to those calculated for boreal lakes from Quebec and Finland and Lake Baikal but significantly lower than Siberian thermokarst lakes and Alberta glacial lakes. Using a bootstrapping approach, we estimated the total organic carbon pool to be 0.26 ± 0.02 Mt and a total sediment pool of 25.7 ± 1.71 Mt within a hydroacoustically derived sediment volume of ca. 32 990 557 m3. The total organic carbon pool is substantially smaller than Alaskan yedoma, thermokarst lake sediments and Alberta glacial lakes but shares similarities with Finnish boreal lakes. Temporal variability in sediment and carbon accumulation dynamics at Lake Rauchuagytgyn is controlled predominantly by palaeoclimate variation that regulates lake ice-cover dynamics and catchment glacial, fluvial and permafrost processes through time. These processes, in turn, affect catchment and within-lake primary productivity as well as catchment soil development. Spatial differences compared to other lake systems at a trans-regional scale likely relate to the high-latitude, mountainous location of Lake Rauchuagytgyn.
17
Myasnikova, Nadezda A., Alexander V. Orlov, Maxim S. Potakhin, and Dmitry A. Subetto. "GRAIN SIZE DISTRIBUTION OF BOTTOM SEDIMENTS IN SMALL LAKES OF THE SHOKSHA RIDGE, KARELIA, AS A PROXY FOR PALEO-HYDRODYNAMIC SEDIMENTATION ENVIRONMENTS." Географический вестник = Geographical bulletin, no. 2 (2024): 6–23. http://dx.doi.org/10.17072/2079-7877-2024-2-6-23.
Full textAbstract:
The paper examines the grain size distribution of bottom sediments of lakes in the Shoksha Ridge area, Karelia, to elucidate howdeglaciation and formation of the Onego Ice Lake basin proceeded. A sequence of bottom sediments of Lake Anashkino and two sediment sequences of Lake Rzhanoe were studied, and lithostratigraphy of the sediment cores was described. The grain size compositions of the 9.32-10.32m sequence from Lake Anashkino and the 2.5-6.52 m sequence from Lake Rzhanoye were analyzed. The study revealed features of the bottomsediment fractions distribution along the depth of occurrence. Paleo-hydrodynamic sedimentation environments were identified using grain sizeanalysis. Lake Anashkino bottom sediments of a 9.96–10.31 m horizon, represented by silt and fine-grained sand, were deposited under conditions of highly dynamic shallowing (decrease in the water level of Onego Ice Lake). The upper part of sediments (9.32–9.92 m), represented by clayey silt mixed with fine-grained sand, accumulated under weak flow conditions. Paleo-hydrodynamic sedimentationenvironments in Lake Rzhanoye were characterized by alternation of highflow conditions (5.36-6.23 m, 6.31-6.32 m, 6.47-6.48 m) and weak flowconditions (2.50-4.88 m, 6.28-6.29 m, 6.30-6.31 m, 6.37-6.45 m, 6.51-6.52 m). This is possibly due to the dynamics of the decrease in the waterlevel of Onego Ice Lake and the formation of small isolated lakes.In the process of the formation of bottom sediments of small lakes of the Shoksha Ridge during the period of intensive changes in thelandscapes, outlines and levels of Onego Ice Lake at the transition from the late Pleistocene to Holocene, against a shift from nival to humid climate,we note a change in sedimentation conditionsin the bottom sediments of the two studied lakes – Anashkino and Rzhanoe – from highly dynamic(flowing conditions, decrease in water level of Onego Ice Lake) to weakly flowing, in the conditions of isolation of the lakes and formation ofmodern small lakes.
18
Kļaviņš, Māris, Ilga Kokorīte, Valērijs Rodinovs, and Maruta Jankevica. "Past human impact and pollutant loading reconstruction in Lake Engure as a tool for lake basin management." Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences. 68, no. 1-2 (April 1, 2014): 31–37. http://dx.doi.org/10.2478/prolas-2014-0003.
Full textAbstract:
Abstract Environmental pollution of lakes and rivers is considered as one of the most important environmental problems. Analysis of nutrient and trace element accumulation in sedimentary phases of lakes can reflect the overall regional pollution level, and the observed accumulation patterns of pollutants in sediment profiles can be used to reconstruct the history of anthropogenic impacts. As pollutants in sediments are associated with other substances, it is important not only to study total concentrations of pollutants, but also their speciation forms. The aim of this study was to describe phosphorus (including speciation forms) and trace element concentrations in sediment profiles of Lake Engure and to evaluate human impact on organic matter accumulation and properties in lake sediments. The concentrations of the studied elements in sediments of Lake Engure are at background levels, which is clearly evident when compared with metal concentrations in lake sediments in West European countries. The analysis of element concentration changes in sedimentary profiles provided information about trends in recent accumulation (within the last 100 years) and on the balance between natural and human-induced accumulation processes. Analysis of nutrient concentrations in sediments aided in identifying background values as targets for lake management activities.
19
Moreton, Steven G., Gunhild C. Rosqvist, Sarah J. Davies, and Michael J. Bentley. "Radiocarbon Reservoir Ages from Freshwater Lakes, South Georgia, Sub-Antarctic: Modern Analogues from Particulate Organic Matter and Surface Sediments." Radiocarbon 46, no. 2 (2004): 621–26. http://dx.doi.org/10.1017/s0033822200035669.
Full textAbstract:
Lake sediments have the potential to preserve proxy records of past climate change. Organic material suitable for radiocarbon dating often provides age control of such proxy records. Six shallow freshwater lakes on the sub-Antarctic island of South Georgia were investigated for carbon reservoir effects that may influence age-depth profiles from lake sediment records in this important region. Paired samples of particulate organic matter (POM) from the water column and surface sediment (bulk organic carbon) were analyzed by accelerator mass spectrometry 14C. POM in 4 lakes was found to be in equilibrium with the atmosphere (~107% modern), whereas 2 lakes showed significant depletion of 14C. In each lake, the surface sediment ages were older than the paired POM age. Surface sediment ages showed a much greater range of ages compared to the equivalent POM ages, even for lakes located in close proximity. We conclude that sediment disturbance during coring, bioturbation, and periodic resuspension of sediments are likely factors causing the difference in the apparent age of surface sediments.
20
Tu, Luyao, Paul Zander, Sönke Szidat, Ronald Lloren, and Martin Grosjean. "The influences of historic lake trophy and mixing regime changes on long-term phosphorus fraction retention in sediments of deep eutrophic lakes: a case study from Lake Burgäschi, Switzerland." Biogeosciences 17, no. 10 (May 20, 2020): 2715–29. http://dx.doi.org/10.5194/bg-17-2715-2020.
Full textAbstract:
Abstract. Hypolimnetic anoxia in eutrophic lakes can delay lake recovery to lower trophic states via the release of sediment phosphorus (P) to surface waters on short timescales in shallow lakes. However, the long-term effects of hypolimnetic redox conditions and trophic state on sedimentary P fraction retention in deep lakes are not clear yet. Hypolimnetic withdrawal of P-rich water is predicted to diminish sedimentary P and seasonal P recycling from the lake hypolimnion. Nevertheless, there is a lack of evidence from well-dated sediment cores, in particular from deep lakes, about the long-term impact of hypolimnetic withdrawal on sedimentary P retention. In this study, long-term sedimentary P fraction data since the early 1900s from Lake Burgäschi provide information on benthic P retention under the influence of increasing lake primary productivity (sedimentary green-pigment proxy), variable hypolimnion oxygenation regimes (Fe∕Mn ratio proxy), and hypolimnetic withdrawal since 1977. Results show that before hypolimnetic withdrawal (during the early 1900s to 1977), the redox-sensitive Fe∕Mn-P fraction comprised ∼50 % of total P (TP) in the sediment profile. Meanwhile, long-term retention of total P and labile P fractions in sediments was predominantly affected by past hypolimnetic redox conditions, and P retention increased in sedimentary Fe- and Mn-enriched layers when the sediment-overlaying water was seasonally oxic. However, from 1977 to 2017, due to eutrophication-induced persistent anoxic conditions in the hypolimnion and to hypolimnetic water withdrawal increasing the P export out of the lake, net burial rates of total and labile P fractions decreased considerably in surface sediments. By contrast, refractory Ca–P fraction retention was primarily related to lake primary production. Due to lake restoration since 1977, the Ca–P fraction became the primary P fraction in sediments (representing ∼39 % of total P), indicating a lower P bioavailability of surface sediments. Our study implies that in seasonally stratified eutrophic deep lakes (like Lake Burgäschi), hypolimnetic withdrawal can effectively reduce P retention in sediments and potential for sediment P release (internal P loads). However, after more than 40 years of hypolimnetic syphoning, the lake trophic state has not improved nor has lake productivity decreased. Furthermore, this restoration has not enhanced water column mixing and oxygenation in hypolimnetic waters. The findings of this study are relevant regarding the management of deep eutrophic lakes with mixing regimes typical for temperate zones.
21
Leidonald, R., Z. A. Harahap, and A. Muhtadi. "The distribution of Siombak lake sediments, a tropical tidal lake in Indonesia." IOP Conference Series: Earth and Environmental Science 977, no. 1 (June 1, 2022): 012117. http://dx.doi.org/10.1088/1755-1315/977/1/012117.
Full textAbstract:
Abstract Siombak Lake is one of Indonesia’s tropical tidal lakes located in Medan City, North Sumatra Province. This lake is very dynamic because the lake water level is fluctuating according to the Belawan waters’ tidal (Malacca Strait). This study aims to determine the distribution of sediments in Siombak Lake. The research was conducted from December 2018 - August 2019. The observation locations were taken at 8 points representing all depth layers. The technique used was the filtering analysis using the wet sieve method with stratified sediment filters in different diameters (4.75 mm, 1.7 mm, 250 μm, 850 μm, 150 μm). The data analyzed were weight percentage, texture type, C-organic, the content of nitrogen and phosphorus. The results of the analysis of sediment samples show that there are 3 sediment textures, namely loam, silt loam, and sandy loam. The C- Organic content in the sediments of Siombak Lake ranges from 1.73 - 5.10% at high tide and 1.91-4.40% at low tide. Nitrogen levels in the sediments range from 0.15 - 2.40% at high tide and 0.14-2.35% at low tide. Meanwhile, phosphorus levels in the sediments range between 5.95 - 19.86 ppm at high tide and 1.27-16.35 ppm at low tide.
22
Yang, Yuyin, Ningning Li, Wei Wang, Bingxin Li, Shuguang Xie, and Yong Liu. "Vertical profiles of sediment methanogenic potential and communities in two plateau freshwater lakes." Biogeosciences 14, no. 2 (January 24, 2017): 341–51. http://dx.doi.org/10.5194/bg-14-341-2017.
Full textAbstract:
Abstract. Microbial methanogenesis in sediment plays a crucial role in CH4 emission from freshwater lake ecosystems. However, knowledge of the layer-depth-related changes of methanogen community structure and activities in freshwater lake sediment is still limited. The present study was conducted to characterize the methanogenesis potential in different sediment-layer depths and the vertical distribution of microbial communities in two freshwater lakes of different trophic status on the Yunnan Plateau (China). Incubation experiments and inhibitor studies were carried out to determine the methanogenesis potential and pathways. 16S rRNA and mcrA genes were used to investigate the abundance and structure of methanogen and archaeal communities, respectively. Hydrogenotrophic methanogenesis was mainly responsible for methane production in sediments of both freshwater lakes. The layer-depth-related changes of methanogenesis potential and the abundance and community structure of methanogens were observed in both Dianchi Lake and Erhai Lake. Archaeal 16S rRNA and mcrA genes displayed a similar abundance change pattern in both lakes, and the relative abundance of methanogens decreased with increasing sediment-layer depth. Archaeal communities differed considerably in Dianchi Lake and Erhai Lake, but methanogen communities showed a slight difference between these two lakes. However, methanogen communities illustrated a remarkable layer-depth-related change. Order Methanomicrobiales was the dominant methanogen group in all sediments, while Methanobacteriales showed a high proportion only in upper layer sediments. The trophic status of the lake might have a notable influence on the depth-related change pattern of methanogenesis activity, while the methanogen community structure was mainly influenced by sediment depth.
23
Amano, Koji, and Takehiko Fukushima. "On the Longitudinal and Vertical Changes in Lake Estuarine Sediments." Water Science and Technology 20, no. 6-7 (June 1, 1988): 143–53. http://dx.doi.org/10.2166/wst.1988.0198.
Full textAbstract:
In order to obtain environmental information about lake water and watersheds, the vertical and longitudinal distributions of physical and chemical properties in lake sediments were investigated. The concentrations of several substances (e.g., nutrients, metals, and chemicals) in the sediments were determined at fifty sampling sites in sixteen shallow lakes in Japan. The vertical profiles of particle size, particle organic carbon, particle organic nitrogen, total phosphorus, some metals (Ti, Mn, Fe, Zn, and Cu), and LAS were analysed. Various sediment properties, such as the sedimentation conditions and the redox conditions, were related to the vertical profiles observed, and traces of historical changes in the water and watersheds were found in the sediments. Longitudinal changes in the sediments between the mouths of the rivers and the deepest points of the lakes were clearly observed, and it was expected that these changes would correlate with one of the estuarine characteristics since they reflect the spatial variation in average composition of the particulate matter and in the average water quality. Some significant relationships between the lake sediments and the lake or watershed type were observed, indicating the possibility that lake sediments may be one of the most important indices for understanding lake environments.
24
Huang, Wei, Xing Chen, Kun Wang, and Xia Jiang. "Seasonal characteristics of phosphorus sorption by sediments from plain lakes with different trophic statuses." Royal Society Open Science 5, no. 8 (August 2018): 172237. http://dx.doi.org/10.1098/rsos.172237.
Full textAbstract:
Phosphorus (P) sorption in sediments plays a significant role in trophic status of a lake. This study investigated the characteristics of P sorption in sediments from three lakes with different trophic statuses (moderately eutrophic, lightly eutrophic and moderately trophic) through kinetic, batch equilibrium and thermodynamic experiments. Results show that pseudo-second-order kinetics best describe P sorption in sediments from the three lakes. Fitting by modified Langmuir and Freundlich isotherms indicates that the moderately trophic lake sediment has higher sorption capacity (maximum of 0.848 mg g −1 at 35°C) than the sediments of the other two lakes at different temperatures (5, 15, 25 and 35°C). Thermodynamic results indicate that the processes of P sorption of the three sediments are spontaneous, entropy-driven and endothermic reactions. The risk of P release in sediments was analysed according to the calculated results of isotherms combined with the change in P fraction. Sediments from the moderately eutrophic lake act as a source in summer. The lightly eutrophic and moderately trophic lakes act as sources in spring and winter, and a pool in summer and autumn, respectively. Furthermore, the amounts of reductant-soluble P, calcium-bound P and iron-bound P are significantly related to the sorption capacity of sediments from the three lakes ( p < 0.05). The different sediments have different P release risk, and P fraction in sediment is one of the significant factors of P sorption.
25
Jiao, Li Ping, Xia Sun, and Yang Luo. "Chinese Arctic Yellow River Station Research Monitoring Program. 1. Polycyclic Aromatic Hydrocarbons in Sediment from Svalbard." Applied Mechanics and Materials 522-524 (February 2014): 25–33. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.25.
Full textAbstract:
Surface sediments of the west coast of Svalbard near Ny-Ålesund Spitsbergen were collected. PAHs of lake sediments (mean: 260, range: 11 - 1100 ng/g dry wt) were higher than previously report of surface lake sediment in Svalbard 1995, suggesting significant PAH contamination is occurring due to long-term atmospheric transport and local coal mining and fossil fuel sources, pointing to the role of Arctic lakes as potential reservoirs of semi-volatile organic compounds, including PAHs. Compound-specific analysis revealed different PAH patterns between Svalbard lakes and European high mountain lakes, showing higher proportions of low molecular weight compounds and lower levels of high molecular weight PAHs in Svalbard lakes. PAH indicator ratios suggest that the majority of PAHs in lake sediments have pyrogenic origins (coal mining, fossil fuel and biomass combustion), while coastal marine sediments were mainly contaminated by petroleum-derived PAHs (shipping activities in coastal areas, and perhaps as a result of an oil spill in 1986). Sediment fluxes of PAHs were estimated to be 0.2 - 22 ng cm-2yr-1. The current PAH levels exceeded Canadian sediment quality guidelines, suggesting the presence of possible risks for aquatic organisms and the need for further studies.
26
Astles, Brittany C., John Chételat, Michael J. Palmer, and Jesse C. Vermaire. "Experimental investigation of short-term warming on arsenic flux from contaminated sediments of two well-oxygenated subarctic lakes." PLOS ONE 17, no. 12 (December 21, 2022): e0279412. http://dx.doi.org/10.1371/journal.pone.0279412.
Full textAbstract:
Legacy arsenic (As) contamination from past mining operations remains an environmental concern in lakes of the Yellowknife area (Northwest Territories, Canada) due to its post-depositional mobility in sediment and potential for continued remobilization to surface waters. Warmer temperatures associated with climate change in this subarctic region may impact As internal loading from lake sediments either by a direct effect on sediment porewater diffusion rate or indirect effects on microbial metabolism and sediment redox conditions. This study assessed the influence of warmer temperatures on As diffusion from contaminated sediment of two lakes with contrasting sediment characteristics using an experimental incubation approach. Sediments from Yellowknife Bay (on Great Slave Lake) contained predominately clay and silt with low organic matter (10%) and high As content (1675 μg/g) while sediments of Lower Martin Lake had high organic matter content (~70%) and approximately half the As (822 μg/g). Duplicate sediment batches from each lake were incubated in a temperature-controlled chamber, and overlying water was kept well-oxygenated while As flux from sediment was measured during four weekly temperature treatments (7°C to 21°C, at ~5°C intervals). During the experiment, As diffused from sediment to overlying water in all cores and temperature treatments, with As fluxes ranging from 48–956 μg/m2/day. Arsenic fluxes were greater from Yellowknife Bay sediments, which had higher solid-phase As concentrations, compared to those of Lower Martin Lake. Short-term warming did not stimulate As flux from duplicate cores of either sediment type, in contrast with reported temperature enhancement in other published studies. We conclude that warmer temperatures were insufficient to strongly enhance sediment As diffusion into overlying oxic waters. These observations are relevant for evaluating climate-warming effects on sediment As mobility in subarctic lakes with little or no thermal stratification and a well-oxygenated water column.
27
Harasimiuk, Andrzej, Bogumił Wicik, and Tomasz Grabowski. "The lake deposits in Płock Basin (case studies of Lakes Rakutowskie and Żłoby)." Limnological Review 10, no. 1 (January 1, 2010): 23–28. http://dx.doi.org/10.2478/v10194-011-0003-7.
Full textAbstract:
The lake deposits in Płock Basin (case studies of Lakes Rakutowskie and Żłoby)Reconstruction of development of Lakes Rakutowskie and Żłoby in the late Pleistocene and Holocene was the aim of this research. Analysis of content of calcium carbonate, organic matter and C14 datings (7 samples) were done for two cores of sediments of 750 cm long. An average rate of accumulation was counted. Sediments of Lake Rakutowskie show homogeneity along the core which indicates similarity of sedimentation conditions. Sediments of Lake Żłoby were diversified and show variety related to cyclic changes. A common feature is a thick layer of fine sand without carbonate deposited during the older dryas, shown in both cores. The difference in sediment features of both lakes (which have similar depths) indicates that the Lake Żłoby is the more dynamic, filtering element, preceding Lake Rakutowskie in system of water catchment.
28
Srdoč, Dušan, Bogomil Obelić, Nada Horvatinčić, Ines Krajcar-Bronić, Elena Marčenko, Joseph Merkt, How Kin Wong, and Adela Sliepčević. "Radiocarbon Dating of Lake Sediment from Two Karst Lakes in Yugoslavia." Radiocarbon 28, no. 2A (1986): 495–502. http://dx.doi.org/10.1017/s0033822200007633.
Full textAbstract:
Samples of sediment cores from two lakes in the karst area of northwest Yugoslavia were analyzed. Both Lakes Kozjak and Prošće are in the Plitvice National Park, Central Croatia. 14C dating, sedimentologic, seismic, and isotopic studies, and distribution of diatoms are presented.14C dating of lake marl revealed a uniforn sedimentation rate in Lake Prošće as opposed to Lake Kozjak. Both lake sediments belong to the Holocene period. 14C dating of lake sediment is in agreement with seismic profiles, sedimentologic analysis, and diatom frequency measurements both in an undisturbed as well as in a disturbed lake sediment.
29
Rowan, D. J., J. Kalff, and J. B. Rasmussen. "Profundal Sediment Organic Content and Physical Character Do Not Reflect Lake Trophic Status, but Rather Reflect Inorganic Sedimentation and Exposure." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 7 (July 1, 1992): 1431–38. http://dx.doi.org/10.1139/f92-158.
Full textAbstract:
An analysis of profundal sediment data from 83 north-temperate lakes shows that increasing inorganic sedimentation and exposure (or lake surface area) results in lower organic content and water content, and greater bulk density. Because sedimentation rates are unavailable for most lakes, we estimate sedimentation rates from readily available catchment sediment loads using a mass-balance model. The mass-balance estimate of sediment retention (per square metre of depositional zone) is an excellent predictor of measured inorganic sedimentation rates for a data set covering 19 lakes (R2 = 0.92). Multiple regressions are used to predict organic content, water content, and bulk density of profundal sediment from inorganic sedimentation rates and either exposure or lake surface area, which are surrogates for the energy of the depositional environment. These analyses explain 76, 74, and 66% of the between-lake variation in the three sediment parameters, respectively. Sediment organic content is not related to lake trophic status (chlorophyll a) and is negatively correlated with net organic matter sedimentation rates. The common occurrence of organic-rich sediments in oligotrophic shield lakes is, therefore, not a reflection of high organic matter inputs, but rather the extremely low inputs of mineral sediments to these lakes.
30
Potakhin, M. S., N. A. Belkina, and D. A. Subetto. "The Lake Onego watershed: morphology of lakes and classification of the bottom sediments." Limnology and Freshwater Biology, no. 4 (2022): 1526–28. http://dx.doi.org/10.31951/2658-3518-2022-a-4-1526.
Full textAbstract:
Abstract. The data on the lake morphometry and sediment lithostratigraphy of the Lake Onego watershed were collected. The classification of lakes was carried out according to the genetic features of relief. Four types of the lakes have been identified for the catchment area. The structural features of lake basins and bottom sediments were determined for each type of lakes.
31
Gonsiorczyk, Thomas, Peter Casper, and Rainer Koschel. "Phosphorus-binding forms in the sediment of an oligotrophic and an eutrophic hardwater lake of the Baltic Lake District (Germany)." Water Science and Technology 37, no. 3 (February 1, 1998): 51–58. http://dx.doi.org/10.2166/wst.1998.0173.
Full textAbstract:
The vertical distribution of various phosphorus (P)-binding forms, associated potential P-binding partners and the composition of dry material were investigated in the bottom sediments of the dimictic oligotrophic Lake Stechlin and the dimictic eutrophic Lake Feldberger Haussee. Reductant soluble P (Fe- and Mn-bound) at the sediment surface (0−1 cm) was considerably higher in the oligotrophic Lake Stechlin (1.29 g kg−1) than in the eutrophic Lake Haussee (0.32 g kg−1). The amounts of dissolved, loosely adsorbed, metal oxide- and calcium carbonate bound P were higher in the eutrophic lake. The depth profiles of the investigated P species indicated that the mobilization of Fe- and Mn-bound P is the most important mechanism of P-release in oligotrophic lakes, whereas the mobilization of recently sedimented labile organic bound P seems to be the driving force of P-release in eutrophic lakes. In both lakes autochthonous calcite precipitations occurs during the summer months. The coprecipitation of P with calcite is an important self-cleaning mechanism in eutrophic hardwater lakes and contributes to the permanent burial of P in the sediments. Although, the precipitation of calcite is inhibited by the presence of high concentrations of soluble reactive P, the coprecipitation of P with calcite seems to be enhanced.
32
Wang, W. W., X. Jiang, B. H. Zheng, J. Y. Chen, L. Zhao, B. Zhang, and S. H. Wang. "Composition, mineralization potential and release risk of nitrogen in the sediments of Keluke Lake, a Tibetan Plateau freshwater lake in China." Royal Society Open Science 5, no. 9 (September 2018): 180612. http://dx.doi.org/10.1098/rsos.180612.
Full textAbstract:
The lakes distributed in the Tibetan Plateau constitute a lake group with the highest altitude, largest lakes and largest area in the world and are important in global climate and environmental effects. Freshwater lakes in the Tibetan Plateau possess high ecological values and high vulnerability. The migration and transformation of nitrogen in sediments are critical to lake ecosystems, but information on sedimentary nitrogen in the freshwater lakes in the Tibetan Plateau is limited. A case study was conducted in Keluke Lake, China, to reveal the effects of sedimentary nitrogen on water quality in plateau freshwater lakes. Nitrogen speciation, mineralization potential and release flux were analysed through a sequential extraction method, waterlogged incubation experiment and Fick's first diffusion law, respectively. The content of total nitrogen (TN) was 1295.75–6151.69 mg kg −1 , and 94.2% of TN was organic nitrogen (ON). The contents of three nitrogen fractions were in the order of hydrolysable nitrogen > residual nitrogen > exchangeable nitrogen. Ammonia nitrogen ( N H 4 + − N ) was the main mineralization product, and hydrolysable ON was the most significant contributor. The sediments showed a great mineralization potential, with a potentially mineralizable nitrogen value of 408.76 mg N kg −1 of sediment, that was mainly affected by hydrolysable ammonium nitrogen. The N H 4 + − N diffusion flux ranged from 24.14 to 148.75 mg m −2 d −1 , and the sediments served as an internal nitrogen source. Nitrogen release from sediments was considerably influenced by exchangeable ammonia nitrogen. The sediments in Keluke Lake pose a potential nitrogen release risk and threaten the water quality of the lake. The total content, speciation, mineralization of ON and the release flux at sediment–water interface should be considered comprehensively to evaluate the effects of nitrogen in sediments to water quality.
33
Baranov, Viktor, Jörg Lewandowski, and Stefan Krause. "Bioturbation enhances the aerobic respiration of lake sediments in warming lakes." Biology Letters 12, no. 8 (August 2016): 20160448. http://dx.doi.org/10.1098/rsbl.2016.0448.
Full textAbstract:
While lakes occupy less than 2% of the total surface of the Earth, they play a substantial role in global biogeochemical cycles. For instance, shallow lakes are important sites of carbon metabolism. Aerobic respiration is one of the important drivers of the carbon metabolism in lakes. In this context, bioturbation impacts of benthic animals (biological reworking of sediment matrix and ventilation of the sediment) on sediment aerobic respiration have previously been underestimated. Biological activity is likely to change over the course of a year due to seasonal changes of water temperatures. This study uses microcosm experiments to investigate how the impact of bioturbation (by Diptera, Chironomidae larvae) on lake sediment respiration changes when temperatures increase. While at 5°C, respiration in sediments with and without chironomids did not differ, at 30°C sediment respiration in microcosms with 2000 chironomids per m 2 was 4.9 times higher than in uninhabited sediments. Our results indicate that lake water temperature increases could significantly enhance lake sediment respiration, which allows us to better understand seasonal changes in lake respiration and carbon metabolism as well as the potential impacts of global warming.
34
Rao, S. S., M. D. Dickman, and H. G. Thode. "Isotopic and Diatom Evidence of Bacterial Sulphate Reduction in Sediments." Water Quality Research Journal 24, no. 2 (May 1, 1989): 215–32. http://dx.doi.org/10.2166/wqrj.1989.013.
Full textAbstract:
Abstract Sulphur contents and sulphur isotope ratios (δ34 So/00 values) in deep sediments (10–12 cms; circa 50–100 years before the present) and surface sediments (0–2 cm; circa 0–10 years before the present) from eight lakes located north of Lake Superior, Canada indicated that surface sediments had a significantly higher sulphur content (largely organic sulphur) per gram dry weight and a lower sulphur isotope ratio than the deeper layers. The increased sulphur content and decreased sulphur isotope ratios (δ34 S0/00 values) in the surficial sediments were much greater for the lakes near and downwind from the Wawa sintering plant than for more remote lakes reflecting the impact of the sintering plant emissions on the lake environment. A significant relationship was observed between the sulphate reducing bacterial populations and the magnitude of the isotope shift in the study lakes. It was evident from the data that the greater the abundance of sulphate reducers the greater was the surface sediment sulphate content and the degree of isotope fractionation in the anaerobic and organic rich sediments. The surface sediments of the eight study lakes revealed isotopic evidence of bacterial sulphate reduction. The deeper sediments, however, did not reveal such a condition due to the absence of sulphate reducers. The rate of lake acidification as inferred from the downcore diatom inferred pH profile for each of the study lakes was not significantly correlated with the amount of sulphur in the lake sediments, nor was it correlated with the density of sulphate reducing bacteria or shifts in the sulphur isotope ratios (δ34S).
35
Pazdur, Anna, M. F. Pazdur, Tomasz Goslar, Bogumił Wicik, and Maurice Arnold. "Radiocarbon Chronology of Late Glacial and Holocene Sedimentation and Water-Level Changes in the Area of the Gościąż Lake Basin." Radiocarbon 36, no. 2 (1994): 187–202. http://dx.doi.org/10.1017/s0033822200040492.
Full textAbstract:
We obtained 14C ages on samples of lake marl and other sediments from cores taken in Gościąż Lake and its environs. Comparison of 14C dates of bulk samples of laminated sediment with varve chronology and available AMS dates of terrestrial macrofossils indicates a reservoir correction of 2000 ± 120 yr for the basal series of lake sediments. 14C dates obtained on peat layers underlying the oldest lacustrine sediments in Gościąż and other lakes consistently locate the beginning of organogenic sedimentation in this area at ca. 13 ka bp. We distinguished three periods of lacustrine gyttja sedimentation in cores taken in Gościąż and adjacent lakes: 11.8–10.2 ka, 8–7 ka and 2.7–2.1 ka bp. From the 14C dates of lithological boundaries in these cores, we reconstruct a pattern of lake-level changes during the last 12 ka, remarkably similar to Swedish lakes and generally agreeing with available records from European and American lakes. The behavior of Gościąż Lake during the last 12 ka fairly well reflects global climate changes in the temperate zone during the Late Glacial and Holocene periods.
36
Belzile, Nelson, Helen A. Joly, and Hongbo Li. "Characterization of humic substances extracted from Canadian lake sediments." Canadian Journal of Chemistry 75, no. 1 (January 1, 1997): 14–27. http://dx.doi.org/10.1139/v97-003.
Full textAbstract:
Humic substances (HS) were extracted from the sediments of four Sudbury area lakes, namely, Tilton, Clearwater, Silver, and Ramsey Lakes, with the aid of 0.1 M Na4P2O7 and 0.5 M NaOH solutions. The HS (humic and fulvic acids) were purified and characterized using the methods of elemental analysis, visible spectroscopy (E4/E6 ratio), FTIR, and solid-state 13C CPMAS NMR. A substantial amount of information with regard to the composition and chemical nature of lake sediment HS was obtained. The results obtained for the Sudbury area lake sediments were compared with one another and with HS from other sources, such as soils. The elemental composition, atomic ratios, E4/E6 ratios, and FTIR and NMR features of the samples from the above lakes were found to be nearly identical, suggesting that HS formed in the Sudbury area have similar chemical properties. Compared with soil HS, the Sudbury lake sediments HS have undergone a low degree of aromatic condensation and are considerably more aliphatic in nature. Keywords: humic substances, characterization, lake sediments, extraction, 13C NMR.
37
Shin, I. Chan, Tetsuji Akatsuka, Hisayuki Azumi, Lan Ao, Nozomi Amahashi, Maki Oyagi, Noriko Ishida, et al. "Grain size distribution and chemistry of the brackish Lake sediment in Korea." Environmental Engineering Research 26, no. 5 (October 5, 2020): 200365–0. http://dx.doi.org/10.4491/eer.2020.365.
Full textAbstract:
To determine the grain size distribution and chemical characteristics of bottom surface sediments in shallow brackish lagoons, we studied sediment samples collected from the entire horizontal lake area and in vertical profiles from three stations in Lakes Youngrang and Hwajinpo, on the eastern coast of Korea. Vertical and horizontal grain size distributions of the bottom sediments indicated predominantly sand- and silt in both lakes. The vertical distribution of C/N ratios ranged from 6.14 to 11.92 in Lake Youngrang, and 6.74 to 12.34 in Lake Hwajinpo. The horizontal distribution of C/N ratios in Lake Youngrang ranged from 6.1 to 17.6, whereas they ranged from 4.4 to 12.1 in Lake Hwajinpo. C/N ratios showed locally different responses to the origin of allochthonous (partial region) and autochthonous (entire region) organic materials. Horizontally, bottom sediment with low δ<sup>13</sup>C and high δ<sup>15</sup>N in Lake Youngrang were likely to be influenced by autochthonous organic material derived from primary production, and would be affected by N inputs from sources. In contrast, high δ<sup>13</sup>C and low δ<sup>15</sup>N sediments in Lake Hwajinpo were likely to be influenced by cyanobacteria.
38
Rada, Ronald G., David E. Powell, and James G. Wiener. "Whole-Lake Burdens and Spatial Distribution of Mercury in Surficial Sediments in Wisconsin Seepage Lakes." Canadian Journal of Fisheries and Aquatic Sciences 50, no. 4 (April 1, 1993): 865–73. http://dx.doi.org/10.1139/f93-099.
Full textAbstract:
We quantified total mercury in surficial sediments (uppermost 5 cm) of six small seepage lakes. Fifty cores were taken from each lake, based on a random sampling design stratified by water depth. Volumetric concentrations (mass per volume of wet sediment) more accurately portrayed the depth distribution of mercury in the lakes than did dry-weight concentrations, which underrepresented the significance of the shallow-water sediments as a reservoir of potentially available mercury. Estimates of whole-lake burdens (masses) of mercury in the surficial sediment, which represent the maximum amount of sedimentary mercury available for methylation, ranged from 45 to 149 g. These sedimentary pools of mercury greatly exceeded the inventories of the metal in water, seston, and fish, and the release of mercury from the sediments could significantly increase its bioaccumulation. Areal burdens of mercury (mass per unit of lake area) varied fivefold among lakes (1.65–7.84 g/ha) and were strongly correlated with lake pH, but were not correlated with dissolved organic carbon, conductance, or chlorophyll a of lakes. We hypothesize that the observed variation in areal burdens of mercury was partly due to variation among lakes in the pH-related efflux of gaseous mercury (Hg0) from the lakes to the atmosphere.
39
Wu, Dun, Hai Liu, Jian Wu, and Xia Gao. "Spatial Distribution, Ecological Risk Assessment and Source Analysis of Heavy Metals Pollution in Urban Lake Sediments of Huaihe River Basin." International Journal of Environmental Research and Public Health 19, no. 22 (November 8, 2022): 14653. http://dx.doi.org/10.3390/ijerph192214653.
Full textAbstract:
Heavy metals in freshwater lake sediments often exist in various chemical forms. However, the investigation and evaluation of heavy-metal elements in the sediments of the study area have not been reported, and there is a lack of objective understanding of the concentration level of heavy-metal elements. Therefore, this study is the first to report the concentrations, sources, and potential ecological risks of heavy metals in the sediments of Chengdong Lake and Chengxi Lake in Huoqiu County, Anhui Province, China. The spatial distribution, pollution characteristics, potential pollution sources, and ecological risks of heavy metals in the sediments of Chengxi Lake and Chengdong Lake of Huoqiu City in the middle section of Huaihe River in Anhui Province, China have not been reported. In this study, the sediment samples of the two Lakes were collected systematically, and the concentrations of heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) were determined. The potential sources of heavy-metal elements in sediments were quantitatively analyzed according to the principal component analysis–absolute principal component fraction–multiple linear regression (PCA–APCS–MLR) receptor model. Descriptive statistics data showed that the enrichment degree of heavy metals in Chengxi Lake was higher than that in Chengdong Lake. The geo-accumulation index (Igeo) and pollution load index (PLI) indicated that there was moderate pollution for Cu, As, Hg, Ni, and Zn. The calculation results of the potential ecological risk index (Er) of the two lakes indicated that Cd (Er,max = 92.22, n = 60) and Hg (Er,max = 64.39, n = 60) showed a certain potential ecological risk in a small amount of sediment, while other heavy metals were classified as low risk. The mean sediment quality guideline quotient indicated that there was a moderate degree of potential adverse biological toxicity in lake sediments. Spatially, the seriously polluted contamination zones were the central position of Chengxi Lake and the northeast end of Chengdong Lake. The PCA–APCS–MLR receptor model revealed that Cr, Ni, Cu, and Zn were mainly from natural sources while Cd, As, Hg, and Pb elements were mainly from industrial sources and pesticide sources.
40
Vincent, S. G. T., J. H. Salahudeen, P. S. Godson, S. R. Abhijith, A. V. Nath, K. A. Krishnan, N. S. Magesh, S. K. Kumar, and S. A. Moses. "Environmental factors influencing methanogenic activity in two contrasting tropical lake sediments." Journal of Environmental Biology 42, no. 2 (March 1, 2021): 211–19. http://dx.doi.org/10.22438/jeb/42/2/mrn-1413.
Full textAbstract:
Aim: To investigate the influence of environmental variables on the abundance and activity of methanogenic archaea (MA) in Akkulam-Veli and Vellayani Lake sediments. Methodology: Sediment and overlying water samples (n=5 each) were collected from Veli and Vellayani lakes of Thiruvananthapuram, Kerala. Samples were analysed for environmental variables using standard protocols. Multivariate analysis was done to study the influence of environmental variables on abundance and activity of MA. Results: Environmental variables of overlying water and sediment showed significant variation between the two lakes. Salinity and sulphate were more in Akkulam-Veli than Vellayani, as Akkulam-Veli is a brackish lake and temporarily connected with Arabian Sea. Highly reduced sediments of Akkulam-Veli favoured more population of methylotrophic and acetoclastic MA than Vellayani. A distributional difference of MA with depth was observed in both lakes, which is attributed to availability of more labile organic matter. The methylotrophic MA activity was not significantly different between the two lakes; however, their abundance was significantly different. Nevertheless, methane production was higher in Vellayani than in Akkulam-Veli Lake. PCA revealed that Corg and labile organic matter (LOM) were the important environmental variables influencing methane production potential. Interpretation: Anthropogenic activities like sewage and waste disposal results in increased input of organic matter in lake sediments. The labile organic matter fraction in the sediments favours methanogenic activity thereby resulting in methane production and release from the lakes. Key words: Labile organic matter, Methanogenic archaea, Methane production, Sulphate reduction, Tropical lakes
41
Wu, Xue, Yancai Wang, Yirong Chang, Zhengzheng Hao, Lixin Jiao, and Rui Zhang. "Research Progress on the Occurrence, Adsorption, and Release of Phosphorus in the Sediments of Dianchi Lake and Prospects for Its Control." Water 17, no. 11 (May 29, 2025): 1652. https://doi.org/10.3390/w17111652.
Full textAbstract:
Phosphorus plays a key role in water eutrophication. The release of endogenous phosphorus from sediments maintains eutrophication in Dianchi Lake. This study aimed to summarize and analyze the research trends, occurrence characteristics, adsorption and release characteristics, influencing factors, and prospects of internal phosphorus pollution control in Dianchi Lake based on a literature search and data integration. The results revealed that sediment phosphorus in Dianchi Lake has been widely studied. From previous studies, the total phosphorus (TP) content and various forms of phosphorus in the Dianchi Lake sediments have decreased since 2010. The TP contents measured in Dianchi Lake in previous research were considerably different owing to the influence of sampling depth and dredging projects. The TP content in the sediments of Dianchi Lake was higher but its release risk was lower than those in other lakes in China. The risk of release was higher in Caohai and North Waihai than that in Central Waihai and South Waihai. In addition to environmental factors at the sediment–water interface, sediment characteristics, and ecosystem degradation are important factors that affect phosphorus migration and transformation. Over the past 30 years, sediment dredging has been the primary measure for reducing the internal pollution load in Dianchi Lake. However, more accurate sediment dredging and systematic vegetation–algae–sediment co-management measures are needed for water ecosystem restoration in Dianchi Lake. This study provides new insights into the study of internal phosphorus pollution.
42
Yuan, Xu Yin, Quan Liu, Ji Zhou Li, Jun Feng Ji, and Chang Ping Mao. "Risk Assessment of Organochlorine Compounds in Water and Surface Sediments from Taihu Lake and Nanjing Section of Changjiang, China." Advanced Materials Research 356-360 (October 2011): 624–29. http://dx.doi.org/10.4028/www.scientific.net/amr.356-360.624.
Full textAbstract:
Samples of surface water and sediment were collected in Taihu Lake and Nanjing section of Changjiang. Organochlorine compounds(OCCs) of samples were detected to investigate the characteristics and ecological risk of them in the lake and river. The concentrations of OCCs in water of Nanjing section of Changjiang were higher than those in Taihu Lake, but the concentrations of OCCs in sediments were higher in Taihu Lake. HCHs of Taihu sediments were relatively enriched, indicating the agricultural source of compounds. PCBs of Changjiang sediments were higher compared to Taihu sediments, denoting a obvious industrial source. Comparing with other compartments in China, HCHs of the study area were higher than most sediment of Chinese rivers, DDTs didn’t show high contents in sediments, PCBs was in relatively low levels. By contrast with the relevant sediment quality guidelines of these compounds, the ecological risk of OCCs in sediments were evaluated. The OCCs of sediments in Taihu Lake and Nanjing section of Changjiang didn’t show high ecological risk.
43
Kolpakova, Marina. "Heavy metal contamination in bottom sediments of saline endorheic lakes of Kulunda and Barabinsk steppes (Western Siberia, Russia)." E3S Web of Conferences 80 (2019): 03009. http://dx.doi.org/10.1051/e3sconf/20198003009.
Full textAbstract:
The article presents the results of assessment of heavy metals contamination in bottom sediments of saline lakes located on the territory of Kulunda and Barabinsk steppes of Western Siberia, Russia. The territory is characterized by large amount of lakes (more than 5000), including the Chany lake, which is the biggest lake of south of Western Siberia. By calculation the geochemical parameters, such as Enrichment factor, Contamination factor, Geoaccumulation index, Pollution load index, the common level of bottom sediments was classified as unpolluted. However, in comparison with average level of bottom sediment on that territory the lake sediments are enriched with the following elements: Sr> Rb> Zn> V> Cr> Ni> Cu> As> Pb> Th> U> Mn> Fe> K> Ti.
44
Shaw, J. F. H., and E. E. Prepas. "Temporal and Spatial Patterns of Porewater Phosphorus in Shallow Sediments, and its Potential Transport into Narrow Lake, Alberta." Canadian Journal of Fisheries and Aquatic Sciences 46, no. 6 (June 1, 1989): 981–88. http://dx.doi.org/10.1139/f89-127.
Full textAbstract:
During 1985 and 1986, summer and spatial patterns of porewater soluble reactive phosphorus (SRP) from sediments ≤ 15-m depth were examined at Narrow Lake, a deep, mesoeutrophic Albertan lake. At three sites (different in depth and macrophyte colonization), trends in porewater SRP concentrations ([SRP]) in the top 5 cm of the sediment from May to August varied, possibly due to root uptake of SRP by macrophytes. At a depth of 5 m, mean (in the top 5 cm of the sediment) and variance of porewater [SRP] at one site (<0.15 m2) were the same as over the entire lake. Excluding data from macrophyte sites, porewater [SRP] were positively related to depth of the water column (P < 0.0001). Molecular diffusion of SRP from sediments with and without macrophytes located in the trophogenic zone was calculated. During summer, molecular diffusion from shallow sediments to the trophogenic zone was 0.05 mg∙m−2 d−1, or 29% of atmospheric deposition of phosphorus (P) (the major external source of P to the lake). A sampling strategy is discussed to enable the calculation of whole-lake P transport from shallow sediments to the trophogenic zone in lakes with similar morphometry and trophic status to Narrow Lake.
45
Pu, Wenmiao, Mingyu Wang, Dan Song, Wei Zhao, Xuran Sheng, Tangbin Huo, Xue Du, and Xin Sui. "Bacterial Diversity in Sediments from Lianhuan Lake, Northeast China." Microorganisms 12, no. 9 (September 20, 2024): 1914. http://dx.doi.org/10.3390/microorganisms12091914.
Full textAbstract:
Lake microbiota play a crucial role in geochemical cycles, influencing both energy flow and material production. However, the distribution patterns of bacterial communities in lake sediments remain largely unclear. In this study, we used 16S rRNA high-throughput sequencing technology to investigate the bacterial structure and diversity in sediments across different locations (six independent lakes) within Lianhuan Lake and analyzed their relationship with environmental factors. Our findings revealed that both the alpha and beta diversity of sediment bacterial communities varied significantly among the six independent lakes. Furthermore, changes between lakes had a significant impact on the relative abundance of bacterial phyla, such as Pseudomonadota and Chloroflexota. The relative abundance of Pseudomonadota was highest in Habuta Lake and lowest in Xihulu Lake, while Chloroflexota abundance was lowest in Habuta Lake and highest in Tiehala Lake. At the genus level, the relative abundance of Luteitalea was highest in Xihulu Lake compared to the other five lakes, whereas the relative abundances of Clostridium, Thiobacillus, and Ilumatobacter were highest in Habuta Lake. Mantel tests and heatmaps revealed that the relative abundance of Pseudomonadota was significantly negatively correlated with pH, while the abundance of Chloroflexota was significantly positively correlated with total phosphorus and total nitrogen in water, and negatively correlated with electrical conductivity. In conclusion, this study significantly enhances our understanding of bacterial communities in the different lakes within the Lianhuan Lake watershed.
46
Heslop, J. K., K. M. Walter Anthony, A. Sepulveda-Jauregui, K. Martinez-Cruz, A. Bondurant, G. Grosse, and M. C. Jones. "Thermokarst lake methanogenesis along a complete talik profile." Biogeosciences 12, no. 14 (July 24, 2015): 4317–31. http://dx.doi.org/10.5194/bg-12-4317-2015.
Full textAbstract:
Abstract. Thermokarst (thaw) lakes emit methane (CH4) to the atmosphere formed from thawed permafrost organic matter (OM), but the relative magnitude of CH4 production in surface lake sediments vs. deeper thawed permafrost horizons is not well understood. We assessed anaerobic CH4 production potentials from various depths along a 590 cm long lake sediment core that captured the entire sediment package of the talik (thaw bulb) beneath the center of an interior Alaska thermokarst lake, Vault Lake, and the top 40 cm of thawing permafrost beneath the talik. We also studied the adjacent Vault Creek permafrost tunnel that extends through ice-rich yedoma permafrost soils surrounding the lake and into underlying gravel. Our results showed CH4 production potentials were highest in the organic-rich surface lake sediments, which were 151 cm thick (mean ± SD: 5.95 ± 1.67 μg C–CH4 g dw−1 d−1; 125.9 ± 36.2 μg C–CH4 g C−1org d−1). High CH4 production potentials were also observed in recently thawed permafrost (1.18 ± 0.61 μg C–CH4g dw−1 d−1; 59.60± 51.5 μg C–CH4 g C−1org d−1) at the bottom of the talik, but the narrow thicknesses (43 cm) of this horizon limited its overall contribution to total sediment column CH4 production in the core. Lower rates of CH4 production were observed in sediment horizons representing permafrost that has been thawing in the talik for a longer period of time. No CH4 production was observed in samples obtained from the permafrost tunnel, a non-lake environment. Our findings imply that CH4 production is highly variable in thermokarst lake systems and that both modern OM supplied to surface sediments and ancient OM supplied to both surface and deep lake sediments by in situ thaw and shore erosion of yedoma permafrost are important to lake CH4 production.
47
Heslop, J. K., K. M. Walter Anthony, A. Sepulveda-Jauregui, K. Martinez-Cruz, A. Bondurant, G. Grosse, and M. C. Jones. "Thermokarst-lake methanogenesis along a complete talik profile." Biogeosciences Discussions 12, no. 6 (March 24, 2015): 4865–905. http://dx.doi.org/10.5194/bgd-12-4865-2015.
Full textAbstract:
Abstract. Thermokarst (thaw) lakes emit methane (CH4) to the atmosphere formed from thawed permafrost organic matter (OM), but the relative magnitude of CH4 production in surface lake sediments vs. deeper thawed permafrost horizons is not well understood. We assessed anaerobic CH4 production potentials from various depths along a 590 cm long lake sediment core that captured the entire sediment package of the talik (thaw bulb) beneath the center of an interior Alaska thermokarst lake, Vault Lake, and the top 40 cm of thawing permafrost beneath the talik. We also studied the adjacent Vault Creek permafrost tunnel that extends through ice-rich yedoma permafrost soils surrounding the lake and into underlying gravel. Our results showed CH4 production potentials were highest in the organic-rich surface lake sediments, which were 151 cm thick (mean ± SD 5.95 ± 1.67 μg C-CH4 g dw−1 d−1; 125.9± 36.2 μg C-CH4 g C−1org d−1). High CH4 production potentials were also observed in recently-thawed permafrost (1.18± 0.61 μg C-CH4g dw−1 d−1; 59.60± 51.5 μg C-CH4 g C−1org d−1) at the bottom of the talik, but the narrow thicknesses (43 cm) of this horizon limited its overall contribution to total sediment column CH4 production in the core. Lower rates of CH4 production were observed in sediment horizons representing permafrost that has been thawed in the talik for longer periods of time. No CH4 production was observed in samples obtained from the permafrost tunnel, a non-lake environment. Our findings imply that CH4 production is highly variable in thermokarst-lake systems and that both modern OM supplied to surface sediments and ancient OM supplied to both surface and deep lake sediments by in situ thaw as well as shore erosion of yedoma permafrost are important to lake CH4 production.
48
Afzal, Shahzad, Mohammad Younas, and Khadim Hussain. "Selenium Speciation of Surface Sediments from Saline Lakes of the Soan-Sakesar Valley Salt-Range, Pakistan." Water Quality Research Journal 34, no. 4 (November 1, 1999): 575–88. http://dx.doi.org/10.2166/wqrj.1999.029.
Full textAbstract:
Abstract The chemical species of selenium from the surface sediments from three eutroph-ic lakes of the Soan-Sakesar Valley were examined. The major objectives of the study were to examine the oxidation states of selenium in the lake sediments. The following selenium concentrations were observed from lakes Uchhali, Khabbaki and Jahlar, respectively: total selenium: 4.03, 1.55 and 1.4 mg/kg; Se+VI: 0.86, 0.39 and 0.31 mg/kg; Se+IV: 0.95, 0.27 and 0.25 mg/kg; Se-II:1.15, 0.45 and 0.33; and Se0: 1.17, 0.48 and 0.53 mg/kg. Lake sediments have higher nitrogen (0.04—0.35% of dry weight) and phosphorus (0.04—0.29% of dry weight) levels due to agriculture drainage water and sewage waste from small villages. X-ray diffraction analysis has shown that albite, calcite, chlorite, illite and quartz minerals were present in the sediments of lakes Uchhali, Khabbaki and Jahlar. Kaolinite was present only in lakes Uchhali and Khabbaki and goethite only in Lake Uchhali. Linear relationships were observed between selenium fractions, and minerals present in these lakes point out the phenomena of adsorption on the surface of these minerals. The organic C contents of 2.2, 2.8 and 3.1% dry weight in lakes Uchhali, Khabbaki and Jahlar, respectively, show linear relationships with Se-II, Se0 and total selenium. It suggests that Se in the sediments is highly associated with the sediment organic fraction. The results indicate that nutrient loads and organic C are responsible for the high microbial activity, which reduces sele-nates to more insoluble Se species in the lake sediments.
49
Liu, Bo, Xiaofei Zhang, Yi Tong, Wen Ao, Zenglong Wang, Senlin Zhu, and Yanping Wang. "Quantification of Nutrient Fluxes from Sediments of Lake Hulun, China: Implications for Plateau Lake Management." Sustainability 15, no. 11 (May 26, 2023): 8680. http://dx.doi.org/10.3390/su15118680.
Full textAbstract:
Dramatic changes in lake water conditions may induce sensitive feedback in sediments, such as the release of phosphate and ammonia. There is a lack of the understanding of sediment nutrient release fluxes and their responses to various environmental factors in plateau lakes. In this study, nutrient contents in the water and sediment, sediment nutrient release rates, and their responses to various influential factors in a steppe shallow plateau lake, Lake Hulun, China, were investigated. Sediment is a large store of nutrients, with bioavailable phosphorus of 555 mg kg−1 in surface lake sediments. If water became anoxic, sediments will release appreciable amounts of phosphate (2.1 mg P m−2 d−1) and ammonia (40.0 mg N m−2 d−1), three times greater than those in oxic conditions. Raised temperatures greatly increased sediment phosphate release rates, while the highest temperature (23 °C) slightly decreased ammonia release rates due to strong nitrification. Assuming a whole year of internal loading, ammonia and dissolved reactive phosphorus concentrations in water column would increase by an estimated 0.22 mg N L−1 and 0.01 mg P L−1, respectively, which is equal to 2 and 0.5 times of their ambient concentrations. A pH increase from 8.4 to 9.4 significantly decreased internal nitrogen and phosphorus release rates by around three times. Overall, dissolved oxygen (DO) and pH had a greater impact on sediment nutrient release from lake sediments compared to temperature, and further increased the eutrophic status in the overlying water when these three parameters varied within the normal seasonal range (temperature: 1.9–23.1 °C, DO: oxic and anoxic; pH: 7.5–9.4). With the periodic low DO and frequency of drought in the future, lake management strategies that mitigate water eutrophication, such as water diversion, may need to be considered.
50
Schiff, Sherry L., and Robert F. Anderson. "Limnocorral Studies of Chemical and Biological Acid Neutralization in Two Freshwater Lakes." Canadian Journal of Fisheries and Aquatic Sciences 44, S1 (December 18, 1987): s173—s187. http://dx.doi.org/10.1139/f87-293.
Full textAbstract:
Twenty-nine 1 m diameter limnocorrals were installed in two Canadian Shield lakes to examine the relative importance of individual acid neutralization processes. Once the water column alkalinity was depleted, the within-lake alkalinity production processes were confined to the lake sediments. The flocculent organic-rich sediments of a shallow dystrophic lake (Lake 114) neutralized acid at a significantly greater rate than the sandy littoral sediments of an oligotrophy lake (Lake 302). Since the water column alkalinity of Lake 114 is much lower than Lake 302, ambient alkalinity is not a good predictor of acid neutralization capacity in the sediments. In both lakes, HNO3 was neutralized at a substantially higher rate than HCl or H2SO4. The rates of nitrate consumption, sulfate consumption, and abiotic acid neutralizing processes are independent of each other. Denitrification to an uncharged end-product is the primary mechanism of NO3− removal. The principal source of non-anion-specific buffering in the enclosure experiments was Ca2+ release from the sediments in Lake 302 and Ca2+ and NH4+ release in Lake 114. There is no significant difference between the organic-rich sediments of Lake 114 and the sandy sediments of Lake 302 in the concentration of exchangeable cations (μeq∙cm−3) for all cations except NH4+ and Mn2+. Alkalinity production in epilimnetic sediments is an important component of the resistance of softwater lakes to anthropogenic acidification.