Sedimentological and limnological evolution of recreational lakes in a former asbestos mining region (Québec, Canada): insights from paleolimnology

2020 ◽  
Author(s):  
Reinhard Pienitz ◽  
Olivier Jacques
Keyword(s):  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Ecological Condition ◽  
Nutrient Concentrations ◽  
Mineral Matter ◽  
Mining Activities ◽  
Fine Grained ◽  
Efficient Management ◽  
A Chain

<p>The Bécancour River basin in southern Québec (Canada) has been impacted by more than a hundred years of asbestos mining activities in the Thetford Mines region. Several recreational water bodies located downstream from the city are suffering from high sediment and contaminant loads and eutrophication. In order to prepare an efficient management of the fluvial lakes, we completed paleolimnological investigations to evaluate the extent of their deterioration and identify catchment disturbances that influenced their present-day condition. Here we present the results of a multi-proxy study of sediment cores collected from a chain of 5 lakes. The sedimentary records from these lakes indicate severe perturbations associated with the complete draining of Lac Noir, a former lake near Thetford Mines excavated and drained for mining purposes between 1955-1959. Radiometric <sup>210</sup>Pb dating revealed extreme increases in the sediment accumulation rate following this event. Analyses of loss-on-ignition, carbon (C) and nitrogen (N) isotopes, grain-size, and X-ray microfluorescence indicated that the post-1960 sediments were enriched in fine-grained mineral matter and had higher metal and nutrient concentrations as compared to older sediments at the bottom of the cores. Changes in the δ<sup>13</sup>C and C/N ratios and the predominance of diatom taxa (class Bacillariophyceae) typical of nutrient-rich waters (e.g., Cyclostephanos invisitatus, Cyclotella meneghiniana) also showed that the 1955-1959 event led to a rapid eutrophication of some lakes. Results from our study illustrate that the asbestos mining activities had dramatic impacts on lake biota and contaminant levels, and suggest that major restoration efforts will be needed to improve their ecological condition.</p>

Pigment Preservation in Lake Sediments: A Comparison of Sedimentary Environments in Trout Lake, Wisconsin

1991 ◽  
Vol 48 (3) ◽  
pp. 472-486 ◽  
Author(s):  
James P. Hurley ◽  
David E. Armstrong
Keyword(s):  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Sediment Surface ◽  
Water Interface ◽  
Sedimentary Pigments ◽  
Sedimentary Environments ◽  
Trout Lake ◽  
Secondary Carotenoids ◽  
Β Carotene

Fluxes and concentrations of a phorbins and major algal carotenoids were quantified in sediment trap material and sediment cores from two basins of Trout Lake, Wisconsin (TrDH and TrAB). The basins were chosen to contrast the influence of oxygen content at the sediment–water interface (TrDH, oxic and TrAB, reducing), sediment accumulation rate, and focusing. Pigment diagenesis occurred in both basins, but transformations and destruction were more extensive in TrDH. Although untransformed chlorophyll a was the major phorbin deposited at the sediment surface of both basins (51–64 mol%), pigment destruction, coupled with transition to pheophytin, accounted for substantial losses, especially in oxic TrDH sediments. Fucoxanthin, peridinin, and diadinoxanthin, despite representing > 70% of the deposited carotenoid flux, were substantially degraded or transformed in both basins. However, preservation was relatively high for secondary carotenoids, such as diatoxanthin and β-carotene, and for a major cryptomonad pigment, alloxanthin. Residual profiles in sediments show that pigment sedimentation from the epilimnion and accumulation in the permanent sediments are not directly related and that diagenesis must be considered in interpreting sedimentary pigments.

Time averaging and stratigraphic unmixing: reconstructing ecological decline in molluscan production (Holocene, Brijuni, NE Adriatic)

2020 ◽  
Author(s):  
Adam Tomašových ◽  
Martin Zuschin ◽  
Ivo Gallmetzer ◽  
Alexandra Haselmair
Keyword(s):  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Coralline Algae ◽  
Time Averaging ◽  
Sedimentation Rates ◽  
Amino Acid Racemization ◽  
Ecological History ◽  
Shell Bed ◽  
Warm Temperate

<p>The northeastern Adriatic seafloor is formed by warm-temperate bioclastic carbonates with coralline algae, bryozoans and mollusks. These sediments represent a mixture of past and present-day production owing to low sedimentation rates and bioturbation. Although low sedimentation rates do not allow resolution of ecological history at centennial or even millennial scales on the basis of raw stratigraphic data, age unmixing based on radiocarbon-calibrated amino acid racemization shows that one of the major molluscan sediment producers – the infaunal suspension-feeder Timoclea ovata  – markedly peaked in production ~5,000 years during the maximum flooding and earliest highstand phase and significantly diminished in abundance during the late highstand phase at Brijuni, with a large proportion of dead shells now present in surface sediments representing shells that are several centuries old. This species still occurs in living assemblages but our analyses indicate that its former production was by several orders of magnitude higher. In contrast, stratigraphic trends in absolute and proportional abundance of this species in ~1.5 m-thick sediment cores show a gradual or a very mild upcore decline, indicating that raw stratigraphic data do not efficiently detect millennial-scale ecological dynamic. The temporal decline in production of Timoclea ovata is associated with an increase in water depth and an increase in sediment-accumulation rate, and led to a transition from molluscan oyster-scallop shell bed to late highstand bryomol sediments.</p>

scholarly journals SEDIMENT ACCUMULATION PROFILE IN MANGROVE RESTORATION AREA OF LEMBAR BAY-LOMBOK ISLAND

2017 ◽  
Vol 9 (1) ◽  
pp. 301-313
Author(s):  
Mohammad Sumiran Paputungan ◽  
Alan Frendy Koropitan ◽  
Tri Prartono ◽  
Ali Arman Lubis
Keyword(s):  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Coastal Region ◽  
Sediment Accumulation Rate ◽  
Ecosystem Functions ◽  
Sampling Location ◽  
Mangrove Restoration ◽  
Mangrove Area ◽  
Lombok Island

Mangrove restoration is really needed for restoring its ecosystem functions, so that it could be able to support fisheries activity and to protect coastal by extreme weather. In addition, mangrove is able to accumulate sediment that important in protecting the coastal area from sea level rise. Therefore,  the aim of this study is to investigate sediment accumulation rate in mangrove area during post restoration. Sampling location were divided into three different stations based on estimated restoration ages, such as ≥ 15  years old (Station 1), 4 - 10 years old (Station 2) and 2 - 8 years old (Station 3). Sediment cores were carried out by inserting 7.6 cm diameter and 100 cm length of polyvinyl chloride pipes. Sedimentation rate is measured by using Pb-210 radionuclide analysis. The results show that the sediment accumulation rate in the last 20th years from all station ranges from 0.17 to 0.42 g/cm2/year. The highest accumulation rate is found at oldest year old station while the lowest accumulation rate is found at younger year old station of mangrove restoration area. Restoration process is clearly able to recover the mangrove’s role in trapping sediment in coastal region. Keywords: sediment accumulation, mangrove restoration, Lembar Bay-                   Lombok Island 

scholarly journals Evaluating the historical sedimentation patterns in two different Mediterranean deep environments (Sardinia and Sicily Channels)

2019 ◽  
Vol 20 (3) ◽  
pp. 542 ◽  
Author(s):  
NOUR EL HOUDA HASSEN ◽  
NAFAÂ REGUIGUI ◽  
MOHAMED AMINE HELALI ◽  
NEZHA MEJJAD ◽  
ABDELMOURHIT LAISSAOUI ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Water Depth ◽  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Inverse Correlation ◽  
Accumulation Rates ◽  
Deep Sediment ◽  
210Pb And 137Cs ◽  
Excess 210Pb

The sediment accumulation rate in the Sardinia and Sicily channels in the central part of the Mediterranean Sea was studied by using short-lived radionuclides (210Pb and 137Cs) in two deep sediment cores. Different sedimentation regimes were identified indicating substantial differences in accumulation rates and historical patterns. The 210Pb-derived mean accumulation rate found in the Strait of Sardinia was 0.05 g.cm-2.y-1, lower than that in Sicily Channel (0.1 g.cm-2.y-1) suggesting an inverse correlation with water depth. Excess 210Pb inventories were 24 ± 1 and 6.0 ± 0.4 kBq.m-2, while the fluxes to the sediment were 745 ± 31 and 188 ± 11 Bq.m-2.y-1 in Sicily and Sardinia channels, respectively. 137Cs failed to use for the validation of the established chronologies, while its inventories found 450 Bq.m-2 and 355 Bq.m-2 in the Sicily and Sardinia channel, respectively.

scholarly journals Vertical and lateral flux on the continental slope off Pakistan: correlation of sediment core and trap results

2014 ◽  
Vol 11 (12) ◽  
pp. 3107-3120 ◽  
Author(s):  
H. Schulz ◽  
U. von Rad
Keyword(s):  
Continental Slope ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Lower Boundary ◽  
Distribution Patterns ◽  
Sediment Traps ◽  
Accumulation Rates ◽  
Fine Grained ◽  
Minimum Zone ◽  
The Individual

Abstract. Due to the lack of bioturbation, the varve-laminated muds from the oxygen minimum zone (OMZ) off Pakistan provide a unique opportunity to precisely determine the vertical and lateral sediment fluxes in the nearshore part of the northeastern Arabian Sea. West of Karachi (Hab area), the results of two sediment trap stations (EPT and WPT) were correlated with 16 short sediment cores on a depth transect crossing the OMZ. The top of a distinct, either reddish- or light-gray silt layer, 210Pb-dated as AD 1905 ± 10, was used as an isochronous stratigraphic marker bed to calculate sediment accumulation rates. In one core, the red and gray layer were separated by a few (5–10) thin laminae. According to our varve model, this contributes < 10 years to the dating uncertainty, assuming that the different layers are almost synchronous. We directly compared the accumulation rates with the flux rates from the sediment traps that collected the settling material within the water column above. All traps on the steep Makran continental slope show exceptionally high, pulsed winter fluxes of up to 5000 mg m−2 d−1. Based on core results, the flux at the seafloor amounts to 4000 mg m−2 d−1 and agrees remarkably well with the bulk winter flux of material, as well as with the flux of the individual bulk components of organic carbon, calcium carbonate and opal. However, due to the extreme mass of remobilized matter, the high winter flux events exceeded the capacity of the shallow traps. Based on our comparisons, we argue that high-flux events must occur regularly during winter within the upper OMZ off Pakistan to explain the high accumulations rates. These show distribution patterns that are a negative function of water depth and distance from the shelf. Some of the sediment fractions show marked shifts in accumulation rates near the lower boundary of the OMZ. For instance, the flux of benthic foraminifera is lowered but stable below ~1200–1300 m. However, flux and sedimentation in the upper eastern Makran area are dominated by the large amount of laterally advected fine-grained material and by the pulsed nature of the resuspension events at the upper margin during winter.

Relationships among Tubificid Abundances, Sediment Composition, and Accumulation Rates in Lake Erie

1989 ◽  
Vol 46 (2) ◽  
pp. 223-231 ◽  
Author(s):  
J. A. Robbins ◽  
T. Keilty ◽  
D. S. White ◽  
D. N. Edgington
Keyword(s):  
Organic Carbon ◽  
Carbon Flux ◽  
Lake Erie ◽  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Tubifex Tubifex ◽  
Sediment Reworking ◽  
Organic Carbon Flux ◽  
Limnodrilus Hoffmeisteri

Sediment cores taken at 15 sites within the three main depositional basins of Lake Erie from 1976 to 1982 were sectioned in 1-cm intervals and analyzed for the abundance and vertical distribution of benthic organisms, 137Cs, and 210Pb (in some cores) and for surficial (upper 2 cm) organic and inorganic carbon. Zoobenthos populations were dominated (>85%) by tubificids (Limnodrilus hoffmeisteri, Quistadrilus multisetosus, and Tubifex tubifex) and varied in abundance from 6600 to 55 300 individuals∙m−2. The depth above which 90% of the individuals occurred correlated significantly with their abundance and with radiometrically determined mixed depths. Rates of sediment reworking by tubificids exceeded sedimentation rates by 5–80 times, indicating that worms alone can produce the observed zone of constant tracer activity at the sediment–water interface. Tubificid abundance was not significantly related to organic carbon but instead correlated strongly with the sediment accumulation rate and organic carbon flux. In Lake Erie the abundance of tubificids may be limited by the rate of supply of nutrients as measured roughly in terms of the organic carbon flux.

Recent trends in sediment and nutrient accumulation rates in coastal, freshwater Lake Sibaya, South Africa

2013 ◽  
Vol 64 (11) ◽  
pp. 1087 ◽  
Author(s):  
Marc S. Humphries ◽  
Claudia R. Benitez-Nelson
Keyword(s):  
South Africa ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Freshwater Lake ◽  
Total Carbon ◽  
Nutrient Concentrations ◽  
Bulk Sediment ◽  
Accumulation Rates ◽  
Nitrogen And Phosphorus ◽  
Recent Trends

Eutrophication of aquatic systems has emerged as one of the most pressing issues confronted by scientists and environmental managers. In this study, we used two sediment cores from Lake Sibaya, a coastal freshwater lake in South Africa, to infer historical variations in bulk sediment accumulation and nutrient (C, N and P) biogeochemistry. Cores were dated using 210Pb, 137Cs and 14C, and dates were used to calculate bulk sediment accumulation rates and nutrient concentrations over the last 250 years. In the western section of the lake, stratigraphic variations in total carbon, nitrogen and phosphorus increased abruptly to near-constant levels around the beginning of the 20th century, a trend that appears to be consistent with the onset of human settlement and land clearance in the catchment. In contrast, sedimentation rates have remained relatively constant over this period, despite recent land use change in the catchment. Results of this study suggest that recent increases in development pressure have yet to further influence sedimentation in Lake Sibaya, thus providing values against which future monitoring efforts can be compared. This study represents the first report on recent trends in sedimentation and nutrient biogeochemistry in Lake Sibaya. The results have broad implications for other ecologically sensitive areas within the Maputaland ecoregion of coastal southern Africa.

Rates of Sediment Accumulation in Pollen Cores from Small Lakes and Mires of Eastern North America

1988 ◽  
Vol 30 (3) ◽  
pp. 284-297 ◽  
Author(s):  
Robert Stabler Webb ◽  
Thompson Webb
Keyword(s):  
North America ◽  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Linear Interpolation ◽  
Climatic Conditions ◽  
Eastern North America ◽  
Small Lakes ◽  
Data Set ◽  
Depositional Processes

Data from 291 small lakes and mires in eastern North America provide information on the natural variability of rates of sediment accumulation in these environments over the last 18,000 yr. Accumulation rates were calculated by linear interpolation between radiocarbon and biostratigraphic dates from sediment cores taken for pollen analysis. Within the data set, the rates were lognormally distributed with a mean accumulation rate of 91 cm/103 yr, and a range from less than 1 to over 3500 cm/103 yr. The accumulation rate data were divided into five subsets that were temporally or spatially distinct and therefore represent different geomorphic and climatic conditions at the time of deposition. Sediments deposited in basins north of 50°N, south of 40°N, and before 10,000 yr B.P. accumulated at much slower rates than sediments accumulating in midlatitude basins (between 40° and 50°N) between 10,000 and 330 yr B.P. Sediment accumulation over the last 330 yr has, on average, been at rates four to five times faster than any time previously. Inorganic sediments that could be radiocarbon-dated have accumulated at significantly lower rates than organic sediments, reflecting differences in depositional processes. For midlatitude basins during the Holocene, the most likely rate of continuous sediment accumulation within our data set is 65 cm/103 yr. Rates below 10 cm/103 yr are likely to be associated with nonconstant processes of sediment accumulation.

scholarly journals ESTIMATION OF SEDIMENT ACCUMULATION RATE IN JAKARTA BAY USING NATURAL RADIONUCLIDE UNSUPPORTED 210Pb

2010 ◽  
Vol 7 (3) ◽  
pp. 309-313 ◽  
Author(s):  
Ali Arman Lubis ◽  
Barokah Aliyanta ◽  
Yulizon Menry
Keyword(s):  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Mixing Layer ◽  
Natural Radionuclide ◽  
Sediment Accumulation Rate ◽  
Gravity Core ◽  
Unsupported 210Pb ◽  
Pips Detector ◽  
Alpha Spectrometer

The investigation of sediment accumulation rate has been carried out in Jakarta Bay. The aim of this study is to estimate the accumulation rate of sediment  using natural radionuclide 210Pb as a tracer, through the profile of unsupported 210Pb. Sediment cores of 40 cm and 30 cm length were collected using gravity core from 2 locations (TJ22 and TJ17A) in Jakarta Bay. Samples were sliced at 2 cm length, prepared and analyzed using PIPS detector Alpha Spectrometer. The result shows that in TJ22 consist of 3 layers; LS1 in the depth of (0-2) cm as a mixing layer, LS2 (2-16) and LS3 (16-26) cm and TJ17A has 3 layers; LS1 in the depth of (0-6) cm, LS2 (6-18) cm and LS3 (18-24) cm. Accumulation rate of sediment of LS2 and LS3 in TJ22 are 0.583 cm/y and 0.074 cm/y and in TJ17A are 0,852 cm/y and 0.115 cm/y, respectively. The accumulation rate of sediment since 30 years ago is higher than previous period.   Keywords: Natural radionuclide, 210Pb, sediment, accumulation rate.

scholarly journals SEDIMENT ACCUMULATION PROFILE IN MANGROVE RESTORATION AREA OF LEMBAR BAY-LOMBOK ISLAND

2017 ◽  
Vol 9 (1) ◽  
pp. 301
Author(s):  
Mohammad Sumiran Paputungan ◽  
Alan Frendy Koropitan ◽  
Tri Prartono ◽  
Ali Arman Lubis
Keyword(s):  
Accumulation Rate ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Coastal Region ◽  
Sediment Accumulation Rate ◽  
Ecosystem Functions ◽  
Sampling Location ◽  
Mangrove Restoration ◽  
Mangrove Area ◽  
Lombok Island

<p><em>Mangrove restoration is really needed for restoring its ecosystem functions, so that it could be able to support fisheries activity and to protect coastal by extreme weather. In addition, mangrove is able to accumulate sediment that important in protecting the coastal area from sea level rise. Therefore,  the aim of this study is to investigate sediment accumulation rate in mangrove area during post restoration</em><em>.</em><em> Sampling location were divided into three different stations based on estimated restoration ages, such as </em><em>≥ 15 </em><em> years old (Station 1), 4</em><em> </em><em>-</em><em> </em><em>10 years old (Station 2) and 2</em><em> </em><em>-</em><em> </em><em>8 years old (Station 3).</em><em> </em><em>Sediment cores </em><em>were </em><em>carried out</em><em> </em><em>by inserting 7.6 cm diameter</em><em> and 100 cm length of</em><em> </em><em>polyvinyl chloride</em><em> pipes. </em><em>Sedimentation rate is measured by using Pb-210 radionuclide analysis</em><em>. The result</em><em>s</em><em> </em><em>show that</em><em> </em><em>the sediment accumulation rate in the last 20<sup>th</sup> years from all station </em><em>ranges from 0.17 to 0.42 g/cm<sup>2</sup>/year. The highest accumulation rate is found at oldest year old station while the lowest accumulation rate is found at younger year old station of mangrove restoration area. Restoration process is clearly able to recover the mangrove’s role in trapping sediment in coastal region.</em></p><p><em> </em></p><p><strong>Keywords</strong>:<em> sediment accumulation, mangrove restoration, Lembar Bay-                   </em><em>Lombok Island </em></p>

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