Contribution of suspended particulate matter and zooplankton to MeHg contamination of the food chain in midnorthern Quebec (Canada) reservoirs

1997 ◽  
Vol 54 (4) ◽  
pp. 821-831 ◽  
Author(s):  
Y Plourde ◽  
M Lucotte ◽  
P Pichet
Keyword(s):  
Particulate Matter ◽  
Suspended Particulate Matter ◽  
Continuous Flow ◽  
Methyl Mercury ◽  
Organic Matter Content ◽  
Matter Content ◽  
Flooded Soils ◽  
Natural Lakes ◽  
Suspended Particulate ◽  
Organic Particles

Suspended particulate matter (SPM) retained by continuous-flow centrifugation, suspended matter of 20-150 mu m diameter, and zooplankton exceeding 150 mu m were sampled in the LG-2 and LA-1 reservoirs and in four natural lakes in northern Quebec during June, August, and September 1992 and 1993. Inorganic Hg concentrations in the three compartments did not differ significantly between the reservoirs and natural lakes, but methyl mercury (MeHg) concentrations in SPM (mean of 0.05 ppm) and zooplankton (up to 0.84 ppm) from LG-2 were 7 and 5 times higher, respectively, than in the natural lakes. The MeHg bioamplification factors between SPM and zooplankton ranged from 4 to 9 in the reservoirs and natural lakes. MeHg concentrations in SPM reached a maximum during August and were positively correlated with organic matter content. High MeHg concentrations were observed in the SPM and zooplankton sampled in August in a small impoundment separated from LA-1 by the LA-40 dike, which had been flooded for about 1 year. These data suggest that methylation and transfer of MeHg from flooded soils to SPM and zooplankton are rapidly accomplished. The process involves the bioaccumulation of MeHg by phytoplankton and (or) the ingestion of suspended soil-derived organic particles by zooplankton.

Geochemistry of Mercury in Two Hydroelectric Reservoirs in Quebec, Canada

1993 ◽  
Vol 50 (2) ◽  
pp. 269-281 ◽  
Author(s):  
Patrick Louchouarn ◽  
Marc Lucotte ◽  
Alfonso Mucci ◽  
Pierre Pichet
Keyword(s):  
Close Association ◽  
Organic Matter Content ◽  
Matter Content ◽  
Depth Interval ◽  
Flooded Soils ◽  
Hydroelectric Reservoirs ◽  
Erosion Processes ◽  
Natural Lakes ◽  
Mechanical Erosion ◽  
Atmospheric Inputs

Carbon, nitrogen, phosphorus, and iron oxyhydroxide profiles were used to explain the retention of Hg in sediments of natural lakes and flooded soils in Quebec. In lake sediments, Hg levels increased from background concentrations of approximately 100 ng/g beneath the 10- to 16-cm depth interval to 150–490 ng/g near the surface. This increase was attributed to atmospheric inputs to the environment. In forest soils, the close association of Hg with the surficial organic horizon appears to be a potential source of contamination for the aquatic system through the transport of particulate matter by surface runoff. High organic matter content observed in the flooded soil of LG-2 Reservoir suggests that postsedimentation biodegradation is a slow process. In contrast, at Cabonga Reservoir, an 80% reduction in C, N, and Hg concentrations was observed between the flooded and the adjacent forest soil. Mechanical erosion processes (marling, waves, ice) rather than biodegradation seem responsible for the observed loss in C, N, and Hg. We propose that suspension of the humic horizon from flooded soils could constitute a significant source of Hg contamination to the overlying waters and biota until the exposed littoral zone stabilizes.

Effects of suspended particulate matter from natural lakes in conjunction with coagulation to tetracycline removal from water

Chemosphere ◽  
2021 ◽  
Vol 277 ◽  
pp. 130327
Author(s):  
Zhenkai He ◽  
Xinyu Wang ◽  
Yunhe Luo ◽  
Yazheng Zhu ◽  
Xin Lai ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Suspended Particulate Matter ◽  
Natural Lakes ◽  
Suspended Particulate

Accumulation of total mercury and methyl mercury in insect larvae of hydroelectric reservoirs

1997 ◽  
Vol 54 (4) ◽  
pp. 832-841 ◽  
Author(s):  
A Tremblay ◽  
M Lucotte
Keyword(s):  
Methyl Mercury ◽  
Total Mercury ◽  
Dry Weight ◽  
Insect Larvae ◽  
Flooded Soils ◽  
Hydroelectric Reservoirs ◽  
Natural Lakes ◽  
Suspended Particulate ◽  
Total Variability ◽  
Total Hg

Mean total mercury (Hg) and methyl mercury (MeHg) concentrations in insect larvae from hydrolelectric reservoirs were 3-5 times (up to 10 times) higher than in their counterparts from natural lakes. Taxonomic differences, which may be related to feeding behavior, and substrate type (lake sediment or flooded soils) together explained a large part of the total variability of total Hg (r2 = 0.64) and MeHg (r2 = 0.79) concentrations in insects. MeHg concentrations in flooded soils increased from 0.3-2 ng Hg cdot g dry weight-1 after 1-2 years of flooding to 15-2 ng Hg cdot g dry weight-1 after 16 years of impoundment. Total Hg and MeHg concentrations in insect larvae followed a similar pattern, but only weak correlations of both total Hg and MeHg concentrations were found between flooded soils and insect larvae, suggesting that factors other than MeHg content of flooded soils also affect the accumulation of these compounds in insects. Our results indicate that suspended particulate matter eroded from flooded soils by wave and ice action and bacterial activity enhanced by the release of labile carbon and nutrients from the flooded soils may indirectly transfer MeHg from flooded soils to insect larvae.

Physical and bacterial processes affecting suspended particulate matter in a tidal river

1998 ◽  
Vol 38 (6) ◽  
pp. 327-335
Author(s):  
Yasunori Kozuki ◽  
Yoshihiko Hosoi ◽  
Hitoshi Murakami ◽  
Katuhiro Kawamoto
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Suspended Particulate Matter ◽  
River Mouth ◽  
Tidal River ◽  
Natural Soil ◽  
Size Change ◽  
Run Off ◽  
Suspended Particulate ◽  
And Behavior

In order to clarify the origin and behavior of suspended particulate matter (SPM) in a tidal river, variation of SPM in a tidal river was investigated with regard to its size and constituents. SPM was separated into three groups according to size. Change of contents of titanium and organic substances of each group of SPM was examined. SPM which was discharged by run-off was transported with decomposition and sedimentation in a tidal river. Concentration of SPM with a particle size greater than 0.45 μm increased due to resuspension in a tidal river. Origin of SPM with a size of less than 0.45 μm at upstream areas was from natural soil and most of such SPM which had been transported settled near a river mouth. It was determined from examination of the CN ratio and the ratio of the number of attached bacteria to free bacteria that SPM with a size greater than 1.0 μm at upstream areas was decomposing intensively. At the downstream areas, SPM with a size of less than 0.45 μm came from the sea. SPM with particle size greater than 1.0 μm consisted of plankton and substances which were decomposed sufficiently while flowing.

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