scholarly journals Coupling of methyl and total mercury in a minerotrophic peat bog in southeastern Sweden

2004 ◽  
Vol 61 (10) ◽  
pp. 2014-2023 ◽  
Author(s):  
O Regnell ◽  
T Hammar
Keyword(s):  
Organic Matter ◽  
Annual Cycle ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Bulk Water ◽  
Peat Bog ◽  
Runoff Water ◽  
Discharge Water ◽  
Order Of Magnitude ◽  
Total Hg

During most of an annual cycle, we studied the temporal variation of total mercury (HgT) and methyl mercury (MeHg) in unfiltered and filtered (0.45 µ) peat water from a minerotrophic peat bog in southeastern Sweden. MeHg in bulk water ([MeHgT]) and total Hg in filtered water in discharge water from the peat bog ([HgD]) were an order of magnitude higher than in upland runoff water entering the peat bog. At the discharge end, peat-water [HgD] and [MeHgD] ranged from 8 to 54 pmol·L–1 and from 1 to 32 pmol·L–1, respectively. Whereas the variation of [MeHgT] was explained by changes in [MeHgD], the variation of inorganic HgT [IHgT] = [HgT] – [MeHgT] was explained by changes in particle-bound IHg [IHgP] = [IHgT] – [IHgD]. Filterable organic matter and sulfide in the water both correlated poorly with [HgD]. Neither did the amount of HgT in precipitation and upland runoff water correlate well with the estimated discharge of HgD from the peat bog. However, there was a strong correlation between [HgD] and [MeHgT] in the peat water (r = 0.96). Furthermore, a significant fraction of HgD was MeHg (mean 28%; range 8–60%). These results suggest that methylation increased the mobility of Hg.

Importance of Wetlands as Sources of Methyl Mercury to Boreal Forest Ecosystems

1994 ◽  
Vol 51 (5) ◽  
pp. 1065-1076 ◽  
Author(s):  
Vincent L. St. Louis ◽  
John W. M. Rudd ◽  
Carol A. Kelly ◽  
Ken G. Beaty ◽  
Nicholas S. Bloom ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Forest Ecosystems ◽  
Runoff Water ◽  
Riparian Wetland ◽  
Mercury In Fish ◽  
High Concentrations ◽  
Mercury Production ◽  
Upland Catchments

Wetlands were found to be important sources of methyl mercury to the boreal forest ecosystem. Yields of methyl mercury were about 26–79 times higher from wetland portions of catchments (1.84–5.55 mg∙ha−1∙yr−1) than from purely upland areas (0.07 mg∙ha−1∙yr−1). Mass-balance estimates using methyl mercury inputs in wet deposition and outputs in runoff water indicated that purely upland catchments and lakes were sites of methyl mercury retention or demethylation, while catchments with wetland areas were sites of net methyl mercury production. These observations may explain the high concentrations of mercury in fish taken from lakes that are high in colour because they receive water from wetlands. There was no relationship between the concentration of total mercury and the concentration of methyl mercury in runoff water. Total mercury yields were low from a wetland-dominated catchment, higher from a combination upland/riparian wetland catchment, and highest from a purely upland catchment. The opposite was true for methyl mercury yields from these same catchments. This indicates that environmental factors other than total mercury concentration are controlling the production and loss of methyl mercury from catchments.

Evaluation of centrifugal ultrafilters for size fractionation of total mercury and methylmercury in freshwaters

2013 ◽  
Vol 10 (4) ◽  
pp. 323 ◽  
Author(s):  
David Kocman ◽  
Scott C. Brooks ◽  
Carrie L. Miller ◽  
Xiangping L. Yin
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Total Mercury ◽  
Organic Matter Content ◽  
Matter Content ◽  
Contaminated Water ◽  
Size Fractionation ◽  
East Fork Poplar Creek ◽  
Total Hg ◽  
Nominal Molecular Weight

Environmental context Although mercury associated with colloids is an important part of the aquatic Hg cycle, there is currently no fast and reliable method to separate complexes smaller than traditional filter pore sizes. We test commercially available centrifugal ultrafilters for their applicability to size fractionation of total Hg and methylmercury in freshwaters. Sorption of Hg onto the filters precludes their use for fractionation of inorganic Hg, the approach proved to be very suitable for methylmercury fractionation regardless of sample organic matter content. Abstract Amicon Ultra-15 centrifugal filters with nominal molecular weight cut-offs of 100, 30 and 3kDa, were tested for separating Hg complexes in freshwaters. Experiments used Hg-contaminated water from East Fork Poplar Creek (EFPC) and laboratory-prepared Hg solutions containing Suwannee River natural organic matter (SR-NOM). Investigations focussed on Hg and dissolved organic carbon blank levels, Hg sorption and leaching, Hg mass balance closure and spike recoveries of inorganic and methylmercury (MeHg). Hg spike recoveries for EFPC samples were low (57±16%, n=30) due to sorption. MeHg recovery averaged 87±9% (n=15) suggesting it was less affected by sorptive losses. SR-NOM samples yielded similar dissolved organic matter (DOM) and MeHg size fractionation patterns with ~20% of the MeHg found in the less than 3-kDa fraction. Overall, the distribution of MeHg followed a pattern similar to the DOM, indicating the importance of both sample DOM quantity and quality for MeHg partitioning in aquatic systems. Although the use of these ultrafilters for inorganic Hg in freshwater samples is not recommended, they were successfully used for MeHg in EFPC where the majority of MeHg was found to be either dissolved or associated with phases smaller than 3kDa.

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.

scholarly journals Effect of Industrial Wastewater on Fish in Karoon River

2015 ◽  
Vol 17 (1) ◽  
pp. 109-120
Author(s):  
Zahra Khoshnood ◽  
Reza Khoshnood
Keyword(s):  
Industrial Wastewater ◽  
Total Mercury ◽  
Anthropogenic Activities ◽  
Industrial Site ◽  
Hypophthalmichthys Molitrix ◽  
Karoon River ◽  
Muscle Tissues ◽  
Barbus Grypus ◽  
Standard Values ◽  
Total Hg

Abstract In 2009, 36 fish were sampled from two stations in the Karoon River near an industrial site. Two species of fish, Barbus grypus and Hypophthalmichthys molitrix were analyzed for total mercury (Hg) concentration in liver and muscle tissues. The average concentrations of total Hg in liver of B. grypus were 18.92 and 10.19 μg.g-1 in stations 1 and 2 respectively. The corresponding values for total Hg in edible muscle of Barbus grypus were 8.47 and 0.08 μg.g-1. The average concentrations of Hg in the liver of H. molitrix were 25.49 and 12.52 μg.g-1 in stations 1 and 2 respectively. The values for H. molitrix were 11.88 and 3.2 μg.g-1 in station 1 and station 2 respectively. The results showed that the bioavailability of Hg has increased considerably after industrialization and that these values were higher than the standard values as a result of anthropogenic activities in the region.

scholarly journals Population improvement and synthetic cultivar production in forage kale (Brassica oleracea L.)

Euphytica ◽  
2021 ◽  
Vol 217 (7) ◽  
Author(s):  
John E. Bradshaw
Keyword(s):  
Organic Matter ◽  
Annual Cycle ◽  
Dry Matter ◽  
No Reduction ◽  
Optimum Number ◽  
Breeding Method ◽  
Thiocyanate Ion ◽  
Digestible Organic Matter ◽  
Population Improvement ◽  
Field Transplant

AbstractExperimental results are brought together to demonstrate that forage kale population improvement involving full-sib and selfed families can be done on an annual cycle, followed by production of a synthetic cultivar. Furthermore, this new breeding method compares favourably with the two successful methods used to date, namely triple-cross hybrid cultivars from inbreeding and crossbreeding programmes and open-pollinated cultivars from population improvement programmes. The key findings were that natural vernalization of kale in south east Scotland occurred by mid-December so that plants could be pollinated in a glasshouse with heating and lighting by the end of February and seed harvested by the end of May. The resulting full-sib or selfed families could be assessed in a field transplant trial in the same year, from June to November, thus completing an annual cycle. Self-pollination resulted in shorter plants with lower fresh-weight, dry-matter and digestible organic-matter yields, and undesirably higher contents of S-methylcysteine sulphoxide, the haemolytic anaemia factor, and the goitrogenic thiocyanate ion. As a consequence of digestible organic-matter yield being reduced by as much as 22%, the estimated optimum number of selfed parents in a synthetic cultivar was four to eight. Synthetic cultivars are expected to yield as well as triple-cross hybrids as there was no reduction in yield when the latter were open-pollinated.

scholarly journals Bioavailability and bacterial degradation rates of dissolved organic matter in a temperate coastal area during an annual cycle

2009 ◽  
Vol 113 (3-4) ◽  
pp. 219-226 ◽  
Author(s):  
Christian Lønborg ◽  
Keith Davidson ◽  
Xosé A. Álvarez–Salgado ◽  
Axel E.J. Miller
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Annual Cycle ◽  
Coastal Area ◽  
Bacterial Degradation ◽  
Degradation Rates

Methyl mercury in zooplankton—the role of size, habitat, and food quality

2002 ◽  
Vol 59 (10) ◽  
pp. 1606-1615 ◽  
Author(s):  
Martin Kainz ◽  
Marc Lucotte ◽  
Christopher C Parrish
Keyword(s):  
Organic Matter ◽  
Fatty Acid ◽  
Body Size ◽  
Methyl Mercury ◽  
Size Fraction ◽  
Food Sources ◽  
Calanoid Copepods ◽  
Bacterial Food

Pathways of methyl mercury (MeHg) accumulation in zooplankton include ingestion of organic matter (OM). We analyzed fatty acid (FA) biomarkers in zooplankton to (i) investigate the effect of allochthonous and autochthonous OM ingestion on MeHg concentrations ([MeHg]) in zooplankton and (ii) examine how algal and bacterial food sources affect MeHg bioaccumulation. We partitioned bulk zooplankton samples (i.e., >500, 202, 100, and 53 μm) from Lake Lusignan (Québec) and measured [MeHg] and [FA] in each fraction. [MeHg] increased with increasing body size and was significantly higher in pelagic than in littoral macrozooplankton (>500 μm). The amount of the ingested terrestrial FA biomarker 24:0 indicated that less than 1% of the total FA in zooplankton was derived from allochthonous sources. More than 60% of the ingested FA originated from algal biomarkers and <10% from bacterial biomarkers. Relative amounts of algal-derived essential FA and bacterial FA were not associated with [MeHg] in any size fraction. In pelagic zones, the amount of MeHg in zooplankton related positively to the number of large organisms such as Calanoid copepods and Daphnia. We propose that the accumulation of MeHg in lacustrine zooplankton depends on the zooplankton habitat rather than on the quality of ingested food.

Elevated temperatures drive abiotic and biotic degradation of organic matter in a peat bog under oxic conditions

2022 ◽  
Vol 804 ◽  
pp. 150045
Author(s):  
Roya AminiTabrizi ◽  
Katerina Dontsova ◽  
Nathalia Graf Grachet ◽  
Malak M. Tfaily
Keyword(s):  
Organic Matter ◽  
Elevated Temperatures ◽  
Peat Bog ◽  
Biotic Degradation

scholarly journals Determination of methyl mercury and total mercury in sediment samples collected from canals in HoChiMinh city

2016 ◽  
Vol 19 (4) ◽  
pp. 123-136
Author(s):  
Hien Thai Hoang ◽  
Dong Van Nguyen
Keyword(s):  
Reference Material ◽  
Analytical Method ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Inorganic Mercury ◽  
Absorption Spectrometry ◽  
Internal Reference ◽  
Atomic Fluorescence ◽  
Sediment Samples ◽  
Cold Vapour

In this study, the analysis of methyl mercury (MeHg) and total mercury (T-Hg) was studied using gas chromatographic separation/atomic fluorescence spectrometric detection and cold vapour atomic absorption spectrometry respectively. MeHg was extracted from sediment matrix using HNO3/KCl/CuSO4 into dichloromethane followed ethylation with NaB(C2H5)4 in hexane. Total mercury was digested using three different procedures: EPA 245.1, AOAC 971.21 and our proposed one. The reliability of the analytical method for MeHg was evaluated by the use of the certified reference material ERM CC-580. In addition, the analytical method for total merury was evaluated using a fresh water sediment as an internal reference material, spiked with inorganic mercury, methyl mercury and phenyl mercury. The method detection limits for MeHg and total mercury were 0.08 and 0.15 ng/g (as Hg), respectively. The established analytical methods were applied to analyse MeHg and total mercury in sediment samples collected from canals and rivers in Hochiminh City. The concentrations of methyl mercury and total mercury in sediment samples were 0.08–2.87 ng/g và 14 – 623 ng/g (as Hg, dw). [MeHg]/Σ[Hg] respectirely were in a range of 0.1–2.3 %, which was in good agreement with the published ratios in sediment samples. A good correlation between the concentration of MeHg with total mercury and total organic carbon contents in the studied sediment samples was found.

scholarly journals Linking Cellulose Fiber Sediment Methyl Mercury Levels to Organic Matter Decay and Major Element Composition

AMBIO ◽  
2014 ◽  
Vol 43 (7) ◽  
pp. 878-890 ◽  
Author(s):  
Olof Regnell ◽  
Mark Elert ◽  
Lars Olof Höglund ◽  
Anna Helena Falk ◽  
Anders Svensson
Keyword(s):  
Organic Matter ◽  
Methyl Mercury ◽  
Major Element ◽  
Cellulose Fiber ◽  
Element Composition ◽  
Major Element Composition
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