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.

Rapid Semimicro Method for the Determination of Methyl Mercury in Fish Tissue

1972 ◽  
Vol 55 (3) ◽  
pp. 583-589 ◽  
Author(s):  
J F Uthe ◽  
J Solomon ◽  
B Grift
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Aqueous Ethanol ◽  
Fish Tissue ◽  
Mercuric Iodide ◽  
Mercury In Fish ◽  
Layer Chromatography

Abstract A fast semimicro method for the determination of methyl mercury in fish tissue is described. The procedure involves extracting the methyl mercury into toluene as methyl mercuric bromide, partitioning the bromide into aqueous ethanol as a thiosulfate complex, and re-extracting into benzene as methyl mercuric iodide. Methyl mercury is quantitated with gas chromatography. The method is sensitive to 0.01 ppm. Recoveries of added methyl mercury were 99% and the presence of methyl mercury in the final extract was shown by thin layer chromatography and gas chromatography of the thin layer spot. A variety of mercurial compounds do not interfere in the analyses. The amounts of both methyl and total mercury found in a variety of tissues of aquatic animals are compared. The presence of a demethylase in seal is suggested by the findings of high levels of nonmethyl mercury. Additional cleanup by column chromatography on Florisil was necessary with certain samples. The gas chromatographic columns were kept operational by the intermittent injection of 3M potassium iodide. Due to column bleed and resulting detector contamination, the use of the easily cleaned concentric tube electron capture detector is recommended.

Seasonal Variations in Net Methyl Mercury Production and Total Mercury Removal in a Constructed Wetland

2008 ◽  
Author(s):  
Prithviraj V. Chavan ◽  
Keith E. Dennett ◽  
Mae Sexauer Gustin ◽  
Eric A. Marchand
Keyword(s):  
Constructed Wetland ◽  
Seasonal Variations ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Mercury Removal ◽  
Mercury Production

Mercury in fish in the Derwent Estuary, Tasmania, and its relation to the position of the fish in the food chain

1975 ◽  
Vol 26 (2) ◽  
pp. 223 ◽  
Author(s):  
DA Ratkowsky ◽  
TG Dix ◽  
KC Wilson
Keyword(s):  
Heavy Metals ◽  
Food Chain ◽  
Total Mercury ◽  
Mercury Content ◽  
Food Regulation ◽  
A Value ◽  
Invertebrate Predators ◽  
Mercury In Fish ◽  
Zinc Cadmium ◽  
High Concentrations

Total mercury concentrations are reported for 258 individuals representing 16 species of finfish from the Derwent Estuary, Tasmania. Mercury concentrations in the muscle tissue varied between undetectable levels and a value of 2.0 mg/kg in one specimen of a species of shark. Irrespective of species, the area encompassing Ralphs Bay contained a higher percentage of fish with mercury concentrations in excess of the Tasmanian Food Regulation limit of 0.5 mg/kg than any other area of the Estuary. RaIphs Bay is the area in which oysters were found in a previous study to contain extraordinarily high concentrations of other heavy metals, particularly zinc, cadmium and copper. The fish's position in the food chain appeared to be an important factor determining its mercury content. Approximately 51 % of individual fish of species whose diet consists predominantly of other fish had mercury concentrations in excess of 0.5 mg/kg. In contrast, 24% of invertebrate predators and only 7 % of individuals of herbivorous habit had mercury concentrations in excess of 0.5 mg/kg.

scholarly journals Why the English–Wabigoon river system is still polluted by mercury 57 years after its contamination

FACETS ◽  
2021 ◽  
Vol 6 ◽  
pp. 2002-2027
Author(s):  
John W.M. Rudd ◽  
Carol A. Kelly ◽  
Patricia Sellers ◽  
Robert J. Flett ◽  
Bruce E. Townsend
Keyword(s):  
Surface Sediment ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Inorganic Mercury ◽  
River System ◽  
Lake Surface ◽  
Riverbank Erosion ◽  
Plant Site ◽  
High Mercury ◽  
Mercury Production

Between 1962 and 1969, 10 tonnes of mercury were discharged from a chlor-alkali plant in Dryden, Ontario, to the English–Wabigoon River. Present-day fish mercury concentrations are amongst the highest recorded in Canada. In 2017, the Grassy Narrows Science Team found no evidence of ongoing discharges from the plant site to the river water, even though large quantities of mercury remain at the site. Instead, our data suggest that ongoing erosion of high mercury particles by the river, as it meanders through contaminated floodplains, is responsible for present-day transport of mercury to Clay Lake and to Ball Lake, located 154 km downstream. In Clay Lake, surface sediment total mercury concentrations and inflow water concentrations are still about 15 times above background (86 km downstream), and in Ball Lake mercury concentrations in sediments appeared to be still increasing. The remobilization of legacy inorganic mercury from riverbank erosion between Dryden and Clay Lake stimulates methyl mercury production there, in Clay Lake, and in Ball Lake. The large quantities of methyl mercury produced between Dryden and Clay Lake are mostly dissolved in water and are swept downstream, elevating concentrations in water and biota throughout the system. Several options for remediating the ongoing contamination are discussed.

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.

Gas Chromatographic Determination of Methyl Mercury in Fish, Sediment, and Water

1973 ◽  
Vol 56 (6) ◽  
pp. 1297-1303 ◽  
Author(s):  
James E Longbottom ◽  
Ronald C Dressman ◽  
James J Lichtenberg
Keyword(s):  
Water Samples ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Inorganic Mercury ◽  
Chromatographic Determination ◽  
Chloride Salt ◽  
Mercury In Fish ◽  
Cleanup Procedure ◽  
Very High

Abstract Methyl mercury is extracted as the bromide salt from fish and sediment and as the chloride salt from water samples. All extracts are treated with a common cleanup procedure that results in the conversion of methyl mercury to the iodide salt for electron capture gas chromatographic analysis. Recoveries ranged from an average of 88.5% for water samples to averages of 95.5 and 96.3% for perch and sediments. Methods for controlling contaminants and interferences are discussed for all phases of the method. Particular problems encountered were column poisoning and detector poisoning. When the method was applied to sediment samples collected from a polluted river, a correlation could be established between total mercury and methyl mercury when the concentration of total mercury was in the 0–10 μg/g region. For samples of very high inorganic mercury, the correlation failed.

Distribution, hydrologic transport, and cycling of total mercury and methyl mercury in a contaminated river-reservoir-wetland system (Sudbury River, eastern Massachusetts)

2000 ◽  
Vol 57 (5) ◽  
pp. 1080-1091 ◽  
Author(s):  
Marcus C Waldron ◽  
John A Colman ◽  
Robert F Breault
Keyword(s):  
Point Source ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Riparian Wetlands ◽  
Riparian Wetland ◽  
Net Production ◽  
Stream Discharge ◽  
River Reservoir ◽  
Flow Through ◽  
Eastern Massachusetts

Riparian wetlands contaminated with Hg from an industrial point source were found to be important sites of production and release of methyl mercury (MeHg) in a 40-km reach of the Sudbury River in eastern Massachusetts. Stream discharge and concentration measurements were used to calculate annual mean loads for total Hg (ΣHg) and MeHg in contaminated river reaches, a reservoir, and a riparian wetland downstream from the industrial source. Budgets based on these loads indicate that the annual mean ΣHg load increased sixfold in a reach receiving flow from the point source, but the annual mean MeHg load did not increase. About 23% of the ΣHg load was removed by sedimentation during flow through the reservoir. Net production of MeHg in the reservoir was similar to that reported elsewhere for lakes receiving Hg from atmospheric deposition only. ΣHg concentrations and loads increased significantly as the river passed through the riparian wetland reach. On the basis of flooded wetland area, net production of MeHg was 15 times greater in the wetland reach than in wetland-associated drainages described in other studies.

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