Bioavailability of sediment-associated mercury toHexageniamayflies in a contaminated floodplain river

2000 ◽  
Vol 57 (5) ◽  
pp. 1092-1102 ◽  
Author(s):  
Teresa J Naimo ◽  
James G Wiener ◽  
W Gregory Cope ◽  
Nicolas S Bloom
Keyword(s):  
Food Chain ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Dry Weight ◽  
Contaminated Sediments ◽  
Floodplain River ◽  
Test Water ◽  
Benthic Food

We examined the bioavailability of mercury in sediments from the contaminated Sudbury River (Massachusetts, U.S.A.). Mayfly nymphs (Hexagenia) were exposed in four 21-day bioaccumulation tests to contaminated and reference sediments (treatments) from reservoirs, flowing reaches, palustrine wetlands, and a riverine lake. Mean total mercury (ΣHg) ranged from 880 to 22 059 ng·g dry weight-1in contaminated sediments and from 90 to 272 ng·g-1in reference sediments. Mean final concentrations of methyl mercury (MeHg) in test water were greatest (8-47 ng Hg·L-1) in treatments with contaminated wetland sediments, which had mean ΣHg ranging from 1200 to 2562 ng·g-1. In mayflies, final mean concentrations of MeHg were highest in treatments with contaminated wetland sediments (122-183 ng Hg·g-1), intermediate in treatments with contaminated sediments from reservoirs, flowing reaches, and a riverine lake (75-127 ng Hg·g-1), and lowest in treatments with reference sediments (32-41 ng Hg·g-1). We conclude that the potential entry of MeHg into the benthic food chain was greater in contaminated palustrine wetlands than in the contaminated reservoirs, which had the most contaminated sediments.

Mercury in the Sudbury River (Massachusetts, U.S.A.): pollution history and a synthesis of recent research

2000 ◽  
Vol 57 (5) ◽  
pp. 1053-1061 ◽  
Author(s):  
James G Wiener ◽  
Pamela J Shields
Keyword(s):  
Contaminated Soils ◽  
Methyl Mercury ◽  
Total Mercury ◽  
Sediment Cores ◽  
Inorganic Mercury ◽  
Dry Weight ◽  
Mercury Accumulation ◽  
Industrial Complex ◽  
Pollution History ◽  
Industrial Operations

We review the transport, fate, and bioavailability of mercury in the Sudbury River, topics addressed in the following five papers. Mercury entered the river from an industrial complex (site) that operated from 1917 to 1978. Rates of mercury accumulation in sediment cores from two reservoirs just downstream from the site decreased soon after industrial operations ended and have decreased further since capping of contaminated soils at the site in 1991. The reservoirs contained the most contaminated sediments (some exceeding 50 μg Hg·g dry weight-1) and were depositional sinks for total mercury. Methyl mercury concentrations in biota did not parallel concentrations of total mercury in the sediments to which organisms were exposed, experimentally or as residents. Contaminated wetlands within the floodplain about 25 km downstream from the site produced and exported methyl mercury from inorganic mercury that had originated from the site. Natural burial processes have gradually decreased the quantity of sedimentary mercury available for methylation within the reservoirs, whereas mercury in the lesser contaminated wetlands farther downstream has remained more available for transport, methylation, and entry into food webs.

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 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.

The Organic carbon content of gravel bed herring spawning grounds and the impact of herring spawn deposition

1993 ◽  
Vol 73 (4) ◽  
pp. 863-870 ◽  
Author(s):  
Ian R. Napier
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Dry Weight ◽  
Published Data ◽  
Organic Carbon Content ◽  
Spawning Grounds ◽  
The Past ◽  
Benthic Food ◽  
The Impact

The dry weight and organic carbon content of eggs and components of Clyde spring herring eggs were measured at intervals during their development. Comparison with previously published data suggests that an increase has occurred in the weight of these eggs over the past thirty years. It is clear that only a small proportion of the material deposited in the form of herring spawn actually remains attached to the substratum when the larvae hatch and so is available for potential integration into the benthic food web. This was confirmed by the determination at intervals over two years of the organic carbon content of the gravel sediments on spawning grounds of the Clyde spring herring. Although the deposition of herring spawn resulted in an immediate marked increase in the carbon content of the spawning ground sediments, carbon levels quickly returned to pre-spawning levels and there was no evidence of any permanent or long lasting increase. This held true when the spawn died and decayed in situ and even when it was mixed into the sediment by wave action. The rapid decrease in carbon levels is attributed to the strong water movements which frequently occur over the spawning grounds.

scholarly journals Indirect Effects of Predation in a Freshwater, Benthic Food Chain

Ecology ◽  
1992 ◽  
Vol 73 (5) ◽  
pp. 1662-1674 ◽  
Author(s):  
Christer Bronmark ◽  
Steven P. Klosiewski ◽  
Roy A. Stein
Keyword(s):  
Food Chain ◽  
Indirect Effects ◽  
Benthic Food

A Comparison of Mercury Contamination in Mussel and Ammocoete Filter Feeders

2010 ◽  
Vol 1 (2) ◽  
pp. 142-145 ◽  
Author(s):  
Jamie B. Bettaso ◽  
Damon H. Goodman
Keyword(s):  
Methyl Mercury ◽  
Total Mercury ◽  
Mercury Contamination ◽  
Teleost Fishes ◽  
Trinity River ◽  
Longitudinal Gradients ◽  
History Of ◽  
Filter Feeders ◽  
The Trinity ◽  
Mercury Mining

Abstract The Trinity River, California, has an extensive history of gold and mercury mining, and recent studies demonstrated uptake of legacy mercury contamination by teleost fishes. We investigated mercury concentrations of larval lampreys (ammocoetes; Entosphenus spp.) and western pearlshell mussels (Margaritifera falcata) in the Trinity River to determine whether these two long-lived and sedentary filter feeders show site-specific differences in uptake of this contaminant. We analyzed ammocoetes from four sites in the Trinity River and one reference site in the Mad River for total mercury and mussels from three of the Trinity River sites for total and methyl mercury. We identified longitudinal gradients in ammocoete total mercury levels and methyl mercury in mussels. We found a 70% increase in total mercury in ammocoetes between two of the sample sites, suggesting a potential point source of contamination. Ammocoetes contained levels of mercury 12 to 25 times those of mussels from the same site. Our data indicate that ammocoetes may be a preferred organism to sample for mercury contamination and ecological effects compared with mussels in the Trinity River.

Trophic Structure and Biomagnification of Total Mercury in Ray Species Within a Benthic Food Web

2019 ◽  
Vol 77 (3) ◽  
pp. 321-329 ◽  
Author(s):  
Daniela A. Murillo-Cisneros ◽  
Todd M. O’Hara ◽  
Fernando R. Elorriaga-Verplancken ◽  
Alberto Sánchez-González ◽  
Emigdio Marín-Enríquez ◽  
...  
Keyword(s):  
Food Web ◽  
Trophic Structure ◽  
Total Mercury ◽  
Benthic Food Web ◽  
Benthic Food

Evaluation of claws as an alternative route of mercury elimination from the herring gull (Larus argentatus)

2019 ◽  
Vol 48 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Agnieszka Grajewska ◽  
Lucyna Falkowska ◽  
Andrzej Reindl
Keyword(s):  
Alimentary Tract ◽  
Total Mercury ◽  
Dry Weight ◽  
The Body ◽  
Larus Argentatus ◽  
Organic Form ◽  
Internal Organs ◽  
Epidermal Structure ◽  
Herring Gulls ◽  
Wide Range

Abstract Mercury enters the body of seabirds in its most toxic organic form, i.e. methylmercury, mainly via the alimentary tract. Inside the body, mercury is transformed into less toxic forms and accumulates in the internal organs. The process of mercury removal from the body, most effective during the formation of new feathers and claws, is beneficial for the bird. The presented research was undertaken on account of the high affinity of mercury to keratin – a protein that forms feathers and claws – to compare the concentration levels (HgTOT) in these structures and to assess their contribution to the purification of the body of herring gulls (Larus argentatus) Bird feathers are the only epidermal structure that is extensively described in the literature, whereas the claws have so far been poorly researched. The study has shown that mercury in claws is built in as effectively as in feathers, and the obtained concentrations were within a wide range of 127.2–5341.5 ng HgTOT g–1 of dry weight. In addition, the concentrations of total mercury accumulated in the claws were a better reflection of Hg levels in internal organs compared to feathers.

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.

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