Back to Search
Start Over
Evidence for regulation of monomethyl mercury by nitrate in a seasonally stratified, eutrophic lake.
- Source :
-
Environmental science & technology [Environ Sci Technol] 2009 Sep 01; Vol. 43 (17), pp. 6572-8. - Publication Year :
- 2009
-
Abstract
- The accumulation of monomethyl mercury (CH3Hg+) in aquatic ecosystems is a redox sensitive process that is accelerated under sulfate-reducing conditions. While nitrate (NO3-) reduction is energetically favored over sulfate reduction, the influence of NO3 on the accumulation of CH3Hg+ has not been reported in the literature. We examined temporal and vertical patterns in redox constituents and CH3Hg+ concentrations in the hypolimnion of a dimictic lake, Onondaga Lake, prior to and following increases in NO3- inputs. Detailed water-column profiles and a long-term record revealed marked decreases in the accumulation of CH3Hg+ in the anoxic hypolimnion coinciding with long-term decreases in the deposition of organic matter coupled with recent increases in NO3-concentrations. CH3Hg+ concentrations in the hypolimnion were substantially abated when No3 was present above the sediment-water interface. A decrease in the peak hypolimnetic mass of CH3Hg+ and shortening of the period of elevated CH3Hg+ concentrations resulted in more than a 50% decline in the accumulated CH3Hg+. N03- regulation of CH3Hg+ accumulation may be a widespread phenomenon in oxygen-limited freshwater and terrestrial environments, and could have an important notpreviously recognized, effect on the biogeochemistry of mercury.
- Subjects :
- Environmental Monitoring
Fresh Water microbiology
Methylmercury Compounds analysis
New York
Oxidation-Reduction
Oxygen analysis
Oxygen chemistry
Sulfates analysis
Sulfates chemistry
Sulfides analysis
Sulfides chemistry
Water Pollutants, Chemical analysis
Eutrophication
Fresh Water chemistry
Methylmercury Compounds chemistry
Nitrates chemistry
Seasons
Water Pollutants, Chemical chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 0013-936X
- Volume :
- 43
- Issue :
- 17
- Database :
- MEDLINE
- Journal :
- Environmental science & technology
- Publication Type :
- Academic Journal
- Accession number :
- 19764219
- Full Text :
- https://doi.org/10.1021/es900887b