Mercury methylation in the hypolimnetic waters of lakes with and without connection to wetlands in northern Wisconsin
(2005) In Canadian Journal of Fisheries and Aquatic Sciences 62(2). p.400-411- Abstract
- Rates of Hg methylation and demethylation were measured in anoxic hypolimnetic waters of two pristine Wisconsin lakes using stable isotopes of Hg as tracers. One of the lakes is a clear-water seepage lake situated in sandy terrain with minimal wetland influence. The other is a dark-water lake receiving channelized inputs from a relatively large terrestrial wetland. Methyl mercury (MeHg) accumulated in the anoxic hypolimnia of both lakes during summer stratification, reaching concentrations of 0.8 ng center dot L-1 in the clear-water lake and 5 ng center dot L-1 in the dark-water lake. The stable isotopic assays indicated that rate constants of Hg-(II) methylation (K-m) ranged from 0.01 to 0.04 center dot day(-1) in the clear-water lake and... (More)
- Rates of Hg methylation and demethylation were measured in anoxic hypolimnetic waters of two pristine Wisconsin lakes using stable isotopes of Hg as tracers. One of the lakes is a clear-water seepage lake situated in sandy terrain with minimal wetland influence. The other is a dark-water lake receiving channelized inputs from a relatively large terrestrial wetland. Methyl mercury (MeHg) accumulated in the anoxic hypolimnia of both lakes during summer stratification, reaching concentrations of 0.8 ng center dot L-1 in the clear-water lake and 5 ng center dot L-1 in the dark-water lake. The stable isotopic assays indicated that rate constants of Hg-(II) methylation (K-m) ranged from 0.01 to 0.04 center dot day(-1) in the clear-water lake and from 0.01 to 0.09 center dot day(-1) in the dark-water lake, depending on the depth stratum. On average, K-m was threefold greater in the dark-water lake. Hypolimnetic demethylation rate constants (K-dm) averaged 0.03 center dot day(-1) in the clear-water lake and 0.05 center dot day(-1) in the dark-water lake. These methylation rates were sufficient to account for the observed accumulation of MeHg in hypolimnetic water during summer in both lakes. Despite substantial export of MeHg from the wetland to the dark-water lake, our study indicates that in-lake production and decomposition of MeHg dominated the MeHg cycle in both lakes. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/146156
- author
- Eckley, CS ; Watras, CJ ; Hintelmann, H ; Morrison, K ; Kent, AD and Regnell, Olof LU
- organization
- publishing date
- 2005
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Canadian Journal of Fisheries and Aquatic Sciences
- volume
- 62
- issue
- 2
- pages
- 400 - 411
- publisher
- Canadian Science Publishing, NRC Research Press
- external identifiers
-
- wos:000228083800015
- scopus:21244456473
- ISSN
- 1205-7533
- DOI
- 10.1139/F04-205
- language
- English
- LU publication?
- yes
- id
- b1cc0efe-9f1e-495f-9b0b-979d6a2556ac (old id 146156)
- alternative location
- http://pubs.nrc-cnrc.gc.ca/cgi-bin/rp/rp2_abst_e?cjfas_f04-205_62_ns_nf_cjfas2-05
- date added to LUP
- 2016-04-01 12:26:50
- date last changed
- 2022-03-05 23:38:38
@article{b1cc0efe-9f1e-495f-9b0b-979d6a2556ac,
abstract = {{Rates of Hg methylation and demethylation were measured in anoxic hypolimnetic waters of two pristine Wisconsin lakes using stable isotopes of Hg as tracers. One of the lakes is a clear-water seepage lake situated in sandy terrain with minimal wetland influence. The other is a dark-water lake receiving channelized inputs from a relatively large terrestrial wetland. Methyl mercury (MeHg) accumulated in the anoxic hypolimnia of both lakes during summer stratification, reaching concentrations of 0.8 ng center dot L-1 in the clear-water lake and 5 ng center dot L-1 in the dark-water lake. The stable isotopic assays indicated that rate constants of Hg-(II) methylation (K-m) ranged from 0.01 to 0.04 center dot day(-1) in the clear-water lake and from 0.01 to 0.09 center dot day(-1) in the dark-water lake, depending on the depth stratum. On average, K-m was threefold greater in the dark-water lake. Hypolimnetic demethylation rate constants (K-dm) averaged 0.03 center dot day(-1) in the clear-water lake and 0.05 center dot day(-1) in the dark-water lake. These methylation rates were sufficient to account for the observed accumulation of MeHg in hypolimnetic water during summer in both lakes. Despite substantial export of MeHg from the wetland to the dark-water lake, our study indicates that in-lake production and decomposition of MeHg dominated the MeHg cycle in both lakes.}},
author = {{Eckley, CS and Watras, CJ and Hintelmann, H and Morrison, K and Kent, AD and Regnell, Olof}},
issn = {{1205-7533}},
language = {{eng}},
number = {{2}},
pages = {{400--411}},
publisher = {{Canadian Science Publishing, NRC Research Press}},
series = {{Canadian Journal of Fisheries and Aquatic Sciences}},
title = {{Mercury methylation in the hypolimnetic waters of lakes with and without connection to wetlands in northern Wisconsin}},
url = {{https://lup.lub.lu.se/search/files/2927065/625084.pdf}},
doi = {{10.1139/F04-205}},
volume = {{62}},
year = {{2005}},
}