کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4431263 | 1619894 | 2009 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Temporal analysis of net fluvial methylmercury loading in a dystrophic and a clear water lake Temporal analysis of net fluvial methylmercury loading in a dystrophic and a clear water lake](/preview/png/4431263.png)
The concentration of methylmercury (MeHg) in aquatic ecosystems is the net result of the highly dynamic abiotic and biotic processes of mercury methylation and demethylation. In this study, we conduct an examination of the net fluvial loading of methylmercury (MeHgNet = MeHgWatershed − MeHgLake outflow) across a 3 year time frame in both a dystrophic lake and an oligotrophic lake. A significant portion of MeHgNet variance in both lakes could be attributed to a seasonal pattern (11.4%, p = 0.009; oligotrophic, and 27.0%, p < 0.0001; dystrophic) which in both cases, was most correlated with air temperature. The dystrophic lake appeared to be a net source of methylmercury (MeHgNet = − 1.9 ± 0.3 mg MeHg d− 1) while the oligotrophic lake appeared to be a net sink (MeHgNet = 0.4 ± 0.2 mg MeHg d− 1), indicating that there was net methylation in the dystrophic lake and net demethylation in the oligotrophic lake. Higher MeHg loading to the lakes occurred during the summer and between seasons there was a difference in MeHgNet of 1.1 ±0.3 mg MeHg d− 1 and 3.1 ± 0.6 mg MeHg d− 1. Seasonal patterns of MeHgNet in the oligotrophic lake lagged behind the dystrophic lake by 39 days. The short term variation in MeHgNet was dominated by precipitation (t = 2.73, p = 0.008; dystrophic, t = 2.53, p = 0.017; oligotrophic).
Journal: Science of The Total Environment - Volume 407, Issue 16, 1 August 2009, Pages 4696–4702