TY - JOUR
T1 - Changes in the long-term supply of mercury species to the upper mixed waters of a recovering lake
AU - Todorova, Svetoslava G.
AU - Driscoll, Charles T.
AU - Effler, Steven W.
AU - O'Donnell, Susan
AU - Matthews, David A.
AU - Todorov, Dimitar L.
AU - Gindlesperger, Stephanie
N1 - Funding Information:
Support for this work was provided by U.S. EPA and Honeywell, Inc. in terms of graduate assistantship and research funding. The opinions expressed and conclusions reached do not represent those of the funding agencies. This is contribution No. 316 of the Upstate Freshwater Institute.
PY - 2014/2
Y1 - 2014/2
N2 - We quantified internal processes that supply methylmercury from hypolimnetic reducing zones to the upper waters of a Hg-contaminated lake, Onondaga Lake, NY, USA. Diffusive transport continuously supplied methylmercury to the epilimnion under summer stratification, while fall mixing resulted in a pulsed release of methylmercury to the upper mixed waters. These processes were the main internal sources of methylmercury to the epilimnion, and together almost equaled the total external supply. The wind-driven entrainment represented an additional stochastic internal supply of methylmercury of approximately 9% in 2006. Considering more than 15 years of data, we estimate 1.8 wind-driven events occur per year. The mass of methylmercury inputs to the epilimnion exceeded the measured increase, suggesting that loss processes are important in regulating methylmercury accumulation. The relative contribution of internal sources of methylmercury to the epilimnion has decreased in recent years, shifting the importance to the external inputs.
AB - We quantified internal processes that supply methylmercury from hypolimnetic reducing zones to the upper waters of a Hg-contaminated lake, Onondaga Lake, NY, USA. Diffusive transport continuously supplied methylmercury to the epilimnion under summer stratification, while fall mixing resulted in a pulsed release of methylmercury to the upper mixed waters. These processes were the main internal sources of methylmercury to the epilimnion, and together almost equaled the total external supply. The wind-driven entrainment represented an additional stochastic internal supply of methylmercury of approximately 9% in 2006. Considering more than 15 years of data, we estimate 1.8 wind-driven events occur per year. The mass of methylmercury inputs to the epilimnion exceeded the measured increase, suggesting that loss processes are important in regulating methylmercury accumulation. The relative contribution of internal sources of methylmercury to the epilimnion has decreased in recent years, shifting the importance to the external inputs.
KW - Diffusive mixing
KW - Entrainment
KW - Methyl mercury
KW - Onondaga Lake
KW - Turnover
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U2 - 10.1016/j.envpol.2013.11.005
DO - 10.1016/j.envpol.2013.11.005
M3 - Article
C2 - 24316069
AN - SCOPUS:84889644917
SN - 0269-7491
VL - 185
SP - 314
EP - 321
JO - Environmental Pollution
JF - Environmental Pollution
ER -