Importance of a Coastal Artificial Lake in Methylmercury Production: A Case Study of Lake Changpo, Korea

• Published in: Ocean science journal Vol. 54; no. 1; pp. 51 - 64
• Main Authors: Kundu, Sampa Rani, Kim, Eunhee, Han, Seunghee, Lee, Byeong-Gweon
• Format: Journal Article
• Language: English
• Published: Seoul Korea Institute of Ocean Science & Technology and The Korean Society of Oceanography 01.01.2019; Springer Nature B.V; 한국해양과학기술원
• Subjects: Agricultural land; Aquatic Pollution; Artificial lakes; Case studies; Distribution patterns; Earth and Environmental Science; Earth Sciences; Fish; Freshwater; Freshwater fishes; Freshwater lakes; Inland water environment; Lakes; Marine & Freshwater Sciences; Mercury; Methyl mercury; Methylmercury; Oceanography; Organic matter; Rainy season; Sediment; Sediment samplers; Sediment samples; Sediments; Spatial distribution; Suspended particulate matter; Temporal distribution; Total suspended solids; Waste Water Technology; Water column; Water Management; Water Pollution Control; Wet season; 해양학; South Korea; methylmercury; coastal artificial lake; mercury; lake Changpo; mercury methylation
• ISSN: 1738-5261; 2005-7172
• DOI: 10.1007/s12601-018-0064-5

Lake Changpo (LC) is an artificial freshwater lake surrounded by wetlands and farmlands, inundated with water during the wet season, on the southwest coast of Korea. To investigate the temporal and spatial distribution of total mercury (THg) and methylmercury (MeHg) in LC and adjacent Cheonggye Bay (CB), water and sediment samples were collected five times from August 2009 to August 2010. In addition, fish samples were collected to examine Hg levels. The THg concentration in the unfiltered water of LC ranged from 1.6 to 5.0 ng/L and had a positive relationship with total suspended solids (TSS). This positive relation indicates that TSS is an important source of THg in LC. The MeHg levels were highest during August and ranged from 0.03 to 0.19 ng/L in unfiltered water and from 0.01 to 0.10 ng/L in filtered water. Both the THg and MeHg levels in the sediments were significantly correlated with the organic matter content of the sediments. Overlapping of the spatial and temporal distribution patterns of MeHg and %MeHg between the water column and sediments suggests that production and diffusion of MeHg from the sediment, particularly during warm summer, was the primary source of MeHg in the water column. In addition, higher THg and MeHg concentrations were found in catfish, a bottom-dweller fish. Thus, the higher THg and MeHg concentrations in LC compared to CB demonstrate that artificial lakes could be a significant site for Hg methylation and an additional source of MeHg to coastal seas.