Role of mariculture in the loading and speciation of mercury at the coast of the East China Sea.
The effects of mariculture on mercury (Hg) contamination and speciation in water, sediment and cultured fish in a typical mariculture zone located in Xiangshan bay, Zhejiang province, east China, were studied. Water, sediment and fish samples were collected from mariculture sites (MS) and from corresponding reference sites (RS) 2500 m away from the MS. The THg concentration in overlying water in Xiangshan bay reached as high as 16.6 ± 19.5 ng L-1, indicating that anthropogenic sources in this bay may contribution on Hg contamination in overlying water. Mariculture activities resulted in an increase in THg concentration in water from surface and bottom layers, which may be attributed to the discharge of domestic sewage and the accumulation of unconsumed fish feed and fish excreta in the benthic environment. Methylmercury (MeHg) concentrations in the bottom layer of overlying water and top surface layer of porewater underneath MS were higher than at RS, implying that mariculture activities promote Hg methylation in the interface between sediments and water. In addition, the concentrations of MeHg in sediment and porewater were significantly higher in summer than winter. It was observed that THg and MeHg contents in the muscle of blackhead seabream (Acanthopagrus schlegelii) (fed by the trash fish) were significantly higher (p < 0.001) than those in red snapper (Lutjanus campechanus) or perch (Perca fluviatilis) (fed by pellet fish feed). The THg and MeHg concentrations in the fish meat were closely related to the feeding mode, which indicate that fish feed rather than environmental media is the major pathway for Hg accumulation in fish muscle.
School of Environmental and Resource Sciences, Zhejiang Agricultural and Forest University, Lin'an, Zhejiang Province 311300, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Lin'an, Zhejiang Province 311300, China; Department of Science and Environmental Studies, The Hong Kong University of Education, Tai Po, Hong Kong Special Administrative Region.
Peng
P
Liang
School of Environmental and Resource Sciences, Zhejiang Agricultural and Forest University, Lin'an, Zhejiang Province 311300, China.
Xuefei
X
Gao
School of Environmental and Resource Sciences, Zhejiang Agricultural and Forest University, Lin'an, Zhejiang Province 311300, China.
Qiongzhi
Q
You
School of Environmental and Resource Sciences, Zhejiang Agricultural and Forest University, Lin'an, Zhejiang Province 311300, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Lin'an, Zhejiang Province 311300, China.
Jin
J
Zhang
School of Environmental and Resource Sciences, Zhejiang Agricultural and Forest University, Lin'an, Zhejiang Province 311300, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Lin'an, Zhejiang Province 311300, China.
Yucheng
Y
Cao
College of Law and Political Science, Zhejiang Agriculture and Forestry University, Lin'an, Zhejiang Province 311300, China.
Chan
C
Zhang
Department of Science and Environmental Studies, The Hong Kong University of Education, Tai Po, Hong Kong Special Administrative Region.
Ming-Hung
MH
Wong
School of Environmental and Resource Sciences, Zhejiang Agricultural and Forest University, Lin'an, Zhejiang Province 311300, China; Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province, Lin'an, Zhejiang Province 311300, China. Electronic address: shengchunwu@126.com.
Sheng-Chun
SC
Wu
D000818:Animals; D002681:China; D004777:Environment; D004784:Environmental Monitoring; D005399:Fishes / Q000254:growth & development / Q000378:metabolism*; D008767:Methylmercury Compounds / Q000737:chemistry* / Q000378:metabolism; D017747:Seafood / Q000032:analysis; D012623:Seawater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000378:metabolism
D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical
Aquaculture; Marine ecosystem; Mercury; Organic matter