Croucher Institute of Environmental Sciences, Department of Biology, Hong Kong Baptist University, PR China.
Chemosphere. 2011 Feb;82(7):1038-43. doi: 10.1016/j.chemosphere.2010.10.061. Epub 2010 Nov 13.
To study the influence of mariculture on mercury (Hg) speciation and distribution in sediments and cultured fish around Hong Kong and adjacent mainland China waters, sediment samples were collected from six mariculture sites and the corresponding reference sites, 200-300 m away from the mariculture sites. Mariculture activities increased total mercury, organic matter, carbon, nitrogen and sulfur concentrations in the surface sediments underneath mariculture sites, possibly due to the accumulation of unconsumed fish feed and fish excretion. However, methylmercury (MeHg) concentrations and the ratio of MeHg to THg (% MeHg) in sediments underneath mariculture sites were lower than the corresponding reference sites. The % MeHg in sediments was negatively correlated (r = -0.579, p < 0.05) with organic matter (OM) content among all sites, indicating that OM may have inhibited Hg methylation in surface sediments. Three mariculture fish species were collected from each mariculture site, including red snapper (Lutjanus campechanus), orange-spotted grouper (Epinephelus coioides) and snubnose pompano (Trachinotus blochii). The average MeHg concentration in fish muscle was 75 μg kg⁻¹ (wet weight), and the dietary intake of MeHg through fish consumption for Hong Kong residents was 0.37 μg kg⁻¹ week⁻¹, which was lower than the corresponding WHO limits (500 μg kg⁻¹ and 1.6 μg kg⁻¹ week⁻¹).
为了研究水产养殖对香港及周边中国大陆水域沉积物和养殖鱼类中汞（Hg）形态和分布的影响，采集了六个水产养殖区及其对应参照区的沉积物样本，这些样本距离水产养殖区 200-300 米。水产养殖活动增加了水产养殖区底泥中的总汞、有机质、碳、氮和硫的浓度，这可能是由于未消耗的鱼饲料和鱼类排泄物的积累。然而，水产养殖区底泥中的甲基汞（MeHg）浓度和 MeHg 与总汞（THg）的比例（% MeHg）低于相应的参照区。所有采样点中，沉积物中的% MeHg 与有机质（OM）含量呈负相关（r = -0.579，p < 0.05），表明 OM 可能抑制了表层沉积物中 Hg 的甲基化。从每个水产养殖区采集了三种养殖鱼类，包括红鲷鱼（Lutjanus campechanus）、青石斑鱼（Epinephelus coioides）和金鼓鱼（Trachinotus blochii）。鱼类肌肉中的平均 MeHg 浓度为 75 μg kg⁻¹（湿重），香港居民通过食用鱼类摄入的 MeHg 为 0.37 μg kg⁻¹周⁻¹，低于世界卫生组织（WHO）的相应限量（500 μg kg⁻¹和 1.6 μg kg⁻¹周⁻¹）。
