Formation and distribution of methylmercury in sediments at a mariculture site: a mesocosm study

Purpose The aim of the present study was to investigate the differences of methylmercury (MeHg) formation and distribution between mariculture (aquaculture) sediments (MS) and reference sediments (RS) collected from a site in Hong Kong. Materials and methods The MS and RS samples were split into four batches, three of which were spiked with HgCl 2 aqueous solution to a concentration of 0.8, ,2 and 8 mg k g −1 in sediment samples SP1, SP2, and SP3, respectively, while the rest served as a control batch (referred to as C). Results and discussion The results showed that the highly Hg-polluted sediment produced greater amounts of MeHg. During the culture period, MeHg concentrations in sediments decreased over time. The decreasing percentage increased in the order of SP3