title: The influence of mariculture on mercury distribution in sediments and fish around Hong Kong and adjacent mainland China waters.
abstract: 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).
authors.affiliation: Croucher Institute of Environmental Sciences, Department of Biology, Hong Kong Baptist University, PR China.
authors.forename: Peng
authors.initials: P
authors.lastname: Liang
authors.forename: Ding-Ding
authors.initials: DD
authors.lastname: Shao
authors.forename: Sheng-Chun
authors.initials: SC
authors.lastname: Wu
authors.forename: Jian-Bo
authors.initials: JB
authors.lastname: Shi
authors.forename: Xiao-lin
authors.initials: XL
authors.lastname: Sun
authors.forename: Fu-Yong
authors.initials: FY
authors.lastname: Wu
authors.forename: S C L
authors.initials: SC
authors.lastname: Lo
authors.forename: Wen-Xiong
authors.initials: WX
authors.lastname: Wang
authors.forename: Ming H
authors.initials: MH
authors.lastname: Wong
mesh_terms: D000818:Animals; D017756:Aquaculture; D002244:Carbon / Q000032:analysis; D002681:China; D004032:Diet / Q000706:statistics & numerical data; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D005260:Female; D019015:Geologic Sediments / Q000737:chemistry*; D006801:Humans; D008628:Mercury / Q000032:analysis* / Q000378:metabolism; D009132:Muscles / Q000378:metabolism; D009584:Nitrogen / Q000032:analysis; D009792:Oceans and Seas; D010473:Perciformes / Q000378:metabolism*; D018570:Risk Assessment; D017747:Seafood / Q000032:analysis / Q000706:statistics & numerical data; D013455:Sulfur / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D014874:Water Pollutants, Chemical; D013455:Sulfur; D002244:Carbon; D008628:Mercury; D009584:Nitrogen