Mercury accumulation in hydrothermal vent mollusks from the southern Tonga Arc, southwestern Pacific Ocean.
We provide the mercury (Hg) and monomethylmercury (MMHg) levels of the plume water, sulfide ore, sediment, and mollusks located at the hydrothermal vent fields of the southern Tonga Arc, where active volcanism and intense seismic activity occur frequently. Our objectives were: (1) to address the potential release of Hg from hydrothermal fluids and (2) to examine the distribution of Hg and MMHg levels in hydrothermal mollusks (mussels and snails) harboring chemotrophic bacteria. While high concentrations of Hg in the sediment and Hg, As, and Sb in the sulfide ore indicates that their source is likely hydrothermal fluids, the MMHg concentration in the sediment was orders of magnitude lower than the Hg (<0.001%). It suggests that Hg methylation may have not been favorable in the vent field sediment. In addition, Hg concentrations in the mollusks were much higher (10-100 times) than in other hydrothermal vent environments, indicating that organisms located at the Tonga Arc are exposed to exceedingly high Hg levels. While Hg concentration was higher in the gills and digestive glands than in the mantles and residues of snails and mussels, the MMHg concentrations in the gills and digestive glands were orders of magnitude lower (0.004-0.04%) than Hg concentrations. In summary, our results suggest that the release of Hg from the hydrothermal vent fields of the Tonga Arc and subsequent bioaccumulation are substantial, but not for MMHg.
School of Environmental Science & Engineering, Gwangju Institute of Science & Technology (GIST), Gwangju 500-712, Republic of Korea.
Seyong
S
Lee
Korean Bioinformation Center, Korea Institute of Bioscience & Biotechnology, Daejeon 305-806, Republic of Korea.
Se-Joo
SJ
Kim
Deep-Sea and Seabed Resources Research Center, Korea Institute of Ocean Science & Technology, Gyeonggi-do 426-744, Republic of Korea; Marine Biology Major, University of Science & Technology, Daejeon 305-350, Republic of Korea.
Se-Jong
SJ
Ju
Deep-Sea and Seabed Resources Research Center, Korea Institute of Ocean Science & Technology, Gyeonggi-do 426-744, Republic of Korea.
Sang-Joon
SJ
Pak
Deep-Sea and Seabed Resources Research Center, Korea Institute of Ocean Science & Technology, Gyeonggi-do 426-744, Republic of Korea.
Seung-Kyu
SK
Son
School of Environmental Science & Engineering, Gwangju Institute of Science & Technology (GIST), Gwangju 500-712, Republic of Korea.
Jisook
J
Yang
School of Environmental Science & Engineering, Gwangju Institute of Science & Technology (GIST), Gwangju 500-712, Republic of Korea. Electronic address: shan@gist.ac.kr.
Seunghee
S
Han
D000818:Animals; D001419:Bacteria / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D005880:Gills / Q000737:chemistry; D060086:Hydrothermal Vents / Q000737:chemistry*; D008628:Mercury / Q000032:analysis*; D008767:Methylmercury Compounds / Q000032:analysis*; D008974:Mollusca / Q000737:chemistry* / Q000382:microbiology; D010140:Pacific Ocean; D014058:Tonga; D014874:Water Pollutants, Chemical / Q000032:analysis*
D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D008628:Mercury
Hydrothermal vents; Mercury; Mollusks; Monomethylmercury; Tonga Arc