气候变化领域集成服务门户(CCPortal): Mercury Cycling in the North Pacific Subtropical Gyre as Revealed by Mercury Stable Isotope Ratios

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DOI	10.1029/2018GB006057
	Mercury Cycling in the North Pacific Subtropical Gyre as Revealed by Mercury Stable Isotope Ratios
	Motta L.C.; Blum J.D.; Johnson M.W.; Umhau B.P.; Popp B.N.; Washburn S.J.; Drazen J.C.; Benitez-Nelson C.R.; Hannides C.C.S.; Close H.G.; Lamborg C.H.
发表日期	2019
ISSN	0886-6236
EISSN	1944-9224
起始页码	777
结束页码	794
卷号	33 期号:6
英文摘要	The oceans are an important global reservoir for mercury (Hg), and marine fish consumption is the dominant human exposure pathway for its toxic methylated form. A more thorough understanding of the global biogeochemical cycle of Hg requires additional information on the mechanisms that control Hg cycling in pelagic marine waters. In this study, Hg isotope ratios and total Hg concentrations are used to explore Hg biogeochemistry in oligotrophic marine environments north of Hawaii. We present the first measurements of the vertical water column distribution of Hg concentrations and the Hg isotopic composition in precipitation, marine particles, and zooplankton near Station ALOHA (22°45′N, 158°W). Our results reveal production and demethylation of methylmercury in both the euphotic (0–175 m) and mesopelagic zones (200–1,000 m). We document a strong relationship between Hg isotopic composition and depth in particles, zooplankton, and fish in the water column and diurnal variations in Δ199Hg values in zooplankton sampled near the surface (25 m). Based on these observations and stable Hg isotope relationships in the marine food web, we suggest that the Hg found in large pelagic fish at Station ALOHA was originally deposited largely by precipitation, transformed into methyl-Hg, and bioaccumulated in situ in the water column. Our results highlight how Hg isotopic compositions reflect abiotic and biotic production and degradation of methyl-Hg throughout the water column and the importance of particles and zooplankton in the vertical transport of Hg. ©2019. American Geophysical Union. All Rights Reserved.
英文关键词	demethylation; mercury; mercury at Station ALOHA; mercury bioaccumulation; mercury isotopes; methylation
语种	英语
scopus关键词	bioaccumulation; biogeochemical cycle; concentration (composition); degradation; food web; gyre; isotopic composition; isotopic ratio; marine environment; mercury (element); methylation; nutrient cycling; pelagic environment; pollution exposure; stable isotope; subtropical region; zooplankton; Hawaiian Islands; Pacific Ocean; Pacific Ocean (North)
来源期刊	Global Biogeochemical Cycles
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129725
作者单位	Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, United States; School of Earth, Ocean and Environment, University of South Carolina, Columbia, SC, United States; Department of Earth Sciences, University of Hawai‘i at Mānoa, Honolulu, HI, United States; Department of Oceanography, University of Hawai‘i at Mānoa, Honolulu, HI, United States; Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, United States; Department of Ocean Sciences, University of California, Santa Cruz, CA, United States
推荐引用方式 GB/T 7714	Motta L.C.,Blum J.D.,Johnson M.W.,et al. Mercury Cycling in the North Pacific Subtropical Gyre as Revealed by Mercury Stable Isotope Ratios[J],2019,33(6).
APA	Motta L.C..,Blum J.D..,Johnson M.W..,Umhau B.P..,Popp B.N..,...&Lamborg C.H..(2019).Mercury Cycling in the North Pacific Subtropical Gyre as Revealed by Mercury Stable Isotope Ratios.Global Biogeochemical Cycles,33(6).
MLA	Motta L.C.,et al."Mercury Cycling in the North Pacific Subtropical Gyre as Revealed by Mercury Stable Isotope Ratios".Global Biogeochemical Cycles 33.6(2019).