气候变化领域集成服务门户(CCPortal): Deciphering the Role of Water Column Redoxclines on Methylmercury Cycling Using Speciation Modeling and Observations From the Baltic Sea

CCPortal

DOI	10.1029/2018GB005942
	Deciphering the Role of Water Column Redoxclines on Methylmercury Cycling Using Speciation Modeling and Observations From the Baltic Sea
	Soerensen A.L.; Schartup A.T.; Skrobonja A.; Bouchet S.; Amouroux D.; Liem-Nguyen V.; Björn E.
发表日期	2018
ISSN	0886-6236
EISSN	1944-9224
起始页码	1498
结束页码	1513
卷号	32 期号:10
英文摘要	Oxygen-depleted areas are spreading in coastal and offshore waters worldwide, but the implication for production and bioaccumulation of neurotoxic methylmercury (MeHg) is uncertain. We combined observations from six cruises in the Baltic Sea with speciation modeling and incubation experiments to gain insights into mercury (Hg) dynamics in oxygen depleted systems. We then developed a conceptual model describing the main drivers of Hg speciation, fluxes, and transformations in water columns with steep redox gradients. MeHg concentrations were 2–6 and 30–55 times higher in hypoxic and anoxic than in normoxic water, respectively, while only 1–3 and 1–2 times higher for total Hg (THg). We systematically detected divalent inorganic Hg (HgII) methylation in anoxic water but rarely in other waters. In anoxic water, high concentrations of dissolved sulfide cause formation of dissolved species of HgII: HgS2H− (aq) and Hg (SH)2 0 (aq). This prolongs the lifetime and increases the reservoir of HgII readily available for methylation, driving the high MeHg concentrations in anoxic zones. In the hypoxic zone and at the hypoxic-anoxic interface, Hg concentrations, partitioning, and speciation are all highly dynamic due to processes linked to the iron and sulfur cycles. This causes a large variability in bioavailability of Hg, and thereby MeHg concentrations, in these zones. We find that zooplankton in the summertime are exposed to 2–6 times higher MeHg concentrations in hypoxic than in normoxic water. The current spread of hypoxic zones in coastal systems worldwide could thus cause an increase in the MeHg exposure of food webs. ©2018. American Geophysical Union. All Rights Reserved.
英文关键词	anoxia; hypoxia; mercury; methylation; methylmercury; redoxcline
语种	英语
scopus关键词	anoxic conditions; bioaccumulation; bioavailability; experimental study; incubation; iron; mercury (element); methylation; methylmercury; oxygen; redox conditions; speciation (chemistry); sulfide; sulfur; toxicity; water column; zooplankton; Atlantic Ocean; Baltic Sea
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/129786
作者单位	Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden; John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, United States; Department of Chemistry, Umeå University, Umeå, Sweden; Now at D-USYS Department, ETH Zürich, Zürich, Switzerland; Institut des Sciences Analytiques et de Physico-chimie pour l'Environnement et les Materiaux, CNRS/UNIV PAU & PAYS ADOUR, Pau, France; School of Science and Technology, Örebro University, Örebro, Sweden
推荐引用方式 GB/T 7714	Soerensen A.L.,Schartup A.T.,Skrobonja A.,et al. Deciphering the Role of Water Column Redoxclines on Methylmercury Cycling Using Speciation Modeling and Observations From the Baltic Sea[J],2018,32(10).
APA	Soerensen A.L..,Schartup A.T..,Skrobonja A..,Bouchet S..,Amouroux D..,...&Björn E..(2018).Deciphering the Role of Water Column Redoxclines on Methylmercury Cycling Using Speciation Modeling and Observations From the Baltic Sea.Global Biogeochemical Cycles,32(10).
MLA	Soerensen A.L.,et al."Deciphering the Role of Water Column Redoxclines on Methylmercury Cycling Using Speciation Modeling and Observations From the Baltic Sea".Global Biogeochemical Cycles 32.10(2018).