法国海洋研究所Torres-Rodriguez和Heimbrger-Boavida, Lars-Eric的团队，在研究受测量限制的大洋中脊热液喷口的汞通量中取得新进展。这一研究成果发表在2023年12月12日出版的国际学术期刊《自然—地球科学》上。
研究人员综合了排出流体、地幔柱流体、海水和岩石样本的观察，量化了大西洋中脊跨大西洋地质断层热液喷口的汞释放通量。排出流体(4,966±497pmoll-1)中富集的大部分(67-95%)的汞被迅速稀释，达到基底海水水平(0.80pmoll-1)。一小部分汞(2.6-10%)被清除到跨大西洋地质断层岩丘中。
逐步扩大之前的工作和新发现，研究人员提出每年来自于大洋中脊的汞通量估计为1.5-64.7t。与人为输入相比，这种热液通量很小。这表明，海洋中存在的大部分汞可能是人为来源，实施《Minamata公约》中概述的减排措施可以有效降低全球海洋中的汞含量，进而降低海洋鱼类中的汞含量。
据悉，甲基汞是一种主要通过食用海鱼威胁全球人口的强效毒素。热液喷口直接将天然汞释放到海洋中，但其全球通量仍然很少受到限制。为了确定人为输入对海洋汞含量增加的影响程度，估算天然汞含量就显得至关重要。
附：英文原文
Title: Mercury fluxes from hydrothermal venting at mid-ocean ridges constrained by measurements
Author: Torres-Rodriguez, Natalia, Yuan, Jingjing, Petersen, Sven, Dufour, Aurlie, Gonzlez-Santana, David, Chavagnac, Valrie, Planquette, Hlne, Horvat, Milena, Amouroux, David, Cathalot, Ccile, Pelleter, Ewan, Sun, Ruoyu, Sonke, Jeroen E., Luther, George W., Heimbrger-Boavida, Lars-Eric
Issue&Volume: 2023-12-12
Abstract: Methylmercury is a potent toxin threatening the global population mainly through the consumption of marine fish. Hydrothermal venting directly delivers natural mercury to the ocean, yet its global flux remains poorly constrained. To determine the extent to which anthropogenic inputs have increased oceanic mercury levels, it is crucial to estimate natural mercury levels. Here we combine observations of vent fluids, plume waters, seawater and rock samples to quantify the release of mercury from the Trans-Atlantic Geotraverse hydrothermal vent at the Mid-Atlantic Ridge. The majority (67–95%) of the mercury enriched in the vent fluids (4,966±497pmoll-1) is rapidly diluted to reach background seawater levels (0.80pmoll-1). A small Hg fraction (2.6–10%) is scavenged to the Trans-Atlantic Geotraverse mound rocks. Scaling up our findings and previous work, we propose a mercury flux estimate of 1.5–64.7t per year from mid-ocean ridges. This hydrothermal flux is small in comparison to anthropogenic inputs. This suggests that most of the mercury present in the ocean must be of anthropogenic origin and that the implementation of emissions reduction measures outlined in the Minamata Convention could effectively reduce mercury levels in the global ocean and subsequently in marine fish.
DOI: 10.1038/s41561-023-01341-w
Source: https://www.nature.com/articles/s41561-023-01341-w