The Marano and Grado Lagoon (northern Adriatic Sea, Italy) is contaminated mainly by mercury (Hg) of mining and industrial origin. This work aims to investigate the sedimentary records of Hg of a tidal flat–saltmarsh (TF–S) system and to understand the role played by tidal fluxes in terms of the transport, accumulation and release of Hg due to the periodic flow of the tide. The complex history of the sources of Hg in the area of the TF–S system has resulted in several fluctuations of Hg in sediments over time; due to its higher sedimentation rate (1.3 cm year⁻¹) than the subtidal areas of the Grado lagoon, the outer area of the TF–S system is more active in terms of accumulation (from 56 to 81 mg m⁻² year⁻¹) than the inner area. Fluxes were estimated at the mouth of a principal tidal creek by combining discrete hourly tidal flow measurements with weighed measurements of dissolved (DHg) and particulate (PHg) mercury obtained via water sample collection. Mercury, mainly in particulate form, is drained by the tidal creek from the marsh during a tidal semi-cycle. The highest flux of PHg was recorded during ebb tide in July (1071 mg). The calculation of the quantitative flows of PHg and DHg highlighted a tendency for Hg to be exported from the TF–S to the lagoon channel during a tidal semi-cycle. However, the results obtained here for the Hg fluxes do not allow for the depiction of a constant positive or negative budget as that found in the literature for macro-scale budget calculations at lagoon tidal inlets. A possible explanation for there being no constant trend in the PHg and DHg budget is that our TF–S system is located in a lagoon area where previous findings reported accretion or a balance situation between erosion and sedimentation processes.

中文翻译：

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在受污染的沿海泻湖环境（北亚得里亚海）中，潮滩-盐沼系统作为汞源-汇的作用

马拉诺和格拉多泻湖（意大利北亚得里亚海）主要受到采矿和工业来源的汞（Hg）的污染。这项工作旨在调查潮滩-盐沼（TF-S）系统中汞的沉积记录，并了解潮汐流在潮汐的周期性流动下在汞的迁移，积累和释放方面的作用。 。TF–S系统区域中汞源的复杂历史导致沉积物中汞的时间随时间波动。由于其沉积速率（比Grado泻湖的潮下带高）（1.3 cm年^-1），TF-S系统的外部在积聚方面更为活跃（从56到81 mg m - ²年^-1）比内部区域大。通过将离散的每小时潮汐流量测量值与通过水样本收集获得的溶解性（DHg）和颗粒状（PHg）汞的加权测量值结合起来，可以估算主要小河口的流量。在潮汐半周期中，潮汐小溪将主要以颗粒形式存在的汞从沼泽中排出。在七月份的退潮期间记录到了最高的PHg通量（1071 mg）。PHg和DHg定量流的计算突显出在潮汐半周期中Hg从TF-S排放到泻湖通道的趋势。但是，此处获得的汞通量结果不允许描述恒定的正预算或负预算，正如文献中关于泻湖潮汐口的宏观预算计算所见。