Department of Biology, Ecosystem Management Research Group, University of Antwerp, Wilrijk, Belgium.
PLoS One. 2013 Aug 7;8(8):e70381. doi: 10.1371/journal.pone.0070381. eCollection 2013.
Flux calculations demonstrate that many estuaries are natural filters for trace metals. Yet, the underlying processes are poorly investigated. In the present study, it was hypothesized that intertidal marshes contribute significantly to the contaminant filter function of estuaries. Trace metal concentrations and sediment characteristics were measured along a transect from the subtidal, over an intertidal flat and marsh to a restored marsh with controlled reduced tide. Metal concentrations in the intertidal and restored marsh were found to be a factor two to five higher than values in the subtidal and intertidal flat sediments. High metal concentrations and high accretion rates indicate a high metal accumulation capacity of the intertidal marshes. Overbank sedimentation in the tidal marshes of the entire estuary was calculated to remove 25% to 50% of the riverine metal influx, even though marshes comprise less than 8% of the total surface of the estuary. In addition, the large-scale implementation of planned tidal marsh restoration projects was estimated to almost double the trace metal storage capacity of the present natural tidal marshes in the estuary.
通量计算表明，许多河口是痕量金属的天然过滤器。然而，潜在的过程还没有得到充分的研究。在本研究中，假设潮间带沼泽对河口的污染物过滤功能有重要贡献。沿着从潮下带、潮间带平原和沼泽到一个受控制的退潮恢复沼泽的剖面，测量了痕量金属浓度和沉积物特征。发现潮间带和恢复沼泽中的金属浓度比潮下带和潮间带平原沉积物中的金属浓度高 2 到 5 倍。高金属浓度和高淤积率表明潮间带沼泽具有很高的金属积累能力。整个河口的潮间带沼泽的漫滩沉积被计算为可以去除 25%至 50%的河流金属流入量，尽管沼泽仅占河口总面积的不到 8%。此外，据估计，大规模实施计划中的潮汐沼泽恢复项目，几乎可以使河口现有天然潮汐沼泽的痕量金属储存能力增加近一倍。
