Organic Cu-complexation at the shallow marine hydrothermal vent fields off the coast of Milos (Greece), Dominica (Lesser Antilles) and the Bay of Plenty (New Zealand)
Organic Cu-complexation at the shallow marine hydrothermal vent fields off the coast of Milos (Greece), Dominica (Lesser Antilles) and the Bay of Plenty (New Zealand)
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米洛斯岛（希腊）、多米尼加岛（小安的列斯群岛）和丰盛湾（新西兰）海岸浅海热液喷口场的有机铜络合作用
DOI：
10.1016/j.marchem.2014.10.012
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发表时间：
2015
期刊：
影响因子：
3
通讯作者：
Koschinsky
中科院分区：
文献类型：
--
作者：
Kleint;Kuzmanovski;Powell;Bühring;Sander;Koschinsky
海底热液喷口向海洋释放大量富含金属的流体。其中一些金属是生物必需的（如铁），而另一些可能是有毒的（如铜）。生活在这些栖息地的生物产生小的有机分子，配体能够与不同的金属形成络合物，以提高其生物利用度或降低其毒性。虽然对一些深海喷口的金属络合作用进行了研究，但对浅海热液喷口系统进行的类似研究相当罕见。在这项研究中，总溶解铜浓度（[Cu]T）和相应的铜结合配体浓度（[L]Cu）在浅水热液喷口区米洛斯（希腊），多米尼加（小安的列斯群岛）和丰盛湾（新西兰）进行了研究，通过伏安配体滴定，使用竞争配体平衡吸附溶出伏安法米洛斯、多米尼加和丰盛湾是三个非常不同的环境，我们的数据表明，与深海热液喷口相比，它们的溶解铜总量相对较少，在深海热液喷口中，已发现[Cu] T和[L] Cu浓度分别高达400 nM和4000 nM。在该数据集中，[Cu]Trises高达21.53 nM，然而，大多数样品在0.5 nM-3 nM范围内。[L] Cu在2.07 nM和23.9 nM之间变化，有一个例外，达到56.8 nM。条件稳定常数（Log K）在11.57 ~ 14.01之间。假设所研究的三个地点是浅海热液喷口的代表，与深海系统相比，由于络合作用而进入海洋的Cu通量似乎相对较低。我们的数据表明，在大多数情况下，铜的稳定络合，这可能会降低铜对这些混合的光化学合成社区的毒性作用。然而，多米尼加的一个孔隙水样本显示[Cu]Tover [L]Cu过量，这将为大多数海洋生物创造一个剧毒环境。我们进一步表明，配体-铜比和络合物稳定常数是在一个类似的范围内的深海喷口，这可能表明类似的络合参数和过程在浅，深海热液喷口。
Hydrothermal vents at the seafloor release large volumes of metal-rich fluids into the ocean. Some of these metals are biologically essential (such as Fe), while others may be toxic (e.g. Cu). Organisms living at these habitats produce small organic molecules, ligands that are able to form complexes with different metals, to either enhance their bioavailability or to decrease their toxicity. While some deep-sea vents have been studied with respect to metal complexation, comparable studies at shallow marine hydrothermal vent systems are rather rare. In this study, total dissolved Cu concentrations ([Cu]T) and corresponding Cu binding ligand concentrations ([L]Cu) at the shallow water hydrothermal vent fields off the coast of Milos (Greece), Dominica (Lesser Antilles) and the Bay of Plenty (New Zealand) were examined by a voltammetric ligand titration, using competitive ligand equilibration–adsorptive stripping voltammetry (CLE–AdCSV).Milos, Dominica and the Bay of Plenty are three very different environments and our data show that they are relatively depleted in total dissolved Cu, compared to deep-sea hydrothermal vents where [Cu]Tand [L]Cuconcentrations up to 400 nM and 4000 nM have been found, respectively. In this data set, [Cu]Trises up to 21.53 nM, however, most samples are in the range of 0.5 nM–3 nM. [L]Cuvaries between 2.07 nM and 23.9 nM, with one exception, reaching 56.8 nM. Conditional stability constants (Log K) range between 11.57 and 14.01.Assuming that the three investigated sites are representative for shallow marine hydrothermal vents, the Cu-flux into the ocean due to complexation appears to be relatively low compared to deep-sea systems. Our data indicate a stable complexation of Cu in most cases, which may lower the toxic effect of Cu on these mixed photic–chemosynthetic communities. However one pore water sample from Dominica showed an excess [Cu]Tover [L]Cu, which would create a highly toxic environment for most marine organisms. We further show that ligand–Cu ratios and complex stability constants are in a similar range as the ones at deep-sea vents, which may indicate similar complexation parameters and processes at shallow and deep-sea hydrothermal vents.