Department of Soil Science, Luiz de Queiroz College of Agriculture, University of São Paulo (ESALQ-USP), Piracicaba, São Paulo 13418-900, Brazil; Department of Oceanography, Universidade Federal do Espírito Santo, Vitória, Espírito Santo 29075-910, Brazil.
Department of Biology, University of Southern Denmark, Odense M 5230, Denmark.
Mar Pollut Bull. 2021 Nov;172:112912. doi: 10.1016/j.marpolbul.2021.112912. Epub 2021 Sep 8.
After the largest mining tailings spill in Brazil, the Rio Doce estuarine ecosystem was severely impacted by metal contamination. In a 28-day laboratory experiment, we examined the effects of the polychaeta Laeonereis sp. on fluxes of oxygen and metal across the sediment-water interface. The density-dependent effect of Laeonereis sp. in the oxygen and metal fluxes was tested at low and high (74 and 222 ind m, respectively) densities, and compared with defaunated controls. The higher worm density had an amplified effect on the oxygen flux, sediment uptake of Al and Mn, and Fe oxidation compared with the control, but no significant effects on other metals (Ba, Cd, Co, Cr, Cu, Ni, and Zn). Higher worm density increased the oxidation of Fe phases, but no effect in the solid phase of other metals. Consequently, Laeonereis sp. bioturbation prevents the reduction of Fe phases and the release of metal-bound-contaminants to estuarine systems.
巴西发生最大规模的采矿尾矿泄漏事件后，里约多斯河河口生态系统受到金属污染的严重影响。在一项为期 28 天的实验室实验中，我们研究了多毛类环节动物 Laeonereis sp. 对氧和金属穿过沉积物-水界面通量的影响。在低（74 个/平方米）和高（222 个/平方米）密度下，测试了 Laeonereis sp. 在氧和金属通量中的密度依赖性效应，并与去生物控制组进行了比较。与对照组相比，较高的蠕虫密度对氧气通量、Al 和 Mn 的沉积物吸收以及 Fe 氧化有放大效应，但对其他金属（Ba、Cd、Co、Cr、Cu、Ni 和 Zn）没有显著影响。较高的蠕虫密度增加了 Fe 相的氧化，但对其他金属的固相没有影响。因此，Laeonereis sp. 的生物扰动防止了 Fe 相的还原和金属结合污染物向河口系统的释放。
