Faculty of Science and Engineering, Southern Cross University, Lismore, NSW, Australia; Department of Environmental Management and Toxicology, Faculty of Life Sciences, University of Benin, Benin City, Nigeria.
Faculty of Science and Engineering, Southern Cross University, Lismore, NSW, Australia.
Environ Pollut. 2022 Nov 15;313:120110. doi: 10.1016/j.envpol.2022.120110. Epub 2022 Sep 5.
Nickel (Ni) and manganese (Mn) are well known for the production of steel and alloys and are commonly found co-occurring in Ni ores. They are metals of environmental concern and contamination in the marine environment is problematic single exposures and in combination. Several studies have documented the effects of single metal exposure on the model anemone E. pallida, but research on the effects of metal mixtures is far less common. This novel study assesses the accumulation and stress effects of Ni and Mn over a 12-d exposure period. E. pallida were exposed in two separate experiments; Ni alone and Ni in combination with Mn, to assess accumulation, along with any effect on the density of symbionts and anemone tentacle length. Anemones were transferred to ambient seawater to assess depuration and recovery over 6 d. Anemone tissue accumulated Ni at a magnitude of five times higher in a mixture of 0.5 mg Ni/L with 2.5 mg Mn/L compared to the same concentration in a single Ni exposure experiment. In both experiments, Ni and Mn preferentially accumulated in the Symbiodinium spp. compared to the anemone tissue, but Ni depuration was more rapid in the mixture than Ni alone exposure. This study reveals a significant reduction in anemone Symbiodinium spp. density after exposure to Ni and Mn mixtures, but not with Ni exposure alone. A significant dose-dependent reduction in tentacle length was observed in anemones after 12 d of the Ni exposure both with and without Mn. The estimated sublethal concentration that causes tentacle retraction in 50% of test anemones (EC50) by Ni was 0.51 (0.25-0.73) mg/L, while in combination with Mn the EC50 was 0.30 mg Ni/L (confidence limits not calculatable). The present data reveals the importance of testing metal effects in combination before establishing safe limits for marine invertebrates.
镍（Ni）和锰（Mn）是钢铁和合金生产中众所周知的金属，并且通常在镍矿石中共同存在。它们是环境关注的金属，在海洋环境中污染是一个问题，无论是单一暴露还是混合暴露。多项研究记录了单一金属暴露对模式海葵 E. pallida 的影响，但关于金属混合物影响的研究则要少得多。这项新研究评估了 Ni 和 Mn 在 12 天暴露期内的积累和应激效应。E. pallida 在两个单独的实验中暴露于 Ni 单独和 Ni 与 Mn 的混合物中，以评估积累情况以及对共生体密度和海葵触手长度的任何影响。海葵被转移到环境海水中，以在 6 天内评估净化和恢复情况。海葵组织在 0.5 mg/L Ni 与 2.5 mg/L Mn 的混合物中的积累量是单一 Ni 暴露实验中相同浓度的五倍。在这两个实验中，Ni 和 Mn 优先在共生体 Symbiodinium spp. 中积累，而不是在海葵组织中积累，但 Ni 在混合物中的净化速度比单独暴露于 Ni 时更快。这项研究表明，在暴露于 Ni 和 Mn 混合物后，海葵共生体密度显著降低，但单独暴露于 Ni 时则没有。在 12 天的 Ni 暴露后，观察到触手长度有显著的剂量依赖性降低，无论是单独暴露于 Ni 还是 Ni 和 Mn 混合物。Ni 引起 50%测试海葵触手回缩的亚致死浓度（EC50）为 0.51（0.25-0.73）mg/L，而与 Mn 结合时 EC50 为 0.30 mg Ni/L（置信限不可计算）。目前的数据揭示了在为海洋无脊椎动物建立安全限值之前，在组合中测试金属效应的重要性。
