Programa de Pós-Graduação Em Sistemas Costeiros e Oceânicos (PGSISCO), Universidade Federal Do Paraná, Caixa Postal 61, 83255-976, Pontal Do Paraná, PR, Brazil; Centro de Estudos Do Mar, Universidade Federal Do Paraná, Caixa Postal 61, 83255-976, Pontal Do Paraná, PR, Brazil.
Centro de Estudos Do Mar, Universidade Federal Do Paraná, Caixa Postal 61, 83255-976, Pontal Do Paraná, PR, Brazil.
J Environ Manage. 2021 Jan 1;277:111421. doi: 10.1016/j.jenvman.2020.111421. Epub 2020 Oct 15.
Mangrove forests worldwide are threatened environments considered vulnerable to chronic contamination by hydrophobic contaminants such as polycyclic aromatic hydrocarbons (PAHs). These ecosystems have a key role in the dynamics of biogenic and anthropogenic carbon storage and provide proper conditions for accumulation. One of most important subtropical mangrove swamps in the South Atlantic is located in the Paranaguá Estuarine System (PES), the largest bay of South Brazil surrounded by well-preserved Atlantic rainforests; however, the PES is under imminent risks of damage, e.g., due to incidental oil spills during port operations. In this scenario, PAHs were assessed for the first time in the mangrove sediments of the PES. The concentrations of 16 priority PAHs (EPA) (<DL - 234.3 ng g, 36 samples) were higher than those observed in previous studies for bottom sediments and had a similar order of magnitude as those for other human-impacted mangroves but were lower than those of other heavily impacted mangroves. A moderate level of anthropic contamination was observed, and the main probable sources of PAHs were navigation and domestic effluents. Bulk parameters (TOC/TN ratio and δC) showed the estuarine land-sea gradient and helped define the preferential sites of PAH deposition due to its correlation with TOC and fine sediments. Marine hydrodynamics and/or dilution processes had a major influence on PAH distribution, resulting in higher concentrations in the inner/sheltered areas of the estuary and lower values in the outer zone of the estuary with higher hydrodynamic energy. The environmental features and anthropogenic forcing of the PES added to the relative absence of a detailed evaluation of the levels of and environmental risks posed by PAHs in other subtropical mangrove ecosystems located in the Southern Hemisphere, reinforcing the importance of the current study.
全球的红树林生态系统受到慢性污染的威胁，这些污染物包括疏水性污染物如多环芳烃（PAHs）。这些生态系统在生物源和人为源碳储存的动态中起着关键作用，并为积累提供了适当的条件。南大西洋最重要的亚热带红树林沼泽之一位于巴拉那瓜河口系统（PES），这是南巴西南部最大的海湾，周围环绕着保存完好的大西洋雨林；然而，PES 面临着迫在眉睫的破坏风险，例如，由于港口作业中的偶然溢油事故。在这种情况下，首次对 PES 红树林沉积物中的 PAHs 进行了评估。16 种优先 PAHs（EPA）（<DL - 234.3 ng g，36 个样本）的浓度高于以前对底泥的观察结果，其数量级与其他受人为影响的红树林相似，但低于其他受严重影响的红树林。观察到中等程度的人为污染，PAHs 的主要可能来源是航行和生活污水。总体参数（TOC/TN 比和 δC）显示了河口陆海梯度，并有助于确定 PAH 沉积的优先地点，因为它与 TOC 和细沉积物相关。海洋水动力和/或稀释过程对 PAH 分布有重大影响，导致河口内部/遮蔽区域的浓度较高，而河口外部区域的浓度较低，该区域的水动力能量较高。PES 的环境特征和人为压力增加了对其他位于南半球亚热带红树林生态系统中 PAHs 水平和环境风险的详细评估的相对缺乏，这加强了当前研究的重要性。
