Zhang Zhe-Xuan, Sachs Julian P, Wang Yao-Ping, Chen Zhao Liang, Huguet Arnaud, He Ding
Department of Ocean Science and Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Clear Water Bay, New Territories 999077, Hong Kong, China.
School of Oceanography, University of Washington, Seattle, WA 98195, USA.
Mar Pollut Bull. 2025 Oct;219:118309. doi: 10.1016/j.marpolbul.2025.118309. Epub 2025 Jun 20.
Mangroves contribute to long-term carbon sequestration and are considered as blue carbon ecosystems; however, they are facing increasing anthropogenic pressures, with trace metals emerging as an environmental concern. Despite their toxicological impacts, the mechanisms governing trace metal retention in mangrove sediments require further investigation, particularly their association with natural organic compounds. Here, we employed Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) to analyze a wide range of lipids in mangrove sediments from two pristine sites and one anthropogenically disturbed site collected in the Leizhou Peninsula (South China). Our study reveals distinct molecular fingerprints of lipids between these ecosystems: (i) pristine mangroves contain a higher proportion of biologically recalcitrant and aromatic compounds, while (ii) anthropogenically disturbed mangroves show a greater prevalence of biologically labile compounds potentially linked to sewage contamination. Mercury (Hg) was found to be particularly associated with more biologically labile and less aromatic lipids, whereas other trace metals, such as chromium (Cr), zinc (Zn), arsenic (As), and lead (Pb), are preferentially associated with biologically recalcitrant and aromatic lipids. One possible interpretation is that lipidomic profiles and their binding capacities for these trace metals differ among mangrove ecosystems, allowing them to retain distinct trace metals, and vice versa. Such potential lipid-metal interactions still need to be verified through future experimental binding studies or speciation analyses across broader geographic areas. This work has potential implications for understanding the fate of trace metals and organic matter in mangrove ecosystems and for developing sustainable management strategies.
红树林有助于长期碳固存，被视为蓝碳生态系统；然而，它们正面临越来越大的人为压力，痕量金属已成为一个环境问题。尽管有其毒理学影响，但红树林沉积物中痕量金属的保留机制仍需进一步研究，特别是它们与天然有机化合物的关联。在此，我们采用傅里叶变换离子回旋共振质谱（FT-ICR MS）分析了在中国南方雷州半岛采集的两个原始地点和一个受人为干扰地点的红树林沉积物中的多种脂质。我们的研究揭示了这些生态系统之间脂质的不同分子指纹：（i）原始红树林含有较高比例的生物难降解和芳香族化合物，而（ii）受人为干扰的红树林中生物易降解化合物的比例更高，这些化合物可能与污水污染有关。发现汞（Hg）特别与生物易降解性更强、芳香性更低的脂质相关，而其他痕量金属，如铬（Cr）、锌（Zn）、砷（As）和铅（Pb），则优先与生物难降解和芳香族脂质相关。一种可能的解释是，不同红树林生态系统中脂质组学特征及其对这些痕量金属的结合能力不同，这使得它们能够保留不同的痕量金属，反之亦然。这种潜在的脂质-金属相互作用仍需通过未来更广泛地理区域的实验性结合研究或形态分析来验证。这项工作对于理解红树林生态系统中痕量金属和有机物质的归宿以及制定可持续管理策略具有潜在意义。
