School of Geosciences, University of Sydney, Sydney, NSW 2006, Australia.
School of Geosciences, University of Sydney, Sydney, NSW 2006, Australia.
Sci Total Environ. 2014 Feb 15;472:1010-22. doi: 10.1016/j.scitotenv.2013.11.096. Epub 2013 Dec 15.
Currently, coastal intertidal environments are under stress from increased contaminant loads due to urbanization and other anthropogenic disturbances. Mangrove habitats are abundant in tropical and sub-topical intertidal zones and frequently act as a metal bio-filter in estuarine systems. Mangrove reforestation is often considered as one of the management options to protect estuarine-marine habitats. The main objective of the present investigation was to assess the bio-indicator potential of Avicennia marina by determining heavy metal concentrations in pneumatophore (aerial root) tissues and ambient sediments from Sydney Estuary (Australia). We collected mangrove sediments and pneumatophores in fifteen locations covering five major embayments of the estuary for a detailed biogeochemical investigation. Metal concentrations in sediment were mostly above Australian interim sediment quality guidelines (ISQG)-Low and in few instances above ISQG-High values. Enrichment factors (EFs >6, especially of Cu, Pb and Zn) suggest "very severe" modification of sediment in Sydney Estuary in all but one embayment which was mainly due to rapid changes in land use in connection with urbanization. High bio-concentration factors (BCFs) were observed for Cu and Ni in comparison with other metals (i.e., As, Cd, Co, Cr, Pb and Zn). A strong, positive relationship between metals in sediments and pneumatophores suggests potential use of these tissues as a bio-indicator of estuarine contamination and that metals are entering the biotic environment. The study further highlights a positive role of mangroves in sequestering metals from sediments and the water column and thus protecting estuarine environments from pollution.
目前，由于城市化和其他人为干扰，沿海潮间带环境承受着污染物负荷增加的压力。红树林生境在热带和亚热带潮间带丰富，经常在河口系统中充当金属生物过滤器。红树林造林通常被认为是保护河口-海洋生境的管理选择之一。本研究的主要目的是通过测定悉尼港（澳大利亚）的通气根组织和环境沉积物中的重金属浓度来评估海桑的生物指标潜力。我们在河口的五个主要海湾的 15 个地点收集了红树林沉积物和通气根，进行了详细的生物地球化学研究。沉积物中的金属浓度大多高于澳大利亚临时沉积物质量指南（ISQG）-低值，在少数情况下高于 ISQG-高值。富集因子（EF>6，特别是 Cu、Pb 和 Zn）表明，除了一个海湾外，悉尼港的所有沉积物都受到了“非常严重”的干扰，而这个海湾主要是由于城市化导致的土地利用迅速变化。与其他金属（如 As、Cd、Co、Cr、Pb 和 Zn）相比，Cu 和 Ni 的生物浓缩系数（BCF）较高。沉积物和通气根中的金属之间存在很强的正相关关系，这表明这些组织可能被用作河口污染的生物指标，并且金属正在进入生物环境。该研究进一步强调了红树林从沉积物和水柱中吸收金属的积极作用，从而保护河口环境免受污染。
