Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences, Ministry of Education, Beijing, 100871, China; State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing, 100871, China.
State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, China.
Chemosphere. 2022 Nov;307(Pt 4):136150. doi: 10.1016/j.chemosphere.2022.136150. Epub 2022 Aug 23.
Benthic bioaccumulation of hazardous materials has been a great challenge to the health of lake ecosystems. As representative benthic macroinvertebrates, freshwater mussels and their accumulation characteristics have been regarded as effective indicators for assessing potential risks induced by sedimentary metal(loid)s in lakes. Here we profile organ-specific accumulation of 35 metal(loid)s in a freshwater mussel (Hyriopsis cumingii) and their correlations to metal speciation in sediments of Poyang Lake, the largest lake of China. Significant organ-specific characteristics of metal accumulation were found in gills, though higher thallium (Tl) and selenium (Se) were found in the hepatopancreas, and greater arsenic (As) mostly accumulated in gonads. Pearson correlation analysis revealed that the bioaccumulation of silver (Ag), cobalt (Co), and rare earth elements (ΣREE) in gills and As in gonads were closely associated with those in bioavailable fraction of sediments. Based on the biochemical analysis in the major organs, gills exhibited the highest enzymatic activity compared with hepatopancreas and gonads. Sedimentary metals, particularly for available Ag, Co, and ΣREE, play key roles in causing lipid peroxidation in gills and significantly promote the activities of superoxide dismutase (SOD)/glutathione reductase (GR), while many metals (e.g., cadmium, manganese, Se) inhibit the glutathione (GSH) content in gonads and hepatopancreas. Our study indicates a high physiological sensitivity of mussels to these target metals, which highlights the significance of organ-specific accumulation of metal(loid)s in understanding the potential ecological risks of sedimentary metal(loid)s in lake ecosystems.
底栖生物对有害物质的生物积累对湖泊生态系统的健康构成了巨大挑战。作为有代表性的底栖大型无脊椎动物，淡水贻贝类及其积累特征已被视为评估湖泊沉积物中金属（类）潜在风险的有效指标。本研究描绘了鄱阳湖淡水贻贝（Hyriopsis cumingii）中 35 种金属（类）在各组织器官中的特异性积累特征，及其与沉积物中金属形态的关系。贻贝各组织器官对金属的积累具有明显的组织特异性，其中鳃对金属的积累能力最强，而肝胰腺中铊（Tl）和硒（Se）的含量较高，性腺中砷（As）的含量较高。Pearson 相关性分析表明，鳃中银（Ag）、钴（Co）和稀土元素（ΣREE）以及性腺中 As 的生物积累与沉积物中生物可利用态金属的积累密切相关。基于主要器官的生化分析，与肝胰腺和性腺相比，鳃表现出最高的酶活性。沉积物金属，特别是可利用态 Ag、Co 和 ΣREE，在引起贻贝鳃组织脂质过氧化方面起着关键作用，并显著促进超氧化物歧化酶（SOD）/谷胱甘肽还原酶（GR）的活性，而许多金属（如镉、锰、硒）则抑制性腺和肝胰腺中谷胱甘肽（GSH）的含量。本研究表明贻贝对这些目标金属具有较高的生理敏感性，突出了金属（类）在器官水平上的积累对理解湖泊生态系统中沉积物金属（类）潜在生态风险的重要性。
