Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
Chemosphere. 2023 Jul;329:138600. doi: 10.1016/j.chemosphere.2023.138600. Epub 2023 Apr 10.
Bioaccumulation through diet is the predominant source of metal(loid)s in fishes; however, the trophic transfer of metal(loid)s from the diet to aquatic organisms remains largely unclear. In this study, aquatic organisms and five potential food sources (leaf litter, coarse and fine particulate organic matter (CPOM and FPOM, respectively), epilithon and fish) were collected around the Shimen Realgar Mine of China. Stomach content analysis and stable nitrogen and carbon isotope analysis, combined with a new Bayesian mixing model (MixSIAR), were used to quantify diet compositions of aquatic organisms. The δC and δN values varied among fish sizes and sampling sites and were probably related to the diet shift of aquatic organisms. The MixSIAR modelling results showed that the aquatic organisms' food sources were mainly composed of FPOM (9%-68%) and epilithon (15%-65%), with leaf litter, CPOM and fish accounting for smaller proportions (2%-30%). Concentrations ranged from 0.91 to 1298 mg/kg for As, 0.01-1.30 mg/kg for Cd, 0.12-37.79 mg/kg for Pb, 0.63-1158 mg/kg for Cr, 1.22-411 mg/kg for Cu, 0.82-1772 mg/kg for Mn, 0.31-542 mg/kg for Ni and 21.84-1414 mg/kg for Zn in all the collected samples, including the aquatic organisms and the relevant food sources. The metal(loid) concentrations in the CPOM, FPOM and epilithon were significantly higher than those in aquatic organisms and leaf litter. In addition, the biomagnification factors were all less than 1, indicating a biodilution from diet to freshwater organisms. The predominant As species were organic As in aquatic organisms, while inorganic As was common in their food sources, indicating that As biotransformation occurred within the freshwater food chain.
生物通过饮食积累金属（类），是鱼类金属（类）的主要来源；然而，金属（类）从饮食到水生生物的营养转移仍然很大程度上不清楚。在这项研究中，我们在中国石门雄黄矿周围收集了水生生物和五种潜在的食物来源（叶凋落物、粗和细颗粒有机物质（CPOM 和 FPOM）、附生藻类和鱼类）。我们通过胃内容物分析和稳定氮和碳同位素分析，结合新的贝叶斯混合模型（MixSIAR），来量化水生生物的饮食组成。δC 和 δN 值在鱼类大小和采样地点之间存在差异，可能与水生生物的饮食变化有关。MixSIAR 建模结果表明，水生生物的食物来源主要由 FPOM（9%-68%）和附生藻类（15%-65%）组成，叶凋落物、CPOM 和鱼类占比较小（2%-30%）。在所采集的所有样本中，砷的浓度范围为 0.91-1298 mg/kg，镉的浓度范围为 0.01-1.30 mg/kg，铅的浓度范围为 0.12-37.79 mg/kg，铬的浓度范围为 0.63-1158 mg/kg，铜的浓度范围为 1.22-411 mg/kg，锰的浓度范围为 0.82-1772 mg/kg，镍的浓度范围为 0.31-542 mg/kg，锌的浓度范围为 21.84-1414 mg/kg，包括水生生物和相关食物来源。CPOM、FPOM 和附生藻类中的金属（类）浓度明显高于水生生物和叶凋落物。此外，生物放大因子均小于 1，表明从饮食到淡水生物的生物稀释作用。水生生物中主要的砷形态为有机砷，而其食物来源中常见的是无机砷，这表明砷在淡水食物链中发生了生物转化。
