Yang Shaomei, Li Yanping, Chen Fengyuan, Chen Shanshan, Luo Xin, Duan Wei, Liao Yongyan, Jiang Hao, Pan Ke
Beibu Gulf Marine Ecological Environment Field Observation and Research Station of Guangxi, Marine Environmental Monitoring Centre of Guangxi, Beihai, 536000, China.
Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
Mar Environ Res. 2024 Apr;196:106393. doi: 10.1016/j.marenvres.2024.106393. Epub 2024 Feb 6.
Understanding the metal concentrations in oysters is important because of its relevance to human health and biomonitoring. However, metal concentrations in oysters are highly variable in nature and not well explained by metal exposure. This study examined the metal contamination in farm oysters Crassostrea hongkongensis grown in Qinzhou Bay, south China. Cadmium (Cd), zinc (Zn), nickel (Ni), and copper (Cu) concentrations in the oysters varied between 7.9 and 72.2, 282-17003, 0.37-47.7 and 37-4012 μg g, respectively, showing large metal variability among different individuals. Oyster metal concentrations decreased with increasing body size and significantly higher levels were observed in wet season. Low salinity and slower oyster growth due to inferior growth conditions could be responsible for the elevated metal concentrations in the wet season. Biokinetic modeling showed that the coupling of ingestion rate and growth can cause 2.8-4.2 folds differences in the oyster Cd and Zn concentrations, respectively, suggesting the significant role of oyster bioenergetics in contributing to the metal variability. Modeling data revealed that Cd and Zn concentrations in oyster tissues reach maximum levels when oysters have their lowest growth efficiency. This suggests that any factors influencing the energy budget in oysters could simultaneously alter their metal concentrations, which might be the reason why oyster metal concentrations are so variable in the natural environment.
了解牡蛎中的金属浓度很重要，因为它与人类健康和生物监测相关。然而，牡蛎中的金属浓度在自然界中高度可变，且金属暴露并不能很好地解释这种现象。本研究调查了在中国南方钦州湾养殖的香港巨牡蛎（Crassostrea hongkongensis）中的金属污染情况。牡蛎中镉（Cd）、锌（Zn）、镍（Ni）和铜（Cu）的浓度分别在7.9至72.2、282至17003、0.37至47.7和37至4012μg/g之间变化，不同个体之间的金属含量差异很大。牡蛎的金属浓度随着体型的增大而降低，并且在雨季观察到的金属浓度显著更高。低盐度以及生长条件较差导致牡蛎生长缓慢，可能是雨季金属浓度升高的原因。生物动力学模型表明，摄食率和生长的耦合分别会导致牡蛎中镉和锌浓度出现2.8至4.2倍的差异，这表明牡蛎生物能量学在导致金属含量变化方面发挥了重要作用。模型数据显示，当牡蛎生长效率最低时，其组织中的镉和锌浓度达到最高水平。这表明任何影响牡蛎能量收支的因素都可能同时改变其金属浓度，这可能就是牡蛎金属浓度在自然环境中如此多变的原因。
