Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, PR China; College of Environment, Hohai University, Nanjing, 210098, PR China.
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, PR China; College of Environment, Hohai University, Nanjing, 210098, PR China.
Environ Pollut. 2016 May;212:550-558. doi: 10.1016/j.envpol.2016.01.091. Epub 2016 Mar 11.
Many heavy metals in sediments and water have potential adverse effects on aquatic organisms such as Corbicula fluminea (O.F. Müller, 1774), a bivalve species frequently used as a biomonitor for metal pollution. Studies over the past decades examining the heavy metal uptake by C. fluminea, very few has investigated the effect of hydrodynamic conditions on accumulation of heavy metal by C. fluminea. Therefore, in this study, to investigate the mechanism of intracellular and extracellular accumulation of metal, individuals of C. fluminea were exposed to cadmium (Cd)-treated water under three different hydrodynamic conditions. These included exposures in two set ups: three rates of rotation (500, 350, 200 r/min) in beakers for 10 days, and then exposure to Cd-treated sediment under two naturally turbulent water conditions (14 cm/s and 3.2 cm/s) in experimental flumes for 23 days. Hydrodynamic force increased the burrowing rate but decreased the activity of C. fluminea. After 10 days of exposure, the extracellular concentrations of Cd in the tissues of C. fluminea in the sand group were significantly higher than that in the gravel groups. The intracellular and extracellular concentrations of Cd in the tissues of C. fluminea dramatically increased in the Cd-treated sediment test. Moreover, the concentration of the extracellular Cd adsorbed on the tissues of C. fluminea in the 14 cm/s and 3.2 cm/s groups was significantly higher than that in the control group, whereas the effect of hydrodynamic force on absorption of Cd by C. fluminea was not obvious. These results suggest that hydrodynamic condition plays an important role in extracellular accumulation of Cd by C. fluminea. In future study, when using C. fluminea to assess Cd pollution in aquatic environment, extracellular Cd adsorbed on the tissue should be removed to avoid the influence of hydrodynamics.
许多沉积物和水中的重金属对水生生物如河蚬（Corbicula fluminea）具有潜在的不利影响，河蚬是一种常被用作金属污染生物监测器的双壳类物种。过去几十年的研究表明，河蚬对重金属的吸收作用，很少有研究调查水动力条件对河蚬积累重金属的影响。因此，在这项研究中，为了研究金属细胞内和细胞外积累的机制，将河蚬个体暴露在三种不同水动力条件下的镉（Cd）处理水中。这些暴露包括在两个设置中进行：在烧杯中以 500、350 和 200 转/分的三种转速旋转 10 天，然后在实验水槽中以两种自然紊流条件（14cm/s 和 3.2cm/s）下暴露于 Cd 处理的沉积物中 23 天。水动力增加了挖掘速度，但降低了河蚬的活动。暴露 10 天后，沙组河蚬组织中的细胞外 Cd 浓度明显高于砾石组。Cd 处理沉积物试验中，河蚬组织的细胞内和细胞外 Cd 浓度显著增加。此外，14cm/s 和 3.2cm/s 组中吸附在河蚬组织上的细胞外 Cd 浓度明显高于对照组，而水动力对河蚬吸收 Cd 的影响不明显。这些结果表明，水动力条件在河蚬细胞外积累 Cd 方面起着重要作用。在未来的研究中，当使用河蚬评估水生环境中的 Cd 污染时，应去除吸附在组织上的细胞外 Cd，以避免水动力的影响。
