Zhou Guang-Jie, Vehniäinen Eeva-Riikka, Hiltunen Minna, Rigaud Cyril, Taipale Sami
Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou, 510632, China.
Department of Biological and Environmental Science, University of Jyväskylä, 40014, Jyväskylä, Finland.
Oecologia. 2025 May 14;207(6):81. doi: 10.1007/s00442-025-05723-2.
Natural and synthetic particles co-occur in the aquatic environment. However, little information is available about the effects of natural particles on freshwater animals and how these effects differ from those of synthetic particles, especially under the scenarios of decreasing dietary quality and increasing cyanobacteria in the aquatic environment. Therefore, this study evaluated apical and molecular effects of polypropylene (PP) microplastics (MPs) and three natural non-food particles (i.e., kaolin, peat, and sediment) on the freshwater invertebrate Daphnia magna fed either a green alga or a mixture of green alga and cyanobacterium. After the 21-d chronic exposure of 10 mg/L PP when using the green alga Acutodesmus sp. as diet, the size of D. magna was significantly reduced, and the molting time was significantly extended compared with the control. However, the chronic effects of PP were masked when the cyanobacterium Pseudanabaena sp. was added to their diet. The natural particles kaolin, peat, and sediment posed insignificant effects on D. magna regardless of dietary quality. The expression of molting-related genes (e.g., ecr-a) and oxidative stress-related genes (e.g., sod2) was significantly upregulated in D. magna with the exposure of both natural and synthetic particles. The predicted no-effect concentration of PP was derived as 0.025 mg/L, raising concerns relating to their toxicity and risks in the contaminated aquatic environment. This study will improve our understanding of the effects and risks of natural and synthetic particles in freshwater environments, as well as facilitate ecoenvironmental authorities to make informed decisions on the appropriate management of MPs.
天然颗粒和合成颗粒在水生环境中同时存在。然而，关于天然颗粒对淡水动物的影响以及这些影响与合成颗粒的影响有何不同的信息却很少，尤其是在水生环境中饮食质量下降和蓝藻增加的情况下。因此，本研究评估了聚丙烯（PP）微塑料（MPs）和三种天然非食物颗粒（即高岭土、泥炭和沉积物）对以绿藻或绿藻与蓝藻混合物为食的淡水无脊椎动物大型溞的顶端效应和分子效应。当以绿藻Acutodesmus sp.为食物，对大型溞进行10 mg/L PP的21天慢性暴露后，与对照组相比，大型溞的体型显著减小，蜕皮时间显著延长。然而，当在其食物中添加蓝藻假鱼腥藻时，PP的慢性影响被掩盖了。无论饮食质量如何，天然颗粒高岭土、泥炭和沉积物对大型溞的影响都不显著。在暴露于天然和合成颗粒的大型溞中，蜕皮相关基因（如ecr-a）和氧化应激相关基因（如sod2）的表达均显著上调。PP的预测无效应浓度为0.025 mg/L，这引发了人们对其在受污染水生环境中的毒性和风险的担忧。本研究将增进我们对淡水环境中天然和合成颗粒的影响及风险的理解，并有助于生态环境部门就微塑料的适当管理做出明智决策。
