Background

Numerous studies have measured the harmful effects of microplastics (MPs) and nanoplastics (NPs) (e.g., ingestion, temporal bioconcentration, acute and chronic responses, and the trophic transfer from primary producers to consumers) on aquatic invertebrates due to their ubiquitous and persistent nature in waterbodies.

Objective

An experimental water flea model, Moina macrocopa, was exposed to different concentrations (0.001, 0.01, 0.1, 1, 10, 50, 100, and 500 μg L⁻¹) of polystyrene microbeads (1 μm). The effects of polystyrene microbeads were investigated by measurement of multigenerational survival rate, growth, and reproduction parameters with further analysis of biochemical responses across three generations.

Results

Exposure to polystyrene microbeads resulted in clear ingestion and egestion in feces. The survival rate was significantly decreased by relatively higher concentrations of polystyrene microbeads compared to control groups. Multigenerational experiments across three generations revealed that exposure to relatively higher concentrations of polystyrene microbeads reduced the growth rate with longer intermolt durations compared to that in the first generation of each group, but similar patterns were observed in reproduction parameters between generations. Initial exposure to polystyrene microbeads resulted in oxidative stress and the induction of antioxidant defense, while 14-day exposure significantly inhibited the antioxidant response.

Conclusion

Our results suggest that the detrimental effects of prolonged exposure to polystyrene microbeads would be concentration dependent and harmful for the maintenance of water flea populations by induction of oxidative stress and failure in antioxidant defense.

中文翻译：

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水蚤 Moina macrocopa 对微塑料的生化和生理反应：一项多代研究

背景

大量研究测量了微塑料 (MPs) 和纳米塑料 (NPs) 对水生无脊椎动物的有害影响（例如，摄入、时间生物浓度、急性和慢性反应以及从初级生产者到消费者的营养转移），因为它们无处不在和持久性在水体中。

客观的

实验性水蚤模型Moina macrocopa暴露于不同浓度（0.001、0.01、0.1、1、10、50、100 和 500 μg L ^-1）的聚苯乙烯微珠（1 μm）。通过测量多代存活率、生长和繁殖参数以及对三代生化反应的进一步分析来研究聚苯乙烯微珠的影响。

结果

暴露于聚苯乙烯微珠导致清晰的摄入和排泄的粪便。与对照组相比，相对较高浓度的聚苯乙烯微珠显着降低了存活率。跨三代的多代实验表明，与每组的第一代相比，暴露于相对较高浓度的聚苯乙烯微珠会降低生长速度，同时换毛持续时间更长，但在几代之间的繁殖参数中观察到类似的模式。最初接触聚苯乙烯微珠会导致氧化应激和抗氧化防御的诱导，而 14 天的接触显着抑制了抗氧化反应。

结论

我们的研究结果表明，长时间接触聚苯乙烯微珠的有害影响将是浓度依赖性的，并且通过诱导氧化应激和抗氧化防御失败对水蚤种群的维持有害。