Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan, 650091, China; Institute of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Trans-Boundary Eco-security, Yunnan University, Kunming, 650091, China; Yunnan International Cooperative Center of Plateau Lake Ecological Restoration and Watershed Management & Yunnan Think Tank of Ecological Civilization, Kunming, Yunnan, 650091, China.
Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, School of Ecology and Environmental Sciences, Yunnan University, Kunming, Yunnan, 650091, China; Yunnan International Cooperative Center of Plateau Lake Ecological Restoration and Watershed Management & Yunnan Think Tank of Ecological Civilization, Kunming, Yunnan, 650091, China.
Water Res. 2024 Jan 1;248:120877. doi: 10.1016/j.watres.2023.120877. Epub 2023 Nov 15.
Although many studies have reported the negative effects of microplastics on aquatic organisms, most research is focused on individual scales. Individual studies highlight harm mechanisms, but understanding broader ecological effects necessitates evidence from multiscale perspectives, particularly those based on interspecific interactions. Therefore, in this study, we investigated the impacts of different microplastic concentrations (0, 0.4, 2, and 10 mg/L) on individual characteristics (physiology, behavior, and grazing rate) and population dynamics of two cladoceran species Daphnia magna and Scapholeberis kingi, and their interrelationships within communities in the absence and presence of predators (larvae of Agriocnemis pygmaea). We used 32-38 μm polyethylene microplastics; these particles were detected in the guts of D. magna, especially at higher concentrations, but were not found in S. kingi. Consequently, with increasing microplastic concentrations, the grazing and reproductive capacity of D. magna diminished, weakening their dominance in the coexistence system without damselfly larvae. Additionally, as microplastic concentration increased, D. magna faced greater oxidative damage and a reduction in mobility, making this species more susceptible to predation by damselfly larvae and less dominant in the predator-inhabited coexistence system. This study reveals the mechanism by which asymmetric impacts of microplastics on individual traits altered interspecific competition between zooplankton species, thereby illuminating the role of microplastics in altering zooplankton communities.
尽管许多研究报告了微塑料对水生生物的负面影响，但大多数研究都集中在个体尺度上。个别研究强调了危害机制，但要了解更广泛的生态效应，需要从多尺度的角度来证明，特别是基于种间相互作用的证据。因此，在这项研究中，我们调查了不同浓度的微塑料（0、0.4、2 和 10 mg/L）对两种枝角类物种大型溞和秀丽白虾个体特征（生理、行为和摄食率）和种群动态的影响，以及在没有和有捕食者（小绿浮蝽幼虫）存在的情况下，它们在群落中的相互关系。我们使用了 32-38 μm 的聚乙烯微塑料；这些颗粒在大型溞的肠道中被检测到，尤其是在较高浓度下，但在秀丽白虾中未被发现。因此，随着微塑料浓度的增加，大型溞的摄食和繁殖能力下降，使其在没有小绿浮蝽幼虫的共存系统中优势地位减弱。此外，随着微塑料浓度的增加，大型溞面临更大的氧化损伤和移动性降低，使其更容易受到小绿浮蝽幼虫的捕食，在有捕食者存在的共存系统中优势地位降低。这项研究揭示了微塑料对个体特征的不对称影响改变了浮游动物物种之间的种间竞争的机制，从而阐明了微塑料在改变浮游动物群落中的作用。
