School of Ecology and Environmental Sciences & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Yunnan University, Kunming, Yunnan 650091, People's Republic of China.
School of Ecology and Environmental Sciences & Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments, Yunnan University, Kunming, Yunnan 650091, People's Republic of China; Instititue of International Rivers and Eco-security, Yunnan Key Laboratory of International Rivers and Trans-Boundary Eco-security, Yunnan University, Kunming 650091, People's Republic of China.
J Hazard Mater. 2022 May 15;430:128415. doi: 10.1016/j.jhazmat.2022.128415. Epub 2022 Feb 4.
The negative effects of microplastics on the normal growth of aquatic organisms have been well studied, but relatively little is known about their potential adverse effects on the function and stability of aquatic ecosystems. We investigated here the effects of polyethylene (PE) microplastics on several aspects of plankton ecosystems, including Daphnia magna behavior, the grazing rate of D. magna on Chlorella vulgaris cells, trophic-cascade effects in the C. vulgaris-D. magna-larval damselfly food chain, the life-history of D. magna, and the stability and persistence of the D. magna-larval damselfly system. PE microplastics decreased the D. magna grazing rate as a result of reductions in their heart rate and hopping frequency. In the trophic-cascade experiment, PE microplastics increased the foraging success of larval damselflies on grazers due to hopping inhibition in grazers, which ultimately strengthened the trophic-cascade effect on algal growth. Long-term exposure to PE microplastics reduced the stability and persistence of the grazer population via increased predation risk and reduced reproductive capacity for grazer species. This study provides evidence that microplastics can affect the trophic cascade strength and stability of plankton ecosystems via behavior-mediated indirect interactions, suggesting that microplastics have more extensive impacts on aquatic ecosystems than presently recognized. ENVIROMENTAL IMPLICATION: The massive production and environmental releasing of microplastics have become ubiquitous in the global environment. The negative effects of microplastics on the normal growth of aquatic organisms have been well studied, but little is known about potential adverse effects on the function and stability of aquatic ecosystems. Here, we found that microplastics increased the positive impacts of larval damselflies on algal growth, and reduced the stability and persistence of plankton ecosystems via a behavior-mediated indirect interaction. To our knowledge, this is the first systematic study assessing the effects of microplastics on the community-level characteristics of a freshwater ecosystem. SYNOPSIS: PE microplastics affect trophic cascade strength and reduce the stability and persistence of plankton ecosystems via behavior-mediated indirect interactions.
微塑料对水生生物正常生长的负面影响已得到充分研究，但对其对水生生态系统功能和稳定性的潜在不利影响知之甚少。在这里，我们研究了聚乙烯（PE）微塑料对浮游生物生态系统的几个方面的影响，包括大型溞的行为、大型溞对小球藻细胞的摄食率、小球藻-大型溞-幼虫豆娘食物链中的营养级联效应、大型溞的生活史，以及大型溞-幼虫豆娘系统的稳定性和持久性。PE 微塑料通过降低心率和跳跃频率来降低大型溞的摄食率。在营养级联实验中，PE 微塑料通过抑制摄食者的跳跃来增加幼虫豆娘对摄食者的觅食成功率，从而最终加强了对藻类生长的营养级联效应。长期暴露于 PE 微塑料会通过增加捕食风险和降低摄食者的繁殖能力来降低摄食者种群的稳定性和持久性。这项研究提供了证据表明，微塑料可以通过行为介导的间接相互作用影响浮游生物生态系统的营养级联强度和稳定性，这表明微塑料对水生生态系统的影响比目前认识的更为广泛。环境影响：微塑料的大规模生产和环境释放已经在全球环境中无处不在。微塑料对水生生物正常生长的负面影响已得到充分研究，但对其对水生生态系统功能和稳定性的潜在不利影响知之甚少。在这里，我们发现微塑料通过行为介导的间接相互作用增加了幼虫豆娘对藻类生长的积极影响，并降低了浮游生物生态系统的稳定性和持久性。据我们所知，这是第一项系统评估微塑料对淡水生态系统群落水平特征影响的研究。概要：PE 微塑料通过行为介导的间接相互作用影响营养级联强度，并降低浮游生物生态系统的稳定性和持久性。
