How do microplastics affect the marine microbial loop? Predation of microplastics by microzooplankton
How do microplastics affect the marine microbial loop? Predation of microplastics by microzooplankton
复制标题
微塑料如何影响海洋微生物循环？
DOI：
10.1016/j.scitotenv.2020.144030
复制
发表时间：
2021-03-01
影响因子：
9.8
通讯作者：
Jiang, Yong
中科院分区：
文献类型：
--
作者：
Geng, Xianhui;Wang, Jun;Jiang, Yong
原生动物在海洋生态系统中物质和能量传递的重要过程——微生物循环中起着不可或缺的作用。海洋环境中微塑料的数量大大增加，但小型纳米塑料和微塑料对海洋生物的潜在影响尚不清楚。在这里，我们进行了一系列不同浓度（约1 μ m）的微塑料珠的摄食实验，以表征浮游纤毛原生动物对微塑料的反应，并进行了一系列额外的四种不同粒径的微塑料暴露实验，以探讨摄食反应是否具有尺寸选择性。随着微塑料浓度的增加，暴露期间纤毛虫的数量、体型和生物量急剧下降。与无微塑料处理相比，所有微塑料处理的捕食者生物量都显著减少。例如，在暴露72 h时，观察到最高微塑料浓度处理的生物量相对于对照减少了96.59%。不同直径微塑料对纤毛虫生物量影响不明显；但与无穗对照相比，生物量仍显著下降。这些发现表明，海洋中的微塑料对原生浮游动物的生长产生了负面影响，这些原生浮游动物可能在进食过程中意外摄入了这些微小颗粒。总的来说，本研究为了解微塑料对海洋生态系统微生物环的影响提供了基础和新颖的数据。(C) 2020 Elsevier B.V.版权所有
Protozoans play an integral role in the microbial loop, an important process of material and energy transfer in marine ecosystems. The number of microplastics in the marine environment has greatly increased, but the potential impacts of small nanoplastics and microplastics on marine organisms remain unclear. Here, we conducted a series of feeding experiments with various concentrations of microplastic beads (ca. 1 mu m) to characterize the response of the planktonic ciliated protozoan Strombidium sulcatum to microplastics and a set of additional exposure experiments with four different particle diameters of microplastics to explore whether the feeding response exhibited size selectivity. As the microplastic concentration increased, the number, body size, and biomass of ciliates decreased sharply during the exposure period. Predator biomass in all microplastic treatments was markedly reduced relative to the microplastic-free control. For example, at 72 h of exposure, the biomass in the highest microplastic concentration treatment was observed to decrease by 96.59% relative to the control. There was no obvious difference in the biomass of ciliates exposed to various diameters of microplastics; however, compared with the free bead control, the biomass still significantly decreased. These findings suggest that microplastics in the ocean negatively affect the growth of protozoan microzooplankton that might have accidentally ingested these tiny particles during the feeding process. Generally, this study provides basic and novel data for understanding the effect of microplastics on the microbial loop in marine ecosystems. (C) 2020 Elsevier B.V. All rights reserved.