摘要

微塑料对整个海洋生态系统构成了巨大的威胁，但对浮游植物的影响知之甚少，尤其是有害的甲藻。本研究利用梯度浓度（0,5）评价了微聚氯乙烯（mPVC）对甲藻（Karenia mikimotoi）不同时期（0,24,48,72和96h）生长，叶绿素含量和光合效率的影响。 ，25,50和100mgL-1）mPVC，大小为1μm。 PVC微塑料对K. mikimotoi生长，叶绿素含量和光合效率具有剂量依赖性不利影响。随着mPVC浓度的增加，藻细胞密度降低，在100mgL-1的mPVC下，24h时最高抑制率（IR）为45.8％。单个藻类细胞总叶绿素含量和叶绿素含量在96h时下降，ФPSⅡ和Fv / Fm分别下降25.3％和17.1％。 SEM图像提供了一种直观的可视方法来观察微塑料和微藻之间的行为和相互作用。从SEM图像中发现，微藻被微塑料珠包裹。物理阻断和聚集也是K. mikimotoi的细胞毒性的原因。我们的研究澄清了PVC微塑料可以减少藻类生长，叶绿素含量和光合效率，有利于评估塑料对水生生态系统的可能影响。

Microplastics pose a great threat to entire marine ecosystems, but little is known about their impacts on phytoplankton, especially for the harmful dinoflagellates. In this study, effects of micro polyvinyl chloride (mPVC) on the growth, chlorophyll content and photosynthetic efficiency of the dinoflagellate Karenia mikimotoi at different periods (0, 24, 48, 72 and 96 h) were assessed using gradient concentrations (0, 5, 25, 50 and 100 mg L-1) of mPVC with a size of 1 μm. PVC microplastics had dose-dependent adverse effects on K. mikimotoi growth, chlorophyll content and photosynthetic efficiency. The density of algal cell decreased with increasing mPVC concentrations and the highest inhibitory rate (IR) was 45.8% at 24 h under 100 mg L-1 of mPVC. The total chlorophyll content and chlorophyll content in a single algal cell decreased at 96 h and the ФPSⅡ and Fv/Fm decreased 25.3% and 17.1%, respectively. The SEM images provided an intuitive visual method to observe the behaviors and interactions between microplastics and microalgae. It was found from the SEM images that microalgae was wrapped by microplastic beads. The physical blockage and aggregation were also responsible for the cytotoxicity of K. mikimotoi. Our study clarified that PVC microplastics can reduce algal growth, chlorophyll content and photosynthetic efficiency, and it is beneficial to evaluate the possible impact of plastics on aquatic ecosystems.

https://www.ncbi.nlm.nih.gov/pubmed/30731314