picoplankton

例句：

1. 1.The picoplankton are tiny organisms that live in the water's surface layer.
   微型浮游生物是生活在水表层的微小生物。
2. 2. Picoplankton play an important role in maintaining the balance of marine ecosystems.
   微型浮游生物在维持海洋生态系统平衡中起着重要作用。
3. 3.Researchers have found that picoplankton can be a significant source of nutrients for larger marine organisms.
   研究人员发现，微型浮游生物可以为更大的海洋生物提供重要的营养物质来源。