Dynamic Change in the Composition of Photosynthetic Picoeukaryotes during Spring Season Observed from the Research Platform in the East China Sea

Abstract

Photosynthetic picoeukaryotes (PPEs) are major oceanic primary producers. However, the diversity of such community remains poorly understood, especially in the shelf waters of the East China Sea. In this study, daily observations of environmental factors and PPEs diversity were carried out to understand changes of PPEs dynamics during offshore spring bloom for about two months from the Ieodo Ocean Research Station located on shelf area of the East China Sea. High-throughput tag sequencing (using the MiSeq system) method was used to reveal the diversity of plastid 16S rRNA genes. Results showed that the dominant PPEs were changing at the class level during the study period. Mamiellopphyceae group was the most dominant PPEs contributing about 50 percent of the total sequence numbers followed by prymnesiophyceae, cryptophyceae, dinophyceae, bacillariophyceae, prasinophyceae, and chrysophyceae. However, degree of dominance in each class was also changed during the bloom stage. This changing pattern of PPEs community composition may be reflecting eco-physiological characteristic of each classes. The preliminary research results indicated great potentiality of using the Ieodo station asa collaborative MBON research platform for open-ocean in the East China Sea.