Abstract
To analyse temporal distributions of microplankton populations and relationships to environmental conditions in marine ecosystems, a dataset of microplankton communities was investigated using a range of statistical methods. A total of 164 microplankton species comprising 100 microalgae and 64 ciliates were identified from 120 samples, respectively. Both planktonic microalga and ciliate assemblages showed temporal patterns and were significantly correlated between their temporal variations in abundance. The microplankton communities were characterized by 14 ciliates (e. g. Strombidium sulcatum, Tintinnopsis tubulosoides and Strombidium cheshiri) and 18 microalgae (e. g. Skeletonema costatum and Alexandrium tamarense). Multiple regression analyses showed that the interspecies correlations among these dominant species represented a complex network with a clear seasonal shift. Temporal pattern of microplankton communities was significantly correlated with the environmental variables such as temperature, salinity and nitrate nitrogen. The results suggest the clear species distribution and temporal dynamics of microplankton communities in response to environmental changes, and multivariate statistical approaches were a useful tool to reveal the species distribution patterns and complex microplanktonic interspecies correlations in marine ecosystems.