The researchers studied phytoplankton in the Yangtze River Estuary and nearby waters in autumn 2006. They found that diatoms were the most common type of phytoplankton, followed by dinoflagellates. Thalassiosira rotula and Skeletonema costatum were the dominant species. Phytoplankton cell abundance varied from 0.13 to 59.69 cells/L, with an average of 4.39 cells/L. High cell abundance was observed at the Yangtze River mouth and offshore. Trichodesmium thiebautii, a type of phytoplankton, was mainly found in the surface water of the eastern part of the survey area. The researchers identified two different phytoplankton provinces in the study area based on their analysis.