Distribution Patterns of Picosized and Nanosized Phytoplankton Assemblages in the East China Sea and the Yellow Sea: Implications on the Impacts of Kuroshio Intrusion

Abstract

AbstractKuroshio, the strongest west boundary current of the Pacific Ocean, has significant impacts on the oceanographic conditions and ecological processes of the Pacific‐Asian marginal seas through exchange of water, heat, and materials. In two cruises organized in the East China Sea (ECS) and the Yellow Sea in the spring 2014, observations of picosized and nanosized phytoplankton assemblages using flow cytometry reflected potential impacts of Kuroshio intrusion on phytoplankton communities, particularly in the ECS. The distribution pattern of Prochlorococcus in the ECS clearly depicts the intrusion route of Nearshore Kuroshio Branch Current from the main stream of Kuroshio northeast to Taiwan Island to the coastal waters adjacent to the Changjiang River estuary, an important “red tide zone” in the coastal waters of China. High abundance of photosynthetic nanoeukaryotes in the coastal waters adjacent to the Changjiang River estuary reflects the occurrence of diatom and dinoflagellate blooms during the investigation. The presence of Prochlorococcus in the coastal waters adjacent to the Changjiang River estuary offers a strong evidence that waters and materials associated with Nearshore Kuroshio Branch Current could be transported into the red tide zone adjacent to the Changjiang River estuary and will affect dynamics of harmful algal blooms in this region.