Spatial variation in zooplankton communities in relation to key environmental factors in the Yellow Sea and East China Sea during winter

Abstract

The zooplankton composition, abundance, community structure, and diversity in the Yellow Sea and East China Sea, major wintering grounds of many fishery species, were studied based on net plankton samples collected in winter of 2016. A total of 68 taxa (mostly at the species level) were recorded. Copepods clearly dominated the zooplankton community, and the dominant species were Oithona similis, Paracalanus parvus, Microsetella norvegica, and Calanus sinicus. Three zooplankton communities (Groups 1–3) were identified via cluster analysis. Group 1, which was characterized by the highest mean total zooplankton abundance and lowest community diversity, mainly consisted of warm-temperate species found in the middle region of the southern Yellow Sea. Stations distributed in the northern East China Sea were included in Group 3, where many tropical and subtropical species were found and zooplankton exhibited the highest species number and community diversity. Group 2, which was located in the coastal area and transitional region between Groups 1 and 3, contained Labidocera euchaeta as the representative species. Seawater temperature was more important in shaping the spatial patterns of zooplankton communities than other environmental factors in the study area during winter. In addition, water currents showed a great influence on zooplankton composition and community structure. Overall, the results of this study provide information regarding food availability for wintering fish and contribute to a better understanding of zooplankton dynamics in the area during winter.