Study of zooplankton ecology in Zhejiang coastal upwelling system-Zooplankton biomass and abundance of major groups

The studied area is a shallow water area that belongs to the East China Sea continent shelf.The distribution of zooplankton biomass is higher inshore than offshore.The maximum abundance is in the inshore edge of the centre of upwelling, which is the superposed area of the salinity front and temperature front, due to the fact that the mixture of three different waters has brought about a concentration of nutrients.The herbivorous Euphausia, Copepoda and Tunicata are the major groups of the abundant area.Tunicata possess the possibility to compete against other kinds of herbivorous zooplankton.This means that there is negative correlation between the distribution of Tunicata and that of Copepoda and Euphausia.The positions of maximum areas of zooplankton biomass, phytoplankton individual and the concentration of phosphates and chlorophyll-a overlap one another.In the centre of upwelling, zooplankton can not adapt itself to the environment of lower temperature and less oxygen even with rich nutrient substances.