The Role of Microzooplankton in the Carbon Cycle in the Xiamen Harbor in Winter

Based on the dilution technique and analysis of partical removal in bottle incubations,microzooplankton herbivorous activity and its contribution to the diet of certain dominant copepods(Centropages tenuiremis) was carried out simultaneously at Baozhu Island of Xiamen Harbor in February,2004.The results showed that the microzooplankton grazing pressure on the phytoplankton stock and the primary production was 38 % and 63 % respectively.The clearance rates of Centropages tenuiremis for ciliates and phytoplankton reached 3.08mL·ind~(-1)·h~(-1) and 0.31mL·ind~(-1)·h~(-1) respectively,the ingestion rates reached 0.44(μg·ind~(-1)·d~(-1)) and 0.24μg·ind~(-1)·d~(-1).The ratio of the ciliates to the diet of Centropages tenuiremis was between 65 % and 95 %.These results support the idea that herbivourous microzooplankton are important in determining the production and fate of phytoplankton and play the nutritional link's role between phytoplankton and copepods in marine ecosystem of Xiamen Harbor in winter.