长江口水域浮游动物生物量及其年间变化

根据2000～2003年长江口邻近海域2个季节8个航次海洋调查资料，对长江口邻近海域浮游动物生物量及其年间变化进行研究。结果表明：5月高生物量分布区在交汇水团的海水一侧，而交汇水团的淡水一侧生物量较低。8月高生物量分布在交汇水团的两侧，交汇水团的生物量较低。长江口生物量的年间变动与外海水势力有关。高生物量分布区往往位于长江口水域的东侧，当外海暖水势力强盛时，高生物量分布区向长江口伸展，使整个水域浮游动物生物量增高，而当外海暖水势力较弱时，高生物量分布区范围缩小。2001至2003年浮游动物生物量逐年迅速降低与此有密切的关系。浮游动物优势种组成及丰度变化是影响长江口饵料生物量变化的重要因素。

ZOOPLANKTON BIORMASS AND ITS VARIATION IN WATER NEAR CHANGJIANG ESTUARY

Based on the data of eight voyage′s cruise investigations in May and August from 2000 to 2003 in the water near the Changjiang estuary, this paper dealt with the approach for the zooplankton biomass and its variation in the area. Results showed that the higher biomass was distribution at the warm current side of the mixed formed by the warm current and the Changjiang freshwaters, while the lower biomass was located at the side of freshwaters in May. In August the higher biomass was distributed at both sides of freshwater and marine waters with the lower biomass in the mixed waters.The annual difference of biomass was related with the force of warm current near the Changjiang estuary in which the higher biomass was in the east. The high biomass area spreads towards the Changjiang estuary to make biomass expanding in waters when the force of warm current became stronger. On contrary, the high biomass area beflated because the force of warm current became weaker. This is why the biomass in the area reduced gradually from 2001 to 2003.The change in the dominant specids of zooplankton was the important reason influencing the diet biomass of Changjiang estuary.