鄱阳湖及其支流长江江豚种群数量及分布

在1997 年11 月至1998 年11 月的134 d 中, 大致按一年四季, 分4 次对鄱阳湖及其主要支流中的长江江豚种群数量、数量的季节变动、分布、行为、江豚栖息地环境、人类活动对江豚的影响进行了考察。江豚的分布主要集中在鄱阳湖湖区, 赣江、信江、抚河等主要支流的中下游和支流入湖的湖口附近。冬、春、秋3 个季节鄱阳湖水系长江江豚种群数量的估计值分别为91 头、431 头和260头。即, 鄱阳湖江豚的种群数量约为100～400 头,其种群数量随季节、水位、鱼类资源的变化而呈现出相应的变化。

DISTRIBUTION AND POPULATION SIZE OF YANGTZE FINLESS PORPOISE IN POYANG LAKE AND ITS BRANCHES

Four surveys, roughly representing four seasons of the year, were taken from November 1997 through November 1998 with totally about 120 days. Population size of Yangtze finless porpoise, Neophocaena phocaenoides asiaeorientalis, and its seasonal changing, distribution, behavior, habitat, impacts by human activities, etc., have been studied in Poyang Lake and its main branches in this study. Main distribution areas were in the open lake, and lower reaches of its main branches, such as Ganjiang River, Xinjiang River, Fuhe River, etc., and their estuaries. Estimated population sizes of the porpoise in the lake, including its main branches, were 91 in winter, 431 in spring, and 260 in autumn respectively during the year. Namely, its population size was estimated roughly between 100 and 400. The population dynamic varied in different seasons, water levels, and fish resources.