洞庭湖、鄱阳湖白鱀豚和长江江豚的生态学研究

１９９７年至１９９９年对洞庭湖和鄱阳湖的湖区及其支流的白豚和长江江豚的分布、数量和活动规律进行了系统的调查。调查结果表明，白豚已在洞庭湖和鄱阳湖绝迹。长江江豚随着水位的变化，其分布范围、数量和活动规律也随之而变化。长江江豚在洞庭湖的分布范围主要集中在从城陵矾到鲶鱼口一带，其种群数量大致力１００～１５０头。洞庭湖各支流中已看不到江豚的踪迹。在鄱阳湖主要分布在湖口至龙口一带，老爷庙至小矶山是其集中分布区。赣江南北支、抚河下游及康山河在涨水季节也有少量江豚活动。洞庭湖和鄱阳湖大规模的围湖造田，湖区的迅速淤积变浅，大桥的修建，有害渔具渔法的大量使用，船舶数量的大量增加是长江江豚迅速减少的重要原因，两大湖泊中的长江江豚急待保护。

STUDIES ON THE DISTRIBUTION, POPULATION SIZE AND THE ACTIVE REGULARITY OF LIPOTES VEXILLIFER AND NEOPHOCAENA PHOAENOIDES IN DONGTING LAKE AND BOYANG LAKE

Surveys on the distribution, population size and the active regularity of Lipotes vexillifer and Neophocaena phocaenoides in Dongting Lake and Boyang Lake were carried out from 1997 to 1999. The investigation results indicated that Baiji became extinct in the two lakes. With the change of water level of lakes, the distribution area, population size and active regularities of finless porpoise varied accordingly. In Dongting Lake finless porpoises were concentrated in the water section between Chenglingji and Nianyukou which is about 50 km long. This animal could not be found in the branches flowing into Dongting Lake now. The population size of finless porpoise in this Lake is about 100-150 individuals. The finless porpoise in Boyang Lake was distributed in the area from Hukou and Longkou which is 180 km long. Furthermore, the concentrical areas of finless porpoise is the 20 km long section between Laoyemiao and Xiaojishan in this lake. The small amount of finless porpoises could be found in some branches of Boyang Lake during flood season, such as the Gan river, Fu river and Kangshan river. Human activities are responsible to the decline of finless porpoise abundance in the two lakes. The finless porpoise in the two lakes must be protected as soon as possible.