中文摘要：

江西鄱阳湖是长江江豚（Neophocaena phocaenoides）的重要栖息地, 湖中栖息着约 400 头江豚。多年的

英文摘要：

The Poyang Lake in Jiangxi Province is an important habitat of the Yangtze finless porpoises.There are about 400 individuals of porpoise inhabiting in the lake.The surveys conducted in recent years indicated that one of the threats faced by the animals might be from the heavy boat traffic in the lake.For estimating the possible negative effects of the boat traffic on the animals in the lake,an acoustic observation with the aid of an underwater acoustic data logger was conducted in the confluence of Poyang Lake and the Yangtze River from 27 June to 1 July 2007.In this observation,the passive acoustic data logger was fixed at the monitor station（latitude： 29°42′38″ N,longitude： 116°11′11″ E） and was deployed to monitor and record continually periphery underwater noise of the boat traffic and pulse events of sonar signals of porpoises that presented within 300 m around the station.During the 109h of investigation,494 vessels and 13,413 click trains were recorded by the logger.These data were analyzed by using a customized program developed on Igor Pro 5.01（WaveMetrics,USA）,and the results were used for investigating the effects of boat traffic on the acoustic behavior of finless porpoises in the waters.A weak negative correlation between the presence of porpoises and ships was observed（r = 0.029,N = 6550,P 0.05）,The time difference between ships and adjacent click trains was 49.1s（±62.8s） and 72.9% of which were within 60s,and no significant difference was observed among pre-,during,and post-boat encounters（Z = 0.370,P 0.05）.The phonation rate of click trains recorded by the acoustic data logger declined significantly during the vessel present（in-noise） situations（Z = 10.050,P 0.05）,whereas both the duration of click trains and inter-click intervals did not show significant differences（Z = 0.275,P 0.05;Z = 0.119,P 0.05）.No significant differences were observed in the phonation rate of click trains,the duration of click trains,as well as the inter-click intervals of the