广西北海水域中华白海豚种群数量和分布动态及保护对策研究-动物学专业论文.docxVIP

II II Studies On Population Abundance , Distribution and Conservation Strategies of the Indo-Pacific Humpback Dolphin （Sousa chinensis）in Beihai Waters The Indo-Pacific humpback dolphins (Sousa chinensis) are medium sized and robust body. It is discontinuously distributed in coastal waters of the western Pacific and the Indian Ocean. Throughout most of its range it has not been well studied. According to many researchers, known areas of occurrence in China include the inshore of southern China, referring to west seashore of Taiwan, from the Beibu Gulf to Jiangsu, entering the lower reaches of the ZhuJiang River, the JiulongJiang River, and the MinJiang River, and ascending up the Yangtse River as far as Wuhan. In present studies, population size and distribution characteristic of Indo-Pacific Hump-backed dolphin were surveyed from June, 2003 to May, 2004 in the Beihai Waters, Guangxi. It was used in this study, the boat-based transect line sampling and Route methods. Analyses suggested that overall population abundance in the survey area was around 100 animals, 19 groups. Over half of total abundance was found in the Guangxi Hepu Dugong Natural Reserve and its adjacent waters. The rest animals were sighted at the Dafengjiang River estuary and its neighboring region. Sea area between N21o21＇and N21o30＇seemed to be the most important habitation of the Indo-Pacific Humpback Dolphin in the Guangxi, Hepu Dugong National Natural Reserve and its adjacent waters. Relatively high frequencies of sighting implicated that the Dolphins were likely to inhabit this region as the center and radiated. One pathway is from the Sanniang Bay, Xiliujiao and Qinzhou Bay to the east coastal waters; the other way ran from Guantou Peak and Daguansha to the west, Shatian and Yingpan waters. Additionally, influencing factors to Sousa were put forward based on the present studies.Some measures were provided for the conservation and management to decrease the threat mentioned above. Moreover,