碩士 / 國立中山大學 / 海下科技暨應用海洋物理研究所 / 102 / Visual investigation of cetaceans are often limited by the weather, sea conditions and coastal water depth and other factors. In order to compenstate for the shortage of visual observation, this study used passive acoustics monitoring system to measure the whistle of Chinese White Dolphins and ambient noise in west coast of Taiwan. This study deployed two underwater acoustic recorders (SM2M) in New Huwei River of Yun-Lin coastal area (site YL) and Waisanding sandbar (site WS). Total of 68- and 45-days acoustic data were collected in YL and WS respectively. There are two parts of analysis according to recording data. One analysis explored the changes and trends of ambient noise, to understand the different of the two sites by spectrogram and spectrum, distribution of sound pressure level (SPL), as well as significant sound sources. Results shows that the low-frequency noise in WS is lower than YL due to the contributions of shipping and fishing noises. In two sites , ambient noise at 1 to 2 kHz contains periodic changes due to daily cycle of local croakers (Sciaenidae). Another analysis focused on the significant fishing boat noise, whose frequency range overlaps the whistle of Chinese White Dolphins. This analysis explored whether Chinese White Dolphins respond to passage of boats by using changes in total number of whistles before and after boat passing to understand potential variation of dolphin’s behavior. Results indicate a significant increase in the number of whistles after fishing boats passed. The increase in the number of whistles produced by dolphins after fishing boats pass, strongly suggests that the noise from transiting boats affects dolphin''s group communication, so dolphins need to re-establish vocal contact with associates after the masking noise of the boat has passed
| Identifer | oai:union.ndltd.org:TW/102NSYS5281010 |
| Date | January 2014 |
| Creators | Lien-Han Kuo, 郭連翰 |
| Contributors | Ruey-Chang Wei, 魏瑞昌 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 99 |
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