2010年9月
Density estimation of Yangtze finless porpoises using passive acoustic sensors and automated click train detection
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
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- 巻
- 128
- 号
- 3
- 開始ページ
- 1435
- 終了ページ
- 1445
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1121/1.3442574
- 出版者・発行元
- ACOUSTICAL SOC AMER AMER INST PHYSICS
A method is presented to estimate the density of finless porpoises using stationed passive acoustic monitoring. The number of click trains detected by stereo acoustic data loggers (A-tag) was converted to an estimate of the density of porpoises. First, an automated off-line filter was developed to detect a click train among noise, and the detection and false-alarm rates were calculated. Second, a density estimation model was proposed. The cue-production rate was measured by biologging experiments. The probability of detecting a cue and the area size were calculated from the source level, beam patterns, and a sound-propagation model. The effect of group size on the cue-detection rate was examined. Third, the proposed model was applied to estimate the density of finless porpoises at four locations from the Yangtze River to the inside of Poyang Lake. The estimated mean density of porpoises in a day decreased from the main stream to the lake. Long-term monitoring during 466 days from June 2007 to May 2009 showed variation in the density 0-4.79. However, the density was fewer than 1 porpoise/km(2) during 94% of the period. These results suggest a potential gap and seasonal migration of the population in the bottleneck of Poyang Lake. (c) 2010 Acoustical Society of America. [DOI: 10.1121/1.3442574]
- リンク情報
- ID情報
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- DOI : 10.1121/1.3442574
- ISSN : 0001-4966
- Web of Science ID : WOS:000281799800053