碩士 / 國立臺灣海洋大學 / 環境生物與漁業科學學系 / 98 / In this study we used echosounder data collected by SIMRAD EK500 equipped on the Ocean Researcher II in the northeastern waters of Taiwan during 2006- 2008 to build distribution model of total biomass from coastal to continent slop (10~300 m), and to find the effect of seafloor relief. We calculated the index of sound scattering intensity of each voyage among surface, middle, and lower layers, including mean volume backscatting strength (Sv) of 38kHz and 120kHz. We used the Sv to analyze effects of layer, area, and slope on the biomass distribution and apply to GLM(Generalized Linear Model) for Sv value. The major results of this research are as following:
1. We analyzed Sv values of different layers in the 28 transects showing that biomass density changed decreasingly by the depth of waters and the distance to coastal. The mean decreasing rate for 38kHz and 120kHz were -0.58 and -0.34 dB/nm.
2. The decreasing phenomenon of 38kHz is more significant than those of 120kHz, which imply that the distribution density of larger organisms decreasing faster than small organisms. Small organisms disperse from coastal to offshore in the surface layer and large organisms are more dependent on the seafloor relief.
3. According to all transects of 38 kHz and 120 kHz, we estimated the total biomass distribution density of coastal, continent and slope were 22:9:6 and 17:11:9, respectively.
4. The GLM analysis show that temporal factors (year, month) and spatial factors (layer, area, and slope) were major factors of biomass variation, which explain 60.8% and 40.05% variation of SV for 38kHz and 120kHz, respectively.
| Identifer | oai:union.ndltd.org:TW/098NTOU5451031 |
| Date | January 2010 |
| Creators | Hsuan-Lin Chen, 陳宣霖 |
| Contributors | Hsueh-Jung Lu, 呂學榮 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 87 |
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