• The Journal of the Acoustical Society of Korea
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• v.23 no.8
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• pp.562-569
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• 2004

An experiment for observation of the distribution of the seagrass (zostera marina) beds and characteristics of high-frequency backscattering by the photosynthesis was conducted off the coast. Acoustic data were taken as a function of the grazing angles and the relative azimuth angles on the seagrass beds of which bottom type was sandy-mud. The transmitted source signal was a 120 kHz CW waveform. Mapping of the seagrass beds distribution was drawn up using the seagrass backscattering strength with azimuth and grazing angles. The result of the comparison backscattering strength distribution of the seagrass beds was shown to be the similar to the photograph of real seagrass beds. The seagrass backscattering strength was also compared between day and night to verify the effects of the acoustical scattering by the bubbles of Photosynthetic oxygen formed on the seagrass. In these results. it is clear that observation of the seagrass beds between day and night showed the different characteristics because the bubbles of Photosynthetic oxygen affect the acoustical scattering.

• The Journal of the Acoustical Society of Korea
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• v.24 no.2
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• pp.97-102
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• 2005

Acoustic experiments were performed with Zostera marina to study the characteristics of backscattering of seagrass living in the bottom interface. Field experiments were conducted in the Dongdae man, Namhae for day and night to consider the effects of air-bubble from photosynthesis of seagrass. The multi-frequency (30$\~$120 kHz) responses were measured and the distributions of back scattering strength due to the movement of seagrass were Presented by PDF (probability density function) at 120 120 kHz. The results were shown both the frequency dependence and diurnal variation of the backscattering strength between day and night. This diurnal variation may be caused by the amount of oxygen in dissolved bubbles formed by Photosynthesis of seagrass.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.191-194
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• 2004

본 연구에서는 해양의 기초 생산자인 잘피 (Zostera marina)의 후방산란 특성을 일주기 동안 관측 하였다. 해상 실험은 2004년 2월 $25\~29$일 기간 중 남해 동대만에서 실시 하였다. 그랩(Grab)을 이용하여 해초지의 입도를 분석 하였으며 주파수별 산란 특성을 고려하기 위해서 17, 30, 50, 80, 100, 그리고 120kHz 음원을 해초지에 수직 지향하여 주, 야간 잘피의 후방 산란을 측정하였다. 실험 환경 분석을 위해 파고와 조석 및 잘피의 생체량(biomass)측정을 실시 하였다. 광합성 시 해초지에서 발생되는 산소 공기는 해수에 의해 용존 되거나 산소 가스 형태로 존재하게 된다. 이들 공기 방울에 의해서 형성되는 공기 방울 층은 음 세기의 감쇠를 야기 시킨다. 실험 결과 주, 야간 동안 음의 산란 강도 변화를 확인 하였다.