• Title/Summary/Keyword: Timed varied threshold

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The relationship between fish and zooplankton in south-western region of the East Sea using hydroacoustics (음향을 이용한 동해 남서부해역에서 어류와 동물플랑크톤의 관계)

  • HAN, Inseong;OH, Wooseok;YOON, Eun-A;SUH, Youngsang;LEE, Kyounghoon;SHIN, Hyeongho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.4
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    • pp.376-385
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    • 2017
  • This study was conducted to understand the relationships between fish and zooplankton of distribution in the coastal waters of the East Sea from May to August 2016 using hydroacoustic. To distinguish between fish and zooplankton, we used the time varied threshold (TVT) method at the frequency of 120 kHz. As a result, the mean nautical area scattering coefficient (NASC) of fish was highest at $913m^2/n.mile^2$ in June and lowest at $315m^2/n.mile^2$ in July. The mean NASC of zooplankton was highest at $247m^2/n.mile^2$ in May and lowest at $70m^2/n.mile^2$ in July. The mean NASC of fish and zooplankton showed a significant difference (P < 0.05) with high correlation ($R^2=0.84$). In addition, there was no significant difference in the mean NASC of fishes and zooplankton by depth (t-test, person correction = -0.17, p > 0.05).