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A Study on the Estimation of Fish School Abundance Using Sonar Image

소너 화상을 이용한 어군량 추정에 관한 연구

  • Published : 2003.05.01

Abstract

The quantification of fish school abundance was carried out by using luminance of pixel on scanning sonar image, and compared with the indices of fish school abundance e.g. school number, school area and weighted school area. The survey was carried out in Funka Bay off southern Hokkaido, Japan using research vessel Ushio-Maru during December 1999. A 180-degree scanning sonar with a frequency of 164kHz was used. The school number was counted both left and right 40-degree radial lines from the center of own vessel mark on a scanning image. The school area was measured approximately as an ellipse from the school length and width. The weighted school area was calculated by multiplying school area and average value of inner pixel luminance. A quantification of pixel luminance was also measured to integrate squared pixel luminance value on these lines. Fish school and school bottom were discriminated by the produced sonar echogram using pixel luminance value on these lines. The relationships between the quantified luminance value and other abundance indices such as school area and weighted school area revealed a good correlation. Therefore, the quantified luminance is a useful method in estimating fish school abundance in the acoustic survey using sonar.

소너를 이용한 어군량 조사에서 자동화가 용이하고 고기의 분포상태에 관계없이 측정이 가능한 에코적분법에 관한 정량화법의 기초 연구로서, 소너 화상의 휘도를 2 승 적분하여 어군량을 정량화하고 이 값을 다른 어군량 지표와 비교, 분석한 결과를 요약하면 다음과 같다. 1. 휘도를 이용하여 작성한 에코그램으로부터 어군과 해저를 분명하게 식별하는 것이 가능하여 화상을 이용한 어군량의 정량화에 있어서 휘도는 유용한 정보이다. 2. 소너 화상으로부터 계수법에 의하여 얻어진 어군의 수는 픽셀 휘도의 2승 적분치에 정의 상관을 나타내었으나, 어군의 계수법은 어군의 규모에 관계하지 않고 어군을 계수하기 때문에 오차가 클것으로 판단되어 정량화법으로서는 좋은 방법이라 할 수 없다. 3. 면적측정법으로 계측된 어군면적은 픽셀 휘도의 2승 적분치에 비례하고 유의한 상관을 나타내었으므로, 어군량 지표로서 유용 가능하다고 판단된다. 4. 소너 화상의 휘도를 2 승 적분하여 얻어진 어군량 정보는 고기의 분포상태에 관계없이 측정이 가능하여 어군량을 정량화하는 방법으로서 유용할 것으로 판단된다.

Keywords

References

  1. McClendon, R. I. (1968) : Detection of fish schools by sonar (eastern tropical Pacific, July-November 1967), Commer. Fish. Rev. 30, 26-29.
  2. Hewitt, R. P., Smith, P. E. and Brown, J. C. (1976) : Developments and use of sonar mapping for pelagic stock assessment in the California current, Fish. Bull. US. 74, 281-300.
  3. Misund, O. A. (1993) : Abundance estimation of fish schools based on a relationship between school area and school biomass, Aquat. Living Resour. 6, 235-241. https://doi.org/10.1051/alr:1993024
  4. Misund, O. A., Aglen, A., Hamre, J., Ona, E., Rottingen, I., Skagen, D. and Valdemarsen, J. W. (1996) : Improved mapping of schooling fish near the surface : comparison of abundance estimates obtained by sonar and echo integration, ICES J. Mar. Sci. 53, 383-388. https://doi.org/10.1006/jmsc.1996.0053
  5. Misund, O. A., Aglen, A., Beltestad, A. K. and Dalen, J. (1992) : Relationships between the geometric dimensions and biomass of schools, ICES J. Mar. Sci. 49, 305-315. https://doi.org/10.1093/icesjms/49.3.305
  6. Forbes, S. T. and Nakken, O. (1972) : Manual of methods for fisheries resource survey and appraisal, Part 2 : The use of acoustic instruments for fish detection and abundance estimation, FAO Man. Fish. Sci. 5, 100-133.
  7. Johannesson, K. A. and Losse, G. F. (1977) : Methodology of acoustic estimations of fish abundance in some UNDP/FAO resource survey project, Rapp. P. - v. Reun. Cons. int. Explor. Mer. 170, 296-318.
  8. MacLennan, D. N. and Simmonds, E. J. (1992) : Fisheries Acoustics, CHAPMAN & HALL, 325.
  9. Misund, O. A., Aglen, A. and Fronaes, E. (1995) : Mapping the shape, size, and density of fish schools by echo integration and a high-resolution sonar, ICES J. Mar. Sci. 52, 11-20. https://doi.org/10.1016/1054-3139(95)80011-5
  10. 丹羽洋智 (1999) : 群れは雁行形態をどのように 維持すゐか, 第9回数理生物學シンポヅウム, 9.
  11. Enzenhofer, H. J., Olsen, N. and Mulligan, T. J. (1998) : Fixed-location riverine hydro-acoustics as a method of enumerating migrating adult Pacific salmon - comparison of split-beam acoustics vs. visual counting. Aquat. Living Resour. 11, 61-74. https://doi.org/10.1016/S0990-7440(98)80062-4
  12. Simond, E. J., Williamson, N. J., Gerlotto, F. and Aglen, A (1992) : Acoustic survey design and analysis procedure - a compre-hensive review of current practice, ICES Coop. Res. Rep. 187, 56-88.