- Volume 39 Issue 2
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.
- 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.
- 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
- 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.
- MacLennan, D. N. and Simmonds, E. J. (1992) : Fisheries Acoustics, CHAPMAN & HALL, 325.
- 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.
- 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
- 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
- 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
- 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.
- 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
- McClendon, R. I. (1968) : Detection of fish schools by sonar (eastern tropical Pacific, July-November 1967), Commer. Fish. Rev. 30, 26-29.
- 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.