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Multichannel False Color Echograms as a Biological Interpretative Tool

  • N. A. Cochrane
  • D. D. Sameoto

Abstract

Image processing systems permit display of multichannel acoustic backscatter echograms as false color imagery. This technique for rapid visual assessment is illustated with 51 and 200 kHz acoustic data from Emerald Basin located in the central Scotian Shelf. Direct multilevel net sampling shows that strong 200 kHz scattering layers below 100 m depth are compatible with “Rayleigh” scattering from copepods. Layers in the upper 60 m scattering with nearly equal strengths at 51 kHz and 200 kHz are ascribed to comparatively large fish scattering in the “geometric” regime.

Keywords

False Color Target Strength Fluid Sphere Noise Cancellation Copepod Density 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Anderson, V.C., 1950, Sound scattering from a fluid sphere, J. Acoust. Soc. Am., 22: 246.CrossRefGoogle Scholar
  2. Clay, C.S. and Medwin, H., 1977, “Acoustical Oceanography Principles and Applications”, John Wiley, New York.Google Scholar
  3. Greenlaw, C.F., 1979, Acoustical estimation of zooplankton populations, Limnol. Oceanogr., 24: 226.CrossRefGoogle Scholar
  4. Greenlaw, C.F., 1977, Backscattering spectra of preserved zooplankton, J. Acoust. Soc. Am., 62: 44.ADSCrossRefGoogle Scholar
  5. Greenlaw, C.F. and Pearcy, W.G., 1985, Acoustical patchiness of mesopelagic micronekton, J. Marine Res., 43: 163.CrossRefGoogle Scholar
  6. Greenlaw, C.F. and Johnson, R.K., 1982, Physical and acoustical properties of zooplankton, J. Acoust. Soc. Am. 72: 1706.ADSCrossRefGoogle Scholar
  7. Holliday, D.V. and Pieper, R.E., 1980, Volume scattering strengths and zooplankton distributions at acoustic frequencies between 0.5 and 3 MHz, J. Acoust. Soc. Am., 67: 375.CrossRefGoogle Scholar
  8. Johnson, R.K., 1977, Sound scattering from a fluid sphere revisited, J. Acoust. Soc. Am., 61: 375.ADSCrossRefGoogle Scholar
  9. Pieper, R.E., 1979, Euphausiid distribution and biomass determined acoustically at 102 kHz, Deep-Sea Res., 26: 687.CrossRefGoogle Scholar
  10. Richter, K.E., 1985, Acoustic scattering at 1.2 MHz from individual zooplankters and copepod populations, Deep-Sea Res., 32: 149.CrossRefGoogle Scholar
  11. Sameoto, D.D., 1982, Zooplankton and micronekton abundance in acoustic scattering layers on the Nova Scotian Slope, Can. J. Fish. Aquat. Sci., 39: 760.CrossRefGoogle Scholar
  12. Sameoto, D.D., Jaroszynski, L.O. and Fraser, W.B., 1980, BIONESS, a new design in multiple net zooplankton samplers, Can. J. Fish. Aquat. Sci., 37: 722.CrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • N. A. Cochrane
    • 1
  • D. D. Sameoto
    • 2
  1. 1.Atlantic Oceanographic Laboratory Department of Fisheries and OceansBedford Institute of OceanographyDartmouthCanada
  2. 2.Marine Ecology Laboratory Department of Fisheries and OceansBedford Institute of OceanographyDartmouthCanada

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