Evaluation of the Dual Beam Acoustic Fish Target Strength Measurement Method

• Published in: Journal of the Fisheries Research Board of Canada
• Main Authors: Traynor, J. J., Ehrenberg, J. E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1979
• Subjects: Theragra chalcogramma
• Online Access: http://dx.doi.org/10.1139/f79-149; http://www.nrcresearchpress.com/doi/pdf/10.1139/f79-149

During surveys to assess fish stocks, the acoustic scattering properties of the fish population are required to obtain stock size measurements. The recently developed dual beam technique of target strength measurement has shown great promise as a method for fish target strength measurement. An improved dual beam target strength measurement system is described, and we report the application to a marine population of walleye pollock (Theragra chalcogramma). In addition, we discuss field calibration using a ping-pong ball as a standard target. Results of target strength measurements of the fish and ping-pong ball are compared with predicted values based on simulation analyses of the technique operating under the noise conditions observed in the field. The agreement between field results and theoretical predictions were quite good. Key words: hydroacoustic, walleye, pollock, dual beam, target strength measurement, fish assessment