Comparison of walleye pollock target strength estimates determined from in situ measurements and calculations based on swimbladder form

• Published in: The Journal of the Acoustical Society of America
• Main Authors: Foote, Kenneth G., Traynor, Jimmie J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 1988
• Subjects: pollock; Theragra chalcogramma; swimbladders
• Online Access: http://hdl.handle.net/11250/108007; https://doi.org/10.1121/1.396190

Journal home page: http://scitation.aip.org/jasa/ The target strength of walleye pollock (Theragra chalcogramma) at 38 kHz has been determined in each of two ways: (1) in situ measurement with dual-beam and split-beam echo sounders, and (2) theoretical calculation based on the swimbladder form. Respective probability density functions of target strength are compared. The several estimates of mean target strength (T-bar S-bar) determine the relation T-bar S-bar =20 log l–66.0, where l is the fish fork length in centimeters.