caa a22 4500 39755155X CHVBK 20180308164751.0 cr unu---uuuuu 161202e199604 xx s 000 0 eng 10.1006/jmsc.1996.0031 doi (NATIONALLICENCE)oxford-10.1006/jmsc.1996.0031 Traynor Jimmie J. Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA Target-strength measurements of walleye pollock (Theragra chalcogramma) and Pacific whiting (Merluccius productus) [Elektronische Daten] [Jimmie J. Traynor] The importance of knowledge about the target-strength (TS) characteristics of the surveyed fish population to the accuracy of acoustic assessments using echo integration is well known. The most commonly used TS to length (L) relationship for walleye pollock is based on swimbladder morphology measurements and in situ TS measurements TS (in dB)=20 log L−66.0 for fish length in centimeters. For Pacific whiting, TS measurements have not been made over an adequate range of fish lengths to determine the appropriate relationship for use in scaling echo-integration surveys. However, results presented in this paper and elsewhere suggest a smaller TS (about 2 dB for a given length) for 40-60 cm fish. Measurements of the TS of walleye pollock and Pacific whiting were made with a SIMRAD EK500 in the present study. The appropriateness of the currently used TS to length relationship for echo integration scaling is discussed for pollock. The application of a TS to length relationship for Pacific whiting is considered. An attempt to use a system with a transducer lowered through the water column to reduce noise-induced bias is described. © 1996 International Council for the Exploration of the Sea Regular Articles nationallicence acoustics nationallicence Merluccius productus nationallicence Pacific whiting nationallicence target strength nationallicence Theragra chalcogramma nationallicence walleye pollock nationallicence ICES Journal of Marine Science Oxford University Press 53/2(1996-04), 253-258 1054-3139 53:2<253 1996 53 icesjms https://doi.org/10.1006/jmsc.1996.0031 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1006/jmsc.1996.0031 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Traynor Jimmie J. Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, WA 98115, USA NATIONALLICENCE 773 0- ICES Journal of Marine Science Oxford University Press 53/2(1996-04), 253-258 1054-3139 53:2<253 1996 53 icesjms Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford