In situ acoustic target strength of juvenile capelin
A dispersed, monospecific aggregation of juvenile (0+) capelin was detected acoustically in shallow (20–70 m) water in Bonavista Bay, northeastern Newfoundland in January 2000. This provided a rare opportunity to measure acoustic target strength (TS) of very small (mean length=51 mm) capelin in situ...
Published in: | ICES Journal of Marine Science |
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Main Authors: | , |
Format: | Text |
Language: | English |
Published: |
Oxford University Press
2001
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Subjects: | |
Online Access: | http://icesjms.oxfordjournals.org/cgi/content/short/58/1/342 https://doi.org/10.1006/jmsc.2000.1015 |
Summary: | A dispersed, monospecific aggregation of juvenile (0+) capelin was detected acoustically in shallow (20–70 m) water in Bonavista Bay, northeastern Newfoundland in January 2000. This provided a rare opportunity to measure acoustic target strength (TS) of very small (mean length=51 mm) capelin in situ . Mean observed TS at 38 kHz was −61.0 dB. Observed TS was similar to TS predicted by the Norwegian-Icelandic capelin TS-length relationship (TS=19.1 log L (cm)−74), but ∼2 dB lower than predicted by the existing TS-length relationship for capelin in Newfoundland waters at 38 and 49 kHz (TS=20 log L (cm)−73.1). Combining present data with previous 38 kHz data indicates the relationship TS=23.3 log L (cm)−77.1 (r2=0.95, n=6) for capelin of lengths 5–14 cm in Newfoundland waters. |
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