Comparison of krill (Euphausia superba) density estimates using 38 and 120 kHz echosounders

Everson, I.; Goss, C.; Murray, W.A.. 1993 Comparison of krill (Euphausia superba) density estimates using 38 and 120 kHz echosounders. Marine Biology, 116 (2). 269-275. 10.1007/BF00350017

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Official URL: https://doi.org/10.1007/BF00350017

Abstract/Summary

A series of observations, using a dual-frequency calibrated echosounder operating at 38 and 120 kHz, of a patch of Euphausia superba close to South Georgia in 1986 is described. Sea state is shown to cause significant noise close to the surface, but to cause no significant signal attenuation. There is a consistent difference of ∼5 dB between the signal levels at the two frequencies which is in line with the difference noted from independent observations, theoretical models and in studies on encaged aggregations of krill.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1007/BF00350017
Programmes:	BAS Programmes > Pre 2000 programme
ISSN:	0025-3162
Date made live:	05 Sep 2017 10:41 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/517710

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1007/BF00350017

Programmes:

BAS Programmes > Pre 2000 programme

ISSN:

0025-3162

Date made live:

05 Sep 2017 10:41 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/517710