Some results of abundance estimation studies with echo integrators

Two examples of acoustic fish stock abundance estimation are given. The first is the estimation of the exploited Barents Sea capelin stock; the second is measurement of the size of the unexploited blue whiting stock. Surveys of both species were undertaken at the time of the year when conditions wer...

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Bibliographic Details
Main Authors: Midttun, Lars, Nakken, Odd
Format: Article in Journal/Newspaper
Language:English
Published: ICES 1977
Subjects:
Barents Sea
Online Access:http://hdl.handle.net/11250/108114
id ftimr:oai:imr.brage.unit.no:11250/108114
record_format openpolar
spelling ftimr:oai:imr.brage.unit.no:11250/108114 2023-05-15T15:38:47+02:00 Some results of abundance estimation studies with echo integrators Midttun, Lars Nakken, Odd 1977 440245 bytes application/pdf http://hdl.handle.net/11250/108114 eng eng ICES urn:issn:0074-4336 http://hdl.handle.net/11250/108114 253-258 170 Rapports et Procès-Verbaux des Réunions Journal article Peer reviewed 1977 ftimr 2021-09-23T20:15:48Z Two examples of acoustic fish stock abundance estimation are given. The first is the estimation of the exploited Barents Sea capelin stock; the second is measurement of the size of the unexploited blue whiting stock. Surveys of both species were undertaken at the time of the year when conditions were favourable i.e. the fish were located as pelagic scattering layers and unmixed with other species. When the echo-sounder is operated with a TVG equal to 20 log R + 2 aR, the integrated echo intensity is proportional to the number of fish per unit area. To obtain absolute values, the system is calibrated on scattered recordings when single fish can be counted. Article in Journal/Newspaper Barents Sea Institute for Marine Research: Brage IMR Barents Sea
institution Open Polar
collection Institute for Marine Research: Brage IMR
op_collection_id ftimr
language English
description Two examples of acoustic fish stock abundance estimation are given. The first is the estimation of the exploited Barents Sea capelin stock; the second is measurement of the size of the unexploited blue whiting stock. Surveys of both species were undertaken at the time of the year when conditions were favourable i.e. the fish were located as pelagic scattering layers and unmixed with other species. When the echo-sounder is operated with a TVG equal to 20 log R + 2 aR, the integrated echo intensity is proportional to the number of fish per unit area. To obtain absolute values, the system is calibrated on scattered recordings when single fish can be counted.
format Article in Journal/Newspaper
author Midttun, Lars
Nakken, Odd
spellingShingle Midttun, Lars
Nakken, Odd
Some results of abundance estimation studies with echo integrators
author_facet Midttun, Lars
Nakken, Odd
author_sort Midttun, Lars
title Some results of abundance estimation studies with echo integrators
title_short Some results of abundance estimation studies with echo integrators
title_full Some results of abundance estimation studies with echo integrators
title_fullStr Some results of abundance estimation studies with echo integrators
title_full_unstemmed Some results of abundance estimation studies with echo integrators
title_sort some results of abundance estimation studies with echo integrators
publisher ICES
publishDate 1977
url http://hdl.handle.net/11250/108114
geographic Barents Sea
geographic_facet Barents Sea
genre Barents Sea
genre_facet Barents Sea
op_source 253-258
170
Rapports et Procès-Verbaux des Réunions
op_relation urn:issn:0074-4336
http://hdl.handle.net/11250/108114
_version_ 1766370098780569600

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