Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen

Echo integration is an established method for stock estimation. However, this method is not free of errors like every other measuring method. Especially the variation between day and night behaviour of fish may lead to large measuring errors. A new method is represented detecting such systematic err...

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Main Author: Bethke, Eckhard
Format: Article in Journal/Newspaper
Language:German
Published: 2000
Subjects:
Online Access:http://aquacomm.fcla.edu/3260
http://aquaticcommons.org/3260/
http://aquaticcommons.org/3260/1/00-3_Seite139-143.pdf
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spelling ftaquaticcommons:oai:generic.eprints.org:3260 2023-05-15T17:47:06+02:00 Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen Bethke, Eckhard 2000 application/pdf http://aquacomm.fcla.edu/3260 http://aquaticcommons.org/3260/ http://aquaticcommons.org/3260/1/00-3_Seite139-143.pdf de ger http://aquaticcommons.org/3260/1/00-3_Seite139-143.pdf Bethke, Eckhard (2000) Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen. Informationen für die Fischwirtschaft aus der Fischereiforschung, 47(3), pp. 139-143. Engineering Article NonPeerReviewed 2000 ftaquaticcommons 2020-02-27T09:20:15Z Echo integration is an established method for stock estimation. However, this method is not free of errors like every other measuring method. Especially the variation between day and night behaviour of fish may lead to large measuring errors. A new method is represented detecting such systematic errors, exemplified by investigations during the international hydroacoustic survey on the spring spawning herring in the Norwegian Sea. For this method all measured sA-values are sorted by starting time of the measuring unit distance. In order to reduce random influences a moving average over five time intervals is computed. When displaying these values in a diagram makes it is very easy to detect systematic errors based on the differences in day-night behaviour. For both species, herring and blue whiting, stock estimations are calculated based on the measured sA-values and the results of the analysed trawl catches. The influence of the differnt day and night behaviour of herring on the results of its biomass estimation is rather low. For blue whiting the measured values were about three time higher during day time than during night time. The result of this investigation should initiate a change of the evaluation procedure for stock estimation based on hydroacoustic measurements. Article in Journal/Newspaper Norwegian Sea International Association of Aquatic and Marine Science Libraries and Information Centers (IAMSLIC): Aquatic Commons Norwegian Sea
institution Open Polar
collection International Association of Aquatic and Marine Science Libraries and Information Centers (IAMSLIC): Aquatic Commons
op_collection_id ftaquaticcommons
language German
topic Engineering
spellingShingle Engineering
Bethke, Eckhard
Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen
topic_facet Engineering
description Echo integration is an established method for stock estimation. However, this method is not free of errors like every other measuring method. Especially the variation between day and night behaviour of fish may lead to large measuring errors. A new method is represented detecting such systematic errors, exemplified by investigations during the international hydroacoustic survey on the spring spawning herring in the Norwegian Sea. For this method all measured sA-values are sorted by starting time of the measuring unit distance. In order to reduce random influences a moving average over five time intervals is computed. When displaying these values in a diagram makes it is very easy to detect systematic errors based on the differences in day-night behaviour. For both species, herring and blue whiting, stock estimations are calculated based on the measured sA-values and the results of the analysed trawl catches. The influence of the differnt day and night behaviour of herring on the results of its biomass estimation is rather low. For blue whiting the measured values were about three time higher during day time than during night time. The result of this investigation should initiate a change of the evaluation procedure for stock estimation based on hydroacoustic measurements.
format Article in Journal/Newspaper
author Bethke, Eckhard
author_facet Bethke, Eckhard
author_sort Bethke, Eckhard
title Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen
title_short Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen
title_full Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen
title_fullStr Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen
title_full_unstemmed Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen
title_sort einfluss des tag-nacht-verhaltens von fischen auf das ergebnis hydroakustischer messungen
publishDate 2000
url http://aquacomm.fcla.edu/3260
http://aquaticcommons.org/3260/
http://aquaticcommons.org/3260/1/00-3_Seite139-143.pdf
geographic Norwegian Sea
geographic_facet Norwegian Sea
genre Norwegian Sea
genre_facet Norwegian Sea
op_relation http://aquaticcommons.org/3260/1/00-3_Seite139-143.pdf
Bethke, Eckhard (2000) Einfluss des Tag-Nacht-Verhaltens von Fischen auf das Ergebnis hydroakustischer Messungen. Informationen für die Fischwirtschaft aus der Fischereiforschung, 47(3), pp. 139-143.
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