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...
Main Author: | |
---|---|
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 |
id |
ftaquaticcommons:oai:generic.eprints.org:3260 |
---|---|
record_format |
openpolar |
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. |
_version_ |
1766151408326803456 |