Modelling indices of abundance and size-based indicators of cod and flounder stocks in the Baltic Sea using newly standardized trawl survey data
Standardized indices of abundance and size-based indicators are of extreme importance for monitoring fish population status. The main objectives of the current study were to (i) combine and standardize recently performed trawl survey with historical ones, (ii) explore and discuss the trends in abund...
Published in: | ICES Journal of Marine Science |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Oxford University Press (OUP)
2017
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Online Access: | http://dx.doi.org/10.1093/icesjms/fsx005 http://academic.oup.com/icesjms/article-pdf/74/5/1322/31245917/fsx005.pdf |
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croxfordunivpr:10.1093/icesjms/fsx005 2024-06-23T07:52:57+00:00 Modelling indices of abundance and size-based indicators of cod and flounder stocks in the Baltic Sea using newly standardized trawl survey data Orio, Alessandro Florin, Ann-Britt Bergström, Ulf Šics, Ivo Baranova, Tatjana Casini, Michele Poos, Jan Jaap 2017 http://dx.doi.org/10.1093/icesjms/fsx005 http://academic.oup.com/icesjms/article-pdf/74/5/1322/31245917/fsx005.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model ICES Journal of Marine Science volume 74, issue 5, page 1322-1333 ISSN 1054-3139 1095-9289 journal-article 2017 croxfordunivpr https://doi.org/10.1093/icesjms/fsx005 2024-06-04T06:15:15Z Standardized indices of abundance and size-based indicators are of extreme importance for monitoring fish population status. The main objectives of the current study were to (i) combine and standardize recently performed trawl survey with historical ones, (ii) explore and discuss the trends in abundance, and (iii) the trends in maximum length (Lmax) for cod (Gadus morhua) and flounder (Platichthys flesus) stocks in the Baltic Sea. Standardization of catch per unit of effort (CPUE) from trawl surveys from 1978 to 2014 to swept area per unit of time was conducted using information on trawling speed and horizontal opening of the trawls. CPUE data for cod and flounder stocks were modelled using generalized additive models (GAMs) in a delta modelling approach framework, while the Lmax data were modelled using ordinary GAMs. The CPUE time series of the Eastern Baltic cod stock closely resembles the spawning stock biomass trend from analytical stock assessment. The results obtained furnish evidence of the cod spill-over from Subdivisions (SD) 25–28 to SD 24. The decline of Lmax in recent years was evident for both species in all the stocks analysed indicating that the demersal fish community is becoming progressively dominated by small individuals. It is concluded that the standardization of long time series of fisheries-independent data constitutes a powerful tool that could help improve our knowledge on the dynamics of fished populations, thus promoting a long-term sustainable use of these marine resources. Article in Journal/Newspaper Gadus morhua Oxford University Press ICES Journal of Marine Science 74 5 1322 1333 |
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Open Polar |
collection |
Oxford University Press |
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croxfordunivpr |
language |
English |
description |
Standardized indices of abundance and size-based indicators are of extreme importance for monitoring fish population status. The main objectives of the current study were to (i) combine and standardize recently performed trawl survey with historical ones, (ii) explore and discuss the trends in abundance, and (iii) the trends in maximum length (Lmax) for cod (Gadus morhua) and flounder (Platichthys flesus) stocks in the Baltic Sea. Standardization of catch per unit of effort (CPUE) from trawl surveys from 1978 to 2014 to swept area per unit of time was conducted using information on trawling speed and horizontal opening of the trawls. CPUE data for cod and flounder stocks were modelled using generalized additive models (GAMs) in a delta modelling approach framework, while the Lmax data were modelled using ordinary GAMs. The CPUE time series of the Eastern Baltic cod stock closely resembles the spawning stock biomass trend from analytical stock assessment. The results obtained furnish evidence of the cod spill-over from Subdivisions (SD) 25–28 to SD 24. The decline of Lmax in recent years was evident for both species in all the stocks analysed indicating that the demersal fish community is becoming progressively dominated by small individuals. It is concluded that the standardization of long time series of fisheries-independent data constitutes a powerful tool that could help improve our knowledge on the dynamics of fished populations, thus promoting a long-term sustainable use of these marine resources. |
author2 |
Poos, Jan Jaap |
format |
Article in Journal/Newspaper |
author |
Orio, Alessandro Florin, Ann-Britt Bergström, Ulf Šics, Ivo Baranova, Tatjana Casini, Michele |
spellingShingle |
Orio, Alessandro Florin, Ann-Britt Bergström, Ulf Šics, Ivo Baranova, Tatjana Casini, Michele Modelling indices of abundance and size-based indicators of cod and flounder stocks in the Baltic Sea using newly standardized trawl survey data |
author_facet |
Orio, Alessandro Florin, Ann-Britt Bergström, Ulf Šics, Ivo Baranova, Tatjana Casini, Michele |
author_sort |
Orio, Alessandro |
title |
Modelling indices of abundance and size-based indicators of cod and flounder stocks in the Baltic Sea using newly standardized trawl survey data |
title_short |
Modelling indices of abundance and size-based indicators of cod and flounder stocks in the Baltic Sea using newly standardized trawl survey data |
title_full |
Modelling indices of abundance and size-based indicators of cod and flounder stocks in the Baltic Sea using newly standardized trawl survey data |
title_fullStr |
Modelling indices of abundance and size-based indicators of cod and flounder stocks in the Baltic Sea using newly standardized trawl survey data |
title_full_unstemmed |
Modelling indices of abundance and size-based indicators of cod and flounder stocks in the Baltic Sea using newly standardized trawl survey data |
title_sort |
modelling indices of abundance and size-based indicators of cod and flounder stocks in the baltic sea using newly standardized trawl survey data |
publisher |
Oxford University Press (OUP) |
publishDate |
2017 |
url |
http://dx.doi.org/10.1093/icesjms/fsx005 http://academic.oup.com/icesjms/article-pdf/74/5/1322/31245917/fsx005.pdf |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
ICES Journal of Marine Science volume 74, issue 5, page 1322-1333 ISSN 1054-3139 1095-9289 |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/icesjms/fsx005 |
container_title |
ICES Journal of Marine Science |
container_volume |
74 |
container_issue |
5 |
container_start_page |
1322 |
op_container_end_page |
1333 |
_version_ |
1802644410087768064 |