Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea
The Baltic Sea is a stratified, semienclosed sea typified by a low‐salinity surface layer and a deep saline layer of varying volume, salinity, temperature and oxygen concentration. The relationships between these oceanographic factors and the distribution of Baltic cod are presented, utilizing resul...
Published in: | Fisheries Oceanography |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
1998
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1046/j.1365-2419.1998.00051.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2419.1998.00051.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2419.1998.00051.x |
id |
crwiley:10.1046/j.1365-2419.1998.00051.x |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1046/j.1365-2419.1998.00051.x 2024-06-02T08:06:58+00:00 Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea TOMKIEWICZ, JONNA LEHMANN, KLAUS M. JOHN, MICHAEL A. ST. 1998 http://dx.doi.org/10.1046/j.1365-2419.1998.00051.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2419.1998.00051.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2419.1998.00051.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Fisheries Oceanography volume 7, issue 1, page 48-62 ISSN 1054-6006 1365-2419 journal-article 1998 crwiley https://doi.org/10.1046/j.1365-2419.1998.00051.x 2024-05-03T11:59:41Z The Baltic Sea is a stratified, semienclosed sea typified by a low‐salinity surface layer and a deep saline layer of varying volume, salinity, temperature and oxygen concentration. The relationships between these oceanographic factors and the distribution of Baltic cod are presented, utilizing results from a survey carried out during the 1995 spawning period in the Bornholm Basin, at present the main spawning area of this stock. Cod distribution, abundance and population structure were estimated from hydroacoustic and trawl data and related to hydrographic parameters as well as to bottom depth. In the central basin, cod were aggregated in an intermediate layer about 15 m thick. This area of peak abundance was defined at its upper limit by the halocline and at the lower limit by oxygen content. The majority of individuals caught in the basin centre were in spawning or pre‐spawning condition with a high proportion of males to females. On the basin slopes, aggregations of cod were found near the bottom. These individuals were mainly immature and maturing stages with an increasing proportion of females to males with size. Salinity and oxygen conditions were found to be the major factors influencing the vertical and horizontal distribution of adult cod. Abundance of immature cod was also positively related to decreasing bottom depths. The effect of temperature was minor. The observed size‐ and sex‐dependent spawning aggregation patterns, in association with habitat volume and stock size, may influence cod catchability and thereby the assessment and exploitation patterns of this stock. Article in Journal/Newspaper Gadus morhua Wiley Online Library Fisheries Oceanography 7 1 48 62 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
The Baltic Sea is a stratified, semienclosed sea typified by a low‐salinity surface layer and a deep saline layer of varying volume, salinity, temperature and oxygen concentration. The relationships between these oceanographic factors and the distribution of Baltic cod are presented, utilizing results from a survey carried out during the 1995 spawning period in the Bornholm Basin, at present the main spawning area of this stock. Cod distribution, abundance and population structure were estimated from hydroacoustic and trawl data and related to hydrographic parameters as well as to bottom depth. In the central basin, cod were aggregated in an intermediate layer about 15 m thick. This area of peak abundance was defined at its upper limit by the halocline and at the lower limit by oxygen content. The majority of individuals caught in the basin centre were in spawning or pre‐spawning condition with a high proportion of males to females. On the basin slopes, aggregations of cod were found near the bottom. These individuals were mainly immature and maturing stages with an increasing proportion of females to males with size. Salinity and oxygen conditions were found to be the major factors influencing the vertical and horizontal distribution of adult cod. Abundance of immature cod was also positively related to decreasing bottom depths. The effect of temperature was minor. The observed size‐ and sex‐dependent spawning aggregation patterns, in association with habitat volume and stock size, may influence cod catchability and thereby the assessment and exploitation patterns of this stock. |
format |
Article in Journal/Newspaper |
author |
TOMKIEWICZ, JONNA LEHMANN, KLAUS M. JOHN, MICHAEL A. ST. |
spellingShingle |
TOMKIEWICZ, JONNA LEHMANN, KLAUS M. JOHN, MICHAEL A. ST. Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea |
author_facet |
TOMKIEWICZ, JONNA LEHMANN, KLAUS M. JOHN, MICHAEL A. ST. |
author_sort |
TOMKIEWICZ, JONNA |
title |
Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea |
title_short |
Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea |
title_full |
Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea |
title_fullStr |
Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea |
title_full_unstemmed |
Oceanographic influences on the distribution of Baltic cod, Gadus morhua, during spawning in the Bornholm Basin of the Baltic Sea |
title_sort |
oceanographic influences on the distribution of baltic cod, gadus morhua, during spawning in the bornholm basin of the baltic sea |
publisher |
Wiley |
publishDate |
1998 |
url |
http://dx.doi.org/10.1046/j.1365-2419.1998.00051.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-2419.1998.00051.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-2419.1998.00051.x |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
Fisheries Oceanography volume 7, issue 1, page 48-62 ISSN 1054-6006 1365-2419 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1046/j.1365-2419.1998.00051.x |
container_title |
Fisheries Oceanography |
container_volume |
7 |
container_issue |
1 |
container_start_page |
48 |
op_container_end_page |
62 |
_version_ |
1800751968730218496 |