Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod ( Gadus morhua ) in the Southern Gulf of St. Lawrence
I examined the bathymetric pattern of Alantic cod (Gadus morhua) in September in the southern Gulf of St. Lawrence for age groups 3–8 + over the period 1971–91 using data from annual bottom trawl surveys. Mean age of cod tended to increase with depth in all years. The age-specific bathymetric patter...
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1993
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Online Access: | http://dx.doi.org/10.1139/f93-142 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-142 |
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crcansciencepubl:10.1139/f93-142 2024-04-07T07:50:54+00:00 Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod ( Gadus morhua ) in the Southern Gulf of St. Lawrence Swain, Douglas P. 1993 http://dx.doi.org/10.1139/f93-142 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-142 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 50, issue 6, page 1255-1264 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 1993 crcansciencepubl https://doi.org/10.1139/f93-142 2024-03-08T00:37:45Z I examined the bathymetric pattern of Alantic cod (Gadus morhua) in September in the southern Gulf of St. Lawrence for age groups 3–8 + over the period 1971–91 using data from annual bottom trawl surveys. Mean age of cod tended to increase with depth in all years. The age-specific bathymetric patterns underlying this relationship differed markedly between periods of low and high abundance. When abundance was high, cod densities tended to be highest at intermediate depths, and the positive correlation between age and depth reflected a tendency for density to be highest in progressively deeper water for older fish. When abundance was low, density was either unrelated to depth or highest in shallow water, and the positive correlation between age and depth reflected a tendency for older cod to be more widely distributed than younger cod (i.e., density decreased less sharply with depth for older cod). I suggest explanations for this density dependence of cod bathymetric pattern and discuss these results in relation to the factors underlying habitat selection and bathymetric segregation by age in this population. Article in Journal/Newspaper atlantic cod Gadus morhua Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 50 6 1255 1264 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Swain, Douglas P. Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod ( Gadus morhua ) in the Southern Gulf of St. Lawrence |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
I examined the bathymetric pattern of Alantic cod (Gadus morhua) in September in the southern Gulf of St. Lawrence for age groups 3–8 + over the period 1971–91 using data from annual bottom trawl surveys. Mean age of cod tended to increase with depth in all years. The age-specific bathymetric patterns underlying this relationship differed markedly between periods of low and high abundance. When abundance was high, cod densities tended to be highest at intermediate depths, and the positive correlation between age and depth reflected a tendency for density to be highest in progressively deeper water for older fish. When abundance was low, density was either unrelated to depth or highest in shallow water, and the positive correlation between age and depth reflected a tendency for older cod to be more widely distributed than younger cod (i.e., density decreased less sharply with depth for older cod). I suggest explanations for this density dependence of cod bathymetric pattern and discuss these results in relation to the factors underlying habitat selection and bathymetric segregation by age in this population. |
format |
Article in Journal/Newspaper |
author |
Swain, Douglas P. |
author_facet |
Swain, Douglas P. |
author_sort |
Swain, Douglas P. |
title |
Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod ( Gadus morhua ) in the Southern Gulf of St. Lawrence |
title_short |
Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod ( Gadus morhua ) in the Southern Gulf of St. Lawrence |
title_full |
Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod ( Gadus morhua ) in the Southern Gulf of St. Lawrence |
title_fullStr |
Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod ( Gadus morhua ) in the Southern Gulf of St. Lawrence |
title_full_unstemmed |
Age- and Density-Dependent Bathymetric Pattern of Atlantic Cod ( Gadus morhua ) in the Southern Gulf of St. Lawrence |
title_sort |
age- and density-dependent bathymetric pattern of atlantic cod ( gadus morhua ) in the southern gulf of st. lawrence |
publisher |
Canadian Science Publishing |
publishDate |
1993 |
url |
http://dx.doi.org/10.1139/f93-142 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-142 |
genre |
atlantic cod Gadus morhua |
genre_facet |
atlantic cod Gadus morhua |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 50, issue 6, page 1255-1264 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f93-142 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
50 |
container_issue |
6 |
container_start_page |
1255 |
op_container_end_page |
1264 |
_version_ |
1795665703020265472 |