On Recruitment and Distribution of Atlantic Cod ( Gadus morhua) off Newfoundland
The Atlantic cod (Gadus morhua) populations located off Labrador and Northeastern Newfoundland (NAFO areas 2G–3L) have recently declined to the lowest levels of abundance on record. These "northern" cod have historically comprised several geographically recognizable populations with indepe...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1993
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/f93-298 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-298 |
id |
crcansciencepubl:10.1139/f93-298 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/f93-298 2024-09-15T17:55:25+00:00 On Recruitment and Distribution of Atlantic Cod ( Gadus morhua) off Newfoundland deYoung, B. Rose, G. A. 1993 http://dx.doi.org/10.1139/f93-298 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-298 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 50, issue 12, page 2729-2741 ISSN 0706-652X 1205-7533 journal-article 1993 crcansciencepubl https://doi.org/10.1139/f93-298 2024-06-27T04:11:01Z The Atlantic cod (Gadus morhua) populations located off Labrador and Northeastern Newfoundland (NAFO areas 2G–3L) have recently declined to the lowest levels of abundance on record. These "northern" cod have historically comprised several geographically recognizable populations with independent migratory life cycles on the shelf from the Grand Banks to Labrador. A reappraisal of past and recent work suggests that fundamental changes have taken place in the population dynamics of these cod during the past several decades. We focus on two key elements: distribution and recruitment. Distributions have become more southerly and recruitment failures prevail. We argue that these features are related and that northerly spawning and warm ocean conditions are prerequisites for strong recruitment. Cold ocean temperatures are associated with southerly distributions and poor recruitment. We propose the "right site" hypothesis, that egg and larval retention and survival are spatially dependent and that in cold years, spawning tends to occur at southerly locations where larval retention will be poor. We make several testable predictions: regeneration of the northern populations will occur slowly at time scales of decades, regeneration of southern populations will occur more quickly given warming conditions, and the 1991–93 year classes will be poor because of southerly distributions. Article in Journal/Newspaper atlantic cod Gadus morhua Newfoundland Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 50 12 2729 2741 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
The Atlantic cod (Gadus morhua) populations located off Labrador and Northeastern Newfoundland (NAFO areas 2G–3L) have recently declined to the lowest levels of abundance on record. These "northern" cod have historically comprised several geographically recognizable populations with independent migratory life cycles on the shelf from the Grand Banks to Labrador. A reappraisal of past and recent work suggests that fundamental changes have taken place in the population dynamics of these cod during the past several decades. We focus on two key elements: distribution and recruitment. Distributions have become more southerly and recruitment failures prevail. We argue that these features are related and that northerly spawning and warm ocean conditions are prerequisites for strong recruitment. Cold ocean temperatures are associated with southerly distributions and poor recruitment. We propose the "right site" hypothesis, that egg and larval retention and survival are spatially dependent and that in cold years, spawning tends to occur at southerly locations where larval retention will be poor. We make several testable predictions: regeneration of the northern populations will occur slowly at time scales of decades, regeneration of southern populations will occur more quickly given warming conditions, and the 1991–93 year classes will be poor because of southerly distributions. |
format |
Article in Journal/Newspaper |
author |
deYoung, B. Rose, G. A. |
spellingShingle |
deYoung, B. Rose, G. A. On Recruitment and Distribution of Atlantic Cod ( Gadus morhua) off Newfoundland |
author_facet |
deYoung, B. Rose, G. A. |
author_sort |
deYoung, B. |
title |
On Recruitment and Distribution of Atlantic Cod ( Gadus morhua) off Newfoundland |
title_short |
On Recruitment and Distribution of Atlantic Cod ( Gadus morhua) off Newfoundland |
title_full |
On Recruitment and Distribution of Atlantic Cod ( Gadus morhua) off Newfoundland |
title_fullStr |
On Recruitment and Distribution of Atlantic Cod ( Gadus morhua) off Newfoundland |
title_full_unstemmed |
On Recruitment and Distribution of Atlantic Cod ( Gadus morhua) off Newfoundland |
title_sort |
on recruitment and distribution of atlantic cod ( gadus morhua) off newfoundland |
publisher |
Canadian Science Publishing |
publishDate |
1993 |
url |
http://dx.doi.org/10.1139/f93-298 http://www.nrcresearchpress.com/doi/pdf/10.1139/f93-298 |
genre |
atlantic cod Gadus morhua Newfoundland |
genre_facet |
atlantic cod Gadus morhua Newfoundland |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 50, issue 12, page 2729-2741 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f93-298 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
50 |
container_issue |
12 |
container_start_page |
2729 |
op_container_end_page |
2741 |
_version_ |
1810431711083757568 |