Capelin are good for cod: can the northern stock rebuild without them?
The stock of northern cod ( Gadus morhua ) off Newfoundland and Labrador is at its lowest level in recorded history, with no rebuilding of northern spawning aggregations since the fishing moratorium in 1992. Cod diet was historically dominated by capelin ( Mallotus villosus ), which have been scarce...
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fthighwire:oai:open-archive.highwire.org:icesjms:59/5/1018 2023-05-15T16:19:16+02:00 Capelin are good for cod: can the northern stock rebuild without them? Rose, G. A. O'Driscoll, R. L. 2002-01-01 00:00:00.0 text/html http://icesjms.oxfordjournals.org/cgi/content/short/59/5/1018 https://doi.org/10.1006/jmsc.2002.1252 en eng Oxford University Press http://icesjms.oxfordjournals.org/cgi/content/short/59/5/1018 http://dx.doi.org/10.1006/jmsc.2002.1252 Copyright (C) 2002, International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer Regular Articles TEXT 2002 fthighwire https://doi.org/10.1006/jmsc.2002.1252 2013-05-27T03:28:43Z The stock of northern cod ( Gadus morhua ) off Newfoundland and Labrador is at its lowest level in recorded history, with no rebuilding of northern spawning aggregations since the fishing moratorium in 1992. Cod diet was historically dominated by capelin ( Mallotus villosus ), which have been scarce in the northern areas since 1990. Using the study areas Hawke Channel and Trinity Bay within the historical northern cod range, and Placentia Bay (south coast), we examine growth, condition, and reproductive potential with respect to capelin diet in 18 000 cod sampled primarily in January and June of the years 1996–2000. Overall diet weights differed among areas and seasons (Placentia=Hawke>Trinity in January; Placentia>Trinity=Hawke in June). However, just 7 of 3383 cod stomachs (0.2%) from Hawke contained capelin (PFI=0). In contrast, 10% of cod of ages 3–7 in Placentia and Trinity Bays preyed on capelin and overall capelin partial fullness indices (PFI) were 0.2–0.4. Capelin PFIs were correlated with an index of availability (potential contact of capelin within 40 km of cod) calculated from acoustic surveys. Seasonally adjusted cod liver condition was strongly associated with capelin availability (p<0.05), and the liver index was highly correlated with gonad size in mature females (especially 4–6-year-olds). The links between capelin availability and cod diet, growth, condition, and reproductive potential suggest that cod rebuilding requires capelin and tends to mirror capelin distribution (Placentia>Trinity≫Hawke). Text Gadus morhua Newfoundland HighWire Press (Stanford University) Newfoundland ICES Journal of Marine Science 59 5 1018 1026 |
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HighWire Press (Stanford University) |
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Regular Articles |
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Regular Articles Rose, G. A. O'Driscoll, R. L. Capelin are good for cod: can the northern stock rebuild without them? |
topic_facet |
Regular Articles |
description |
The stock of northern cod ( Gadus morhua ) off Newfoundland and Labrador is at its lowest level in recorded history, with no rebuilding of northern spawning aggregations since the fishing moratorium in 1992. Cod diet was historically dominated by capelin ( Mallotus villosus ), which have been scarce in the northern areas since 1990. Using the study areas Hawke Channel and Trinity Bay within the historical northern cod range, and Placentia Bay (south coast), we examine growth, condition, and reproductive potential with respect to capelin diet in 18 000 cod sampled primarily in January and June of the years 1996–2000. Overall diet weights differed among areas and seasons (Placentia=Hawke>Trinity in January; Placentia>Trinity=Hawke in June). However, just 7 of 3383 cod stomachs (0.2%) from Hawke contained capelin (PFI=0). In contrast, 10% of cod of ages 3–7 in Placentia and Trinity Bays preyed on capelin and overall capelin partial fullness indices (PFI) were 0.2–0.4. Capelin PFIs were correlated with an index of availability (potential contact of capelin within 40 km of cod) calculated from acoustic surveys. Seasonally adjusted cod liver condition was strongly associated with capelin availability (p<0.05), and the liver index was highly correlated with gonad size in mature females (especially 4–6-year-olds). The links between capelin availability and cod diet, growth, condition, and reproductive potential suggest that cod rebuilding requires capelin and tends to mirror capelin distribution (Placentia>Trinity≫Hawke). |
format |
Text |
author |
Rose, G. A. O'Driscoll, R. L. |
author_facet |
Rose, G. A. O'Driscoll, R. L. |
author_sort |
Rose, G. A. |
title |
Capelin are good for cod: can the northern stock rebuild without them? |
title_short |
Capelin are good for cod: can the northern stock rebuild without them? |
title_full |
Capelin are good for cod: can the northern stock rebuild without them? |
title_fullStr |
Capelin are good for cod: can the northern stock rebuild without them? |
title_full_unstemmed |
Capelin are good for cod: can the northern stock rebuild without them? |
title_sort |
capelin are good for cod: can the northern stock rebuild without them? |
publisher |
Oxford University Press |
publishDate |
2002 |
url |
http://icesjms.oxfordjournals.org/cgi/content/short/59/5/1018 https://doi.org/10.1006/jmsc.2002.1252 |
geographic |
Newfoundland |
geographic_facet |
Newfoundland |
genre |
Gadus morhua Newfoundland |
genre_facet |
Gadus morhua Newfoundland |
op_relation |
http://icesjms.oxfordjournals.org/cgi/content/short/59/5/1018 http://dx.doi.org/10.1006/jmsc.2002.1252 |
op_rights |
Copyright (C) 2002, International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer |
op_doi |
https://doi.org/10.1006/jmsc.2002.1252 |
container_title |
ICES Journal of Marine Science |
container_volume |
59 |
container_issue |
5 |
container_start_page |
1018 |
op_container_end_page |
1026 |
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1766005642629218304 |