Feeding by grey seals on endangered stocks of Atlantic cod and white hake
High natural mortality is preventing the recovery of collapsed stocks of Atlantic cod and white hake in the southern Gulf of St Lawrence, Canada. Predation by grey seals has been proposed as an important cause of this high mortality. We determined the contribution of cod and hake to the diet of grey...
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fthighwire:oai:open-archive.highwire.org:icesjms:71/6/1332 2023-05-15T15:27:23+02:00 Feeding by grey seals on endangered stocks of Atlantic cod and white hake Hammill, M.O. Stenson, G.B. Swain, D.P. Benoît, H.P. 2014-09-01 00:00:00.0 text/html http://icesjms.oxfordjournals.org/cgi/content/short/71/6/1332 https://doi.org/10.1093/icesjms/fsu123 en eng Oxford University Press http://icesjms.oxfordjournals.org/cgi/content/short/71/6/1332 http://dx.doi.org/10.1093/icesjms/fsu123 Copyright (C) 2014, International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer Original Articles TEXT 2014 fthighwire https://doi.org/10.1093/icesjms/fsu123 2015-02-28T22:23:02Z High natural mortality is preventing the recovery of collapsed stocks of Atlantic cod and white hake in the southern Gulf of St Lawrence, Canada. Predation by grey seals has been proposed as an important cause of this high mortality. We determined the contribution of cod and hake to the diet of grey seals collected along the west coast of Cape Breton Island and in the Cabot Strait, an area where overwintering cod aggregate. Along the coast of Cape Breton Island, the contribution of hake and cod to the diet was 30 and 17%, respectively, by weight using stomach contents and 13 and 9%, respectively, based on intestine contents. In the Cabot Strait, when overwintering aggregations of cod were present, cod accounted for 68% (range 57–80%) of the male diet from stomachs, and 46% (range: 31–64%) of the diet determined from intestines. Among females, cod represented 14% (range: 0–34%) and 9% (range: 3–54%) of the diet from stomachs and intestines, respectively. In Cabot Strait, white hake accounted for up to 17% of the diet by weight from stomachs, and up to 6% of the diet determined from intestines. The mean length of cod consumed by seals was 28 cm (SD = 8.6) along the coast of Cape Breton Island, and 39 cm (SD = 5.7) in Cabot Strait. The mean length of hake consumed by seals was 29 cm (SD = 7.0) along the coast of Cape Breton Island, and 35 cm (SD = 5.6) in Cabot Strait. Cod and hake are more important to the diet of males than that of females. The contribution of cod to the diet of grey seals foraging in the cod overwintering area is much greater than has been reported elsewhere. Text atlantic cod Breton Island HighWire Press (Stanford University) Breton Island ENVELOPE(141.383,141.383,-66.800,-66.800) Cabot ENVELOPE(-54.600,-54.600,-63.383,-63.383) Canada Hake ENVELOPE(15.612,15.612,66.797,66.797) ICES Journal of Marine Science 71 6 1332 1341 |
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collection |
HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
Original Articles |
spellingShingle |
Original Articles Hammill, M.O. Stenson, G.B. Swain, D.P. Benoît, H.P. Feeding by grey seals on endangered stocks of Atlantic cod and white hake |
topic_facet |
Original Articles |
description |
High natural mortality is preventing the recovery of collapsed stocks of Atlantic cod and white hake in the southern Gulf of St Lawrence, Canada. Predation by grey seals has been proposed as an important cause of this high mortality. We determined the contribution of cod and hake to the diet of grey seals collected along the west coast of Cape Breton Island and in the Cabot Strait, an area where overwintering cod aggregate. Along the coast of Cape Breton Island, the contribution of hake and cod to the diet was 30 and 17%, respectively, by weight using stomach contents and 13 and 9%, respectively, based on intestine contents. In the Cabot Strait, when overwintering aggregations of cod were present, cod accounted for 68% (range 57–80%) of the male diet from stomachs, and 46% (range: 31–64%) of the diet determined from intestines. Among females, cod represented 14% (range: 0–34%) and 9% (range: 3–54%) of the diet from stomachs and intestines, respectively. In Cabot Strait, white hake accounted for up to 17% of the diet by weight from stomachs, and up to 6% of the diet determined from intestines. The mean length of cod consumed by seals was 28 cm (SD = 8.6) along the coast of Cape Breton Island, and 39 cm (SD = 5.7) in Cabot Strait. The mean length of hake consumed by seals was 29 cm (SD = 7.0) along the coast of Cape Breton Island, and 35 cm (SD = 5.6) in Cabot Strait. Cod and hake are more important to the diet of males than that of females. The contribution of cod to the diet of grey seals foraging in the cod overwintering area is much greater than has been reported elsewhere. |
format |
Text |
author |
Hammill, M.O. Stenson, G.B. Swain, D.P. Benoît, H.P. |
author_facet |
Hammill, M.O. Stenson, G.B. Swain, D.P. Benoît, H.P. |
author_sort |
Hammill, M.O. |
title |
Feeding by grey seals on endangered stocks of Atlantic cod and white hake |
title_short |
Feeding by grey seals on endangered stocks of Atlantic cod and white hake |
title_full |
Feeding by grey seals on endangered stocks of Atlantic cod and white hake |
title_fullStr |
Feeding by grey seals on endangered stocks of Atlantic cod and white hake |
title_full_unstemmed |
Feeding by grey seals on endangered stocks of Atlantic cod and white hake |
title_sort |
feeding by grey seals on endangered stocks of atlantic cod and white hake |
publisher |
Oxford University Press |
publishDate |
2014 |
url |
http://icesjms.oxfordjournals.org/cgi/content/short/71/6/1332 https://doi.org/10.1093/icesjms/fsu123 |
long_lat |
ENVELOPE(141.383,141.383,-66.800,-66.800) ENVELOPE(-54.600,-54.600,-63.383,-63.383) ENVELOPE(15.612,15.612,66.797,66.797) |
geographic |
Breton Island Cabot Canada Hake |
geographic_facet |
Breton Island Cabot Canada Hake |
genre |
atlantic cod Breton Island |
genre_facet |
atlantic cod Breton Island |
op_relation |
http://icesjms.oxfordjournals.org/cgi/content/short/71/6/1332 http://dx.doi.org/10.1093/icesjms/fsu123 |
op_rights |
Copyright (C) 2014, International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer |
op_doi |
https://doi.org/10.1093/icesjms/fsu123 |
container_title |
ICES Journal of Marine Science |
container_volume |
71 |
container_issue |
6 |
container_start_page |
1332 |
op_container_end_page |
1341 |
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1766357819914715136 |