Broadbill swordfish ( Xiphias gladius) foraging and vertical movements in thenorth‐west Atlantic
Abstract The northern edge of Georges Bank is an important seasonal foraging habitat for swordfish ( Xiphias gladius ) in the North Atlantic, where aggregations support commercial pelagic longline and harpoon fisheries. Following a period of overfishing during the 1990s, the North Atlantic X. gladiu...
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crwiley:10.1111/jfb.14744 2024-09-15T18:22:53+00:00 Broadbill swordfish ( Xiphias gladius) foraging and vertical movements in thenorth‐west Atlantic Logan, John M. Golet, Walt Smith, Sean C. Neilson, John Van Guelpen, Lou Fisheries and Oceans Canada 2021 http://dx.doi.org/10.1111/jfb.14744 https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfb.14744 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jfb.14744 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Journal of Fish Biology volume 99, issue 2, page 557-568 ISSN 0022-1112 1095-8649 journal-article 2021 crwiley https://doi.org/10.1111/jfb.14744 2024-08-30T04:12:50Z Abstract The northern edge of Georges Bank is an important seasonal foraging habitat for swordfish ( Xiphias gladius ) in the North Atlantic, where aggregations support commercial pelagic longline and harpoon fisheries. Following a period of overfishing during the 1990s, the North Atlantic X. gladius stock underwent a period of recovery during the early 2000s and was considered rebuilt in 2009. We analysed stomach contents from X. gladius ( n = 39) harvested by the Canadian harpoon fishery on Georges Bank in 2007 to characterize diet in this important foraging habitat. We used electronic tagging data from X. gladius ( n = 6) on Georges Bank in 2005–2007 to assess vertical habitat preferences and associated prey composition within those zones. We also used stable isotope analysis (δ 13 C and δ 15 N) of X. gladius liver ( n = 2) and common prey types (Paralepididae, Myctophidae, Merluccidae, Ommastrephidae) as a longer‐term record of feeding. Stomach contents were co‐dominated by Paralepididae [31.9% weight (W)] and Ommastrephidae (36.8%W) with secondary contributions from hake (Merluccidae, 6.5%W), Myctophidae (2.9%W) and Sebastidae (2.1%W). X. gladius displayed diel vertical migrations, descending to depths of 300–400 m during daytime followed by residence in surface waters at night. X. gladius liver δ 15 N values were similar to or lower than values of primary stomach contents, likely due to bias of diet consumed in southerly waters with lower nitrogen isotope baselines prior to arrival on Georges Bank. Diet data are similar to results from historical studies from the late 1950s to the early 1980s. This apparent temporal stability to the underlying food web in this region may explain the high X. gladius site fidelity observed in electronic tagging studies and the consistent aggregation of these fish to this region. Article in Journal/Newspaper North Atlantic Wiley Online Library Journal of Fish Biology 99 2 557 568 |
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Open Polar |
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Wiley Online Library |
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crwiley |
language |
English |
description |
Abstract The northern edge of Georges Bank is an important seasonal foraging habitat for swordfish ( Xiphias gladius ) in the North Atlantic, where aggregations support commercial pelagic longline and harpoon fisheries. Following a period of overfishing during the 1990s, the North Atlantic X. gladius stock underwent a period of recovery during the early 2000s and was considered rebuilt in 2009. We analysed stomach contents from X. gladius ( n = 39) harvested by the Canadian harpoon fishery on Georges Bank in 2007 to characterize diet in this important foraging habitat. We used electronic tagging data from X. gladius ( n = 6) on Georges Bank in 2005–2007 to assess vertical habitat preferences and associated prey composition within those zones. We also used stable isotope analysis (δ 13 C and δ 15 N) of X. gladius liver ( n = 2) and common prey types (Paralepididae, Myctophidae, Merluccidae, Ommastrephidae) as a longer‐term record of feeding. Stomach contents were co‐dominated by Paralepididae [31.9% weight (W)] and Ommastrephidae (36.8%W) with secondary contributions from hake (Merluccidae, 6.5%W), Myctophidae (2.9%W) and Sebastidae (2.1%W). X. gladius displayed diel vertical migrations, descending to depths of 300–400 m during daytime followed by residence in surface waters at night. X. gladius liver δ 15 N values were similar to or lower than values of primary stomach contents, likely due to bias of diet consumed in southerly waters with lower nitrogen isotope baselines prior to arrival on Georges Bank. Diet data are similar to results from historical studies from the late 1950s to the early 1980s. This apparent temporal stability to the underlying food web in this region may explain the high X. gladius site fidelity observed in electronic tagging studies and the consistent aggregation of these fish to this region. |
author2 |
Fisheries and Oceans Canada |
format |
Article in Journal/Newspaper |
author |
Logan, John M. Golet, Walt Smith, Sean C. Neilson, John Van Guelpen, Lou |
spellingShingle |
Logan, John M. Golet, Walt Smith, Sean C. Neilson, John Van Guelpen, Lou Broadbill swordfish ( Xiphias gladius) foraging and vertical movements in thenorth‐west Atlantic |
author_facet |
Logan, John M. Golet, Walt Smith, Sean C. Neilson, John Van Guelpen, Lou |
author_sort |
Logan, John M. |
title |
Broadbill swordfish ( Xiphias gladius) foraging and vertical movements in thenorth‐west Atlantic |
title_short |
Broadbill swordfish ( Xiphias gladius) foraging and vertical movements in thenorth‐west Atlantic |
title_full |
Broadbill swordfish ( Xiphias gladius) foraging and vertical movements in thenorth‐west Atlantic |
title_fullStr |
Broadbill swordfish ( Xiphias gladius) foraging and vertical movements in thenorth‐west Atlantic |
title_full_unstemmed |
Broadbill swordfish ( Xiphias gladius) foraging and vertical movements in thenorth‐west Atlantic |
title_sort |
broadbill swordfish ( xiphias gladius) foraging and vertical movements in thenorth‐west atlantic |
publisher |
Wiley |
publishDate |
2021 |
url |
http://dx.doi.org/10.1111/jfb.14744 https://onlinelibrary.wiley.com/doi/pdf/10.1111/jfb.14744 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/jfb.14744 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Journal of Fish Biology volume 99, issue 2, page 557-568 ISSN 0022-1112 1095-8649 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/jfb.14744 |
container_title |
Journal of Fish Biology |
container_volume |
99 |
container_issue |
2 |
container_start_page |
557 |
op_container_end_page |
568 |
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1810462924957810688 |