Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s
The fishery-induced collapse of the Atlantic cod (Gadus morhua) stock on the eastern Scotian Shelf has altered the species composition of this ecosystem. Ecopath mass-balance models of the ecosystem before and after the collapse were developed to explore how the structure, function, and key species...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Online Access: | http://dx.doi.org/10.1139/f05-085 http://www.nrcresearchpress.com/doi/pdf/10.1139/f05-085 |
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crcansciencepubl:10.1139/f05-085 2024-05-12T08:00:57+00:00 Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s Bundy, Alida 2005 http://dx.doi.org/10.1139/f05-085 http://www.nrcresearchpress.com/doi/pdf/10.1139/f05-085 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 62, issue 7, page 1453-1473 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2005 crcansciencepubl https://doi.org/10.1139/f05-085 2024-04-18T06:54:53Z The fishery-induced collapse of the Atlantic cod (Gadus morhua) stock on the eastern Scotian Shelf has altered the species composition of this ecosystem. Ecopath mass-balance models of the ecosystem before and after the collapse were developed to explore how the structure, function, and key species of the ecosystem had changed. For the first time, an analysis of uncertainty was conducted to examine the effects of the uncertainty on model estimates. A comparison of the two Ecopath models indicated that although total productivity and total biomass of the ecosystem remained similar, there were changes in predator structure, trophic structure, and energy flow, many of which were robust to uncertainty. Biomass has significantly increased at trophic levels 3 and 4, and the composition of these trophic levels has changed as a result of the mean increase in trophic level of many species-groups. Piscivory has increased, presumably because of the high abundance of small pelagic fish, and the ratio of pelagic feeders to demersal feeders has increased from 0.3 to 3.0. Thus, the ecosystem has changed from a demersal-feeder-dominated system to a pelagic-feeder-dominated system. Although uncertainty remains concerning some model estimates, the ecosystem has been profoundly altered and exhibits classic symptoms of "fishing down the food web". However, overall system properties were generally conserved. Article in Journal/Newspaper atlantic cod Gadus morhua Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 62 7 1453 1473 |
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Open Polar |
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Canadian Science Publishing |
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crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Bundy, Alida Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
The fishery-induced collapse of the Atlantic cod (Gadus morhua) stock on the eastern Scotian Shelf has altered the species composition of this ecosystem. Ecopath mass-balance models of the ecosystem before and after the collapse were developed to explore how the structure, function, and key species of the ecosystem had changed. For the first time, an analysis of uncertainty was conducted to examine the effects of the uncertainty on model estimates. A comparison of the two Ecopath models indicated that although total productivity and total biomass of the ecosystem remained similar, there were changes in predator structure, trophic structure, and energy flow, many of which were robust to uncertainty. Biomass has significantly increased at trophic levels 3 and 4, and the composition of these trophic levels has changed as a result of the mean increase in trophic level of many species-groups. Piscivory has increased, presumably because of the high abundance of small pelagic fish, and the ratio of pelagic feeders to demersal feeders has increased from 0.3 to 3.0. Thus, the ecosystem has changed from a demersal-feeder-dominated system to a pelagic-feeder-dominated system. Although uncertainty remains concerning some model estimates, the ecosystem has been profoundly altered and exhibits classic symptoms of "fishing down the food web". However, overall system properties were generally conserved. |
format |
Article in Journal/Newspaper |
author |
Bundy, Alida |
author_facet |
Bundy, Alida |
author_sort |
Bundy, Alida |
title |
Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s |
title_short |
Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s |
title_full |
Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s |
title_fullStr |
Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s |
title_full_unstemmed |
Structure and functioning of the eastern Scotian Shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s |
title_sort |
structure and functioning of the eastern scotian shelf ecosystem before and after the collapse of groundfish stocks in the early 1990s |
publisher |
Canadian Science Publishing |
publishDate |
2005 |
url |
http://dx.doi.org/10.1139/f05-085 http://www.nrcresearchpress.com/doi/pdf/10.1139/f05-085 |
genre |
atlantic cod Gadus morhua |
genre_facet |
atlantic cod Gadus morhua |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 62, issue 7, page 1453-1473 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f05-085 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
62 |
container_issue |
7 |
container_start_page |
1453 |
op_container_end_page |
1473 |
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1798843015254507520 |