Hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( Gadus morhua ) declined
Misinterpretations of elevated catch-per-unit-effort (CPUE) in the northern cod (Gadus morhua) fishery contributed to overestimations of stock size, inflated quotas, and unsustainable fishing mortality in the 1980s and early 1990s. We hypothesize that concentration of the fish and fishery led to ext...
Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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Online Access: | http://dx.doi.org/10.1139/f99-207 http://www.nrcresearchpress.com/doi/pdf/10.1139/f99-207 |
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crcansciencepubl:10.1139/f99-207 2024-05-12T08:03:53+00:00 Hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( Gadus morhua ) declined Rose, G A Kulka, D W 1999 http://dx.doi.org/10.1139/f99-207 http://www.nrcresearchpress.com/doi/pdf/10.1139/f99-207 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Fisheries and Aquatic Sciences volume 56, issue S1, page 118-127 ISSN 0706-652X 1205-7533 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 1999 crcansciencepubl https://doi.org/10.1139/f99-207 2024-04-18T06:54:51Z Misinterpretations of elevated catch-per-unit-effort (CPUE) in the northern cod (Gadus morhua) fishery contributed to overestimations of stock size, inflated quotas, and unsustainable fishing mortality in the 1980s and early 1990s. We hypothesize that concentration of the fish and fishery led to extreme hyperstability in the CPUE-abundance relationship. In the late 1980s, migrant cod began to concentrate within the Bonavista corridor, their most southerly cross-shelf migration route. By the spring of 1990, approximately 450 000 t was concentrated within 7000 km 2 at densities quadruple those of the 1980s. Densities remained high through 1992, while abundance declined fivefold. During this period, cod hyperaggregated (local densities increased with decreasing biomass) in the Bonavista corridor and CPUE increased. To the north, no hyperaggregation occurred, and densities and CPUE declined with biomass. In the Bonavista corridor from 1990 to 1993, CPUE was hyperstable with local cod density. Areas of high cod densities (>0.1 fish·m -2 ) shrunk as regional estimates of cod biomass declined. The spatial extent of the fishery contracted proportional to the shrinkage in area occupied by the fish. Hence, CPUE was related to abundance at the local scales of a fishing set (local acoustic density) but not to abundance at regional or stock scales. Article in Journal/Newspaper Gadus morhua Canadian Science Publishing Canadian Journal of Fisheries and Aquatic Sciences 56 S1 118 127 |
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Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Rose, G A Kulka, D W Hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( Gadus morhua ) declined |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Misinterpretations of elevated catch-per-unit-effort (CPUE) in the northern cod (Gadus morhua) fishery contributed to overestimations of stock size, inflated quotas, and unsustainable fishing mortality in the 1980s and early 1990s. We hypothesize that concentration of the fish and fishery led to extreme hyperstability in the CPUE-abundance relationship. In the late 1980s, migrant cod began to concentrate within the Bonavista corridor, their most southerly cross-shelf migration route. By the spring of 1990, approximately 450 000 t was concentrated within 7000 km 2 at densities quadruple those of the 1980s. Densities remained high through 1992, while abundance declined fivefold. During this period, cod hyperaggregated (local densities increased with decreasing biomass) in the Bonavista corridor and CPUE increased. To the north, no hyperaggregation occurred, and densities and CPUE declined with biomass. In the Bonavista corridor from 1990 to 1993, CPUE was hyperstable with local cod density. Areas of high cod densities (>0.1 fish·m -2 ) shrunk as regional estimates of cod biomass declined. The spatial extent of the fishery contracted proportional to the shrinkage in area occupied by the fish. Hence, CPUE was related to abundance at the local scales of a fishing set (local acoustic density) but not to abundance at regional or stock scales. |
format |
Article in Journal/Newspaper |
author |
Rose, G A Kulka, D W |
author_facet |
Rose, G A Kulka, D W |
author_sort |
Rose, G A |
title |
Hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( Gadus morhua ) declined |
title_short |
Hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( Gadus morhua ) declined |
title_full |
Hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( Gadus morhua ) declined |
title_fullStr |
Hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( Gadus morhua ) declined |
title_full_unstemmed |
Hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( Gadus morhua ) declined |
title_sort |
hyperaggregation of fish and fisheries: how catch-per-unit-effort increased as the northern cod ( gadus morhua ) declined |
publisher |
Canadian Science Publishing |
publishDate |
1999 |
url |
http://dx.doi.org/10.1139/f99-207 http://www.nrcresearchpress.com/doi/pdf/10.1139/f99-207 |
genre |
Gadus morhua |
genre_facet |
Gadus morhua |
op_source |
Canadian Journal of Fisheries and Aquatic Sciences volume 56, issue S1, page 118-127 ISSN 0706-652X 1205-7533 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/f99-207 |
container_title |
Canadian Journal of Fisheries and Aquatic Sciences |
container_volume |
56 |
container_issue |
S1 |
container_start_page |
118 |
op_container_end_page |
127 |
_version_ |
1798846004295892992 |