Comparative Modeling of Cod-Capelin Dynamics in the Newfoundland-Labrador Shelves and Barents Sea Ecosystems
The Atlantic cod (Gadus morhua) stocks in the Newfoundland-Labrador Shelves (NL) and Barents Sea (BS) ecosystems have shown divergent trajectories over the last 40 years. Both stocks experienced either an important decline (BS) or a collapse (NL) in the mid-1980s and early 1990s, respectively. After...
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ftimr:oai:imr.brage.unit.no:11250/2767795 2023-05-15T15:27:51+02:00 Comparative Modeling of Cod-Capelin Dynamics in the Newfoundland-Labrador Shelves and Barents Sea Ecosystems Koen-Alonso, Mariano Lindstrøm, Ulf Cuff, Andrew 2021 application/pdf https://hdl.handle.net/11250/2767795 https://doi.org/10.3389/fmars.2021.579946 eng eng Frontiers in Marine Science. 2021, 8 1-15. urn:issn:2296-7745 https://hdl.handle.net/11250/2767795 https://doi.org/10.3389/fmars.2021.579946 cristin:1923110 1-15 8 Frontiers in Marine Science Peer reviewed Journal article 2021 ftimr https://doi.org/10.3389/fmars.2021.579946 2021-09-23T20:14:39Z The Atlantic cod (Gadus morhua) stocks in the Newfoundland-Labrador Shelves (NL) and Barents Sea (BS) ecosystems have shown divergent trajectories over the last 40 years. Both stocks experienced either an important decline (BS) or a collapse (NL) in the mid-1980s and early 1990s, respectively. After these population reductions, the BS stock quickly rebounded and it is currently at record high levels, while the NL stock, despite showing some improvement since the mid-2000s, remains at low levels. Fishing and environmental conditions are known to be important drivers of cod dynamics in both ecosystems, especially the availability of high energy prey like capelin (Mallotus villosus), however, the question of how different or similar these two stocks truly are remains. Could, for example, the NL cod stock rebuild if presented to conditions like the ones experienced by BS cod? To explore such questions, we developed a simple biomass dynamic model for cod using a bioenergetic-allometric approach. This model includes fisheries catches and capelin availability as external drivers and was implemented for both ecosystems. Despite the contrasting trends, the model produced very good fits, and showed some remarkably similar estimated parameters in both systems. We explored these similarities by (a) performing the thought experiment of transferring cod stocks between ecosystems by switching estimated key parameters between models and comparing the output, and (b) implementing an integrated model architecture which allowed fitting common parameters for both stocks to evaluate the similarity of key vital rates. Our results indicate that cod trajectories in NL and BS can be reliably described using simple bioenergetic-allometric arguments, fishery catches, and capelin availability. Model parameters that encapsulate intrinsic vital rates were not significantly different between stocks. This indicates that NL and BS cod stocks are biologically similar, and that the differences in their trajectories are driven by the ecosystem context in which these stocks are embedded, and suggests that the NL stock would be expected to rebuild if enough capelin were available. This also indicates that capelin status and trend should be an important consideration for effective management of these cod stocks. publishedVersion Article in Journal/Newspaper atlantic cod Barents Sea Gadus morhua Newfoundland Institute for Marine Research: Brage IMR Newfoundland Barents Sea Frontiers in Marine Science 8 |
institution |
Open Polar |
collection |
Institute for Marine Research: Brage IMR |
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ftimr |
language |
English |
description |
The Atlantic cod (Gadus morhua) stocks in the Newfoundland-Labrador Shelves (NL) and Barents Sea (BS) ecosystems have shown divergent trajectories over the last 40 years. Both stocks experienced either an important decline (BS) or a collapse (NL) in the mid-1980s and early 1990s, respectively. After these population reductions, the BS stock quickly rebounded and it is currently at record high levels, while the NL stock, despite showing some improvement since the mid-2000s, remains at low levels. Fishing and environmental conditions are known to be important drivers of cod dynamics in both ecosystems, especially the availability of high energy prey like capelin (Mallotus villosus), however, the question of how different or similar these two stocks truly are remains. Could, for example, the NL cod stock rebuild if presented to conditions like the ones experienced by BS cod? To explore such questions, we developed a simple biomass dynamic model for cod using a bioenergetic-allometric approach. This model includes fisheries catches and capelin availability as external drivers and was implemented for both ecosystems. Despite the contrasting trends, the model produced very good fits, and showed some remarkably similar estimated parameters in both systems. We explored these similarities by (a) performing the thought experiment of transferring cod stocks between ecosystems by switching estimated key parameters between models and comparing the output, and (b) implementing an integrated model architecture which allowed fitting common parameters for both stocks to evaluate the similarity of key vital rates. Our results indicate that cod trajectories in NL and BS can be reliably described using simple bioenergetic-allometric arguments, fishery catches, and capelin availability. Model parameters that encapsulate intrinsic vital rates were not significantly different between stocks. This indicates that NL and BS cod stocks are biologically similar, and that the differences in their trajectories are driven by the ecosystem context in which these stocks are embedded, and suggests that the NL stock would be expected to rebuild if enough capelin were available. This also indicates that capelin status and trend should be an important consideration for effective management of these cod stocks. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Koen-Alonso, Mariano Lindstrøm, Ulf Cuff, Andrew |
spellingShingle |
Koen-Alonso, Mariano Lindstrøm, Ulf Cuff, Andrew Comparative Modeling of Cod-Capelin Dynamics in the Newfoundland-Labrador Shelves and Barents Sea Ecosystems |
author_facet |
Koen-Alonso, Mariano Lindstrøm, Ulf Cuff, Andrew |
author_sort |
Koen-Alonso, Mariano |
title |
Comparative Modeling of Cod-Capelin Dynamics in the Newfoundland-Labrador Shelves and Barents Sea Ecosystems |
title_short |
Comparative Modeling of Cod-Capelin Dynamics in the Newfoundland-Labrador Shelves and Barents Sea Ecosystems |
title_full |
Comparative Modeling of Cod-Capelin Dynamics in the Newfoundland-Labrador Shelves and Barents Sea Ecosystems |
title_fullStr |
Comparative Modeling of Cod-Capelin Dynamics in the Newfoundland-Labrador Shelves and Barents Sea Ecosystems |
title_full_unstemmed |
Comparative Modeling of Cod-Capelin Dynamics in the Newfoundland-Labrador Shelves and Barents Sea Ecosystems |
title_sort |
comparative modeling of cod-capelin dynamics in the newfoundland-labrador shelves and barents sea ecosystems |
publishDate |
2021 |
url |
https://hdl.handle.net/11250/2767795 https://doi.org/10.3389/fmars.2021.579946 |
geographic |
Newfoundland Barents Sea |
geographic_facet |
Newfoundland Barents Sea |
genre |
atlantic cod Barents Sea Gadus morhua Newfoundland |
genre_facet |
atlantic cod Barents Sea Gadus morhua Newfoundland |
op_source |
1-15 8 Frontiers in Marine Science |
op_relation |
Frontiers in Marine Science. 2021, 8 1-15. urn:issn:2296-7745 https://hdl.handle.net/11250/2767795 https://doi.org/10.3389/fmars.2021.579946 cristin:1923110 |
op_doi |
https://doi.org/10.3389/fmars.2021.579946 |
container_title |
Frontiers in Marine Science |
container_volume |
8 |
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1766358248458289152 |