Age structure affects population productivity in an exploited fish species

Abstract Long‐term changes in the age and size structure of animal populations are well documented, yet their impacts on population productivity are poorly understood. Fishery exploitation can be a major driver of changes in population age–size structure because fisheries significantly increase mort...

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Published in:Ecological Applications
Main Authors: Ohlberger, Jan, Langangen, Øystein, Stige, Leif Chr.
Other Authors: Research Council, Rutgers, The State University of New Jersey
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2022
Subjects:
Online Access:http://dx.doi.org/10.1002/eap.2614
https://onlinelibrary.wiley.com/doi/pdf/10.1002/eap.2614
https://onlinelibrary.wiley.com/doi/full-xml/10.1002/eap.2614
https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/eap.2614
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spelling crwiley:10.1002/eap.2614 2024-09-15T17:55:34+00:00 Age structure affects population productivity in an exploited fish species Ohlberger, Jan Langangen, Øystein Stige, Leif Chr. Research Council, Rutgers, The State University of New Jersey 2022 http://dx.doi.org/10.1002/eap.2614 https://onlinelibrary.wiley.com/doi/pdf/10.1002/eap.2614 https://onlinelibrary.wiley.com/doi/full-xml/10.1002/eap.2614 https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/eap.2614 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Ecological Applications volume 32, issue 5 ISSN 1051-0761 1939-5582 journal-article 2022 crwiley https://doi.org/10.1002/eap.2614 2024-08-06T04:19:43Z Abstract Long‐term changes in the age and size structure of animal populations are well documented, yet their impacts on population productivity are poorly understood. Fishery exploitation can be a major driver of changes in population age–size structure because fisheries significantly increase mortality and often selectively remove larger and older fish. Climate change is another potential driver of shifts in the demographic structure of fish populations. Northeast Arctic (NEA) cod is the largest population of Atlantic cod ( Gadus morhua ) and one of the world's most important commercial fish stocks. This population has experienced considerable changes in population age–size structure over the past century, largely in response to fishing. In this study, we investigate whether changes in spawner age structure have affected population productivity in NEA cod, measured as recruits per spawning stock biomass, over the past 75 years. We find evidence that shifts in age structure toward younger spawners negatively affect population productivity, implying higher recruitment success when the spawning stock is composed of older individuals. The positive effect of an older spawning stock is likely linked to maternal effects and higher reproductive output of larger females. Our results indicate a threefold difference in productivity between the youngest and oldest spawning stock that has been observed since the 1950s. Further, our results suggest a positive effect of environmental temperature and a negative effect of intraspecific cannibalism by older juveniles on population productivity, which partly masked the effect of spawner age structure unless accounted for in the model. Collectively, these findings emphasize the importance of population age structure for the productivity of fish populations and suggest that harvest‐induced demographic changes can have negative feedbacks for fisheries that lead to a younger spawning stock. Incorporating demographic data into harvest strategies could thus facilitate sustainable ... Article in Journal/Newspaper atlantic cod Climate change Gadus morhua Wiley Online Library Ecological Applications 32 5
institution Open Polar
collection Wiley Online Library
op_collection_id crwiley
language English
description Abstract Long‐term changes in the age and size structure of animal populations are well documented, yet their impacts on population productivity are poorly understood. Fishery exploitation can be a major driver of changes in population age–size structure because fisheries significantly increase mortality and often selectively remove larger and older fish. Climate change is another potential driver of shifts in the demographic structure of fish populations. Northeast Arctic (NEA) cod is the largest population of Atlantic cod ( Gadus morhua ) and one of the world's most important commercial fish stocks. This population has experienced considerable changes in population age–size structure over the past century, largely in response to fishing. In this study, we investigate whether changes in spawner age structure have affected population productivity in NEA cod, measured as recruits per spawning stock biomass, over the past 75 years. We find evidence that shifts in age structure toward younger spawners negatively affect population productivity, implying higher recruitment success when the spawning stock is composed of older individuals. The positive effect of an older spawning stock is likely linked to maternal effects and higher reproductive output of larger females. Our results indicate a threefold difference in productivity between the youngest and oldest spawning stock that has been observed since the 1950s. Further, our results suggest a positive effect of environmental temperature and a negative effect of intraspecific cannibalism by older juveniles on population productivity, which partly masked the effect of spawner age structure unless accounted for in the model. Collectively, these findings emphasize the importance of population age structure for the productivity of fish populations and suggest that harvest‐induced demographic changes can have negative feedbacks for fisheries that lead to a younger spawning stock. Incorporating demographic data into harvest strategies could thus facilitate sustainable ...
author2 Research Council, Rutgers, The State University of New Jersey
format Article in Journal/Newspaper
author Ohlberger, Jan
Langangen, Øystein
Stige, Leif Chr.
spellingShingle Ohlberger, Jan
Langangen, Øystein
Stige, Leif Chr.
Age structure affects population productivity in an exploited fish species
author_facet Ohlberger, Jan
Langangen, Øystein
Stige, Leif Chr.
author_sort Ohlberger, Jan
title Age structure affects population productivity in an exploited fish species
title_short Age structure affects population productivity in an exploited fish species
title_full Age structure affects population productivity in an exploited fish species
title_fullStr Age structure affects population productivity in an exploited fish species
title_full_unstemmed Age structure affects population productivity in an exploited fish species
title_sort age structure affects population productivity in an exploited fish species
publisher Wiley
publishDate 2022
url http://dx.doi.org/10.1002/eap.2614
https://onlinelibrary.wiley.com/doi/pdf/10.1002/eap.2614
https://onlinelibrary.wiley.com/doi/full-xml/10.1002/eap.2614
https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1002/eap.2614
genre atlantic cod
Climate change
Gadus morhua
genre_facet atlantic cod
Climate change
Gadus morhua
op_source Ecological Applications
volume 32, issue 5
ISSN 1051-0761 1939-5582
op_rights http://onlinelibrary.wiley.com/termsAndConditions#vor
op_doi https://doi.org/10.1002/eap.2614
container_title Ecological Applications
container_volume 32
container_issue 5
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