Long-term trend in the maturation reaction norm of two cod stocks
Average age and size at maturation have decreased in many commercially exploited fish stocks during the last decades. This phenomenon could be either a direct phenotypic response to some environmental variation or the evolutionary consequence of some selective pressure. Traditionally used maturation...
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ftiiasalaxendare:oai:pure.iiasa.ac.at:7163 2023-05-15T15:27:43+02:00 Long-term trend in the maturation reaction norm of two cod stocks Barot, S. Heino, M. O'Brien, L. Dieckmann, U. 2004-08 http://pure.iiasa.ac.at/id/eprint/7163/ unknown Wiley-Blackwell Ecological Society of America (ESA) Barot, S. <http://pure.iiasa.ac.at/view/iiasa/1141.html>, Heino, M. <http://pure.iiasa.ac.at/view/iiasa/122.html> orcid:0000-0003-2928-3940 , O'Brien, L., & Dieckmann, U. <http://pure.iiasa.ac.at/view/iiasa/66.html> orcid:0000-0001-7089-0393 (2004). Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14 (4) 1257-1271. 10.1890/03-5066 <https://doi.org/10.1890/03-5066>. Article PeerReviewed 2004 ftiiasalaxendare 2022-04-15T12:31:37Z Average age and size at maturation have decreased in many commercially exploited fish stocks during the last decades. This phenomenon could be either a direct phenotypic response to some environmental variation or the evolutionary consequence of some selective pressure. Traditionally used maturation indices, e.g., the age and size at which 50% of individuals are mature, are not appropriate to assess the causes of changes in maturation because they are influenced, in addition to maturation per se, by growth and survival. To make up for this shortcoming, we use a reaction-norm-based approach to disentangle evolutionary changes and phenotypic plasticity. A method is presented to estimate the reaction norm for age and size at maturation from data commonly gathered for the management of fisheries. This method is applied to data on Georges Bank and Gulf of Maine stocks of Atlantic cod (Gadus morhua). The results show that maturation reaction norms in these stocks have shifted significantly downward, resulting in a tendency to mature earlier at smaller size. These findings support the hypothesis that an evolutionary trend, probably caused by high fishing mortalities, is partially responsible for the observed decrease in age and size at maturation in these cod stocks. Two independent reasons justify this interpretation. First, there is no corresponding trend in growth that would suggest that improved feeding conditions could have facilitated maturation. Second, the results are based on maturation reaction norms, from which the known confounding effects of the growth and mortality variation are removed. Consequences of fisheries-induced evolution for the sustainability of the fishery are discussed. Article in Journal/Newspaper atlantic cod Gadus morhua IIASA DARE (Data Repository of the International Institute of Applied Systems Analysis) |
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description |
Average age and size at maturation have decreased in many commercially exploited fish stocks during the last decades. This phenomenon could be either a direct phenotypic response to some environmental variation or the evolutionary consequence of some selective pressure. Traditionally used maturation indices, e.g., the age and size at which 50% of individuals are mature, are not appropriate to assess the causes of changes in maturation because they are influenced, in addition to maturation per se, by growth and survival. To make up for this shortcoming, we use a reaction-norm-based approach to disentangle evolutionary changes and phenotypic plasticity. A method is presented to estimate the reaction norm for age and size at maturation from data commonly gathered for the management of fisheries. This method is applied to data on Georges Bank and Gulf of Maine stocks of Atlantic cod (Gadus morhua). The results show that maturation reaction norms in these stocks have shifted significantly downward, resulting in a tendency to mature earlier at smaller size. These findings support the hypothesis that an evolutionary trend, probably caused by high fishing mortalities, is partially responsible for the observed decrease in age and size at maturation in these cod stocks. Two independent reasons justify this interpretation. First, there is no corresponding trend in growth that would suggest that improved feeding conditions could have facilitated maturation. Second, the results are based on maturation reaction norms, from which the known confounding effects of the growth and mortality variation are removed. Consequences of fisheries-induced evolution for the sustainability of the fishery are discussed. |
format |
Article in Journal/Newspaper |
author |
Barot, S. Heino, M. O'Brien, L. Dieckmann, U. |
spellingShingle |
Barot, S. Heino, M. O'Brien, L. Dieckmann, U. Long-term trend in the maturation reaction norm of two cod stocks |
author_facet |
Barot, S. Heino, M. O'Brien, L. Dieckmann, U. |
author_sort |
Barot, S. |
title |
Long-term trend in the maturation reaction norm of two cod stocks |
title_short |
Long-term trend in the maturation reaction norm of two cod stocks |
title_full |
Long-term trend in the maturation reaction norm of two cod stocks |
title_fullStr |
Long-term trend in the maturation reaction norm of two cod stocks |
title_full_unstemmed |
Long-term trend in the maturation reaction norm of two cod stocks |
title_sort |
long-term trend in the maturation reaction norm of two cod stocks |
publisher |
Wiley-Blackwell |
publishDate |
2004 |
url |
http://pure.iiasa.ac.at/id/eprint/7163/ |
genre |
atlantic cod Gadus morhua |
genre_facet |
atlantic cod Gadus morhua |
op_relation |
Barot, S. <http://pure.iiasa.ac.at/view/iiasa/1141.html>, Heino, M. <http://pure.iiasa.ac.at/view/iiasa/122.html> orcid:0000-0003-2928-3940 , O'Brien, L., & Dieckmann, U. <http://pure.iiasa.ac.at/view/iiasa/66.html> orcid:0000-0001-7089-0393 (2004). Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14 (4) 1257-1271. 10.1890/03-5066 <https://doi.org/10.1890/03-5066>. |
_version_ |
1766358126820327424 |