2004b. Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14:1257–1271
Abstract. 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...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.145.3482 2023-05-15T15:27:46+02:00 2004b. Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14:1257–1271 S. Barot M. Heino U. Dieckmann The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.145.3482 http://www.iiasa.ac.at/~dieckman/reprints/BarotEtal2004b.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.145.3482 http://www.iiasa.ac.at/~dieckman/reprints/BarotEtal2004b.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.iiasa.ac.at/~dieckman/reprints/BarotEtal2004b.pdf Key words cod fisheries fish stocks management strategies Gadus morhua Georges Bank cod text ftciteseerx 2016-01-07T15:07:06Z Abstract. 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. Text atlantic cod Gadus morhua Unknown |
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English |
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Key words cod fisheries fish stocks management strategies Gadus morhua Georges Bank cod |
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Key words cod fisheries fish stocks management strategies Gadus morhua Georges Bank cod S. Barot M. Heino U. Dieckmann 2004b. Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14:1257–1271 |
topic_facet |
Key words cod fisheries fish stocks management strategies Gadus morhua Georges Bank cod |
description |
Abstract. 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. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
S. Barot M. Heino U. Dieckmann |
author_facet |
S. Barot M. Heino U. Dieckmann |
author_sort |
S. Barot |
title |
2004b. Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14:1257–1271 |
title_short |
2004b. Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14:1257–1271 |
title_full |
2004b. Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14:1257–1271 |
title_fullStr |
2004b. Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14:1257–1271 |
title_full_unstemmed |
2004b. Long-term trend in the maturation reaction norm of two cod stocks. Ecological Applications 14:1257–1271 |
title_sort |
2004b. long-term trend in the maturation reaction norm of two cod stocks. ecological applications 14:1257–1271 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.145.3482 http://www.iiasa.ac.at/~dieckman/reprints/BarotEtal2004b.pdf |
genre |
atlantic cod Gadus morhua |
genre_facet |
atlantic cod Gadus morhua |
op_source |
http://www.iiasa.ac.at/~dieckman/reprints/BarotEtal2004b.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.145.3482 http://www.iiasa.ac.at/~dieckman/reprints/BarotEtal2004b.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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