Reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for Georges Bank and Gulf of Maine Atlantic cod stocks
Average age and size at maturation have decreased in many commercially exploited fish stocks during the last few decades. This phenomenon could be either a direct phenotypic response to some environmental variation, or the evolutionary consequence of some selective pressure. Traditionally used matur...
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ftimr:oai:imr.brage.unit.no:11250/100547 2023-05-15T15:27:18+02:00 Reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for Georges Bank and Gulf of Maine Atlantic cod stocks Barot, S. Heino, Mikko O’Brien, Loretta Dieckmann, Ulf 2002 801849 bytes application/pdf http://hdl.handle.net/11250/100547 eng eng ICES ICES CM documents 2002/Y:03 http://hdl.handle.net/11250/100547 25 s. cod torsk VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 Working paper 2002 ftimr 2021-09-23T20:15:41Z Average age and size at maturation have decreased in many commercially exploited fish stocks during the last few 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, i.e. 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, and to disentangle evolutionary changes and phenotypic plasticity, we use a reaction norm based approach. A method is presented to estimate the reaction norm for age and size at maturation from a type of data commonly gathered for the management of fisheries. This method is applied to data on Georges Bank and Gulf of Maine Atlantic cod stocks. Maturation reaction norms in these stocks have shifted significantly downwards, i.e. there has been a tendency to mature earlier at smaller size. These findings support the hypothesis of an evolutionary trend, probably caused by the selective removal of larger fish and high fishing mortality rates. Consequences of such an evolutionary process for the sustainability of the fishery are discussed. Report atlantic cod Institute for Marine Research: Brage IMR |
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Open Polar |
collection |
Institute for Marine Research: Brage IMR |
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ftimr |
language |
English |
topic |
cod torsk VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 |
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cod torsk VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 Barot, S. Heino, Mikko O’Brien, Loretta Dieckmann, Ulf Reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for Georges Bank and Gulf of Maine Atlantic cod stocks |
topic_facet |
cod torsk VDP::Agriculture and fishery disciplines: 900::Fisheries science: 920::Resource biology: 921 VDP::Mathematics and natural science: 400::Zoology and botany: 480::Ecology: 488 |
description |
Average age and size at maturation have decreased in many commercially exploited fish stocks during the last few 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, i.e. 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, and to disentangle evolutionary changes and phenotypic plasticity, we use a reaction norm based approach. A method is presented to estimate the reaction norm for age and size at maturation from a type of data commonly gathered for the management of fisheries. This method is applied to data on Georges Bank and Gulf of Maine Atlantic cod stocks. Maturation reaction norms in these stocks have shifted significantly downwards, i.e. there has been a tendency to mature earlier at smaller size. These findings support the hypothesis of an evolutionary trend, probably caused by the selective removal of larger fish and high fishing mortality rates. Consequences of such an evolutionary process for the sustainability of the fishery are discussed. |
format |
Report |
author |
Barot, S. Heino, Mikko O’Brien, Loretta Dieckmann, Ulf |
author_facet |
Barot, S. Heino, Mikko O’Brien, Loretta Dieckmann, Ulf |
author_sort |
Barot, S. |
title |
Reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for Georges Bank and Gulf of Maine Atlantic cod stocks |
title_short |
Reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for Georges Bank and Gulf of Maine Atlantic cod stocks |
title_full |
Reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for Georges Bank and Gulf of Maine Atlantic cod stocks |
title_fullStr |
Reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for Georges Bank and Gulf of Maine Atlantic cod stocks |
title_full_unstemmed |
Reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for Georges Bank and Gulf of Maine Atlantic cod stocks |
title_sort |
reaction norms for age and size at maturation: study of the long-term trend (1970-1998) for georges bank and gulf of maine atlantic cod stocks |
publisher |
ICES |
publishDate |
2002 |
url |
http://hdl.handle.net/11250/100547 |
genre |
atlantic cod |
genre_facet |
atlantic cod |
op_source |
25 s. |
op_relation |
ICES CM documents 2002/Y:03 http://hdl.handle.net/11250/100547 |
_version_ |
1766357754177388544 |