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Mollet, Fabian M.; Ernande, Bruno; Brunel, Thomas; Rijnsdorp, Adriaan D.. |
We present a new methodology to estimate rates of energy acquisition, maintenance, reproductive investment and the onset of maturation (four-trait estimation) by fitting an energy allocation model to individual growth trajectories. The accuracy and precision of the method is evaluated on simulated growth trajectories. In the deterministic case, all life history parameters are well estimated with negligible bias over realistic parameter ranges. Adding environmental variability reduces precision, causes the maintenance and reproductive investment to be confounded with a negative error correlation, and tends, if strong, to result in an underestimation of the energy acquisition and maintenance and an overestimation of the age and size at the onset of... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/2010/publication-7386.pdf |
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Brunel, Thomas; Ernande, Bruno; Mollet, Fabian M.; Rijnsdorp, Adriaan D.. |
A new method is presented to estimate individuals’ (1) age at maturation, (2) energy acquisition rate, (3) energy expenditure for body maintenance, and (4) reproductive investment, and the multivariate distribution of these traits in a population. The method relies on adjusting a conceptual energy allocation model to individual growth curves using nonlinear mixed-effects modelling. The method’s performance was tested using simulated growth curves for a range of life-history types. Individual age at maturation, energy acquisition rate and the sum of maintenance and reproductive investment rates, and their multivariate distribution, were accurately estimated. For the estimation of maintenance and reproductive investment rates separately, biases were observed... |
Tipo: Text |
Palavras-chave: Bioenergetics growth model; Individual growth trajectory; Life-history trade-offs; Energy acquisition; Maintenance; Reproductive investment; Sexual maturation. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00124/23537/21378.pdf |
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Mollet, Fabian M.; Engelhard, Georg; Vainikka, Anssi; Laugen, Ane; Rijnsdorp, Adriaan D.; Ernande, Bruno. |
Latitudinal variation in life-history traits is often explained by phenotypically plastic responses or local adaptations to different thermal regimes. We compared growth, maturation schedules and reproductive investment of female sole Solea solea between 8 populations, covering much of the species' distribution in northern Europe, with respect to thermal gradients. An energy allocation model was fitted to size–age data, and probabilistic maturation reaction norms were estimated from size–age–maturity data. We found that northern populations from colder environments had higher rates of energy acquisition and reproductive investment, an intrinsic tendency to mature earlier, and had smaller asymptotic sizes than southern populations from warmer environments.... |
Tipo: Text |
Palavras-chave: Countergradient variation; Phenotypic plasticity; Growth; Maturation reaction norm; Temperature; Mortality-induced evolution. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00124/23523/21360.pdf |
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Heino, Mikko; Baulier, Loic; Boukal, David S.; Ernande, Bruno; Johnston, Fiona D.; Mollet, Fabian M.; Pardoe, Heidi; Therkildsen, Nina O.; Uusi-heikkila, Silva; Vainikka, Anssi; Arlinghaus, Robert; Dankel, Dorothy J.; Dunlop, Erin S.; Eikeset, Anne Maria; Enberg, Katja; Engelhard, Georg; Jorgensen, Christian; Laugen, Ane; Matsumura, Shuichi; Nussle, Sebastien; Urbach, Davnah; Whitlock, Rebecca; Rijnsdorp, Adriaan D.; Dieckmann, Ulf. |
Biological reference points are important tools for fisheries management. Reference points are not static, butmay change when a population's environment or the population itself changes. Fisheries-induced evolution is one mechanism that can alter population characteristics, leading to "shifting" reference points by modifying the underlying biological processes or by changing the perception of a fishery system. The former causes changes in "true" reference points, whereas the latter is caused by changes in the yardsticks used to quantify a system's status. Unaccounted shifts of either kind imply that reference points gradually lose their intended meaning. This can lead to increased precaution, which is safe, but potentially costly. Shifts can also occur in... |
Tipo: Text |
Palavras-chave: Biological reference points; Fisheries-induced evolution; Fisheries management; Population dynamics; Precautionary approach; Uncertainty. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00151/26228/24302.pdf |
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