Consulta: subjectFacets:"Density-dependence"
Registros recuperados: 4
Data/hora: 02/06/2024 10:52:51

North Sea saithe Pollachius virens growth in relation to food availability, density dependence and temperature
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Cormon, Xochitl; Ernande, Bruno; Kempf, Alexander; Vermard, Youen; Marchal, Paul.
North Sea saithe Pollachius virens, a major top predator in the area, supports the fishery economy of several European countries. However, recent stock assessments suggested a decrease in spawning stock biomass along with a decline in saithe mean weight-at-ages. In this context, we investigated North Sea saithe growth characteristics at the population level. First, saithe annual weight increments and age-length relationships were studied. Modelling of saithe age-length relationships was carried out using (1) the traditional von Bertalanffy growth function model, (2) the Verhulst logistic model and (3) an empirical linear model. Second, the effects of environmental factors on saithe growth were investigated. Explanatory environmental factors included food...
Tipo: Text
Palavras-chave: Bottom-up processes; Von Bertalanffy growth function; Logistic growth; Norway pout; Prey availability effects; Density-dependence; Predator-prey interactions; Resource limitation; Competition.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00314/42499/41875.pdf

Changements adaptatifs induits par la pêche chez les populations halieutiques
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Marty, Lise.
Fishing is an important source of mortality in harvested populations and therefore may induce adaptive responses. These responses affect life-history traits in particular, which have consequences for stocks’ dynamics, and thus can alter the demographic direct effect of fishing (i.e. the reduction in stock’s biomass). Fishing-induced adaptive changes depend, non-exclusively, on two processes: evolution and phenotypic plasticity. These two components are observed at the phenotypic level because functional genes coding for the traits undergoing adaptive changes have not yet been identified. These two origins are confounded in individual phenotypes, and the impact of adaptive changes in the long run remains therefore unclear: evolutionary changes are expected...
Tipo: Text
Palavras-chave: : Pêche; Évolution adaptative; Plasticité phénotypique; Norme de réaction; Dérive génétique; Érosion génétique; Age et taille à maturation; Croissance; Survie; Trade-offs; Densité-dépendance; Gadidées de mer du nord; Fishing; Adaptive evolution; Phenotypic plasticity; Reaction norm; Genetic drift; Genetic erosion; Age and size at maturation; Growth; Survival; Trade-offs; Density-dependence; North sea Gadoids.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00079/19013/16591.pdf

Modelling the variability in fish spatial distributions over time with empirical orthogonal functions: anchovy in the Bay of Biscay
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Petitgas, Pierre; Doray, Mathieu; Huret, Martin; Masse, Jacques; Woillez, Mathieu.
Characterizing the space–time variability in spatial distributions as well as understanding its drivers is basic to designing robust spatial management plans. As a prerequisite, we analyse here how this variability relates to population dynamics in conjunction with environmental conditions. For that, spatio-temporal statistical approaches are needed but seldom used in fisheries science. To fill this gap, we showcase the usefulness of the method of empirical orthogonal functions (EOFs). Guidelines are given to apply the method on a series of gridded maps as derived from fisheries survey dataseries that now span over decades. The method is applied to the series, 2000–2012, of the spatial distributions of European anchovy in the Bay of Biscay at spawning...
Tipo: Text
Palavras-chave: Anchovy; Bay of Biscay; Density-dependence; EOF; Habitat; Spatial distribution.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00222/33365/31907.pdf

Larval density, temperature and biological aspects of Chrysomya megacephala (Diptera: Calliphoridae)
Provedor de dados: Arquivo Brasileiro de Medicina Veterinária e Zootecnia
Autores: Reigada,C.; Godoy,W.A.C.
The effect of larval density on the survival, fecundity and body size at two temperatures in experimental populations of C. megacephala was studied. No effect from simultaneous influence of density and temperature on life history characteristics of C. megacephala was found. Significant effects of density and temperature on survival, fecundity and body size were observed. The importance of these results for the population dynamics of C. megacephala is discussed.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Chrysomya megacephala; Density-dependence; Temperature; Survival; Fecundity.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352006000400018