Fréon Pierre. (1995). The influence of environment on stock assessment : an approach with surplus production models. In :
Potier Michel (ed.), Nurhakim S. (ed.). Biodynex : biology, dynamics, exploitation of the small pelagic fishes in the Java Sea. Jakarta : Agency for Agricultural Research and Development, p. 231-254. Biodynex Seminar, Jakarta (IND), 94/03/21-25.
Titre du document
The influence of environment on stock assessment : an approach with surplus production models
Année de publication
1995
Type de document
Colloque
Auteurs
Fréon Pierre
In
Potier Michel (ed.), Nurhakim S. (ed.) Biodynex : biology, dynamics, exploitation of the small pelagic fishes in the Java Sea
Source
Jakarta : Agency for Agricultural Research and Development, 1995,
p. 231-254
Colloque
Biodynex Seminar, Jakarta (IND), 94/03/21-25
Conventional global production models are not suitable for some stocks because fishing effort variations only explain only a small part of the total variability of annual catches. Often the residual variability originates from the influence of environmental phenomena, which affects either the abundance or the catchability of a stock from one year to the next. Therefore an additional environmental variable has been inserted into conventional models in order to improve their accuracy. These variables appear in simple formulae regarding either the stock abundance (surplus production), or the catchabiltiy coefficient, or both. The models are developed from the Schaefer's linear production model, the Fox's exponential model or the Pella and Tomlinson generalized model. CLIMPROD is an experimental expert-system, using artificial intelligence, which provides a statistical and graphical description of the data set and helps the user to select the model corresponding to his case according to objective criteria. The software fits the model to the data set using a non-linear regression routine, assesses the fit with parametric and non-parametric tests, and provides a graphical representation of the results. (Résumé d'auteur)
