The results of four fish surveys (EDUARDO L HOLMBERG 1994 to 1997) are analyzed to detect associations between the sizes of Champsocephalus gunnari (also age classes) , Gobionotothen gibberifrons, Notothenia rossii, Pseudochaeinichthys georgianus, Chaenocephalus aceratus and Dissostichus eleginoides and depth of catch, as well as among C. gunnari age classes. Except D. eleginoides median sizes of all species resulted significantly associated with depth, positively in the case of C. gunnari and N. rossii and negatively for the remaining species. Less association with depth is observed in C. gunnari as the fish grow older, indicating that the spatial separation is controlled by depth. The accumulated catches of age I- present maximum difference with the older age classes at about 150 meters a result which might be used to fish different age fractions of the populations, thus regulating the age composition of the catches.
Spatial distribution of Champsocephalus gunnari size and age are related with depth
Numéro du document:
WG-FSA-97/45
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Résumé