In general, the increased exploitation of the natural organic resources of the world makes it more and more necessary to apply proper resource management procedures in order to avoid overexploitation. In the fisheries field, the managemente is, among other things often based on studies of fish ageing. Such studies have become an important tool, to be used in the elaboration of population dynamic models and of biological parameters like stock recruitment, growth and mortality. In age studies the otoliths and scales of the fish are of basic importance. The reason is that they reflect th occurrence of the biological changes, which take place in the fish during its lifespan. Such changes may derive from for instance the natural growth process of the fish or... |