It is very difficult to achieve this goal. Typically, fisheries undergo stocks permanently at different temporal and spatial scales of exploitation that exceeds the biological capacity and ecological recovery of the species. Plus, the fishery always begins without further study of the population which will be exploited. When these studies exist, and these are more intensive, the population has already changed to another phase, i.e., the response is delayed

One factor that clearly shows these effects are average sizes of the populations subjected to exploitation. Body sizes of fish as well as the quality and quantity of their eggs, are subject to biological changes. Drastic natural events, and fishing pressure, can severely affect the exploited stocks