THE LIMITS TO EXPLOITATION ON LAND AND SEA

The sustainable yield of a population can be related directly to its demographic parameters and density-dependent processes. For fish stocks a direct and simple relationship can be derived relating this yield to the level of natural mortality and the stock and recruitment relationship. For terrestrial mammals, a plethora of different density-dependent processes have been identified. A derivation of a stock and recruitment relationship for terrestrial mammals is described here and applied to data on certain mammals. The comparative response to harvesting of marine species with these terrestrial mammals is then examined.