MAXIMUM SUSTAINABLE YIELD FOR MARINE METAPOPULATION GOVERNED BY COUPLED GENERALISED LOGISTIC EQUATIONS

Abstract

Many important renewable natural resources, such as commercial marine populations, are known to form metapopulations structure. They consist of several inter-connected subpopulations that live in different patches of habitat and have different biological and demographical characteristics. Managing them eitheras a single well-mixed population or barely as several disconnected populations is clearly inappropriate, and may lead to unsustainable utilisation ofthose populations. In this paper, the effect of demographic and biological parameters variability on the maximum sustainable yield for the metapopulation is discussed. The traditional maximum sustainable yield that ignores the variability of these parameters is compared with the maximum sustainable yield that considers this variability. Several insights on how to manage the populations in a sustainable manner are derived and could be used as guidance in the exploitation of precious renewable natural resources. The result of the paper shows that the magnitude of the maximum sustainable yield depends critically on the biological parameters with the respect to the corresponding spatial scale. Different places give different values of maximum sustainable yield. In general, there is a trade-off among biological parameters in different patches determining whether the stock living in one patch should be harvested more conservatively or less conservatively than the stock living in another patch.