Nature reserves as a bioeconomic management tool. A simplified modeling approach

Abstract

This paper demonstrates analytically how a nature reserve may protect the total population, realize maximum sustainable yield (MSY), maximum economic yield (MEY) and consumer surplus (CS) and how this depends on biological growth, migration, reserve size and economic parameters. The pre-reserve population is assumed to follow the logistic growth law and two post-reserve growth models are discussed. For Model A, the post-reserve growth has a common carrying capacity as in the pre-reserve case. In Model B, each sub-population has its own carrying capacity proportionate to its distribution area. Population protection against extinction is assured against low cost harvesting, including zero cost, when relative reserve size is greater than relative migration. Reserve size may be tuned to realize MSY in Model A, but not in Model B. MEY can not be realized in any of the two models, but generally economic yield is greater in Model A than B. CS is greater with a reserve than without.