Assessing environmental impact on mass balance, carrying capacity and growth of exploited populations

Abstract

Population models that have been applied for assessment of exploited populations are also useful for assessment of environmental impacts. Surplus production models have been applied for both fishery and environmental impact assessment; environmental impacts with three different modes of action can be incorporated into the surplus production model. For each of these possible modes of action the equilibrium relations among biomass, yield, level of fishing and level of environmental stress are developed. The resulting equations are applied to describe the results of laboratory experiments in which exploited populations were manipulated to alter the growth coefficient, carrying capacity, or mass balance. The models describe the experimental results.