The ecological effect assessment model: a case study in East China Sea’s ecosystem

摘要

We introduce a modified form of growth inhibition rate as an ecological indicator. The biomasses representing energy held in each trophic level are used to derive the growth inhibition rate of an aquatic ecosystem which measures the biomass decrease of entire ecosystem owing to environmental heavy metal contamination. The ultimate limiting biomass based upon the definition of carrying capacity (Bf) - a parameter of logistic growth model, is used to determine the highest possible biomass. It is stressed that what we determine by this method of growth inhibition rate calculation is a relative modeled index. It is not possible to find the precise inhibition rate of entire ecosystems, because they are far too complex to allow us to know all the details of an ecosystem. The growth inhibition rate indices have been estimated in the East China Sea’s ecosystem to demonstrate the usefulness of the method. The eornparison between EC50 obtained by means of statistics and that computed by the model proposed in this paper is made to validate the reliability of growth inhibition rate calculation.