APPLICATION OF A SURPLUS PRODUCTION MODEL TO ASSESS ENVIRONMENTAL IMPACTS ON EXPLOITED POPULATIONS OF DAPHNIA PULEX IN THE LABORATORY

Abstract The surplus production model is a simple and easily applied model for the assessment of environmental impacts on exploited fish populations. However, its application requires several assumptions about the relationships between the degree of impact and the population response that are difficult to test using field data. To examine these assumptions, the model is applied to exploited laboratory populations of Daphnia pulex exposed to chronic radiation stress. The model describes the observed relationship between equilibrium population size and the level of radiation exposure. It also describes the relationship between yield and population size.