Modeling Daphnia Populations in Wastewater Stabilization Ponds in Minnesota

Abstract

A two-year study of physical, biological, and chemical aspects of Minnesota wastewater treatment ponds was conducted. As a part of this study, the one-dimensional unsteady advection/diffusion lake model MINLAKE was adapted for simulation of pond processes. A special sub-routine to track the ponds' Daphnia population was developed. Toxic effects of ammonia, low dissolved oxygen, and hydrogen sulfide were included in the model. The model and sub-routine were calibrated, and showed reasonable agreement with population data collected during the study. Development of the Daphnia sub-routine and its pelformance in the overall pond model are discussed herein.