Analysis of toxicity tests on Daphnia survival and reproduction

We present a statistical analysis of bioassays for Daphnia survival and reproduction, such as the routine toxicity test that is described in the OECD guideline 202. The analysis is based on the Dynamic Energy Budget theory and a one-compartment kinetics for the toxic compound. It is fully process oriented. We compare a formulation in terms of effects on survival during oogenesis to various direct and indirect effects on the energetics of reproduction. All formulations characterize the effects by a no-effect concentration, a tolerance concentration and the elimination rate. We conclude that all options lead to similar no-effect levels. We compare the analysis to the standard NOEC/EC50 analysis and conclude that our analysis is both simpler and more effective.