• Reproductive toxicology;
  • Ceriodaphnia dubia;
  • Bayesian hierarchical models;
  • Multivariate

Effluents may contain chemicals that impact the mortality, growth, or reproduction of organisms in aquatic systems. A common endpoint analyzed in reproduction toxicology is the total young produced by organisms exposed to toxicants. In the present study, we propose using two Bayesian hierarchical models to analyze the brood-specific reproduction count responses in aquatic toxicology experiments jointly and to estimate the brood-specific concentration associated with a specified level of reproductive inhibition. A simulation study showed that the proposed models outperformed an approach where brood-specific responses were modeled separately. In particular, this method provided potency estimates with smaller bias/variation and better coverage probability. The application of the proposed models is illustrated with an experiment where the impact of Nitrofen was studied. Copyright © 2012 John Wiley & Sons, Ltd.