Algal EC50 toxicity data

EC50 data calculated for the specific growth of algae are presented in Figure 4. The slope and intercept of the MoA 1 plot are similar to the fish acute toxicity data, although there is a greater spread to the data, potentially due to the difficulty in measuring truly dissolved concentrations of test substance in the algal system. Unlike both the fish and the invertebrate MoA 2 data, some inference may be possible from this plot with algae, indicating that for MoA 2 substances, algae may be slightly more predictive although no reason can be provided why algae should behave differently from daphnids or fish to polar narcotics.