Species Sensitivity Distributions - Aquatic
Single Surrogate SSD
If toxicity data for a chemical is available for both a vertebrate and an invertebrate species, SSDs can be improved by using two surrogates. The two surrogate SSD uses the vertebrate surrogate to estimate toxicity to all vertebrate species and the invertebrate surrogate to estimate toxicity to all invertebrate species. Data generated from both surrogates are combined to create one SSD. See the user manual for more on this method.