A fathead minnow Pimephales promelas early life stage toxicity test method evaluation and exposure to four organic chemicals

Abstract

A 32-day test was developed at the Environmental Research Laboratory—Duluth for conducting early life stage (ELS) toxicity tests with fathead minnows Pimephales promelas. These test procedures were evaluated by using the prescribed methods to establish estimated maximum acceptable toxicant concentrations (MATC) for fathead minnows exposed to four previously untested organic chemicals. Toxic effects on early developmental stages demonstrated that larval growth and survival were the most sensitive indicators of toxic stress. Embryo hatch and larval deformities at hatch were the least sensitive indicators of toxicity. The estimated MATCs for fathead minnows exposed to hexachlorobutadiene, 1,2-dichloropropane, 1,3-dichloropropane and 1,2-dichloroethane lie between 6·5 and 13 μg litre −1, 6 and 11 mg litre −1, 8 and 16 mg litre −1 and 29 and 59 mg litre −1, respectively. Results obtained from the four ELS test method evaluations and the estimated MATCs derived from these evaluations demonstrate the consistency of the ELS toxicity test procedures for fathead minnows currently being adopted as standards by the US Environmental Protection Agency and the American Society for Testing and Materials. These ELS test methods produced good replication and, when used to predict long-term chronic toxicity, will provide a rapid means to develop water quality criteria and screen large numbers of single chemicals or complex effluents.