DeWitt, T.H., T.S. Bridges, D.S. Ireland, L.L. Stahl, M.R. Pinza and L.D. Antrim. 2001. Methods for Assessing the Chronic Toxicity of Marine and Estuarine Sediment-associated Contaminants with the Amphipod Leptocheirus plumulosus. EPA 600/R-01/020, Office of Research and Development, U.S. Environmental Protection Agency, Washington, D.C. WED-01-073
A laboratory method is described for determining the chronic toxicity of contaminants associated with whole sediments. Sediments may be collected from estuarine or marine environments or spiked with compounds in the laboratory. The toxicity method outlined uses an estuarine crustacean1 the amphipod Leptocheirus plumulosus. The toxicity test is conducted for 28 d in 1-L glass chambers containing 175 mL of sediment and about 725 mL of overlying water. Test temperature is 25Eħ2EC and the recommended overlying water salinity is 5ħ 2 (for test sediment with pore water at 1 to 1) or 20ħ2 (for test sediment with pore water >10). Four hundred milliliters of overlying water is renewed three times per week, at which times test organisms are fed. The endpoints in the toxicity test are survival, growth, and reproduction of amphipods. Performance criteria established for this test include the average survival of amphipods in negative control treatment must be greater than or equal to 80% and there must measurable growth and reproduction in all replicates of the negative control treatment. This test is applicable for use with sediments from oligohaline to fully marine environments, with a silt content greater than 5% and a clay content less than 85%.