Ecological Systems and Devices Annotation << Back Influence of bottom sediments at the toxicity of heavy metals for daphnia. 1. chrome Medyankina M.V., Philenko O.Ph., Shirokov D.A. The bottom sediments decreased the toxicity of potassium dichromate for cladocera D. magna. The effect of poassium dichromate at the survival of crustaceans most of all was reduced by silt and loam, containing clay and high level of organic substances. The bottom sediments had a different sorption capability and limits of chromium accumulation at the different concentrations in the water that in particular was a reason of changing of pollutants’ toxicity for D. magna.