Toxicity of nine benchmark chemicals to Skeletonema Costatum, a marine diatom

Abstract

AbstractThe purpose of this study was to determine the sensitivity of a marine diatom to eigm common chemicals and one herbicide. The 50% reduction in the number of cells per milliliter and that of total cell volume × 104 μm3/ml was estimated in relation to each of the nine chemicals. Nominal concentrations of triclopyr triethylamine salt (Garlon 3A), K2Cr2O7, 4—chlorophenol and phenol were slightly toxic (>10 mg/L) according to the U.S. Environmental Protection Agency classificatory scheme, while diethanolamine, chlorobenzene, chloroform, acetone and ethanol were classified as practically nontoxic (>100 mg/L). No observed effect levels were found for each of the two cell measurements in relation to each of the chemicals tested for the 5—d period of the test. The range was found to be from 1 to 6,000 mg/L for total cell count and from 0.65 to 6,000 mg/L for total cell volume. Data on the sensitivities of other organisms to the group of common chemicals are also included. The marine diatom proved to be less sensitive to K2Cr2O7 and diethanolamine than the green alga Selenastrum capricornutum.