This National Status and Trends Program's bioeffects assessment study determined the toxicity of sediments in Sabine Lake, Texas, and adjoining Intracoastal Waterway canals.
Surficial sediment samples were collected during August, 1995, from 66 randomly-chosen locations. Laboratory toxicity tests were conducted to measure: reduced survival of adult amphipods exposed to solid-phase sediments; impaired fertilization success and abnormal morphological development in gametes and embryos, respectively, of sea urchins exposed to pore waters; reduced metabolic activity of a marine bioluminescent bacteria exposed to organic solvent extracts; and induction of a cytochrome P-450 reporter gene system in exposures to solvent extracts of the sediments.
Chemical analyses were performed on portions of each sample to quantify the concentrations of trace metals, polynuclear aromatic hydrocarbons, and chlorinated organic compounds.
Based upon the compilation of results from chemical analyses and toxicity tests, the quality of sediments in Sabine Lake and vicinity did not appear to be severely degraded. Chemical concentrations rarely exceeded effects-based numerical guidelines, suggesting that toxicant-induced effects would not be expected in most areas.
None of the samples was highly toxic in acute amphipod survival tests and 23% of samples were highly toxic in sublethal urchin fertilization tests.
Although toxic responses occurred frequently (94% of samples) in urchin embryo development tests performed with 100% pore waters, toxicity diminished markedly in tests done with diluted pore waters.
Microbial bioluminescent activity was not reduced to a great degree and cytochrome P-450 activity was not highly induced in tests done with organic solvent extracts.
Urchin embryological development was highly correlated with concentrations of ammonia and many trace metals.
Cytochrome P-450 induction was highly correlated with concentrations of a number of classes of organic compounds (including the polynuclear aromatic hydrocarbons and chlorinated compounds).
