Record Display for the EPA National Library Catalog
RECORD NUMBER: 25 OF 26
|OLS Field Name||OLS Field Data|
|Main Title||Toxicity of Sediment-Incorporated Drilling Fluids.|
|Author||Clark, J. R. ; Patrick, J. M. ;|
|CORP Author||Environmental Research Lab., Gulf Breeze, FL.|
|Additional Subjects||Drilling fluids ; Toxicity ; Sediments ; Water pollution ; Environmental impacts ; Benthos ; Offshore drilling ; Test methods ; Invertebrates ; Crustacae ; Exposure ; Survival ; Mortality ; Concentration(Composition) ; Barium ; Tables(Data) ; Reprints ; Branchiostoma caribaeum ; Lancelets ; Mysidopsis bahia ; Invertebrates|
The 24, 96, or 168-h LC50s of four used drilling fluids or barite incorporated into sediment were determined in toxicity tests with lancelets (Branchiostoma caribaeum), a benthic chordate. The number of lancelets that did not burrow into contaminated sediments was used to calculate EC50s at the same times that LC50s were determined. Observations of the burrowing behavior allowed quantitation of effects after 24-h exposures to each of the drilling fluids whereas lancelet mortality was sufficient to calculate 24-h LC50s for only one drilling fluid. Drilling fluids were less toxic to lancelets when incorporated into sediments than to mysids (Mysidopsis bahia) or benthic invertebrate communities in water-column exposures.