Acute toxicity to the crab Paragrapsus quadridentatus (H. Milne Edwards), of Kuwait light crude oil, BP/AP dispersant, and an oil-dispersant mixture

Abstract

The acute toxicity to P. quadridentatus, of Kuwait light crude oil, BP/AR dispersant and an oil-dispersant mixture was determined. Observed 96-h LC₅₀ values averaged 1555 mg 1^-1 for oil added to water. A statistically valid 96-h LC₅₀ value for the dispersant was not obtained, but results indicated that a solution containing between 1300 and 2200 mg I^-1 might be expected to produce 50% mortality. A mixture of oil and dispersant in the ratio 4 : 1 gave an observed 96-h LC₅₀ value of 96 mg 1^-1, a 16-fold increase in toxicity over oil alone. The implications of the results are discussed.