The acute toxicity of three oil dispersants

Static bioassay tests were conducted with three oil dispersants at two salinities (32·0 ± 2 g litre⁻¹ and 16·0 ± g litre⁻¹) using fingerlings of the mullet Mugil sp. and hermit crabs Clibinarius africanus as test animals. The acute toxicity was estimated both by graphical interpolation and the approximate nomographic method of Litchfield & Wilcoxon (1949) and is reported as the 24 h, 48 h and 96 h LC(1)₅₀ Lloyd & Tooby, 1979) values. Conco-K was the most toxic, and BP 1,100X the least toxic, to the two test organisms at the two test salinities. Simple observations were made on the behavioural responses of the test animals. The rôle of acute toxicity data in ecological predictions is briefly discussed.