Comparative efficiency of clove oil and rotenone for sampling tropical reef fish assemblages

A quantitative examination of the reef fish assemblage at Orpheus Island, Great Barrier Reef, contrasting clove oil and rotenone, sampled 365 individuals of 47 species with clove oil v. 536 individuals of 53 species with rotenone. Number of species and individuals were not found to differ significantly between the two techniques, largely due to variation among samples. Neopomacentrus bankieri (Pomacentridae) and Eviota queenslandica (Gobiidae) were the most dominant in the samples using either technique. Although the samples appeared to be comparable, only 31 species (45%) in eight families were common to both techniques. Fishes often recovered before collection when using clove oil and were not driven out of the reef during induction to anaesthesia. Although the samples collected with clove oil approximate the results obtained using rotenone, enclosed rotenone stations are the preferred method for providing relatively complete quantitative samples.