Bioconcentration and elimination of avermectin B 1 in sturgeon

The bioconcentration and elimination of avermectin B 1 in sturgeon muscle were investigated with high‐performance liquid chromatography. Mean concentrations of 0.2 and 1 ng·ml −1 in water were maintained for a 22‐d exposure period. The concentrations of avermectin B 1α in muscle tissues reached steady state within 14 to 18 d. The level of avermectin B 1 concentrations in the fish muscles was 7.75 ± 0.88 and 38.29 ± 1.65 ng·g −1 for the low and high concentrations, respectively, on day 22. The half‐life ( t 1/2 ) of the concentrations for the two treated groups was 4.95 and 4.33 d for the low and high concentrations, respectively. Greater than 95% of the tissue concentrations were eliminated from the exposed fish after the 14‐ and 18‐d elimination periods. The estimated values of the bioconcentration factor were 42 L/kg for the low‐concentration group and 41 L/kg for high‐concentration group, and these values were not significantly different (α = 0.05). Avermectin B 1α does not strongly bioconcentrate in individual aquatic organism and would not be expected to biomagnify in the food chain.