Bile analyses of goldfish (Crassius auratus) resident in a New Zealand hydrolake receiving a bleached kraft mill discharge

Bile was collected from goldfish (Crassius auratus) sampled from five sites on a river receiving the biologically treated discharge from a New Zealand bleached kraft mill. The bile was subjected to an alkaline hydrolysis, extracted with dichloromethane and analysed for resin acids and chlorophenolic compounds by GC/MS. The bioaccumulation and persistence in the bile of both saturated and unsaturated resin acids and chlorophenolic compounds was found for sites downstream of the millʹs discharge. Abietanic, 13-abietenic and seco-dehydroabietic acids were the major bile bioaccumulated resin acids and 2,4,6 trichlorophenol was the predominant chlorophenolic compound detected. Elevated levels up to 507 μg/g(dw bile) per resin acid and 61 μg/g(dw bile) per chlorophenol were found adjacent to the millʹs discharge point. Attenuated levels of these compounds were identified at a site 2.4 km downstream where the effluent was partially mixed, while levels at a well mixed site subject to a natural fifty fold dilution, 9.1 km downstream, were only marginally greater than those identified at an upstream (control) site.