Copper bioaccumulation and biokinetic modeling in marine herbivorous fish Siganus oramin

In this study, the kinetics of Cu bioaccumulation in a widespread marine herbivorous fish, Siganus oramin, were investigated, and biokinetic modeling was applied to estimate the Cu levels in the fish sampled from different sites and seasons. The results showed that Cu accumulation in the fish was linearly correlated to the dietary Cu levels in the different prey species, which were proportional to the waterborne Cu concentrations. The Cu found in the subcellular trophically available metal fraction (TAM) in the prey contributed the largest proportion of accumulated Cu in S. oramin. The dietary assimilation efficiencies (AEs) of Cu were 15.56 ± 1.76%, 13.42 ± 2.86%, and 21.36 ± 1.47% for Ulva lactuca, Gracilaria lemaneiformis and Gracilaria gigas, respectively. The calculated waterborne uptake rate constant (ku ) of Cu was 0.023 ± 0.011 L g−1 d−1, and the efflux rate constant (ke ) was 0.055 ± 0.021 d−1. Dietary Cu accounted for 60%-75% of the body Cu in S. oramin, suggesting that dietary uptake could be the primary route for Cu bioaccumulation in herbivorous fish. The biokinetic model demonstrated that the Cu concentrations in the water and fish presented a positive linear relationship, which was in line with our field investigation along the coastal areas of South China. Therefore, we suggested that S. oramin could be used as a biomonitoring organism for Cu pollution in the marine environment. However, the heterogeneities between the pred...
Source: Aquatic Toxicology - Category: Toxicology Source Type: research