Application of canonical correspondence analysis to determine the ecological contribution of phytoplankton to PCBs bioaccumulation in Qinhuai River, Nanjing, China

The distribution and interactions of phytoplankton and 14 polychlorinated biphenyls (PCBs) were investigated using canonical correspondence analysis in autumn in the Qinhuai River, Nanjing, China. Concentrations of PCBs in water and algal samples ranged from 33.78 to 144.84 ng/L and from 0.21 to 19.66 ng/L (0.06 to 3.04 ng/mg biomass), respectively. The predominant residual species of PCBs in water samples were tri- through hexachlorobiphenyls, and the predominant residuals in algae were tri-, tetra-, and heptachlorobiphenyls. The degree of eutrophication affected phytoplankton composition and PCB bioaccumulation, and led to sample site- and algal species specificity of PCB residues in the study area. Chlorophyta, Bacillariophyta, and Euglenophyta had strong capacities to take up PCBs, whereas Cyanophyta was less involved in the transfer of these compounds. Bioaccumulation of PCBs by algae may be affected by water quality, chlorination, phytoplankton composition, and the structure of the PCBs and the algal cell walls.