Bioaccumulation of PAHs in marine zooplankton: an experimental study in the copepod Pseudodiaptomus marinus

Laboratory exposure experiments were performed on the marine coastal zooplankton species Pseudodiaptomus marinus-a keystone species of vast Atlantic and Pacific marine ecosystems, tracing the accumulation of three polycyclic aromatic hydrocarbons (PAHs): phenanthrene, anthracene and pyrene. The experiment was designed to study the bioconcentration of PAHs in phytoplankton (Rhodomonas baltica) and accumulation in copepods (P. marinus), through two different pathways: food and water uptake. For this purpose, water and organism subsamples were collected, ASE (accelerated solvent extraction) extracted, and analyzed for PAHs by GC/MS technique. As a result, experimental bioconcentration (BCF) and bioaccumulation (BAF) factors which showed a significant correlation with the octanol-water partition coefficient (K-ow) were presented for P. marinus. The active feeding route of exposure showed no significant differences versus passive uptake, highlighting the importance of dietary exposure as a major pathway for POPs accumulation in zooplankton; in particular for those which cannot be metabolized.