Molecular approaches in ecotoxicology have greatly enhanced mechanistic understanding of the impact of aquatic pollutants in organisms. High throughput "omic" technologies, including quantitative proteomics methods such as 2D differential in-gel electrophoresis (DIGE), are now being acknowledged to be a promising tool to evaluate the effects of contaminant exposure on organisms and are becoming more widely used in ecotoxicology (1). Information on altered protein expression, including post-transcriptional modifications, can provide protein expression signatures, sets of proteins specific to different stressors, and insight into the possible mode of action (MoA) 1 of chemical pollutants and their higher level toxicological effects (2-5). Contaminant specific MoAs and protein expression signatures may be used for monitorization, especially because the use of omic techniques allows earlier identification of effects than traditional endpoints. However, ecotoxicoproteomic studies are still relatively uncommon and in their infancy (6).Human and veterinary pharmaceuticals are being released into the environment in extremely large quantities on a regular basis. Millions of prescription and nonprescription drugs are purchased and ingested by, or applied on individuals every day and eventually excreted through urine or feces, ultimately entering the effluent of wastewater treatment plants and aquatic environments (7). Frequently, sewage treatment does not affect the chemical structure, and therefore the concentrations of drugs that enter aquatic environments can be sufficient to exert toxicity on nontarget species. Most pharmaceuticals are relatively stable to avoid being biologically From the