Recent studies on fish examining the impact of produced water released offshore have revealed an extremely complex response to oil micro droplets and oil spiked with relevant doses of poly-aromatic hydrocarbons (PAHs) and alkylated phenols (AP). Protein expression signatures (PES) obtained from exposed and control fish show both up and down regulation of between 50-100 proteins, with the majority of responses observed being sex dependent, even in juvenile fish. Produced water is an unstabl e mix of many components which may be unique for individual oil fields. Components in produced water, PAHs, APs and a variety of polar organic compounds (POCs), are over represented in comparison to concentrations found in the oil. The POCs are the least studied components of the produced water both with respect to acute toxicity and long-term effects. In this study we will seek to sample from cod exposure experiments financed through the PROOF, especially "Comparative oral and water based exposures of co d to produced water components", and other programs.
Based on these findings individual proteins will be sought to be identified for further development as biomarkers of chronic exposure to low doses of oil, synthetic mixes of PAHs, APs and POCs at concen trations similar to those found in produced water. The proteome response in both wild and caged cod from the North-sea will be compared against results from the laboratory exposures with the aim of identifying and validating diagnostically important prote ins. To perform the identification of diagnostically important proteins a cooperation with national and international research groups within the field of proteomics will be established. If possible some genomic analyses will be performed on the Cod as coo peration with other research groups to increase the mechanistic interpretation of the proteom responses.