The Water Column Monitoring Programme 2013: Determining the biological effects of two offshore platforms on local fish populations

The biological effects of two offshore oil platforms on local fish populations were assessed as part of the Water Column Monitoring (WCM) programme for 2013. Wild fish were caught with baited rod and line from within the 500 m safety zone of the Veslefrikk and Oseberg Sør platforms during the summer of 2013. Ling, tusk and saithe were caught and sampled from the Veslefrikk platform, whilst haddock, whiting and saithe were caught from the Oseberg Sør platform. Reference fish were caught on a separate research cruise by trawling from a region of the North Sea less impacted by oil and gas activities (around Egersund bank). Reference tusk were not obtained by trawl but caught by local fishermen from a coastal fjord using long line. Contaminant body burden and a suite of biological effects endpoints were measured in all fish groups and included DNA adducts, DNA strand breaks by comet assay, acetylcholine esterase inhibition (AChE), ethoxyresorufin 0-deethylase levels (EROD), lysosomal membrane stability (LMS), histology, PAH metabolites, and PAH body burden. The biomarker data were integrated using the integrated biological response index (IBR/n). Biological responses were observed in fish species from both platforms compared to their respective reference groups with highest responses observed in tusk from the Veslefrikk platform.