Biological and Chemical Assessment of exposure and effects to produced formation water at Harriet A platform in NWS

A comprehensive biological and chemical assessment of the fate, effects and potential risks associated with Produced Formation Water (PFW) were conducted at the Harriet A platform on the Northwest Shelf of Australia. A controlled in situ caging study was conducted using a Australian, tropical reef species, Stripey seaperch (Lutjanus carponotatus), deployed in 6 separate galvanised steel cages set 1m subsurface at 3 stations; Site A (near-field~ 300 m), Site B (far-field, ~ 1000 m) and Site C, a reference site. Samples were collected at T= 0, T= 3 and T=10 days for EROD, cytochrome P450, bile metabolites, CYP1A, CYP2K1- and CYP2M1-like proteins, vitellogenin, GST, HSI, and histopathological assessment of liver and gills. In addition, time-integrated water column samplers (SPMDs) were deployed at all 3 sites to assess in situ petroleum hydrocarbon concentrations. The results from a 3 factor nested ANOVA, demonstrated that were no effects of cages nested in site, and no interactions between cages and time of sampling, therefore the effect of cages was removed from all subsequent analyses. As a result of univariate analysis (ANOVA), bile metabolites, CYP1A, CYP2M1- and CYP2K1-like proteins, and histopathological assessment of livers and gills were statistically significant (p < 0.05) at Site A after 10 days of exposure to PFW, corresponding with higher levels of PAHs at this site. Analysis by Principal Component established trends that the CYP-like proteins explained most of the variation amongst all biomarker responses, and these correlations were driven largely by the effects of site (Site A) and time of sampling (T=10). This study demonstrated that PFW discharged into this shallow tropical ecosystem is causing environmental degradation of water quality within close proximity to the Harriet A platform (~ 300 m). *