Development of Atlantic cod (Gadus morhua) exposed to produced water during early life stages Effects on embryos, larvae, and juvenile fish

Produced water (PW) contains numerous toxic compounds of natural origin such as dispersed oil metals alkylphenols (APs) and polycyclic aromatic hydrocarbons (PAHs) In addition PW also contains many different chemicals which have been added during the oil production process In the study described here cod were exposed to real PW collected from an oil production platform in the North Sea This was done in order to best recreate the most realistic field-exposure regime in which fish will be affected by a wide range of chemicals The biological effects found in this study therefore cannot be assigned to one group of chemicals alone but are the result of exposure to the complex chemical mixture found in real PW Since APs are well known to cause endocrine disruption in marine organisms we focused our chemical analysis on APs in an attempt to better understand the long-term effects of APs from PW on the biology of fish In this study cod were exposed to several concentrations of real PW and 17 beta-oestradiol (E-2) a natural oestrogen at different developmental stages Cod were exposed to PW either during the embryo and early larvae stage (up to 3 months of age) or during the early juvenile stage (from 3 to 6 months of age) Results showed that in general APs bioconcentrate in fish tissue in a dose and developmental stage dependent manner during PW exposure However juveniles appeared able to effectively metabolise the short chain APs Importantly PW exposure had no effect on embryo survival or hatching success However 1% PW clearly interfered with the development of normal larval pigmentation After hatching most of the larvae exposed to 1% PW failed to begin feeding and died of starvation This inability to feed may be linked to the increased incidence of jaw deformities seen in these larvae In addition cod exposed to 1% PW had significantly higher levels of the biomarkers vitellogenin and CYP1A in plasma and liver respectively No similar effects were seen in cod exposed to either 01% or 001% PW (c) 2010 Elsevier Ltd All rights reserved