| dc.description.abstract | 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
17b-oestradiol (E2), 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 0.1% or 0.01% PW. | no_NO |
