Oil Spills Cause Oxidative Stress For Up To 20 Years

Despite not being visible to the human eye, oil spills can affect fish DNA and cause oxidative stress for years afterwards, according to an international collaborative project. The Toxprof research project examined the impacts of oil discharges along the coast of Europe. The researchers studied the effects of common Arabian light crude as well as oil from the Norwegian Ekofisk field, in addition to the diesel fuel commonly used by ships. 

 

The experiments were carried out at the University of Oslo's marine biological station at Drøbak, located on the Oslo Fjord. Seawater was pumped through coarse sand containing oil that was partially broken down by UV radiation. The oil then floated to aquariums containing cod, mussels or spotted goby. In this way the researchers could control the concentrations of the oils' environmentally hazardous components.

 

Ketil Hylland, Professor of Toxicology at the University of Oslo's Department of Biology, says the team was able to work out clear profiles for the impacts of the selected oils, yielding some important answers as to which substances are most toxic. A variety of biomarkers in the gills and liver of the cod and the digestive glands and gills of the mussels were measured. The trials showed that the effects changed over time and lasted more than three weeks. Using different methods, the project participants observed effects that demonstrated that the contaminants in oil can potentially lead to DNA damage and cause oxidative stress in the experimental organisms.

 

The research indicates that even though the oil disappears from the seawater surface and beaches after a spill, the toxic substances in oil can still cause adverse effects long afterwards. Researchers also found that the oil can become more toxic and harmful during the breakdown process.