Even brief exposures of the eggs of Atlantic haddock to low concentrations of dispersed crude oil can cause severe and usually deadly deformities in developing fish, an international research team has found. The findings indicate that oil spills at high latitudes could have serious impacts on some of the world's most important fisheries, including those for haddock, cod and pollock.

The research published today in Scientific Reports by a team of scientists from Norway and NOAA Fisheries' Northwest Fisheries Science Center in Seattle show that crude oil compounds disrupt the development of key organs in embryonic fish. The study was funded by the Research Council of Norway, the VISTA Foundation and Norway's Institute of Marine Research to assess the risks of oil spills in remote northern Norway, in the heart of Atlantic haddock's range.

The international collaboration will provide information to inform environmental risk assessments of proposed oil drilling in northern oceans.

Earlier research showed that the polycyclic aromatic hydrocarbons (PAHs) in crude oil interfere with heart development in fish, causing defects that compromise their later survival. The new research indicates crude oil also lead to extreme craniofacial deformities in embryonic haddock. Other research in the related species Atlantic cod suggests this may be a common response of fish in the cod family, which also includes Pacific cod and pollock.

The earlier the exposure, the more severe the deformities.