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OSLO, Aug. 8 (Xinhua) -- A new research in Norway has shown that even microscopic amounts of oil spill can create malformations and reduce the growth of polar cod, news agency NTB reported on Monday.
In an experiment made by researchers at UiT The Arctic University of Norway, 12,000 eggs from polar cod were exposed to tiny, but realistic amounts of raw oil. Although the oil spills did not kill them, the test has shown that the larvae grew smaller and with malformation.
"The levels that were used in the experiments were so low that it was not be possible to measure them in the laboratory. However, the fact that such small amounts give so clear results is in itself both sensational and important," associate professor Jasmine Nahrgang told the university's online newspaper.
The polar cod, which is a key species in the Artic ecosystem and an important food source for seals, whales and seabirds, spawns in winter under the ice and it takes a long time until the free-floating eggs hatch. That is why the polar cod is vulnerable to oil spills in icy waters.
"We know that the eggs of polar cod will naturally flow around in the surface and under the ice and this is the area that will probably be mostly affected by the oil. The study is therefore not only of ecological, but also of environmental significance and it points to the contexts that we were not aware of until now," Nahrgang said.
The results of the experiment, which were published in the magazine Environmental Pollution, show that even small oil spill in the Artic can be of a very big significance and can have dramatic consequences for the whole system, she said.
The environmental organization Greenpeace believes that the study is one more argument against allowing oil exploration in these areas in the first place and encourages all oil companies to return the permits they have received.
"Prevalence of polar cod has already shrunk a lot due to the climate changes. There is no reason to expose this species for any further threats through oil industry," Truls Gulowsen, general manager of Greenpeace Norway, told NTB.
