The fish of the Athabasca River are being contaminated by bitumen.
According to a study by the journal of 'Environmental Science and Technology', cancer causing agents called, polycyclic aromatic hydrocarbons, are on the rise in the riverbed.
Dr. Kevin Timoney with Tree Line Ecological Centre says the report finds a direct link between industry upriver and harmful substances found in the river downriver food chain.
"There's a tremendous cause for concern, anybody who is living off the wildlife such as the fishes or things that are feeding in the Athabasca Delta should be concerned."
Timoney also says the oil sands industry should not be left to self-regulate, instead the federal government should support independent environmental studies.