Several lesions were found on Athabasca River fish near Fort McKay and Fort McMurray last week during those communities’ first round of fish monitoring, but researchers said it is too early to detect a cause.
Dr. Paul Jones, a toxicologist from the University of Saskatchewan, along with a team of researchers and local fishermen who coordinated the community fishing day, said they detected skin ulcerations on some of the fish, but could not say whether they were the result of upstream industrial activity or not.
“We saw some ulcerations on the skin of the fish, [which is] a weird observation,” he said. “But there were red ulcerations found all the way up and down the river, so it might not be related to oilsands industry.”
Jones said the lesions could be caused naturally, by parasites and bacterial or viral infections, but did not deny that chemicals could be responsible.
“Chemicals can cause the immune system to be compromised, making the fish more prone to infections, so there could be a relation,” he said. “And we are certainly looking for tumours, which are caused by chemicals.”
The project is being led by a team of researchers from the University of Saskatchewan as part of a regional, multi-year fish health study in partnership with the Government of the Northwest Territories’ department of Environment and Natural Resources in order to investigate effects of the oilsands industry on general aquatic health.
Scientists began investigating the health of the Slave and Athabasca Rivers at the end of June in Fort Smith and Fort Resolution. Last week saw the first successful fishing day done around Fort McMurray and Fort McKay, due to recent difficulties posed by high waters loaded with debris.
Thirty fish from each species were caught and dissected with the help of local fishermen.
Apart from taking thousands of photos of fish skin and organs, the scientists are using fresh samples from fish caught to test for biochemical levels.
“We will be doing a general health examination of the fish, similar to when anyone goes to the doctor,” said Jones. “Like going for a check-up and getting tests done. It will give us the entire health status of the fish and the biochemicals.”
Concerned community members have been bringing the scientists examples of fish with large cysts on their lower jaws, but Jones said it is difficult to make any strong conclusions until the biomedical testing is done, and even then it may be a challenge.
“Biomedical testing is difficult to do if the fish were already frozen,” he said. “But we have techniques we can try, so we will make the most of it.”
Still, Jones said that the biomedical tests will serve as better indicators than lesions.
“Lesions are fairly random sorts of events,” he said. “Incidence rates might not be the right indicators.”
All the community fishing days, including those in Fort Resolution, Fort Smith and Fort Chipewyan have now been completed. A second round of community fish monitoring in the Slave and Athabasca Rivers will begin later this fall.