An infectious disease fatal to some kinds of young fish has been found in the North Saskatchewan River watershed.

The Canadian Food Inspections Agency said Friday the discovery of whirling disease affects streams, creeks, lakes and rivers feeding into the North Saskatchewan River up to the Saskatchewan boundary.

The disease, caused by a parasite and affects trout and whitefish, is not considered a threat to human health.

Alberta Environment spokesman Peter Giamberardino said at this point it is too soon to say how the disease will affect fish populations this year.

"We don't have any evidence of significant impacts to these populations," he said.

"Our surveillance this year is really going to hone in on these areas where we have found the disease to be present and see if there have been impacts."

The first Canadian case of a fish with the disease was confirmed last July at Johnson Lake in Banff National Park.

It has since been found in the Bow, Oldman and Red Deer River watersheds.

All other watersheds in the province have now been declared a buffer zone for the disease, meaning a permit is required to move fish and other materials such as sediment.

Sport or recreational fishing will not require a permit.

The name of the disease comes from the circular swimming patterns of infected fish. Those fish may also have deformed heads or bodies and discoloured tails.

Whirling disease can be transmitted to other water bodies by fish and through equipment used for swimming, paddling, boating and angling.

The government of Alberta asks people to clean, drain and dry boats or any equipment that has been in contact with water to prevent the further spread of the disease.

"We remain committed to preventing the spread. That is the best defence against the disease," Giamberardino said.

"We want to prevent the wild trout populations that haven't been impacted by it."

Trout bearing areas that are still negative for the disease include the Peace and Athabasca river watersheds.

Since whirling disease was discovered in the province, Alberta has opened a lab in Vegreville devoted to testing and prevention.

The lab began collecting test samples last August when whirling disease was first discovered.

Keep reading