Stauffer Creek - Whirling Disease
 

This is a bit of a heads up and a request for information.

I fished the North Raven recently, and saw a number of fish with Black Tails swimming around. Unfortunately, I wasn't able to catch any of the ones with black tails to inspect them closer. They were all in the 13 to 17 in range, and looked otherwise healthy.
Of the fish that I did catch, they all looked really healthy, apart from some of the longer ones being a bit skinny.

I also saw like 6 small dead fish (6 - 9" long). At the time, I just assumed they died from poor handling. And they were in deeper water, so I didn't bother to inspect them.

Once I got home, I did some Googling about Whirling Disease status in Alberta, and found that Stauffer indeed has had positive cases of Whirling Disease. https://open.alberta.ca/dataset/9f92...rt-2019-10.pdf have a look at the map on page 56 for Stauffer.

So I ended up getting in touch with a Fisheries Biologist. He confirmed yes, Whirling has been established in the North Raven. But they have not confirmed any population level effects from the disease. He also said unfortunately, the dead fish may not be possible to determine their cause of death without collecting the actual fish. So, if anyone has noticed any signs of Whirling Disease, or comes across any dead fish in the area, feel free to message me, and I can pass on his contact information.


One other concern is the lack of signage at the access points warning people that they could be spreading the disease if they don't properly Dry their gear before moving on to other bodies of water. According to the report above, there are quite a lot of areas already affected by the disease. I had no idea it was that wide spread - and that survey is from 2018. But there are still some unaffected areas - like the Athabasca Drainage. Having a native population of Athabasca Rainbows (Rainbows being the most affected by the disease) it is concerning that there isn;t better signage at areas where the disease is confirmed present.

North Raven is predominantly a brown trout river correct? If so, they are far less susceptible to whirling disease and typically won't die from it.

Good on you for keeping an eye out, the disease (if bad enough) will usually kill fish that are hatched this year, the parasite takes about 3 months after fish hatch to have a full effect and if they are badly infected during that time they will likely die from it (think about 3 inches). So survival into those larger sizes likely wouldn't happen, but that is typical of rainbows and other susceptible trout, browns less so.

Was there this week fishing the upper headwater sections and majority of the trout there was brookies. Saw 3-4 juveniles with black tails sadly.