Whirling Disease is suspected in a radical decline in Rainbow trout in the Crowsnest River. I have fished this river as well. There are Brown tout in the system below the falls:

Whirling disease in the Crowsnest River: an emerging threat to wild salmonids in Alberta

https://cdnsciencepub.com/doi/10.1139/cjfas-2020-0484#:~:text=In%20the%20Crowsnest%20River%2C%20previous,declines%20in%20the%20Crowsnest%20River.

With Whirling disease present in the Bow system and lakes in the National Parks on the Rockies, the Elk system and other East Kootenay Rivers known for their Westslope Cutthroat and Bull Trout fishing must be considered at risk since many people who live in and visit the area do fish in both Alberta and BC waters quite literally in the same day.

Here's a good article about whirling disease though it is specifically referenced to the Bow River in Alberta. I think it is important for anglers and all users to know how each of us who use and enjoy our waterways can help slow the spread of Whirling disease. We are not helpless before it and best I can find it does not result in widespread reduction of fish populations in every system it enters:

Whirling down the Bow River
Joseph Morgan Casat

What a surprise, yet another invasive species we have to deal with.  This time however, the invader is tiny, microscopic.  This invasive species has made its way to the Bow River system in Banff National Park. A first appearance in Canada, the microscopic organism causes Whirling disease, affecting fish in the salmon family like Rainbow trout, everyone’s favorite game fish.

This disease causes a deformed spine and blackened tail, making it look as if someone has pinched and bent the spine near the tail.  It also reshapes the head, making it squarer.

Whirling disease showed up in North America first in Pennsylvania in 1956. Because this disease is endemic to Europe, the fish there have gained a sort of immunity to the parasites. In North America, our fish have little immunity to the disease.  Currently fish populations are being closely monitored around the Great Lakes since it was detected in some American hatcheries, but still was never recorded in Canada…until now.

While there is no risk to human health when consuming infected fish, it can be lethal to the fish it infects. The parasites first infect sludge worms, a common worm found in the sediment of most lakes and rivers.  At some point, infected worms are then consumed by juvenile fish and causes skeletal deformation and neurological damage.  Both of these lead an awkward corkscrew swimming pattern, usually belly up, giving the disease its name. Due to the effects of this disease, it becomes difficult for fish to feed and they are more prone to predation. Once the fish dies, the parasite returns to the water, are consumed by the aquatic worms and the cycle continues. The parasites end up in new places by the movement of infected fish, infected worms, contaminated equipment, birds or water

On August 23, 2016 The Canadian Food Inspection Agency confirmed Whirling disease to be present in fish found in Jonson Lake in Banff. In an attempt to control spreading, the lake was closed soon thereafter.  The concern was that it would flow out of the lake and into the connecting river systems.  Jonson Lake flows into Cascade River which then connects to Bow River. 

On September 7th, a fish taken from just below the confluence of the Cascade and Bow Rivers tested positive for Whirling disease. Recently there have been more cases including several in unnamed commercial aquaculture facilities in Alberta.  It’s also been found in a section of the Lower Bow river to Tunnel mountain, Carrot Creek, all of the Cascade River as well as Cascade creek, and Spray river upstream of the confluence the Bow and Cascade rivers.  It’s spreading quickly.

There is no known cure for the disease but that doesn’t mean we are helpless. Anglers and recreational river users can take steps to prevent the spread of the parasite. Clean, Drain, Dry is a slogan used in attempt to stop the spread of other invasive species via boats. It also applies for the spread of Whirling disease.  The program is intended to encourage boaters to clean, drain and dry their boats before transporting them between different water sheds.

Dispose of fish entrails and carcasses when done fishing. Clean your footwear, waders, lines and flies in a bleach and water solution when moving to a new area, stream or water body. Check online for reports of the disease in waters you intend to fish. By learning to recognize the symptoms of the disease and not transporting infected fish whether dead or alive, you can also reduce the chance of the disease spreading.

https://www.bushwhackersflyfish.com/whirling-disease-in-the-bow-river/

Thanks. I wasn't trolling. I asked because I did not want to make an assumption. If you look at my previous posts over the years you'll find I take all sides to arguments. Your posts create dialogue and I believe that is how people move forward.

Apologies. I don't remember the last time someone asked me whether I was in favor of the Covid shot without trying to troll me.

Everybody knows it? You need a chin strap for your tinfoil hat so it doesn’t fall off.

This shows you aren't paying attention. It's been about 80 years since the last tinfoil wrap product was produced.

Yes, I know you are trolling me, but whatever....
It was poison then and it is poison now. The difference is now that everyone knows it. Sucks for those who who got their 14 boosters.

Thanks. I wasn't trolling. I asked because I did not want to make an assumption. If you look at my previous posts over the years you'll find I take all sides to arguments. Your posts create dialogue and I believe that is how people move forward.

"Montana's Madison River has long been one of the most famous and revered rivers in the world. The river often is listed as the number one trout river in North American and appears in books with titles like "50 places to fish before you die". In the mid 90s everything changed for the river when a microscopic invader had a devastating impact on the river. Whirling disease is a small microbe that affects rainbow trout. The parasite causes deformation in the spinal cord of young trout that causes them to swim in circles, usually resulting in death. In some reaches of the river, mortality of rainbow trout reached levels over 90%. News of the outbreak quickly spread throughout the angling community and the number of fisherman visiting the river drastically decreased. The Madison river became the poster child for whirling disease and the microbe quickly hitchhiked to other rivers around the West producing similar results. Some states, like Colorado, tackled the problem by stocking rainbow trout fingerlings. In Montana, where there all trout in rivers are wild and there is not a hatchery program, fisheries biologists decided to let nature run its course. The gamble paid off, and the trout that did survive the initial massive die offs began showing some resistance to the disease.

Today the Madison River has returned to greatness, and although whirling disease is still present in the river, rainbow trout levels have rebounded to pre whirling disease levels. The Madison is once again one of the favorites of Montana fly fishing guides and outfitters. Many guides also feel that the brown trout fishing in the river is better than it has ever been with numerous fish over 20" frequently being caught. Each of the last few years a few lucky fisherman have managed to hook and land monster browns the taped at over 30" and weighed over 10lbs."

https://www.montanaangler.com/madison-river-fly-fishing/madison-fishing-article#:~:text=In%20the%20mid%2090s%20everything,circles%2C%20usually%20resulting%20in%20death.

great footage Brian; what drone? And was it a long drive to oceans shore? seems like a nice weekend jaunt...

That's the DJI mini 3 pro - they had a bundle at Costco - extra battery and some spare prop blades.

The drive to Ocean Shores is surprisingly long.  About 4.5 hours or driving, significantly longer if your partner wants to stop and eat, stop and shop etc....

It was nice to get down in the off-season. It's REALLY busy there through the summer months.

Yes, I know you are trolling me, but whatever....
It was poison then and it is poison now. The difference is now that everyone knows it. Sucks for those who who got their 14 boosters.

Everybody knows it? You need a chin strap for your tinfoil hat so it doesn’t fall off.

I’ve always admired your boldness to make black and white claims with not a stitch of evidence to back it up. 

Well....people like myself who solve problems systematically, logically, with common sense, and good math skills, tend to show evidence though those skills which is what I did.
And there is much evidence to back up what I said....

My youthful, bright-eyed, naiveté notwithstanding, I have confidence in the province’s response to this threat in its home waters.

Comparing it to DFO’s management of Pacific salmon is a non sequitur.

There is no response plan

I’ve always admired your boldness to make black and white claims with not a stitch of evidence to back it up.